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25 March 2012, Volume 24 Issue 2 Previous Issue    Next Issue
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作物科学
动物科学
园艺科学
植物保护
环境科学
植物保护
环境科学
食品科学
环境科学
生物系统工程
食品科学
农业经济
生物系统工程
农业经济
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作物科学

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Changes of pericarp thickness and soluble sugar during the kernel filling process of spring supersweet corn YAO Jian-qiang;YU Qi-ying;WANG Mei-xing;ZHANG Lian-ying;ZHU Jin-qing;* 2012, 24(2):  0-196.  Abstract ( 769 )   PDF (1152KB) ( 1458 )   The soluble sugar and pericarp thickness with three surfaces through the nine different ripe periods of supersweet corn varieties in different grain harvest time were determined and analyzed. The results showed that the pericarp thickness with three surfaces showed relatively independent trends in different ripe periods of supersweet corn, and the maximal content of soluble sugar appeared in 18-22 days after pollination. The harvest time of supersweet corn in different ripe stages was different. The picking period of fresh ear of precocious supersweet corn variety was 18 days or so after pollination, which was 20 days and 22 days after pollination for middle ripe supersweet corn variety and late ripe supersweet corn variety, respectively． Related Articles | Metrics

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Genetic analysis of segregation distortion in indicajaponica hybrids of rice using RFP markers LIU Zhong-lai;LI Jun;QU Shao-hong;* 2012, 24(2):  0-192.  Abstract ( 641 )   PDF (1372KB) ( 1271 )   To investigate the genetic basis of segregation distortion in indicajaponica hybrid of rice, seven RFP (red fluorescent protein) transgenic lines of japonica rice were crossed with indica rice, and the inheritance of F1 pollens and F2 plants was analyzed using RFP genes integrated at different genomic sites as visual genetic markers. Based on results of the 7F5 transgenic line, a locus near the rice genomic site chr02: 33465170 was responsible for segregation distortion of F1 pollens in the genetic background of the hybrid between japonica rice Nipponbare and indica rice 9311. Pollens from indicajaponica hybrid of the 9A2 transgenic line segregated in 1∶1 (RFP+∶RFP-) ratio while the F2 plants showed segregation distortion, suggesting that a locus linked to the RFP site (chr04: 29587748) controlled segregation distortion of F2 plants by a mechanism irrelevant to the segregation ratio of F1 pollens. The RFP markers facilitated analysis of pollens and progeny plants of indicajaponica hybrids and provide a new means for exploring genetic mechanisms involved in segregation distortion． Related Articles | Metrics

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Analysis on major agronomic traits and development tendency of conventional japonica varieties in Zhejiang Province SHI Jian-yao;YANG Chang-deng 2012, 24(2):  0-201.  Abstract ( 687 )   PDF (1131KB) ( 1155 )   In regional trial and production test, the changes and developments of yield, growth period and other agronomic traits associated with rice resistance of the conventional photosensitive japonica(glutinous) varieties registered by Zhejiang Province during 2000-2010 were analyzed in this paper. The results indicated that the effective panicle number per plant decreased while the number of grains per panicle increased in single season photosensitive japonica varieties. The number of grains per panicle increased more obviously in doubleseason photosensitive japonica rice varieties and the yield gradually increased. Overall, the breeding trend of photosensitive japonica varieties was to the development of large panicle. The resistance to bacterial leaf blight also increased． Related Articles | Metrics

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Analysis on stability in potato varieties NA Tian-cang 2012, 24(2):  0-207.  Abstract ( 649 )   PDF (1133KB) ( 1262 )   With six group data of midlate northwest group country regional trial in 2005-2010, stability analysis of varieties was compared using LR model and AMMI model. The results showed that 92-24-144 had higher dynamic stability and showed consistent performance in 2005-2010. The results of AMMI model indicated that there was difference in stability of different varieties. The stability of Qing 97-1-38 and 92-24-144 were higher while the stability of Zhongshu 36, Gan L981018 and Zhuangshu NO.3 were lower, but most varieties showed consistent performance from year to year. Therefore, the AMMI model had the higher reliability in stability evaluation of variety, which should be adopted in potatoes regional trial analysis． Related Articles | Metrics

