膜覆盖对土壤理化性状的影响

地膜覆盖可提高土壤温度，保持土壤水分含量，改善土壤疏松状况，加速有机质速效Ｎ的分解。     

超声萃取-气相色谱质谱法测定塑料中的邻苯二甲酸二异丁酯

以四氢呋喃为萃取溶剂,采用超声萃取-GC-MS法测试塑料中的邻苯二甲酸二异丁酯含量,以GC-MS的全扫描定性,选择离子监测外标法定量。本方法回收率为94.6%~104.8%,RSD为3.9%~4.3%,检出限0.198 mg/kg。试验结果表明,本方法简便、快速、检出限低,具有良好的准确度和精密度,适用于塑料样品中邻苯二甲酸二异丁酯的快速分析。     

蚕豆不同品种的地膜覆盖效应*——以四川省甘孜州康定县为试点

采用4种不同品种的蚕豆进行覆膜和不覆膜试验,结果证明覆膜栽培的蚕豆生长发育迅速,青鲜荚和籽粒的产量均有不同程度的提高,同时还可利用间作、套种、混作等种植方式来提高经济及生态等各方面效益。     

Experimental investigation and numerical simulation of plastic flow behavior during forward-backward-radial extrusion process

Finite element method was employed to investigate the effect of process parameters of plastic deformation behavior in Forward-Backward-Radial Extrusion (FBRE) process. The result of an axisymmetric model shows that the friction between die components and the sample has a substantial effect on the material flow behavior. Although strain heterogeneity index (SHI) slightly decreases with an increase in friction, large portion of the sample experiences significant strain heterogeneity. Increasing the friction factor also localizes the strain heterogeneity effect in the backward section, and spread the effect in the forward section. Decreasing the friction in the FBRE process can reduce the amount of the strain heterogeneity in the product while decreases the required punch force substantially. Furthermore, an increase in gap thickness increases the deformation in the area close to the lower punch at the expense of the area in the vicinity of the upper punch. The numerical simulation has a good agreement with the experimental results which confirms the accuracy of the proposed finite element model.     

防弹头盔实弹打击力的计算及测试

本文研究实弹射击防弹头盔的打击力计算，描述防弹头盔的测试装置。将该装置分成两个系统：导弹和钢盔及头模为一系统，应用动量定理计算其打击力；头模和测力传感器连同支承杆为一系统。利用文献［１］对防弹衣模拟靶（木模）的动态应变和位移的测定，计算弹击时头模的变形能和动能；同时计算弹击时测力传感器所作的功和支承杆消耗的能量；根据能量守恒原理计算防弹头盔的打击力。计算结果与实测值基本一致。文中所得的结果已应用在ＧＧＫ９３Ｔ型防弹头盔等系列产品的设计中。     

自动控制去湿机在海航仓库中的应用

介绍了对某仓库去湿机的改造情况，实现了开关去湿机的自动化控制，使库内的相对湿度始终保持在合理的范围之内，从而有效地抑制了霉菌的生长。     

Influence of slip system combination models on crystal plasticity finite element simulation of NiTi shape memory alloy undergoing uniaxial compression

The influence of various slip system combination models on crystal plasticity finite element simulation of Ni Ti shape memory alloy subjected to uniaxial compression deformation is investigated according to three combinations of slip systems, including combination of {010}100and {110}111slip modes, combination of {110}100and {110}111slip modes and combination of {110}100, {010}100and {110}111slip modes, which consist of 18, 18 and 24 slip systems, respectively. By means of simulating mechanical response,strain distribution, stress distribution and Schmid factor, it can be found that in terms of simulation accuracy,combination of {110}100and {110}111slip modes is in good agreement with combination of {110}100,{010}100and {110}111slip modes. The contribution of {110}100slip mode to plastic strain is primary in plastic deformation of Ni Ti shape memory alloy, whereas {010}100slip mode, which makes small contribution to plastic deformation, can be regarded as the unfavorable slip mode. In the case of large plastic strain, the {010}100slip mode contributes to the formation of(001) [010] texture component, while {110}100and {110}111slip modes facilitate the formation of γ-fibre(111) texture.     

约束条件下铜合金加热时的塑性变形及变形功

固态焊接加热过程中,受约束焊件因胀大变形不能进行而产生等效塑性压缩变形(EPCD)。本文以H62和QCr0.5铜合金为研究对象,对EPCD及相应的变形功进行了试验研究。结果表明:等效塑性应变ε和变形功W的大小主要与加热温度θ和预压应力σ0有关,σ0一定时,ε随θ升高而增大,其中H62黄铜当θ<550℃和θ>700℃时,ε随θ升高而线性增大,θ在550～700℃之间时,ε的增幅减小;QCr0.5铬青铜的ε随θ升高线性增大,但增幅较H62小;θ一定时,两种铜合金的ε均随σ0增加而近似线性增大;两种铜合金的W随θ的升高而减小,随σ0的增大而增大,且H62的增幅明显大于QCr1.5;当σ0和θ一定时,W随ε的增加呈指数关系增大。     

应用螺纹管Ⅰ期修复左半结肠损伤42例

目的 探讨Ⅰ期修复左半结肠损伤的手术方法。方法 回顾分析了42例应用塑料螺纹管Ⅰ期修复左半结肠损伤的临床资料。结果 42例中有1例出现并发症，但无吻合口瘘及手术死亡等严重并发症，治愈率42／42。结论 塑料螺纹管明显降低了吻合口瘘的发生率，并发症少，住院时间短，生活质量高，可在临床推广。     

浅谈我国模具材料的发展方向

该文介绍了国内外模具材料在产量、品种、工艺方面的发展状况,并对今后我国模具材料的发展方向进行了展望。