Advances in the Corn Fibers

Corn fiber is a concept proposed in 1948,which involves in the polymeric fiber that made from corn as the raw material, and it was turned to lactic acid, transformed into lactide, and polymerized to polylactide or polylactic acid. Since that, some progresses have been made. However, the feature of corn fiber is determined by the molecular weight of polylactide. In general, corn fiber is formed by means of the melt-textile or no-hydrous textile. The situations, technologies, properties of the corn fibers are reviewed, as well as the processing about lactide synthesis, lactide condensation polymerization. It has some professional properties, such as high transparency, well-heat-resistant stability, well-colors, and full biodegradability, as well as the feature in ecological recycle. These means the corn fibers are new-typical and green, full-environmental fibers, especially for China as the second great number of the products of corn. Research and development of corn fibers are launched off in the world. Some problems existes in the corn fiber manufactured field are to be evolved, which are small scale, high cast, little of end-products enrolled in the market. So is down the cast of corn fiber manufactured as the very important works. This means that systemic studies of the fiberous polymerization and processing are crucial and highlighted to in this field.     

Synthesis of Lactide Using Zinc Lactate as a Catalyst

The catalytic efficiency of zinc lactate as a catalyst to prepare lactide from lactic acid was evaluated compared ose commonly used catalysts including zinc oxide, solid superacid and stannous octate, which indicated a much catalytic efficiency of zinc lactate than others. After mensurating the chemical structure and the crystal form of zinc lactate and recycled zinc lactate, the effects of catalyst and oligomerization time on the yield of crude lactide and the content of lactic acid in lactide product were studied. As a result, both zinc lactate and recycled zinc lactate showed same chemical structure and were comprised three crystal forms. Using zinc lactate and recycling zinc lactate as a cata- lyst, the yield of lactide were 75.7% ,72.1% , respectively. These indicate that zinc lactate is a kind of cheap, available, recyclable catalyst, which is significant in the industrial production of lactide.     

环境友好型生物降解材料聚乳酸的性能研究

聚乳酸(PLA)是一类重要的绿色环保型可降解材料,正受到人们越来越多的关注,近年来被广泛应用。笔者简要论述了生物降解材料聚乳酸的物化性能、力学性能及生物降解性能,综述了聚乳酸的合成方法—乳酸直接缩聚法和丙交酯开环聚合法,分析了国内外的生产现状。最后,对聚乳酸的合成及应用前景进行了展望,并指出可生物降解材料聚乳酸一旦工业化,它在医用及降解塑料方面将会有难以估量的应用前景。     

Synthesis of Lactide from Lact-acid Oligmer

As dispensable material to prepare polylactide, the purity and cost of lactide effect the quality and price of polylactide. The oligomer dehydrated from oligomer in last reaction can be used as reaction stuff like fresh lactic acid, but the suitable react condition is not clear. This paper researches the difference between react system of lactic acid and oligomer, including the level of average molecular weight, relative content of composition and the influence of added catalyst. The maximal yield of lactide could reach 28%.     

水稻淀粉合成关键酶的研究进展

淀粉是稻米的主要成份,其组成和性质决定着稻米品质。在水稻淀粉合成过程中,淀粉合成关键酶发挥了重要的作用。综述了ADP-葡萄糖焦磷酸化酶（AGPase）、淀粉合成酶（SS）、淀粉分支酶（SBE）及淀粉脱支酶（DBE）的功能及调控机理,并对目前研究存在的问题进行了探讨。     

稻米蛋白质及其组分研究概况及其对稻米品质的影响

稻米蛋白质是决定其食味品质的重要因素,稻米蛋白质含量通常与米饭的食味品质呈显著负相关。作为典型的数量性状,稻米蛋白质含量受环境因素的影响较大。然而,稻米蛋白质含量及其构成的决定机制及环境因素对其的影响等方面还有诸多不明之处,其影响食味品质的机理也不清晰。本文综述了稻米蛋白质的种类、结构及其分布,稻米蛋白质的合成与积累过程以及蛋白质含量的遗传控制和影响因素,概括了稻米蛋白质及其组分含量与稻米品质关系的研究进展,为优质水稻的品种筛选及调优栽培提供参考和借鉴。     

伞形科根茎类药用植物早期抽薹的研究进展

通过简述伞形科根茎类药用植物发生早期抽薹现象的过程,明确伞形科根茎类药用植物发生早期抽薹的原因和影响因素,推测早期抽薹与某些调控开花的基因表达能力有关。另外,认为植物体内激素合成在一定程度上能够调节早期抽薹现象的发生。植物内源激素的合成、代谢、信号传导等过程特定基因发生差异性表达导致植物发生早期抽薹现象。提出可以从植物内源激素分子基因层面及激素作用机理出发,通过改变伞形科根茎类药用植物生长条件或施加外源性激素等人工手段有效抑制早薹率,这将对提高药用产量和品质有重要意义。     