动物科学

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Prokaryotic expression and immunogenicity detection of SV40-LT gene FU Yu-zhi;LI Chuan-feng;CHEN Zong-yan;WANG Chao;CHEN Tie-qiao;*;LIU Guang-qing;* 2012, 24(2):  0-212.  Abstract ( 650 )   PDF (1387KB) ( 1151 )   In order to obtain the purified SV40-large T antigen (SV40-LT) and its specific antibodies, the high antigen index region of SV40-LT antigen was overexpressed in DE3 cells firstly, and then the purified LT antigen was vaccinated into rabbit, and induced specific antibody against SV40-LT. The results of western blot and ELISA showed that the expression products not only had well immunogenicity, but also could induce rabbit to produce higher levels of antibodies (antibody titre 1∶6400). Related Articles | Metrics

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Development and clinical application of RTPCR method for grass carp reovirus WANG Xiao-feng;XUE Hui;DING Zheng-feng;TANG Jian-qing;XIA Ai-jun;* 2012, 24(2):  0-216.  Abstract ( 1105 )   PDF (1282KB) ( 1270 )   To understand the prevalence of Grass carp reovirus (GCRV)， and for the purpose of early clinical diagnosis， the viral RT-PCR detective method was established. Based on the VP6 gene sequences published in GenBank， a pair of specific primers was designed， and the total RNA of GCRV attenuated vaccine strain GCHV892 was extracted as template to perform RT-PCR reaction， the obtained target band was 712 bp. Then the PCR reaction system and procedure were optimized， the sensitivity and specificity of the method were also considered. The results showed that the minimum detection limit of the sensitivity test was 102 copies·μL-1， in which the recombinant plasmid contained VP6 gene， was adopted as reaction template. The method has good specificity because no crossreactivity was observed between white spot syndrome virus (WSSV)， Aeromonas hydrophila and viral nervous necrosis virus(VNNV). Seven grass carp suspected with hemorrhagic disease were detected by the established assay， and three samples got positive amplification， then one of the positive specimens was cloned and sequenced， the results indicated that the sequence possesses maximum 99% similarity with known sequences in GenBank. Related Articles | Metrics

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Prokaryotic expression and immunologic identification of hemagglutininneuraminidase gene of Goose paramyxovirus E03 strain LI Tong-tong;LI Yin;*;HUANG Xin-mei;ZHAO Dong-min;LIU Yu-zhuo;ZHANG Jing-feng;LIU Fei;LI Xiang-rui 2012, 24(2):  0-220.  Abstract ( 588 )   PDF (1232KB) ( 1156 )   The HN gene of goose paramyxovirus (GPMV) E03 strain was amplified by RT-PCR with the primers designed on the basis of HN gene sequence of GPMV ZJI strain,and then was inserted into the prokaryotic vector pET32a for the construction of prokaryotic expression vector, named pET-HN. Then we transformed pET-HN into Escherichia coli BL21,and identified by SDS-PAGE and Western blot. The target gene was amplified by RT-PCR. SDS-PAGE and Western blot showed the target strap of fusion protein. It was apparent that the HN gene was expressed in E.coli at high level; meanwhile, the prokaryotic expression products of this gene would be a good foundation for immunologic identification about GPMV． Related Articles | Metrics

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Effects of dietary Pb on growth performance and enzyme activities of Jian carp ZHANG Yong-jing;XU Wei-na;LIU Wen-bin*;LI Gui-feng;XIA Wei;SHAO Xian-ping 2012, 24(2):  0-227.  Abstract ( 645 )   PDF (1157KB) ( 1203 )   The effects of dietary lead levels on growth performance, metabolic enzyme activities in serum (ALT, AST and LDH), MDA content and antioxidant defense systems of hepatopancreas of Jian carp(Cyprinus carpio var.Jian) were investigated. Four hundred and eightythree Jian carp (average initial weight, 22.95±0.15 g) were randomly divided into seven treatments and exposed to 0, 2, 5, 10, 20, 50 and 100 mg·kg-1 concentrations of Pb in diet for 60 days. The results showed that weight growth ratio and feed conversation ratio were not significantly affected by dietary Pb (P>0.05), but weight growth ratio presented a downward trend with the increasing Pb concentrations and feed conversation ratio presented an upward trend with the increasing Pb concentrations. After long term Pb exposure, AST activity presented an upward trend with the increasing Pb concentrations, significant increase of AST activity were only found in 100 mg·kg-1 Pb group (P<0.05), ALT and LDH activities presented an upward trend with the increasing Pb concentrations, significant increase of ALT and LDH activities were found in 20, 50 and 100 mg·kg-1 Pb groups (P<0.05). The MDA content in hepatopancreas increased with the increasing Pb concentrations. SOD and GSH-PX activities were induced by dietary Pb. The dietary Pb could lead Pb concentrationdependent toxicity on Jian carp. The changes of the activities of metabolic enzyme activities in serum, MDA content and antioxidant defense systems of hepatopancreas could be used in indication of Pb contamination in diet． Related Articles | Metrics

