基于合成法的定位误差的分析与计算

为保证机床夹具设计的可靠性,定位误差的计算是机床夹具设计过程中必不可少的重要环节之一。为此从定位误差的产生机理出发,介绍了定位误差的概念、产生原因,并给出计算公式,有助于快速实现定位误差的求解。     

多线左旋螺纹的数控车削方法

文章以沈阳数控机床HT1625 FANUC 0I-TC系统为例,通过选用设置合理的切削参数和工艺,探讨多线左旋螺纹的数控车削加工。     

“四全”育人夯实立德树人德育基础——以苏州工业职业技术学院为例

随着社会发展的推动和各种思想文化的交流、交融与交锋,给高职院校的思想政治教育工作带来前所未有的挑战。苏州工业职业技术学院积极探索实践"全员、全程、全方位、全心全意"育人的德育体系,在立德树人背景下,以踏实、务实、求实的作风不断夯实德育基础,努力开创"责任到人,纵向到底,横向到边"的德育工作局面。     

全运会竞赛制度变迁方向探索

通过对历届全运会竞赛规程的竞赛举办时间、地点、项目设置、运动员参赛资格、奖励和计分办法等条款进行分析，认 为全运会经过不断演变，已形成奥运会次年办赛、项目设置以夏季奥运项目为主并兼顾民族传统体育项目和全国各地竞争办赛 的特点；运动员交流办法已趋于完善，奥运会成绩计分、两次计分、球类加倍计分等计分办法逐渐演变成我国全会运会特殊的 计分制度。建议将已经有过办赛经验的省、市援助中、西部欠发达地区申办全运会，制定办赛奖励制度；对交流运动员交流年 限延长至一个全运会周期，重视“新型联合培养”；根据全运会发展需要，进一步加大计分奖励力度。     

东风454拖拉机前驱动桥下端盖漏油原因分析及改进措施

通过现场调查和结构分析,指出东风454拖拉机前驱动桥下端盖漏油原因是有零件损伤和结构设计上的缺陷共同造成的,在提出了不同的改进措施同时,并进行了可行性和成本对比分析。     

山药整地机械化作业技术规范

从作业条件、作业准备、作业方法等方面，介绍山药整地机械化作业技术的要点，论述其整地质量要求及相关参数计算方法，为山药种植产业的规范化及扩大化提供参考。     

Movement and survival of corn rootworm in seed mixtures of SmartStax® insect-protected corn

SmartStax^® insect-protected corn (Zea mays L.) contains genes for six Bacillus thuringiensis (Bt) proteins controlling both lepidopteran pests and the corn rootworm complex (Diabrotica spp.). The properties of SmartStax, particularly the multiple effective modes of action (i.e., each Bt protein provides a high level of control of the target pests with a low probability of cross-resistance among the proteins), have provided the opportunity to add to previously approved structured refuge options by combining the non-Bt refuge seed with SmartStax seed in a seed mix. Seed mixes ensure that a refuge is present in every Bt field, remove concerns about grower compliance with refuge requirements, and provide grower convenience. However, seed mixes could increase the likelihood that larval insects move between Bt and non-Bt plants and vice versa. Assessing the insect resistance management (IRM) value of a seed mix refuge requires an assessment of the amount of larval movement, and the consequences of that movement, for the key target pests. The studies here present such data for control of corn rootworm by SmartStax corn, which contains the rootworm-active protein Cry3Bb1 and the binary protein Cry34Ab1/Cry35Ab1. In a growth chamber experiment, SmartStax was most effective against first instars and significantly effective against second instars, but did not control third instars. In a field study of movement from a heavily infested non-Bt plant onto surrounding plants, a larger percentage of insects successfully dispersed from the infested plant when the surrounding plants were non-Bt plants than when they were SmartStax plants. A paired-plant study showed that few larvae migrated from infested SmartStax plants and survived on nearby non-Bt plants; larvae that migrated from infested non-Bt plants had low survival if the adjacent plants were SmartStax. Replicated field studies of plant-to-plant movement indicated that the non-Bt plants in a 5% or 10% seed mix consistently supported large populations of susceptible insects and represented a productive refuge, whereas the SmartStax plants had few or no survivors. The timing of emergence from seed mix plots containing 5% or 10% non-Bt plants was more similar to that of the non-Bt plots than that of the SmartStax plots. Thus, the available growth chamber and field data indicate that a seed mix of 5% or more will provide an effective refuge for corn rootworm in SmartStax corn.     

黄河干流陕西段鱼类种类组成及群落多样性

为了解黄河陕西段鱼类种类组成及群落结构,2013-2015年调查了黄河陕西段鱼类资源。结果显示:黄河陕西段有鱼类7目15科58种,其中鲤科鱼类最多为36种,占总种类数的61.1%,较20世纪80年代减少了6种。优势种有4种,数量占渔获物总数量50.3%,生物量占65.8%。分析渔获物组成和群落多样性,黄河陕西段鱼类年龄、个体规格小型化趋势明显,不同河段鱼类群落存在明显空间差异,府谷段多样性指数最高,群落结构稳定,港口段丰富度指数最高,资源种类较多,港口和壶口的鱼类群落结构没有相似性。     

Polymerisation of gluten proteins in developing wheat grain as affected by desiccation

The breadmaking quality of wheat is affected by the composition of gluten proteins and the polymerisation of subunits that are synthesised and accumulated in developing wheat grain. The biological mechanisms and time course of these events during grain development are documented, but not widely confirmed. Therefore, the aim of this study was to monitor the accumulation of gluten protein subunits and the size distribution of protein aggregates during grain development. The effect of desiccation on the polymerisation of gluten proteins and the functional properties of gluten were also studied. The results showed that the size of glutenin polymers remained consistently low until yellow ripeness (YR), while it increased during grain desiccation after YR. Hence, this polymerisation process was presumed to be initiated by desiccation. A similar polymerisation event was also observed when premature grains were dried artificially. The composition of gluten proteins, the ratios of glutenin to gliadin and high molecular weight-glutenin subunits to low molecular weight-glutenin subunits, in premature grain after artificial desiccation showed close association with the size of glutenin polymers in artificially dried grain. Functional properties of gluten in these samples were also associated with polymer size after artificial desiccation.     

Disulphide structure of high-molecular-weight (HMW-) gliadins as affected by terminators

This study aimed at elucidating SS-bonds of HMW-gliadins (HGL) from wheat with the focus on terminators of glutenin polymerisation. HGL from wheat flour extracts non-treated or treated with the S-alkylation reagent N-ethylmaleinimide (NEMI) were compared. HGL from wheat flour Akteur were isolated, hydrolysed with thermolysin and the resulting peptides pre-separated by gel permeation chromatography and analysed by liquid chromatography/mass-spectrometry using alternating electron transfer dissociation/collision-induced dissociation. Altogether, 22 and 28 SS-peptides from samples without and with NEMI treatment, respectively, were identified. Twenty-six peptides included standard SS-bonds of α- and γ-gliadins, high-molecular-weight and low-molecular-weight glutenin subunits. Eleven SS-bonds were identified for the first time. Fifteen peptides unique to HGL contained cysteine residues from gliadins with an odd number of cysteines (ω5-, α- and γ-gliadins). Thus, gliadins with an odd number of cysteines, glutathione and cysteine had acted as terminators of glutenin polymerisation. Decisive differences between samples without and with NEMI treatment were not obvious showing that the termination of polymerisation was already completed in the flour. The two HGL samples, however, were different in the majority of ten peptides that included disulphide-linked low-molecular-weight (LMW) thiols such as glutathione and cysteine with the former being enriched in the non-treated HGL-sample.