An effective and simple process for obtaining high strength silkworm (Bombyx mori) silk fiber

This article describes a new process for strengthening natural silk fibers. This process is simple yet effective for mass production of high strength silk fibers, enabled by drawing at a lower temperature and immediately heat setting at a higher temperature. The processing conditions were investigated and optimized to improve the strength. Silk fibers drawn to the maximum ratio at room temperature and then heat set at 200 °C show best tensile properties. Some salient features of the resulting fibers are tensile strength at break reaching 533±10.2 MPa and Young’s modulus attaining 12.9±0.57 GPa. These values are significantly higher than those of natural silk fibers (tensile strength increased by 44 % and Young’s modulus by 135 %). Wide-angle X-ray diffraction and FTIR confirm the transformation of silk I to silk II crystalline structure for the fiber obtained from this process. DSC and TGA data also provide support for the structural change of the silk fiber.     

植物生长调节剂“784—1”对大豆叶肉细胞超微结构的影响

本文应用植物生长调节剂“784—1”进行大豆种子浸种和拌种处理。田间试验与电镜观察结果表明,与对照组比较,叶肉细胞中的线粒体、叶绿体和叶绿体内片层结构呈增多趋势。     

甘蓝型油菜氮素吸收利用的杂种优势表现

以22个甘蓝型油菜品种(系)为亲本(17个母本,5个父本),按NCⅡ交配设计配成85个F1杂种,研究了产量、氮素吸收总量(TNA)和氮素籽粒生产效率(NUEg)的杂种优势表现。以杂种离中亲优势值(Hm)和超优亲优势值(Hb)作为杂种优势的评价指标,以Hm和Hb的显著差异出现率作为一个性状杂种优势潜力的指标。结果表明:产量的Hm正向显著组合数占杂种总数的87.06%;Hb正向显著组合数占杂种总数的60.00%,表明产量的离中亲优势值比超优亲优势强。TNA的Hm正向显著组合数占杂种总数的40.00%;Hb正向显著组合数为18个,占杂种总数的21.18%。NUEg的Hm正向显著组合数占杂种总数的67.06%;Hb正向显著组合数占杂种总数的47.06%。表明氮素籽粒生产效率杂种优势比氮素吸收总量杂种优势更为明显。     

公顷产蔗150吨攻关栽培初报

近几年来 ,广西雒容农场在农业生产上实现了产业化 ,拥有 1 6 50公顷的原料蔗基地和日榨能力 1 50 0吨的小型糖厂。在甘蔗生产方面积累了不少经验 ,自 1 995至 1 999年 ,甘蔗公顷产量维持在 75～ 90吨的幅度。为了提高经济效益 ,加快农场发展的步伐 ,近两年来雒容农场实施了 6 0 0公顷“吨糖田”和 33公顷“公顷产蔗 1 50吨攻关栽培”项目计划 ,收到了良好效果。其中 33公顷“公顷产蔗1 50吨攻关栽培”项目在五大队、六大队和九大队三个点进行 ,笔者现将广西雒容农场九大队“公顷产蔗 1 50吨攻关栽培”项目点攻关栽培情况进行初报。1　基本…     

水稻监测信息系统的应用与改进

为改善农业气象情报服务效果,本文对气象部门1980—1985年水稻系统监测年报进行了整理分析。针对系统监测资料品种更迭频繁,地区生产力差异明显之特点,提出了品种生育期特征系数、品种分夔力与成穗力系数、品种产量系数等参数化特征值概念。通过对资料提供的166项信息的多元回归分析证实:采用组建分地区、分类型按发育进程的中近期配套模式系统,对发育进程和产量及其结构要素作动态追踪预测,现行资料已可用于实践使用,发育期追踪的剩余方差可缩小至1—4天。本文根据试验数据还对现行监测方法的正确性进行了分析,提出了改进意见。     

Study on Advanced Treatment of Secondary Effluent Using Fixed-Bed Filled with Bone Char

The adsorption of a fixed bed filled with bone char was investigated in terms of its efficiency and capacity by determining operational conditions for the purpose of further reduction of organic matter and removal of phosphorus using a continuous flow of real secondary effluent. Simultaneous removals of phosphorus and chemical oxygen demand (COD) were sufficiently achieved by this fixed-bed method. Stable performance was maintained even at a linear flow velocity (abbreviated as LV) of 1.5 m h^–1. Appropriate backwashing and regeneration were required to operate the system continuously for a long period of time. During the regeneration, the use of treated water including Ca²⁺ ion was so effective that phosphorus removal efficiency increased from about 50 to 80%, and afterwards maintained over 65%, until inflow water of the volume up to 150 times as large as the volume of bone char had passed through. Even when the inflow water of the volume rose up to 200 times, the phosphorus removal efficiency could be maintained over 50%. During this operation, the adsorptions of phosphorus and COD onto the bone char surface were observed to be over 6.7 and 35 gL^–1, respectively.     

农药管理中豁免物质的规定

豁免物质的制订对保护消费者的利益、指导各国食品的安全生产和开展食品的公平贸易有非常重要的意义.对日本"肯定列表制度"、美国联邦法规(CFR法规)和欧盟149/2008法规中所列的豁免物质进行了比较分析,对其豁免物质的类型和适用的范围等方面进行了讨论.研究表明,美国对豁免物质的规定最为详细,日本和欧盟的规定对于指导实际生产有一定的参考.     

稳健方法用于光度法药物制剂的多组分测定

将最小平方中位数参数估计方法结合多元线性直接校正技术用于复方苯海拉明滴鼻液紫外光度法多组分同时测定，获得明显优地以最小二乘原理为基础的校正技术的浓度估计，表明该方法有良好的应用价值。     

外来物种琵琶鼠鱼与本地物种鲫鱼混养的初步研究

试验探究了外来物种琵琶鼠鱼(Pterygoplichthys multiradiatus)和本地物种鲫鱼(Crucian carp)混养时的关系,研究入侵物种对生物多样性和生态环境的破坏。结果表明,琵琶鼠鱼与鲫鱼在不同配比的混养情况下,体重均表现为降低,其中琵琶鼠鱼的体重下降更多,但均有正增长的趋势。琵琶鼠鱼与鲫鱼之间存在空间竞争关系,且鲫鱼表现出更强的竞争优势。