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Effects of compound chemical treatment on dry matter and fiber degradation rate of wheat straw in rumen SUN Guo-qiang;LV Yong-yan;CUI Hai-jing;CAI Li-feng 2012, 24(2):  0-231.  Abstract ( 914 )   PDF (1354KB) ( 1210 )   To investigate effects of compound chemical treatment on dry matter(DM) and fiber degradation rate of wheat straw in rumen, urea and calcium hydroxide were added on the basis of straw airdried matter with 2%, 3% and 4% respectively, a total of nine experimental groups, urea and calcium hydroxide added in group1 to group9 in turn were: 2%+2%, 2%+3%, 2%+4%, 3%+2%, 3%+3%, 3%+4%, 4%+2%, 4%+3% and 4%+4%,the control(CK) group was the original wheat straw, DM and fiber degradation rate after 72 hours of different treatments for straw were measured by shortterm artificial rumen technique. The results showed that: group 7, 8 and 9 were significantly higher than CK group and other experimental groups (P<0.01) in DM and acid detergent fiber(ADF) degradation rate after 72 hours, which increased by 90.96 %, 85.24%, 75.03% than CK group in DM degradation rate and 139.38 %, 132.06 %, 130.94 % in ADF degradation rate respectively. There was no significant differences (P>0.05) among group 7,8 and 9. Group 7 and 8 were significantly higher than CK group and other six experimental groups (P<0.01) in neutral detergent fiber (NDF) degradation rate after 72 hours, which was increased by 92.06%, 82.51% respectively, and significantly higher than that of group 9 (P<0.05). Under this experimental condition, the treatment added with 4% urea and 2% calcium hydroxide of wheat straw airdried matter was the most suitable compound chemical treatment． Related Articles | Metrics

园艺科学

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Effect of different preceding crops on the dynamics of soil environment and economic benefits of strawberry under protected cultivation WU Gen-liang;XIN Ya;*;TONG Jian-xin;TONG Ying-fu 2012, 24(2):  0-237.  Abstract ( 733 )   PDF (1269KB) ( 1209 )   The dynamics of soil microbe and nutrient of strawberry under protected cultivation with different preceding crops were studied at three stages, and the economic benefits were also analyzed. The results showed that the number of Fusarium and fungi in soil were improved by 22.2% and 21.6% respectively with melon preceded, and soil available P, available K and organic matter were consumed more with watermelon preceded. Except the treatment of idle greenhouse, all rotation modes reduced the ratio of B/F significantly, and soil fertility was reduced. Preceding rice not only significantly decreased the number of soil Fusarium and fungi by 82.6% and 76.0% respectively, but also improved strawberry yield and rate of big fruit than other treatments. The net income brought by preceding rice mode was higher than melons rotation mode by 11.1%. Apparently, the strawberryrice rotation mode can make the topmost comprehensive benefits． Related Articles | Metrics

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The nutrient formula for soilless cultivation of Agapanthus praecox ssp. orientalis cv. Big Blue WANG Lei;ZHUO Li-huan;*;LI Rui-fa 2012, 24(2):  0-242.  Abstract ( 686 )   PDF (1146KB) ( 1441 )   To improve the production efficiency and the quality of flower, reduce the cost of production and promote the process of popularization and application of Agapanthus praecox, we chose 2-year-old seedlings of Agapanthus praecox from tissue culture as the material and screened the combination of soilless media in preexperiments (corn stalk∶rotted leaf of Agapanthus∶slag=1∶2∶1) as growing media. Based on the modified Hoagland nutrient solution, the test was designed by the orthogonal combination method from the three factors of the concentration, ferric salt and pH at three levels respectively. The effects of different nutrient solution on the morphology and physiological index of Agapanthus praecox were analyzed. The results indicated that Agapanthus praecox poured in the nutrient solution composed of 0.5 times concentration of Hoagland solution added with 1.2 times of ferric salt at pH 6.5 grew robustly, showing rapid accumulation of dry matter and strong resistance to outside stress, which was supposed to be the best formula for soilless cultivation of Agapanthus praecox ssp. Orientalis cv. Big Blue． Related Articles | Metrics

