复方赖诺普利片治疗中国人群原发性高血压的临床试验设计

复方赖诺普利片限定在单药使用不满意时方可使用,对设计要求较高。本文介绍复方赖诺普利片治疗中国人群原发性高血压的临床试验设计,包括病例选择、试验设计、例数估算等。     

托拉塞米注射剂治疗慢性充血性心衰伴水肿临床随机对照研究

目的: 评价国产托拉塞米注射剂治疗慢性充血性心衰伴水肿的临床疗效与安全性。方法: 采用随机对照单盲法平行试验设计,试验组采用托拉塞米注射剂,对照组采用呋塞米注射剂。共入选208例患者,可评价病例201例。观察试验组与对照组用药疗效与安全性。结果: 试验组和对照组有效率分别为99.0%及96.1%;试验组与对照组用药后24小时尿量均较治疗前明显增加;试验组和对照组不良反应发生率分别为3.88%和2.88%(P>0.05)。结论: 托拉塞米注射剂治疗慢性充血性心衰伴水肿临床疗效好,使用安全、方便,有较高的临床应用价值。     

运煤列车防冻液喷嘴喷洒特性的研究

扇形喷嘴的结构和特性在防冻液喷洒系统中扮演着至关重要的作用。基于CFD数值模拟并结合单因素试验和正交试验,研究扇形喷嘴的3个关键参数对喷洒特性的影响。单因素仿真揭示了中心线上的射流速度、喷洒角度、喷嘴流量以及截线水含量随各参数的变化规律,并为正交试验因素水平的选择提供了依据;正交试验可以根据设计目标的需要,选择出一个较优的喷嘴结构参数组合,并通过极差分析得到了各结构参数对喷洒特性影响的主次顺序:偏移量是影响扇形喷嘴喷洒特性的最主要因素,半球直径和切槽角为次要因素。     

预应力混凝土钢绞线拉伸试验方法

预应力混凝土用钢绞线在许多工程(如:高速公路、桥梁、高层建筑等)应用越来越多,但其力学性能测试还是困难的。本文就钢绞线的强度高,仲长率低,端头夹持部分切口敏感易造成端头单丝断裂,导致性能不合问题,介绍我们对试样夹持端头的“保护”措施,以获得准确测试结果的方法。     

倍比分组双盲随机对照试验的盲态分析

目的:双盲随机对照试验中,常规等比分组下的盲态分析容易实现,而对倍比分组的情形尚无有效的盲态分析方法。本文旨在实现倍比分组下双盲随机对照试验的盲态统计分析,以避免知晓分组信息后可能导致的分析偏倚。方法:在试验设计阶段,根据试验各组的整倍比数进行等样本量拆分,并按拆分后的组别进行编码随机分配和药物编盲。在统计分析阶段根据试验各组比例对拆分组的所有可能组合进行统计分析和报告。结果:结合一个两组2∶1倍比分组的临床试验实例,阐明了盲态分析的具体实现过程。本方法在进行一级揭盲后仅知晓各拆分组的编码,无法判断其对应的试验组别,因此在对各种组合进行统计分析时能保持盲态,在二级揭盲确定实际分组后可选定相应的统计分析报告。结论:本方法原理简单、实施容易、符合监管要求,尽管在随机设计、药物编盲、统计分析环节增加了工作量,但能很好实现双盲试验的盲态分析,有效避免因分析阶段破盲而导致的偏倚,对保证临床试验分析的客观性和科学性具有独到的实际应用价值。     

GMAW焊接工艺因素对E501T-1型药芯焊丝发尘率的影响

影响GMAW药芯焊丝发尘率的焊接工艺因素较多,通过选择焊接电流、电弧电压、焊接速度和保护气体气流量作为发尘率的主要影响因素,进行正交试验、单因素试验与交互试验,采用方差分析、单因素分析和回归拟合,得到了焊接工艺因素对发尘率的影响规律,以及降低发尘率的最优焊接工艺参数。结果表明,焊接电流对发尘率的影响最显著,发尘率随电弧电压与焊接电流的变化趋势符合Boltzmann模型,正交分析的优化焊接工艺参数符合该药芯焊丝的焊接工艺规范要求。     

