超疏水导电聚酯织物的制备及其性能

为使织物兼具疏水与导电的性能,使用自制碳黑杂化同质聚酯浆料,先对聚酯织物进行导电整理,再采用溶剂诱导结晶（SINC）的方法在导电织物的表面构造微观粗糙结构,然后用甲基三氯硅烷（MTS）修饰,制备出耐水洗超疏水导电聚酯织物。研究了浆料中聚酯、碳黑的含量以及溶剂诱导结晶处理条件对织物导电及疏水性能的影响,借助场发射扫描电子显微镜、差式扫描量热仪、X射线衍射仪、接触角测量仪等对织物导电、润湿性能、耐用性及表面结构的微观形貌与结晶特点进行表征。结果表明,制备的疏水导电聚酯织物表面电阻率数量级在10 ²～10^３Ω,与水的接触角大于150°,超声水洗12 h后织物表面电阻率数量级不变,与水的接触角不小于140°。     

金属软管点蚀分析

某炼油厂储油罐底翻油用金属软管发生腐蚀泄漏。通过对腐蚀情况宏观形貌和腐蚀发生区域特点的观察,对金属软管内波纹管进行成分分析、金相分析以及对软管内表面腐蚀坑底形貌和腐蚀产物进行扫描电镜和X射线衍射(XRD)分析,确认了发生腐蚀泄漏的原因是在软管内水溶液里浓缩了Cl~-,导致了腐蚀穿孔。     

660 MW超超临界机组汽动引风机并列与运行

汽动引风机以其无启动电流、低厂用电率和高效调节等优点,逐渐在新建机组中得到应用。以国内某新建超超临界机组汽动引风机为研究对象,根据汽动引风机及其管路特性曲线,分析风机并列的最佳工况,介绍了汽动引风机的并列方法,以及风机并列运行后的运行策略。针对汽动引风机运行中存在的裕量不足、排汽压力高和调节特性差等问题,进行原因分析和控制逻辑优化,确保机组运行的安全性和稳定性。     

脉冲光纤激光诱导氧化硬质合金的温度场分布

利用ABAQUS建立了三维瞬态传热模型,计算了激光诱导下的温度场分布情况,并研究了激光参数对温度场的影响。仿真结果表明,工件最高温度随着单脉冲能量的增大以及扫描速度和光斑直径的减小而增大,热影响区的最大深度和宽度随着单脉冲能量的增大以及扫描速度和光斑直径的减小而增大。研究结果为优选激光诱导氧化硬质合金材料时的激光参数提供了重要依据。     

Numerical study on dynamic behavior of slope models including weak layers from deformation to failure using material point method

This paper describes numerical studies on the dynamic behavior of experimental slope models, including various inclined weak layers. These studies were conducted by simulation of shaking table tests using the material point method (MPM), which allows seamless treatment of various considerations, from elastic behavior to discontinuous collapse behavior of slopes, on the basis of an elasto-plastic constitutive law. The simulation results showed that the failure modes, progressive deformation and downward sliding of the numerical slope models, which were similar to that observed in the shaking table tests, can be obtained using the numerical method. In addition, sensitivity analyses of the numerical models used in this study were performed to determine the effects of mesh size, number of particles per cell (PPC) and damping constants on the simulation results. The results of these analyses indicated the use of fine meshes and high damping constants seems to produce sensible results and reduce numerical noises, respectively.     

基于诱导冒落开采模型的相似材料配比试验研究

依据大石桥大岭西山菱镁矿的开采现状, 以模型试验相似理论为基础, 应用正交试验设计法, 设计了基于砂胶比、石膏与水泥质量比、松香酒精溶液占河砂百分比的3因素5水平材料配比方案模拟菱镁矿石, 对不同材料配比方案的试件进行了力学参数测试, 确定了一种能模拟菱镁矿石的最佳材料配比方案。采用极差分析法分析了各个因素对试件力学参数影响的主次关系, 发现影响试件强度参数的主要因素是松香酒精溶液占河砂的百分比, 影响试件变形参数的主要因素是砂胶比。绘制了各因素对试件力学参数影响的直观分析图, 分析了各因素对试件力学参数的影响趋势。     

β-氨基丁酸抑制草莓低温贮藏过程中灰霉病的效果及其机理

以‘红颜’草莓为实验材料,研究β-氨基丁酸(β-aminobutyric acid,BABA)对草莓果实采后贮藏在低温((5±1)℃)条件下灰霉病的抑制效果及相关机理。草莓果实经过20 mmol/L的BABA处理后接种灰葡萄孢霉(Botrytis cinerea)孢子,然后在(5±1)℃的条件下贮藏12 d,结果发现BABA显著抑制了灰霉病的发生和病斑直径的扩展,与对照组相比,处理组几丁质酶(chitinase,CHI)和β-1,3-葡聚糖酶(β-1,3-glucanase,GLU)的活力分别提高了9.2%和54.9%,多聚半乳糖醛酸酶(polygalacturonase,PG)和纤维素酶(cellulose,Cel)的活力分别降低了29.3%和24.4%,同时,BABA提高了FaCHI和FaGLU基因的表达,抑制了FaPG和FaCel基因的表达;此外,体外实验的结果发现,BABA能够破坏灰葡萄孢霉孢子的质膜完整性,导致了孢子内部可溶性蛋白质和可溶性糖的泄漏。结果表明,BABA通过诱导抗病相关酶活力来提高抗病性、延缓果实软化并通过对病原菌的直接抑制作用减轻草莓果实采后灰霉病的发生。     

Shelf life extension of fresh fruit and vegetables by chitosan treatment

Among alternatives that are currently under investigation to replace the use of synthetic fungicides to control postharvest diseases in fresh produce and to extend their shelf life, chitosan application has shown promising disease control, at both preharvest and postharvest stages. Chitosan shows a dual mode of action, on the pathogen and on the plant, as it reduces the growth of decay-causing fungi and foodborne pathogens and induces resistance responses in the host tissues. Chitosan coating forms a semipermeable film on the surface of fruit and vegetables, thereby delaying the rate of respiration, decreasing weight loss, maintaining the overall quality, and prolonging the shelf life. Moreover, the coating can provide a substrate for incorporation of other functional food additives, such as minerals, vitamins, or other drugs or nutraceutical compounds that can be used to enhance the beneficial properties of fresh commodities, or in some cases the antimicrobial activity of chitosan. Chitosan coating has been approved as GRAS substance by USFDA, and its application is safe for the consumer and the environment. This review summarizes the most relevant and recent knowledge in the application of chitosan in postharvest disease control and maintenance of overall fruit and vegetable quality during postharvest storage.