农业院校图书馆网站建设的探讨

对我国25所农业高校图书馆网站的主页元素、内容元素和编程技术等进行比较,分析了存在的缺陷和问题。针对农业高校图书馆网站建设的原则和内容,提出了网站建设的目标定位等原则,建议优化主页设计、丰富信息资源、规范学科导航、提升服务功能、适度设置链接、适时维护更新和应用现代技术手段,并对主页与标识、栏目与层次等提出了具体的建议。     

浅议网络环境下对高校图书馆员的新要求

阐述了网络环境下提高图书馆员素质的新要求,并就如何提高馆员素质的对策进行了分析。     

不同激素处理对假酸浆种子萌发的影响

【目的】假酸浆因种子外被胶质严重影响种子的萌发,探究不同处理对假酸浆种子萌发的影响,增加其种子的萌发率。【方法】以假酸浆种子为试材,采用随机区组法,设置种子放置在纱布上 4 ℃低温处理,以及赤霉素（GA3）、6- 苄氨基腺嘌呤（6-BA）和萘乙酸（NAA）的 MS 培养基处理,定期观察并作记录。【结果】与常温对照相比,种子放置在纱布上 4 ℃低温处理显著促进假酸浆种子萌发,以处理 48 h 发芽率最高为 25 个百分点。MS 培养基添加激素处理中,10 mg/L GA3 处理假酸浆种子发芽率和发芽指数分别为 92.00% 和9.58,比 CK 分别提高 4.27 个百分点和 1.33;1 mg/L 6-BA 处理假酸浆种子发芽率最高、为 96.63%,2 mg/L 6-BA处理发芽势最高、为 73.33%,比 CK 分别增加 8.9 个百分点和 10.07 个百分点;1、2 mg/L NAA 处理假酸浆种子发芽率均为 88.86%,但发芽势和发芽指数均比 CK 低;与 CK 相比,10、50 mg/L GA3 处理假酸浆种子下胚轴长度显著增加,而 6-BA 和 NAA 处理的下胚轴长度显著降低。【结论】低温处理能够显著促进假酸浆种子萌发,MS 培养基添加低浓度激素处理均能提高假酸浆种子的发芽率,通过发芽率、发芽势、发芽指数和下胚轴长度综合比较,假酸浆种子的最佳激素处理为 MS+10 mg/L GA3。     

一种新的对虾病原菌——雷氏普罗威登斯菌

本文从患败血病的中国对虾体内分离到多株细菌，其中三株经人工感染证实为病原菌，又经４０多项形态、生理、生化特性测试，鉴定为雷氏普罗威登斯菌（Ｐｒｏｖｉｄｅｎｃｉａｒｅｔｇｅｒｉ），其主要特性为杆状，革兰氏阴性，周生鞭毛，运动，无自然游动现象，兼性厌氧，苯丙氨酸脱氨酶、柠檬酸盐利用、吲哚、甲基红反应均阳性，发酵甘露醇、肌醇、甘露糖产酸。赖氨酸、鸟氨酸脱羧酶、精氨酸双水解酶、ＶＰ反应均阴性。生长最适温度、ＮａＣｌ、ｐＨ范围分别为２５℃—３０℃、０５％—１５％、７０—９０。对羧苄青霉素、先锋霉素５号、氯霉素、ＳＭＺ＋ＴＭＰ、氟哌酸、链霉素等极为敏感。雷氏普罗威登斯菌引起对虾败血病在国内外尚属首次报道。     

Irreversible competitive inhibitory kinetics of cardol triene on mushroom tyrosinase

Cardol triene was first purified from cashew (Anacardium occidentale L.) nut shell liquid and identified by gas chromatography coupled to mass spectroscopy and nuclear magnetic resonance. The effects of this compound on the activity of mushroom tyrosinase were studied. The results of the kinetic study showed that cardol triene was a potent irreversible competitive inhibitor and the inactivation was of the complexing type. Two molecules of cardol triene could bind to one molecule of tyrosinase and lead to the complete loss of its catalytic activity. The microscopic rate constants were determined for the reaction of cardol triene with the enzyme. The anti-tyrosinase kinetic research of this study provides a comprehensive understanding of inhibitory mechanisms of resorcinolic lipids and is beneficial for the future design of novel tyrosinase inhibitors.     

Granule structure and distribution of allomorphs in C-type high-amylose rice starch granule modified by antisense RNA inhibition of starch branching enzyme

C-type starch, which is a combination of both A-type and B-type crystal starch, is usually found in legumes and rhizomes. We have developed a high-amylose transgenic line of rice (TRS) by antisense RNA inhibition of starch branching enzymes. The starch in the endosperm of this TRS was identified as typical C-type crystalline starch, but its fine granular structure and allomorph distribution remained unclear. In this study, we conducted morphological and spectroscopic studies on this TRS starch during acid hydrolysis to determine the distribution of A- and B-type allomorphs. The morphology of starch granules after various durations of acid hydrolysis was compared by optical microscopy, scanning electron microscopy, and transmission electron microscopy. The results showed that amorphous regions were located at the center part of TRS starch subgranules. During acid hydrolysis, starch was degraded from the interior of the subgranule to the outer surface, while the peripheral part of the subgranules and the surrounding band of the starch granule were highly resistant to acid hydrolysis. The spectroscopic changes detected by X-ray powder diffraction, 13C cross-polarization magic-angle spinning NMR, and attenuated total reflectance Fourier transform infrared showed that the A-type allomorph was hydrolyzed more rapidly than the B-type, and that the X-ray diffraction profile gradually changed from a native C-type to a CB-type with increasing hydrolysis time. Our results showed that, in TRS starch, the A-type allomorph was located around the amorphous region, and was surrounded by the B-type allomorph located in the peripheral region of the subgranules and the surrounding band of the starch granule. Thus, the positions of A- and B-type allomorphs in the TRS C-type starch granule differ markedly from those in C-type legume and rhizome starch.     

反应温度和时间对分光光度法测定乳粉中左旋肉碱的影响

采用分光光度法测定乳粉中左旋肉碱的含量,从温度和时间对反应的影响进行分析研究,确立了最佳反应温度为24℃,最佳反应时间为加入5,5＇-二硫双（2-硝基苯甲酸）和乙酰辅酶A反应6 min后归零,再加入乙酰肉碱转移酶反应6 min。此条件下该方法的回收率为98.3%～99.7%。     

对湖南农业文献信息开发利用的建议

针对本世纪末湖南初步建成农业强省的需要,对开发利用湖南农业文献信息资源,提出了六点建议.     

农民分化对城乡二元结构变迁趋势的影响

中国社会改革进程日渐深入,各种社会问题也日渐突出,在目前社会剧烈变迁的背景下,尤以城市化进程为各阶层所瞩目,而且中国改革的成功与否,城市化问题具有决定性的影响。笔者在中原地区进行一些社会调查时发现了一些现象,通过对其研究,产生了一些新的看法。本文在对中国传统农民文化的研究基础上,提出观点:农民对城乡二元结构的弥合。     

振动式深松中耕联合作业机的设计

研究设计了一种振动式深松中耕联合作业机,阐述了机具结构关系及工作原理;同时,介绍了主要部件的结构设计并对深松部件进行了有限元分析,该研究为蓄水保墒提供了可行的作业机具。