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Tissue culture and rapid propagation of Lindera aggregate (Sims) Kosterm CHEN Zhen;SUN Jun-wei;XU Hai-dan;QIAN Bao-ying;BAO Si-wei 2012, 24(2):  0-246.  Abstract ( 662 )   PDF (1513KB) ( 1409 )   The effects of different culture media on tissue culture and plant regeneration of medical plant Lindera aggregate (Sims) Kosterm were investigated with the explants of young stems with buds sprouting. The results showed that the appropriate culture medium for adventitious buds multiplication was MS basal culture medium supplemented with 6-BA 2.0～3.5 mg·L-1, NAA 0.2 mg·L-1 and Na2S2O31.25% (3% sucrose). The most suitable medium for root regeneration was 1/4 MS culture medium added with IBA 1.0 mg·L-1(2% sucrose, without inositol)． Related Articles | Metrics

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The thought of Taoism in the Scholar Garden of China WANG Ya-qin; 2012, 24(2):  0-251.  Abstract ( 632 )   PDF (1131KB) ( 1993 )   As one of the most important parts of Chinese traditional culture, Taoism has much influence on traditional arts, so does the Scholar Garden. The thoughts of imitation from nature, seclusion and contradiction have been showed quietly in the Scholar Garden. “Imitation from nature” means selecting and assigning material are consistent to the true nature, and garden is a mininature. Seclusion makes the winding path lead to a secluded quiet place, which looks like a flower in the mirror, moon in the water. Contradiction enriches poetic imagery of garden. From the centre of Taoism thought, the Scholar Garden was studied based on the culture and the influence of Taoism on garden construction was investigated. At last, the references to the construction of modern city garden were proposed and the relationship of culture and construction was explored． Related Articles | Metrics

植物保护

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Flowerliving thrips abundance and population dynamics in uncultivated reproductive hosts on Hangzhou landscape area LI Wei-di;BEI Ya-wei;ZHANG Zhi-jun;LU Yao-bin* 2012, 24(2):  0-257.  Abstract ( 1055 )   PDF (1161KB) ( 1224 )   In order to understand the abundance and dynamics of thrips population in uncultivated vegetation, we investigated the species and number of thrips in several kinds of flowers from middle April to middle November at Maojiabu in West Lake landscaped area and analyzed the dynamics of Frankliniella intonsa, F. occidentalis,Thrips hawaiiensis and T. flavus from the flowers of Hypericum chinese, F. intonsa, F. occidentalis, Microcephalothrips sp of Erigeron annuus, F. intonsa, F. occidentalis and T. hawaiiensis of Alternanthera philoxeroides, and F. intonsa, T. hawaiiensis, T. flavus and Scirtothrips dorsalis of Canna indica. Six genus and sixteen species of thrips were observed in all sampled flowers, and the predominant species were F. intonsa, T. hawaiiensis and T. flavus. The predominant species on H. chinese was F. intonsa, and F. occidentalis, T. hawaiiensis and T. flavus occurred occasionally. T. hawaiiensis was the predominant species on E. annuus, the population reached peak in July, the late flower time. F. intonsa and F. occidentalis were the main species on A. philoxeroides at the time of early June and July. There were three peaks on the number of T. hawaiiensis and T. flavus on whole C. indica flower period, which was earlymiddle July, middlelate September and earlymiddle November. Meanwhile, the population was high and it reached the highest value of 101.60±13.89 per flower. The population of F. intonsa was much higher, which reached 12.60±4.35 per flower in the peak. In conclusion, F. intonsa have wide range of suitable plants, H. chinese, A. philoxeroides and C. indica except E. annuus were the suitable plants in this investigation, which could be the source of thrips. The suitable plant of T. hawaiiensis and T. flavus was C. indica, the suitable plant of F. occidentalis was A. philoxeroides and the suitable plant of Microcephalothrips sp was E. annuus in this investigation． Related Articles | Metrics

环境科学

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Agricultural carbon sink and countermeasures for development of lowcarbon agriculture technology in Jiaxing HUANG Jin-fa;WANG Guo-feng;SHI Yan-ping;*;NI Xiong-wei 2012, 24(2):  0-274.  Abstract ( 635 )   PDF (1154KB) ( 1405 )   On the basis of the actual output of agricultural and forestry products and soil carbon content in recent years, the absorption of CO2 by major crops and forests was 6.728 million tons and release of O2 was 4.893 million tons in Jiaxing, and the ecological value of annual carbon sequestration was 10.236 billion yuan, which was far more than the yearly agricultural and forestry products worth of 6.019 billion yuan. In addition, the soil carbon storage capacity was also high up to 8.607 million tons. According to local agricultural characteristics, the technical countermeasures in transformation of traditional agriculture and development of lowcarbon agriculture were proposed． Related Articles | Metrics