单电源双丝埋弧自动焊在压力容器焊接中的应用研究

本文通过利用单电源双丝埋弧自动焊进行的工艺试验，得出其在Q345R钢板的焊接应用上满足焊缝对于力学性能、金相以及化学成分的要求，通过其在产品焊接上的应用，可以证明其在压力容器的生产中可以进行应用，并较传统的单丝埋弧自动焊在工期、效益等方面拥有显著的优势，可以在今后的生产中推广使用。     

钎焊单层金刚石磨具的研究进展

钎焊单层金刚石磨具的研究和应用在国内外越来越受重视,与电镀单层金刚石磨具相比,钎焊单层金刚石磨具具有金刚石出刃高、容屑空间大、金刚石与基体之间的结合强度高等无可比拟的优点。从钎焊机理、钎料选择和钎焊工艺流程三方面介绍国内外钎焊单层金刚石磨具的研究现状,并分析大批量制造单层金刚石磨具存在的问题,指出下一步的研究有四项关键技术值得关注:钎料厚度的实用化控制、优质钎料的开发、钢基体受热变形、金刚石磨粒有序排布技术,为钎焊单层金刚石磨具的产业化提供借鉴。     

线槽注射成型工艺参数优化设计

结合正交试验设计和数值模拟,选择模具温度、熔体温度、注射时间、保压压力和保压时间等5个主要工艺参数为设计变量,分别以最小体积收缩率和最小翘曲变形为目标,进行了线槽注射成型工艺参数的单目标优化设计。再利用加权综合评分法,对线槽注射成型工艺参数进行多目标优化设计,获得了兼顾体积收缩率和翘曲变形的工艺参数组合。     

澳大利亚FMG粉矿烧结性能的试验研究

澳大利亚FMG粉矿属于褐铁矿,储量大且单烧品位高,提高其在烧结中的比例是企业降低生产成本的有效措施之一。烧结杯试验研究表明:FMG粉矿与结构致密的巴西CVRD粗粉、南非粉等进行合理搭配,选择适宜的工艺操作参数,通过实施高碱度厚料层、添加蛇纹石等工艺技术措施,更有利于改善FMG粉矿的烧结性能,在生产中大比例配加FMG粉矿是可行的。     

焙烧氰化尾渣中金、银和铁的回收利用研究进展

焙烧氰化尾渣是黄金生产排放的一类危险固体废物,其中的金、银和铁等有价金属元素仍可作为二次资源利用。系统总结了国内外在回收焙烧氰化尾渣中金、银和铁的研究进展,分析了磁化焙烧法、硫脲浸出法、氯化浸出法、高温氯化焙烧法、强酸预浸-氰化浸出法、直接还原焙烧法和细磨法在资源综合回收利用中的优缺点,指出焙烧氰化尾渣的资源化、减量化和无害化的发展方向。     

Static magnetization study of κ-(BEDT-TTF)2Cu[N(CN)2]Cl under high pressure: Part 2. Low magnetic fields

Low-field measurements have revealed the presence of paramagnetic contribution to the field-cooled magnetization of single crystal of title salt at pressures as high as 1 kbar and 1.5 kbar. This magnetization appears if field is oriented normal to the conducting ac plane, at temperature just below the onset of bulk SC transition, and saturates at fields of a few Oe. Depending on thermal history, it can even dominate over the diamagnetic Meissner signal. This behavior is similar to recently discovered (due to study of HTSC oxides) intensively studied but still remaining not understood Wohlleben effect (or paramagnetic Meissner effect). For the κ-(BEDT-TTF)₂Cu[N(CN)₂]Cl we propose that the coexisting magnetic phase might be a cause for the phenomenon.     

