基于ArcObjects的无林地小班快速定位研究

本文旨在探索一种高效的无林地小班快速定位技术,满足县级林地落界中频繁、快速定位无林地小班的迫切需要,提高遥感判读的效率.在VB编程环境下,采用ArcObjects组件库与数据库技术相结合的方法,提出县域内无林地小班快速定位算法流程,将无林地与有林地边界修正过程中人工繁琐的重复机械操作程序化,实现无林地小班定位的自动化.     

脉冲次数和卵龄对小鼠卵母细胞电活化效果的影响

以一定电场条件、不同次数的电脉冲刺激注射ＨＣＧ后不同时间（１５、１７、１９、２１和２５ｈ）小鼠卵母细胞，研究了不同电场条件下脉冲次数和卵龄对卵母细胞活化效果的影响。     

The influence of soil moisture stress and plant populations on the yield of pickling cucumbers

A 2-year study was conducted on the effects of irrigation and plant populations on yield of pickling cucumbers (Cucumis sativus L). The main plot treatments were no irrigation or irrigation at a frequency necessary to prevent the available soil moisture (ASM) from falling below 25 or 60%. The sub-plots consisted of 49 000 plants/ha (multi-harvest) or 123 000, 185 000 and 247 000 plants/ha (once-over harvest). Irrigation substantially increased the yield and improved the grades of both multi-harvest and once-over harvest pickling cucumbers. Highest yields were obtained from the multi-harvest operation with irrigation at 60% ASM level. Maximum yields were obtained with irrigation at 25% ASM level in the once-over harvest operation. All population densities of the once-over harvest operation produced similar yields when not irrigated. Increasing plant populations from 12 to 25 plants m^?2 did not significantly affect yields under irrigated conditions.     

Molecular characterization of a lipid-modified virulence-associated protein of Rhodococcus equi and its potential in protective immunity.

Virulent strains of Rhodococcus equi produce plasmid-mediated 15- and 17-kDa proteins, which are thermoregulated and apparently surface-expressed. We demonstrated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) that R. equi produce three antigenically-related virulence-associated proteins, a diffuse 18-22-kDa, a 17.5-kDa and a 15-kDa protein. Phase partitioning of whole cells of R. equi strain 103 with Triton X-114 (TX-114) and labelling with [3H]-labelled palmitic acid showed that the two higher molecular weight proteins are hydrophobic and lipid modified. The 15-kDa protein did not partition into TX-114 and was not lipid modified. Cloning and expression of a fragment of the R. equi virulence plasmid in Escherichia coli showed that the three proteins were expressed from a single gene. Sequence analysis of this gene (designated vapA) revealed a 570-bp open reading frame encoding a polypeptide of 189 amino acids with a calculated molecular mass of 19,175 Da. The mature, nonlipid modified protein had a calculated mass of 16,246 Da. The 17.5- and 18-22-kDa forms of the protein are therefore due to lipid modification. No significant sequence homology of the vapA gene with other reported nucleotide sequences were found. Opsonization of virulent R. equi with an IgG1 mouse monoclonal antibody (MAb103) to the VapA protein significantly enhanced uptake in the murine macrophage cell line IC-21. Intraperitoneal injection of mice with Mab103 enhanced initial clearance from the liver of mice challenged intravenously with R. equi. Immunization of mice with the lipid-modified VapA purified by SDS-PAGE fractionation or with acetone precipitated VapA protein following TX-114 extraction resulted in significantly enhanced clearance from the liver and spleen following intravenous challenge. The VapA protein of R. equi appears therefore to be a protective immunogen.     

尾张温柑挂树保鲜试验初报

于11月中旬,用200 ppm 2,4-D和150 ppm多菌灵处理果实,挂树保鲜120 d后,稳果率达100%,好果率达99%,果实平均增重4.63%,可溶性糖含量提高2.4%,净增利润1600元/t,但次年减产5.8%     

氯化低密度聚乙烯的催化合成

The catalyst CP-B was first used for production of chlorinated low density polyethylene(LDPE),so the reaction time was successfully shortened.The influences of the reaction temperature,the reaction time,the proportion of solvent to LDPE,the chlorine flow     

中国种业发展新趋势

自20世纪90年代实施种子工程以来,我国种业出现许多新的特征,管理法制化、企业集团化、投资多元化、育种先进化、品种研发、技术推广企业化、市场国际化等特征越来越明显,民族种子产业得到发展壮大,为我国农业丰收、农村发展、农民增收做出了新的贡献.     

玉米笋采收期的研究

本试验以玉米沈农171×33O单交种及其亲本沈农171自交系为试材,通过1987～1988年的试验,测定了不同采收期玉米笋产量、质量、笋支长棍等指标。试验结果表明:单交种及自交系最佳采收期各不相同,沈农171×330单交种玉米笋最佳采收期为吐丝后第2天,沈农171自交系为吐丝后第1天。     

胡萝卜抗冻蛋白的快速与高效纯化

将胡萝卜抗冻蛋白在大肠杆菌中进行表达后．对获得的包涵体进行了初步的洗涤纯化．分别采用HPLC和Native PAGE法对其进行最终的纯化．结果表明．两种方法都能获得高度纯化的目的蛋白．而且耗时都很少．但Native PAGE法更为经济．且可以同时进行多个样品的纯化．更适用于一般实验室．