植物保护

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Screening of effective fungicides and optimum period for controlling soybean pod anthracnose WANG Guo-rong;SUN Zhi-feng;CHEN Wu-jian;LIN Chai;XIA Guo-mian;LOU Man-qin;LOU Bing-gan;* 2012, 24(2):  0-262.  Abstract ( 979 )   PDF (1124KB) ( 1228 )   The effective fungicides for controlling soybean pod anthracnose were screened and optimum period for it were studied by field experiment. The control effects of 8 fungicides on anthracnose of soybean pod were tested in field. The results showed that thiophanatemethyl should be used as the first choice fungicide to control soybean pod anthracnose, then pyrimethanil and tabuconazole etc. This experiment was conducted to compare the control effect with spraying thiophanatemethyl at the stage of flower beginning, flower flourish and seed filling of soybean, respectively. The optimal control growth stage was the stage of flower beginning. Applying fungicide two times at the stage of flower beginning, flower flourish or seedfilling of soybean, the control efficiency of soybean pods were significantly higher than applying fungicide one time at the same stage. Applying fungicide one time at the stage of flower beginning and flower flourish or seedfilling of soybean respectively, the control efficiency reached more than 95%. This experiment was conducted to control soybean anthracnose after inoculation at different relative humidity (RH). When RH was less than 90%, whether or not spray thiophanatemethyl, soybean anthracnose symptoms were not observed. When RH was 100%, spraying thiophanatemethyl 24 h after inoculation, the control efficiency showed no significant difference from that without inoculation. Spraying thiophanatemethyl 48 h after inoculation, the control efficiency was significantly lower than that without inoculation. Related Articles | Metrics

环境科学

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Study on available silicon contents in cultivated land and its influencing factors in Ningbo city QIN Fangjin;WANG Fei;LU Hong;CEN Tangxiao;WANG Bin;HAN Hongxuan;ZHUANG Yaqi;ZHANG Huan 2012, 24(2):  0-267.  Abstract ( 1083 )   PDF (1129KB) ( 1205 )   An investigation study was conducted to analyze available silicon contents(SiO2)of 747 soil samples in nine counties (cities, districts) of Ningbo city, Zhejiang province and to determine the effects of land utilization, soil types, topography and soil chemical properties on available silicon contents in the soils. The results indicated that available silicon content in the cultivated soils averaged 68 mg·kg-1 and the soil samples with rich (≥130 mg·kg-1), medium (100-130 mg·kg-1), deficient (50-100 mg·kg-1), and very deficient levels (<50 mg·kg-1) accounted for 15.8%, 5.5%, 19.8% and 589% of total soil samples, respectively. The average silicon contents in upland soils (95 mg ·kg-1) were higher than that in paddy soils (61 mg·kg-1) and the soils with deficient silicon accounted for 58.8% and 83.5% of their total soil samples, respectively. Available silicon contents in different soil types decreased in the order: coastal saline soil (133 mg·kg-1)> fluvioaquic soil (110 mg·kg-1)> paddy soil (61 mg·kg-1). Among paddy soils tested, the highest available silicon content (88 mg·kg-1) was obtained from percogenic paddy soil, and the lowest available silicon content(49 mg·kg-1) was obtained from submergic paddy soil. Available silicon contents in different landscape types decreased in the order: coastal plain> waternet plain> valley plain> hills and mountains. Available silicon contents in the soils were significantly correlated with pH and organic matter contents in the soils(P<0.01), and were not significantly correlated with available phosphorus and potassium contents in the soils. Aiming at the present situation of serious deficient silicon in Ningbo city, the corresponding recommendations of application of silicon fertilizer were put forward． Related Articles | Metrics

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Effect of composite inoculants on fermentation of cow manure composting ZHU Feng-xiang;WANG Wei-ping;HONG Chun-lai;CHEN Xiao-yang;YAO Yan-lai;WU Chuan-zhen;XUE Zhi-yong* 2012, 24(2):  0-278.  Abstract ( 780 )   PDF (1151KB) ( 1195 )   The influence of composite inoculants on fermentation of cow manure composting containing different rates of sawdust was studied. The results showed that vaccination of composite inoculants did not affect fermentation process of the composting containing 12% sawdust,but improved fermentation of the composting containing 6% of sawdust rapidly. Meanwhile, vaccination of composite inoculants could not speed up fermentation of fresh cow manure composting without sawdust. In conclusion, vaccination of composite inoculants could promote the fermentation process of cow manure composting containing 6% sawdust, and could reduce the materials consumption and manure handling cost． Related Articles | Metrics