防锈油膜失效过程中的导电行为转变

采用电位-电容法及Mott-Schottky分析技术研究了自腐蚀电位条件下防锈油膜在3%氯化钠溶液中失效过程的导电机制转变行为.研究表明，防锈油膜失效过程中存在半导体导电特征，随着浸泡时间的延长，防锈油膜从浸泡初期的p型半导体转变为n型半导体，防锈油膜逐渐出现两个空间电荷过渡层，并且计算了不同转变时期防锈油膜中的电子给体(ND)和电子受体(NA)的密度.     

Electrochemical synthesis of polyaniline on conducting fabrics of polyester covered with polypyrrole/PW12O403−. Chemical and electrochemical characterization

Polyaniline (Pani) has been electrochemically polymerized on conducting fabrics of polyester covered with polypyrrole/PW₁₂O₄₀^3?, obtaining a double conducting polymer layer. Electrochemical synthesis was performed by potentiostatic synthesis at 1 V. The chemical characterization of the material before and after Pani polymerization was performed by means of X-ray photoelectron spectroscopy (XPS), energy dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FTIR). The morphology of the coatings was observed employing scanning electron microscopy (SEM). The electrochemical characterization was performed by cyclic voltammetry (CV) and scanning electrochemical microscopy (SECM). It has been demonstrated that scan rate is an important parameter that influences the response obtained when characterizing conducting fabrics by CV. High scan rates do not allow the observation of redox peaks. However if lower scan rates are employed its apparition has been reported. The electrochemical deposit of polyaniline enhances the electroactivity of the material as it has been demonstrated by CV. SECM measurements showed local response with positive feedback (electroactive material) for the samples in open circuit conditions. XPS analysis also showed a higher doping level (N⁺/N), consistent with higher material electroactivity.     

铸态高强度高伸长率球铁凸轮轴的试制

采用覆砂铁型铸造工艺试制了铸态高强度、高伸长率球铁凸轮轴铸件,结果表明:铸件本体铸态金相组织为:球化级别2～3级,球墨尺寸为6级以上,珠光体含量超过90%;本体铸态力学性能为:抗拉强度高于800 MPa,伸长率高于5%。主要工艺措施有:(1)采用低S高纯度原铁液以及低S高纯度增碳剂;(2)分别采用含Sb的硅铁和含Mn的硅铁进行包内孕育和随流孕育,孕育剂使用前要预热;(3)覆砂层厚度控制在6～8 mm。     

Conducting polymers electrodeposited on active metals

The papers devoted to study of the conducting polymers electrodeposition on the active metals surface and their properties are reviewed. The application of conducting polymer coatings for protection against corrosion and electrocrystallization of metals on conducting polymer films are also reported.     

A Local Damage Approach to Predict Crack Initiation in Type AISI 316L(N) Stainless Steel

A local damage approach based on plastic strain equivalent to uniform strain and grain diameter of the material is proposed for prediction of crack initiation. Plane strain, plane stress, and 3D FEM simulations are carried out for compact tension (CT) geometry with blunt notch of different a/W ratios under mode-I loading. Elastic-plastic fracture parameters have been estimated based on certain assumptions on blunting at notch tip and micromechanisms of events leading to onset of crack. The various crack initiation parameters evaluated based on proposed local damage approach and initial assumptions have been verified by conducting experiments on CT specimens and subsequent scanning electron microscopy study on fracture surface. The laboratory scale experimental results of AISI 316L(N) stainless steel material are in good agreement with FEM-predicted fracture parameters for notch type of stress raisers. The local damage approach and FEM procedure established in the present study would be easily extendable to the analysis of stress raisers in components for the prediction of crack initiation under elastic-plastic condition.     

