小庄煤矿液态CO2防灭火技术实践

针对小庄煤矿40203综放工作面采空区出现自然发火隐患问题,分析了该工作面自然发火原因、液态CO 2防灭火机理及施工工艺,成功实施了液态CO 2防灭火技术在现场的应用。在向40203综放工作面采空区灌注液态CO 2后,采空区出水温度由灌注前的36℃降至26.5℃,上隅角袋子墙内CO浓度由灌注前的0.0067%降至0.0051%,上隅角采空区19 m处CO浓度由灌注前的0.0072%降至0.0053%,采空区出水温度和CO浓度显著下降并维持稳定。实践表明,该技术成功遏制了采空区遗煤进一步氧化升温,消除了采空区自然发火隐患,保证了工作面的安全回采,也为矿井防灭火工作积累了可借鉴的实践经验。     

水性木器底漆用苯乙烯-丙烯酸树脂的合成与研究

采用半连续溶液聚合法合成了高固含、高透明和易打磨的苯乙烯-丙烯酸树脂,讨论了聚合反应温度、α-甲基苯乙烯/苯乙烯比例、丙烯酸用量、正丁醇用量和正十二烷基硫醇用量对树脂性能的影响,以合成的树脂制备了水性木器底漆,并探讨了各种影响涂膜表干时间和打磨时间的因素。     

聚丙烯／易水解聚酯共混体系的流变性能研究

研究了聚丙烯（PP）和易水解聚酯（EHDPET）单组分以及共混体系的流变性能,考察了温度、剪切速率、异相间的相互作用、共混组成比以及相形态等对熔体黏度以及非牛顿指数的影响。结果表明：在纺丝剪切速率范围,共混熔体的黏度随剪切速率的增加而降低,且低于纯PP和EHDPET。随EHDPET及相容剂含量的增加,熔体黏度增加,分散相的平均粒径变小,流动性变差。     

Novel approach to fast determination of multiple pesticide residues using ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS)

A rapid, high-throughput method employing ultra-performance liquid chromatography with tandem quadrupole mass spectrometry (UPLC-MS/MS) was developed and optimized for simultaneous quantification and confirmation of 64 pesticide residues and their toxic metabolites in fruit extracts prepared by a buffered QuEChERS procedure. The total time required for UPLC-MS/MS analysis was 8 min plus 2 min for re-equilibration to the initial UPLC conditions. Performance characteristics were determined for apple extracts spiked at 10 µg kg^?1. The repeatability of measurements expressed as relative standard deviations was in the range 1.5–13% at this level for most analytes. Thanks to very low limits of quantification (<10 µg kg^?1for the majority of pesticides), an optimized method allows for the reliable control of not only common maximum residue limits (MRLs) set by European Union regulation for various pesticides/fruit combinations, but also of a uniform MRL of 10 µg kg^?1endorsed for baby food.     

电解槽打壳锤头易消耗原因分析及解决对策

针对电解槽打壳锤头消耗快,更换劳动强度大及对铝液品率影响大等缺点,分析了锤头消耗快的原因,从影响锤头寿命的因素着手,提出了解决问题的对策,实施后其使用寿命延长,提高了铝液质量,降低维修成本。     

ADAPTIVE CONTROLLER AND ITS APPLICATION IN FORCE SYSTEM OF ASYMMETRIC CYLINDER CONTROLLED BY SYMMETRIC VALVE

Partial pressure, system vibration and asymmetric system dynamic performance exit in asymmetric cylinder controller by symmetric valve hydraulic system. To solve this problem in the force control system, model reference adaptive controller is designed using equilibrium point stability theory and output error equation polynomial. The reference model is selected in such a way that it meets the system dynamic performance. Hardware configuration of asymmetric cylinder controlled by asymmetric valve hydraulic system is replaced by intelligent control algorithm, thus the cost is lowered and easy to application. Simulation results demonstrate that the proposed adaptive control sheme has good adaptive ability and well solves asymmetric dynamic performance problem. The designed adaptive controller is fairly robust to load disturbance and system parameter variation.     

Investigation of corrosion and container integrity in metal food containers using scanning electron microscopy-X-ray microanalysis

Scanning electron microscopy and x-ray microanalysis were used to investigate microleakage, two incidences of loss of coating integrity, filiform corrosion, and sulfide black corrosion in enamel-lined metal food containers. Microleakage developed in a canned cheese sauce at the side seam weld and was traced to a hot weld and a cold weld defect. An enamel-blistering problem developed in an aseptically processed milk-based product when the tinplate was heated above its melting point; the tin melted under the enamel coating, causing the blistering. An enamel-blistering problem, due to silicon contamination of the metal surface prior to enameling, developed on the bottom of a two-piece can that contained a chicken-based product. A sulfide black problem developed in canned clams, caused by scratches in the coating that were introduced during can manufacturing. A filiform corrosion problem developed on the outside of the easy score line of enameled tinplate lids with a light tin coating 0.08 microns thick.     

编制水电工程设备安装费概算简易法

介绍在编制水电工程概算中，利用与基本直接费及人工费有关的综合系数Ｋ１、Ｋ２值计算设备安装工程单价的简易法，可加快编制概算的速度。     

云南某地高硫铅锌矿选矿试验研究

简介高硫铅锌矿选矿流程试验，经多方案工艺流程比较试验，探索出选别高硫高铅矿的最佳工艺流程及药剂制度，使易选难分矿得到有效分离，获得了高质量铅、锌、硫精矿产品。     

Nonisothermal crystallization,melting behavior,and morphology of PP/EPPE blends

Nonisothermal crystallization, melting behavior, and morphology of polypropylene (PP)/Easy processing polyethylene (EPPE) blends were studied by differential scanning alorimetry (DSC) and scanning electron microscope (SEM). The results showed that PP and EPPE are miscible, and there is no obvious phase separation in microphotographs of the blends. The modified Avrami analysis, Ozawa equation, and also Mo Z.S. method were used to analyze the nonisothermal crystallization kinetics of the blends. Values of Avrami exponent indicated the crystallization nucleation of the blends is homogeneous, the growth of spherulites is tridimensional, and crystallization mechanism of PP is not affected much by EPPE. The crystallization activation energy was estimated by Kissinger method. The result obtained from modified Avrami analysis, Mo Z.S. method, and Kissinger methods were well agreed. The addition of minor EPPE phase favored to decrease the overall crystallization rate of PP, showing some dilution effect of EPPE on PP. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010