食品科学

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Prokaryotic expression of the cellulase of Xanthomonas campestris pv. Campestris and its immobilization WANG Kai-sheng;LIANG Ru-bing*;LIU Xi-peng;LIU Jian-hua;SHAO Zhi-feng 2012, 24(2):  0-294.  Abstract ( 1170 )   PDF (1422KB) ( 1227 )   We cloned the cellulase gene of Xanthomonas campestris pv. Campestris with deleted signal peptide, using PCR (polymerase chain reaction) technique. The gene was ligated into the expression vector pET28a applying CPEC(circular polymerase extension cloning)method to construct a recombinated plasmid pET28a-engXCAΔSP, and then was transformed into the E. Coli rosetta (DE 3).The protein was successfully expressed by 0.4 mmol·L-1 IPTG(isopropyl-βD-1-thiogalactopyranoside) induction, then purified by the affinity NiNTA. Its molecular weight was about 50 kD, which was determined by SDS-PAGE. The activity of recombinant enzyme was 60 U·mg-1. We immobilized the enzyme as well. The optimum reaction temperature and pH value for soluble enzyme and insoluble enzyme were 53℃, 62℃ and 5.4, 5.8,respectively. The results of their enzymatic properties using sodium carboxymethylcellulose (CMC) as the substrate showed that their Vmax were 411 μmol·mL-1·h-1 and 383 μmol·mL-1·h-1 ,while Km were 0.2500% and 0.3125%, respectively. Related Articles | Metrics

环境科学

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Synergism of cellulosedecomposing microorganisms and influence factors of crude enzyme liquid WANG Zhi-gang;XU Wei-hui;LI Yue;ZHONG Peng;WANG Jian-li;MO Ji-xian 2012, 24(2):  0-283.  Abstract ( 1109 )   PDF (1304KB) ( 1407 )   Efficient microbial strains and appropriate reaction conditions are the keys to the biotransformation of cellulose. Based on cellulosedecomposing microorganisms isolated, we studied synergism of cellulosedecomposing microorganisms and properties of crude enzyme liquid. Results showed that synergism was significant between the degrading bacterium, enzyme activity that X2 and X5 mixed culture produced was up to 066 U·mL-1, which increased nearly 1 times than that of singledegrading bacteria. The optimum temperature and pH of crude enzyme were 25℃ and 50 respectively. The inhibitory effect of EDTA on the enzyme activity was more obvious. Ca2+ and Mn2+ were activators of the crude enzyme solution, which could significantly enhance the enzyme activity in the concentration range of the study. The results provided important germplasm resources and technical parameters for the bioconversion of cellulose. Related Articles | Metrics

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Temporalspatial variation analysis of land use structure based on RS and spatial Lorrenze curves in Changping District, Beijing LI Xu;MA Huilan;* 2012, 24(2):  0-289.  Abstract ( 611 )   PDF (1519KB) ( 1215 )   In this study, we acquired land use information of the year 2000, 2003 and 2007 by remote sensing (RS) images in Changping District, Beijing. Changping was divided into 2 subregions by the elevation of 150 meters, named as Mountain Ecological Conservation Zone (MECZ) and Plain Economic Development Zone(PEDZ). The results revealed that the cultivated land converted to building took a dominant role in the changes of land use structure of PEDZ; however, the ratio of all kinds was stable in MECZ. The distribution of different land was studied by spatial Lorrenze curves and spatial Gini coefficient. It was found that the spatial distribution of water field and building land was most uneven in 3 periods, which mainly clustered in PEDZ. Both of cultivated land and woodland were more uniform, and unused land was fiercely varied in study period. The cultivated land, woodland and water field became more uniform in 7 years of study period, but building land was converted to be uneven at first and then become uniform, while unused land absolutely not． Related Articles | Metrics

生物系统工程

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Fault diagnosis of roller bearings based on the wavelet packet analysis JIANG Na;JI Jian-wei*;QI Xiao-xuan;KONG Qing-jiang;XIAO Long-jun;SUN Feng-long 2012, 24(2):  0-314.  Abstract ( 557 )   PDF (1209KB) ( 1195 )   We used the analysis methods which are based on nonstationary signal analysis methods to study the model and algorithm of the roller bearing fault diagnosis. In the full analysis of failure mechanisms and characteristics of the premise, we focused on the wavelet packet analysis of the vibration signal of rolling bearing fault to extract the effective fault characteristics which could reflect the failure modes. We established the BP neural network classifier based on the fault eigenvectors which we have obtained to achieve recognition and diagnosis of the typical failures of rolling bearings． Related Articles | Metrics