利西拉来治疗2型糖尿病的有效性及安全性的Meta分析

目的: 系统评价利西拉来与安慰剂比较治疗2型糖尿病的疗效和安全性。方法: 计算机检索PubMed、EMBASE、OVID、Cochrane、CNKI、VIP、CBM数据库,查找利西拉来与安慰剂比较治疗2型糖尿病的随机对照试验(randomized controlled trial,RCT),对纳入研究进行方法学质量评价,并用RevMan 5.2 软件进行Meta分析。通过Stata 12.0 软件对其是否对称按Begg's法进行分析,另外通过考察单项研究对总合并效应量的影响来进行敏感性分析,以评价结论的稳健性。结果: 共纳入8个RCT,随访时间≤24周的Meta分析结果显示:利西拉来在控制糖化血红蛋白(hemoglobin A1C,HbA1c)＜7%[RR=1.96,95%CI(1.65,2.32),P＜0.00001,Z=7.79]或≤6.5%[RR=2.70,95%CI(2.26,3.23),P＜0.00001,Z=10.83]的达标率方面均优于安慰剂组。总不良反应及低血糖、注射部位反应、胃肠道反应、恶心、呕吐、头晕的发生率与安慰剂组相比,利西拉来组均高于安慰剂。头痛、腹泻的发生率两组相似,无统计学差异。所有不良反应均较轻微,绝大多数患者可以耐受。随访时间为76周时,Meta分析结果显示:利西拉来在控制糖化血红蛋白＜7%[ RR=1.30,95%CI(1.12,1.51),P=0.0005,Z=3.49]或≤6.5%[ RR=1.41,95%CI(1.12,1.78),P=0.004,Z=2.89]的达标率方面均优于安慰剂组。总不良反应、注射部位反应、胃肠道反应、恶心、呕吐的发生率与安慰剂组相比,利西拉来组均高于安慰剂,而低血糖、腹泻两组无明显差异。结论: 利西拉来可以有效控制2型糖尿病患者血糖,利西拉来主要的不良反应是低血糖、注射部位反应、胃肠道反应、恶心、呕吐、头晕、头痛、腹泻,但不良反应较轻微,因此可以用来治疗2型糖尿病,但远期结果有待高质量、大样本、长期随访的临床研究予以验证。     

Rotation of a weakly conducting liquid in crossed electric and magnetic fields

Two problems of rotation of a liquid in crossed electric and magnetic fields are formulated and solved as applied to the study of the principles of the interaction between external electric and magnetic fields and weakly conducting water type liquids (running water, sea water) and their solutions ((10-2-102) 1 m-1). In the first problem, the liquid is contained in the gap of a vertical cylindrical capacitor, while the second problem deals with the liquid in a rectangular cuvette, two lateral vertical walls of which are used as armatures of a plane-parallel capacitor. In either case, a constant vertical magnetic field is applied to the liquid, while a constant voltage is maintained between the armatures of the capacitor. Three sets of boundary conditions are considered in the first case: the capacitor is of infinite length (throughout the height); the capacitor is confined by a solid bottom from below and has a free boundary with the atmosphere at the top; the capacitor has closed ends and the liquid occupies the entire capacitor gap. The results can be used in various practical applications, for example, for pumping of weakly conducting liquids.     

Doping-induced volume changes in poly(3-octylthiophene) solids and gels

The bending beam method (BBM), a sensitive way to detect and make use of volume change in electrically conducting polymers, is used to study poly(3-octylthiophene) (POT) during electrochemical redox (doping/undoping). Films of POT prepared from soluble, chemically polymerized POT, from gels prepared by electropolymerization, and from gels prepared by chemical polymerization of alkylthiophene and difunctional alkyldithiophene, all expand during doping, and then reversibly contract upon undoping, in organic electrolytes. The volume change is, at least partly, due to the counter-anion transport in the conducting polymer. Overoxidation of the POT makes the film shrink after initial swelling. The chemical structure of the film (the density and character of crosslinks) determines the volume change. The soluble POT solid (linear POT) and electropolymerized POT gel (hence, highly crosslinked) have volume changes around 1–2%. The lightly crosslinked, chemically copolymerized POT gel shows a 9% doping-induced volume swelling, indicating the desired electroelastic property.