大豆油脚制备环氧大豆油甲酯的研究

探索一种价廉、无毒增塑剂的合成方法。以废弃大豆油脚为原料制备环氧大豆油甲酯,采用FT-IR和1HNMR方法对产品进行了表征。通过单因素实验和正交实验确定出最佳环氧化工艺条件为：m（大豆油甲酯）：m（甲酸）：m（双氧水）=1：0.2：0.65,反应温度35℃,反应时间5.5h。所得产品环氧值达4.59%,色泽浅,质量稳定。为废弃大豆油脚作为环保增塑剂的开发利用找到了一条新的途径。     

氮素形态对烟草生长及品质影响的研究进展

氮素是烟草生长和发育所必需的营养元素,在烟草生育期对烟株的化学物质合成、能量转换、信号传递等生理过程都有一定的影响。铵态氮和硝态氮是烟草吸收的主要氮素形态,对烟草不同时期、不同部位会产生不同的影响,合理的氮素比例有利于氮素的吸收以及烟叶品质的提高。本文从烟草对不同形态氮素的吸收利用的方式,不同氮素形态对烟草生长发育、品质形成、元素吸收、光合特性及碳氮代谢等方面的影响进行综述,以期为氮素形态对烟草生长影响的相关研究提供依据。     

光质对果树形态建成及果实品质的生理生态效应

光质是影响果树形态建成和品质形成的主导生态因子。形态建成是果实品质形成的物质基础,概述了光质对植物的叶、茎、根和花芽分化等器官的形态建成及其通过光受体和激素调节等方面的作用机理;光质与果实大小、果形指数、可溶性固形物、维生素C、果实色泽及其在膜透性、色素合成过程中的作用机理,以探讨果树形态建成和品质指标的最佳光质,并提出进一步研究的主要问题。     

浙西南竹笋主产县土壤重金属环境质量分析与评价

为了解浙西南山区主产县（区、市）竹笋基地土壤重金属的状况,保障竹笋质量安全,选择安吉、临安、余杭等8 个县44 个竹笋基地,采集132 份土壤样品进行As、Hg、Pb、Cd、Cr、Cu和Zn 7 种重金属的含量分析,以森林食品产地环境通用要求(LY/T 1678—2014)为依据,进行单因子污染指数、综合污染指数评价。结果表明：研究区域7 种重金属含量范围分别为0.79~24.80、0.03~1.05、7.64~316.69、0.00~4.50、2.47~232.21、5.33~542.20、38.63~436.84 mg/kg;变异系数在64.5%~268.5%之间;综合污染指数大小顺序为富阳＞安吉＞德清＞余杭＞临安＞龙游＞莲都＞遂昌。相关分析和聚类分析结果表明：Cd、Zn和As 可能具有同源性或是伴生关系;As、Hg、Cr、Cu和Pb 呈现相互伴随的复合污染现象;而Cd表现其独特的污染来源。8 个县竹笋生产基地土壤重金属环境质量总体良好;部分地区Pb、Hg和Cd处于轻度及以上污染水平,栽培和生产中应采取一定的措施防控Pb、Hg和Cd污染。     

水稻根系形态生理及其与稻米品质关系的研究进展

水稻根系是吸收水分和养分的重要器官,也是合成和分泌植物激素、有机酸等物质的重要场所。根系形态和生理对水稻产量和品质形成有重要影响。本文综述了水稻根系主要形态生理指标及其与稻米品质的关系,并提出了未来加强水稻根系形态生理与稻米品质关系的研究方向,以期为水稻高产优质栽培根系调控提供理论依据。     

Review on Synthesis Refrectory Nanoparticles

In general, the process of synthesis the refractory nanoparticles Is classified as solid state, liquid state and gaseity. The new progress and development in the study of refractory nanoparticles are investigated. The synthesis technology of the refrectory nanoparticle in liquid state is discussed mostly. The refrectory nanoparticles is synthesized by the liquid state. The characteristics and the structure of the refrectory nanoparticles have been studied in this paper.     

A GROUP-DIVIDING SYNTHEIS METHOD FOR SIX-BAR PLANER MECHANISM''DRIVEN BY PNEUMATIC/HYDRATIC DRIVING SYSTEM

The paper employs the combination of the group-dividing synthesis and optimum method to establish the synthesis method used in which the type stepheson six-bar planer mechanism is used as the function generator which is driven by a pneumatic/hydraulic cylinder. The linear superposition technique is used in the whole solving process and the number of the design positions is not limited by the unknown parameters.     

