松林生态系统退化评价及其与马尾松毛虫灾害关系的研究

通过对长沙县丘陵区马尾松林生态系统进行调查研究,选取生物途径、生境途径以及生态系统功能途径3个诊断途径,采取多途径综合诊断的方法对丘陵区马尾松林生态系统退化程度进行诊断,确认其退化程度,在此基础上分析松林生态系统退化程度与马尾松毛虫灾害的关系。结果表明马尾松毛虫灾害发生程度与生态系统退化程度关系密切。生态系统退化越严重的地区,马尾松毛虫灾害越严重,退化较轻的地区,马尾松毛虫灾害较轻或不发生。     

用简易诊断法检查判断液压系统各元件的工作性能

故障的排除首先在于判断，目前基层维修网点大多数没有检测仪器和设备，出了故障乱拆乱卸，导致液压元件工作失灵，甚至整车液压系统瘫痪。拖拉机液压系统产生故障的主要原因是液压元件工作性能恶化引起的。为此，介绍了在没有检测仪器和设备的条件下，如何应用简易诊断法检查判断各液压元件的工作性能。     

不同尿素水平氨化稻草体外培养发酵的产气规律

本试验旨在研究不同尿素水平氨化稻草的体外培养发酵产气规律。选用2头安装有永久性瘤胃瘘管、平均体重为240 kg的西门塔尔牛作为瘤胃液供体,分别使用0(加等量水)、2%、4%、6%和8%的尿素比例(尿素重量∶稻草重量)和80%的水(水重量∶稻草重量)对稻草进行氨化处理,另设未处理稻草作为对照。采用体外产气法测定氨化稻草在体外培养发酵2、4、8、12、24、36、48 h的产气量。结果表明:随着尿素水平的升高,氨化稻草的产气量逐渐升高。2%组48 h产气量与未处理组差异不显著(P>0.05),4%、6%和8%组48 h产气量均极显著高于未处理组(P<0.01)。0%组的48 h产气量均显著低于其他各组(P<0.01)。各组的理论总产气量之间差异不显著(P>0.05),稻草氨化处理以尿素使用量为稻草干物质的4%～6%为宜。     

五味子的生物学作用与应用

五味子富含多种营养成分,具有提高机体免疫功能和抗氧化机能等作用。作者综述了五味子的化学成分、药理作用、应用的研究近况以及在畜牧业中应用的前景。     

甘蓝黑腐病生理小种划分及其抗病性鉴定研究进展

甘蓝黑腐病是十字花科作物的主要病害之一,其病原菌生理小种的划分和抗病性鉴定的方法直接关系到甘蓝抗病育种工作的开展和进程。本文就这两个方面对国内外的研究进展进行了全面综述,并对今后的研究方向进行了展望。     

基于GIS技术的陕西砂梨气候区划

为了给陕西砂梨发展提供气候适应性地域分布依据,应用1971~2000年陕西省及相邻省份的114个气象观测站及其附近200个气象哨的气象观测数据,分析了光、热、水等气象条件对砂梨生长的影响情况,确定了气候区划指标,然后利用GIS技术对陕西省砂梨种植适生区进行了精细化的气候区划。结果表明:陕南的安康、汉中海拔小于600 m的盆地为陕西省砂梨适宜种植区,而陕西的其余大部分地区,因气温偏低、降水不足,不利于优质砂梨的生长,故不宜盲目引种砂梨。     

Attenuated Salmonella carrying pGRIM-19-si-survivin co-expression plasmid inhibits growth of prostate cancer subcutaneous xenografts in vivo

AIM：To explore the effects of pGRIM-19-si-survivin co-expression plasmid carried by human attenuated Salmonella on prostate cancer subcutaneous xenograft growth in nude mice. METHODS：Prostate cancer xenograft model was established in nude mice. Co-expression plasmids carried by attenuated Salmonella were introduced by intraperitoneal injection. The xenograft volumes were monitored timely. Immunohistochemical staining, RT-PCR and TUNEL assay were applied to investigate the related mechanisms that pGRIM-19-si-survivin inhibited tumor growth in vivo. RESULTS：Compared with psi-survivin and pGRIM-19 carried by attenuated Salmonella (control groups), the tumor volumes were reduced markedly in pGRIM-19-si-survivin plasmid group. The mean shrinkage rates were 2.36 and 3.02 times. pGRIM-19-si-survivin co-expression plasmid carried by attenuated Salmonella inhibited survivin expression but strengthened GRIM-19 expression obviously (P<0.05). The mRNA expression of apoptosis-related proteins such as Bcl-xL, Stat3, cyclin D1 and c-Myc was inhibited, and the vascular endothelial growth factor (VEGF) mRNA and Ki67 protein were also inhibited, but the caspase-3 mRNA expression was up-regulated (P<0.05) with significant cell apoptosis. CONCLUSION： pGRIM-19-si-survivin co-expression plasmid carried by human attenuated Salmonella inhibits the growth of prostate cancer subcutaneous xenografts in nude mice by promoting cell apoptosis and inhibiting prostatic cancer proliferation.     

Application of improved genetic algorithm to locating and sizing of distributed generation

A Prüfer-coded genetic algorithm based on the decimal number of nodes is proposed and it is used to solve collaborative optimization planning of access solution of distributed generation(DG)and structure of distribution network.Using graph theory to generate theoretically feasible topology structureand the access nodes and the installed capacity of distributed generation are coded by the Prüfer number.The coding method makes the distribution network operation structure and the access solution of DG combine into the evolution problem of the same chromosomal gene.The length of the chromosome coding of this method is shorter than binary encoding.This solution takes full advantage of the Prüfer-coded to improve computational efficiency and convergence rateand makes some restrictions and improvements in some key parts of the algorithm to solve the problem illegal solution.Finallyfeasibility and superiority of the algorithm is validated by a case study.     

红富士苹果套袋后果皮中花青苷积累与酚类物质代谢的关系

以红富士苹果为试材,分别在山东栖霞和泰安研究了套袋后果皮中酚类物质代谢与花青苷积累的关系。结果表明,套袋后果皮花青苷积累与酚类物质代谢密切相关。果皮中多酚氧化酶（PPO）含量较对照（不套袋果）降低,过氧化物酶（POD）和苯丙氨酸解氨酶（PAL）较对照升高,类黄酮、水溶性酚和花青苷含量较对照增加,果实着色迅速而良好。但在摘袋后气候不利和果袋为劣质单层纸袋条件下,果皮中酚类物质和花青苷含量均低于对照。