食品科学

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Coupling process of taking off citrus segment membrane with enzyme fermentation CHENG Ya-fei;ZHOU Jing-yun;ZHANG Zhi-ping;ZHANG Jun;* 2012, 24(2):  0-299.  Abstract ( 694 )   PDF (1217KB) ( 1131 )   Enzymatic process was the main emphasis in replacing the acidbase method to take off the citrus segment membrane in citrus cans production. However, the cost of the enzymatic process was high and the amount of organic compounds of waste water discharged did not decrease. One stain of Aspergilluse niger with high pectinase yield was screened out using the segment membrane of citrus as the single carbon source. The optimal fermentation conditions for pectinase were found as follows: pH=7, 28℃, 0.5% glutin as nitrogen source, 6% inoculation amount. The activity of the enzyme in fermentation liquor could reach 9.32×103 U·mL-1. The enzyme produced from the membrane fermentation could take off the citrus over 2 times as the original weight. The process provided a low pollution and low cost way of taking off citrus segment membrane． Related Articles | Metrics

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Effects of extraction methods on the properties and composition of grapefruits essential oil SHI Ying-chun;YANG Ying;ZHOU Jin-yun;CHEN Jian-bing;LU Sheng-min;* 2012, 24(2):  0-309.  Abstract ( 698 )   PDF (1291KB) ( 1231 )   Essential oil from grapefruit is an important kind of citrus essential oil, which is popular in the world as a natural fragrant agent with fresh and fullbodied characteristic fruity flavor. To investigate the effects of extraction methods on apparent properties, physical characteristics and chemical compositions of grapefruit essential oil, the oil was extracted from grapefruit peels through distillation and coldpress methods respectively, and compounds contained were detected by gas chromatographymass spectrometry (GC-MS). Yield of essential oil from distillation method was much higher than that of coldpress. However, the color, luster and odor of oil from coldpress method were much more close to those of fresh grapefruits, and its refractive index and relative density were higher, too. There were 39 detectable compounds in the oil from distillation, including 18 oxides with a total content of 14.11 %, while 37 compounds were found in the oil from coldpress, which contained 16 oxides with their total content of 17.18 %. More importantly, the concentrations of characteristic aroma substances, such as linalool, decanal and citral in cold pressed oil, were all higher than those in distillated oil. The results indicated that coldpress method was more suitable to extract grapefruits essential oil with good quality than distillation method. Related Articles | Metrics

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Antioxidant activities of silkworm protein hydrolyzates by bienzyme WANG Wei;WANG Nan;ZHOU Bing;ZHANG Yu;*;WU Xiao-qing;XU Li-hong;WANG Jian-qing 2012, 24(2):  0-304.  Abstract ( 658 )   PDF (1389KB) ( 1190 )   We chose a kind of neutral protease using silkworm pupae protein as materials, combined it with a kind of acid protease, and optimized the combine hydrolyzing sequentially. The antioxidant activities of silkworm protein was analyzed by TAOC, DPPH·scavenging rate,·OH inhibition ability and the superoxide anion inhibition ability. The results showed that the hydrolyzates products had favorable antioxidant activities. Related Articles | Metrics

农业经济

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Effect of rural migrant workers school on the promotion of human capital and social capital : DAI Guo-qin 2012, 24(2):  0-328.  Abstract ( 530 )   PDF (1236KB) ( 1310 )   Human capital(HC) and social capital(SC) have fundamental effect on rural migrant workers’(RMW)survival and development in cities and rural labor forces longterm transfer. Training and education are main ways to promote HC and SC. At present, the opportunities of training and education for RMW are only a few and the results of training and education are not very ideal. Building industry is one of main industries which absorb RMW, and rural migrant workers schools (RMWS) are special training and education platform for RMW in building industry. This paper took Hangzhous RMWS in building sites as an example,investigated the effect of RMWS on the promotion of RMWs HC and SC through empirical study. The results showed that the attending times of RMWS, and the degree of satisfaction to forms and contents of teaching in RMWS were remarkably and positively correlated with HC and SC. Related Articles | Metrics

生物系统工程

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Global parameter sensitivity analysis on water quality model LI Jun;MEI Kun;ZHANG Ming-hua* 2012, 24(2):  0-320.  Abstract ( 663 )   PDF (1166KB) ( 1329 )   The LH-OAT sensitivity analysis method for the global parameters integrates the advantages of the LH sampling method with a random OAT method to ensure the robustness and effectiveness of the parameters. LH-OAT method must rely on complex computer program to achieve, however its application is limited because there is no generic procedures currently available in computer software. This paper investigated the generic procedures to apply LH-OAT method, and successfully used it for the phytoplankton dynamics model which was the core of the WASP water quality model. The results showed that in the condition of adequate supply of nitrogen and phosphorus, the most sensitive parameter was water temperature, followed by the endogenous respiration rate of phytoplankton and the carbon to chlorophyll ratio, and the fourth was zooplankton predation rates on phytoplankton. The reasonable range of each parameter was the key for the successful use of LH-OAT method． Related Articles | Metrics