Fire and explosion hazard analysis of the urea synthesisproduction process

On the basis of identifying and analyzing harmful risk factors in the urea synthesis production process of a factory, the production process is assessed and analyzed using the Dow chemical company fire and explosion index method. The related indexes are f     

小麦SSⅡ-A基因片段的克隆及其RNAi表达载体的构建

可溶性淀粉合成酶Ⅱ（SSⅡ）是小麦籽粒支链淀粉合成的主要角色,但是其三个部分同源基因（SSⅡ-A、SSⅡ-B和SSⅡ-D）对支链淀粉合成的贡献大小目前还未见报道,探究它们对支链淀粉合成的作用,对小麦淀粉合成的遗传操纵和淀粉品质改良具有重要意义。此文通过RT-PCR方法克隆了小麦SSⅡ-A基因cDNA的部分序列（长度为539 bp）,经序列比对发现,它与AB201445.1（Triticum aestivum wSSII-A gene for starch synthase II-A, complete cds）的同源性为100%。以H质粒为中间载体,构建了SSⅡ-A基因片段的发夹结构,并将之连接到pBAC47P上高分子量谷蛋白亚基（HMW-GS）1Dx5启动子的下游,得到了高效特异的SSⅡ-A RNAi表达载体。这些工作为下一步遗传转化获得转基因植株以深入探究SSⅡ-A基因对支链淀粉合成的贡献大小奠定了基础。     

水稻稳定高垩白率突变体的获得与理化特性分析

稻米品质的形成是遗传因素和环境因素相互作用的结果,而环境因素对稻米品质的影响也是通过水稻的生理过程起作用的。本实验经过多年多点种植,从日本晴的T-DNA插入突变体库中筛选出6份稳定高垩白率的突变体材料。检测了可能影响淀粉的合成及淀粉体的精细结构,导致稻米亚垩白的产生和品质下降的蔗糖合酶、ADP-葡萄糖焦磷酸化酶(AGPase)、淀粉合酶、淀粉分支酶、淀粉去分支酶等酶活性的变化,试图从籽粒灌浆过程及淀粉合成途径中关键酶活性变化与成熟籽粒品质的相关性来解释垩白形成的机理。     

不同棚膜对设施桃果实品质的影响

以日光温室栽培的4年生毛桃品种‘台农甜蜜’(Prunus persica cv.tainongtianmi)为试材,研究了涂覆型消雾无滴膜和内添加型消雾无滴膜的光温环境以及对果实品质的综合影响。结果表明：涂覆型消雾无滴膜比内添加型消雾无滴膜具有更好的紫外线-B透过率及保温保湿效果;同时涂覆型消雾无滴膜更有利于促进果实的生长以及糖、淀粉等的合成,可减少有机酸的合成,提高糖酸比,但不利于果实中蛋白质的合成。总体看来,涂覆型消雾无滴膜更有利于提高果实的综合品质。     

灌浆期高温胁迫对甜玉米籽粒糖分积累和蔗糖代谢相关酶活性的影响

为明确高温对甜玉米籽粒产量和品质的影响,以甜玉米厦甜1号和粤甜16为材料, 人工授粉3 d后, 利用人工气候室分别进行昼间高温(HT)35℃和正常气温(CK)处理, 研究了甜玉米籽粒灌浆过程中粒重、糖分积累和蔗糖代谢相关酶活性的动态变化。结果表明, 与正常气温相比, 高温缩短甜玉米灌浆进程, 显著降低粒重、含水量, 提高皮渣率。在最佳采收期(水分含量为68%~74%)甜玉米鲜百粒重分别下降了20.8% (厦甜1号)和16.4% (粤甜16)。在甜玉米籽粒灌浆过程中可溶性糖和蔗糖的含量随授粉后时间先升高后降低, 高温处理不利于可溶性糖和蔗糖积累, 籽粒中糖分含量降低, 淀粉含量升高。籽粒中蔗糖的合成与分解主要由磷酸蔗糖合成酶(SPS)和蔗糖合成酶(SS)催化, SS催化反应是可逆的。高温明显降低SPS和SS合成方向活性, 提高SS分解方向活性, 导致糖分含量降低, 品质变劣。高温缩短两品种SS(合成方向)活性峰值出现的时间, 而对于SPS活性峰值出现时间厦甜1号被缩短, 粤甜16 为不变。     

Application of quantitative trait locus mapping to the development of winter-habit malting barley*

Malting quality and winter-hardiness in barley are ‘ultimate’ phenotypes composed of constituent quantitatively inherited traits. A synthesis of molecular-marker linkage data and field phenotyping to reveal the location of quantitative trait loci (QTL) may assist in the development of winter-habit malting barley varieties. One-hundred doubled haploid progeny from a winter x spring cross were evaluated under fall and spring-planted conditions. Malting quality phenotypes and a 76-point map were used to identify QTL and to assess the effect of spring-and autumn-sowing on QTL expression. Many QTL effects were common to both environments and corresponded to QTL detected in other barley germplasm. While there were significant differences in the magnitude of effects across environments, there were no changes in the favourable allele phase. QTL effects for grain protein and diastatic power level coincided with the locations of known function genes. Coincident QTL for a number of mailing-quality traits on chromosome 7 suggests either the presence of a multi-locus cluster of genes controlling components of malting quality or a regulatory gene or genes controlling the cascade of enzymatic processes that function during the malting process. Based on these results, simultaneous selection for malting quality and cold tolerance should be possible in this genetic background.