农业经济

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Discussion on Tianjin urban fisheries development SONG Jia-hui;LI Jin﹡;HUANG Xue-qun 2012, 24(2):  0-334.  Abstract ( 571 )   PDF (1141KB) ( 1259 )   As an important part of urban agriculture, urban fishery has a fundamental function to the economical and social development in the city. On the basis of definition and analysis of urban fisheries connotation, characteristic, type, developing direction, this paper deeply analyzed development status of Tianjin urban fishery and found that it was still in early stage. Problems such as low level of industrial development, unscientific development mode and weak capability of innovation were discovered. Finally, development paths, directions and corresponding measures of Tianjin urban fishery were put forward from industrial transformation and upgrading as well as transforming development mode． Related Articles | Metrics

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Macrocontrol measures and their effects on pork market CHEN Shu 2012, 24(2):  0-342.  Abstract ( 626 )   PDF (1311KB) ( 1187 )   The macrocontrol measures of pork market have become a significant issue which is closely related to peoples livelihood and popular feelings. It has also become a great task for government dealing with inflation and stable supply. Since 2007, the government has taken more macrocontrol measures to rein in pork prices, but the periodic fluctuation of pork prices has been intensified. Through analyses, the paper has pointed out the following opinions. The reserve policies in the light of pork circulation area can stabilize pork prices to some extent. However, the expected effects of macrocontrol measures on production area were far from satisfactory whether in the aspect of strength or direction. The comprehensive effects on production area have contrarily increased the fluctuation of pork prices. Therefore, it is necessary to analyze and evaluate the effects of macrocontrol measures separately from the circulation aspect and production aspect when effects of those government measures are studied. Related Articles | Metrics

综述

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Monosporascus cannonballus of melon and its research progress WU Cheng-cheng;LI Li;ZHANG Hui-juan;LI Da-yong;SONG Feng-ming 2012, 24(2):  0-354.  Abstract ( 797 )   PDF (1153KB) ( 1236 )   Monosporascus cannonballus is one of most destructive diseases on cucurbit crops including melon, and become prominent in melon production worldwide. In this review, we concluded disease symptom, soilborne diseases, pathogenic features, disease cycle and control strategies of the Monosporascus cannonballus of melon. We also discussed briefly on the perspective for the future studies on Monosporascus cannonballus． Related Articles | Metrics

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Current research on plant allelopathy and its application in agricultural production YANG Tian-tian;DU Hai-rong;CHEN Gang;*;DENG Peng;ZHEN Wei-wei 2012, 24(2):  0-348.  Abstract ( 810 )   PDF (1151KB) ( 1996 )   Allelopathy is commonly defined as the direct or indirect effects (stimulative or inhibitory) by one plant or another through production of chemical compounds that escape into environment, this phenomenon exists extensively in the agroecosystem, together with the plants competition on light, water, nutrients and space, constitutes the interaction between different plants. In agricultural production, plant allelopathy influences the monoculture, crop rotation, crop cover, and takes an important role in getting rid of the obstacles of continuous cropping, regulating crops growth and preventing the pests and weeds and so on. In recent years, plant allelopathy was paid more attention by researchers all around the world. The categories, ways of releasing allelochemicals, and the research background, latest development, as well as the prospects of plant allelopathy applied in agricultural production were reviewed in this paper based on many references collected. Then the potential values in development of new varieties were also proposed. The further research in this field will be mainly focused on the cultivation of new allelopathic varieties which can avoid pests and suppress weeds as well as the application of plantbased pesticides. Furthermore, allelochemicals can be used as herbicides and the possibility of artificial synthesis will be investigated so that the pollution of chemical herbicides can be reduced. In the end, the existing problems and direction in the study on plants allelopathy were advanced. Related Articles | Metrics

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Achievements on eliminating the selection marker of transgenic plant HE Hai-yan;ZHOU Jie;LI Ya-li;ZHAO Jian-hua;LIU Zhong-lai 2012, 24(2):  0-359.  Abstract ( 624 )   PDF (1136KB) ( 1247 )   The markerfree technology has been an important content of safetransgenic research. On one hand, removal of selective marker genes could help to eliminate the publics fear of transgenic; on the other hand it would help scientists to multitransformate the foreign genes into the transgenic plants. This review summarized several methods of removing correlative marker genes and gave a prospect of their development． Related Articles | Metrics