International transferability of accident modification functions for horizontal curves

Studies of the relationship between characteristics of horizontal curves and accident rate have been reported in several countries. The characteristic most often studied is the radius of a horizontal curve. Functions describing the relationship between the radius of horizontal curves and accident rate have been developed in Australia, Canada, Denmark, Germany, Great Britain, New Zealand, Norway, Portugal, Sweden, and the United States. Other characteristics of horizontal curves that have been studied include deflection angle, curve length, the presence of transition curves, super-elevation in curves and distance to adjacent curves. This paper assesses the international transferability of mathematical functions (accident modification functions) that have been developed to relate the radius of horizontal curves to their accident rate. The main research problem is whether these functions are similar, which enhances international transferability, or dissimilar, which reduces international transferability. Accident modification functions for horizontal curve radius developed in the countries listed above are synthesised. The sensitivity of the functions to other characteristics of curves than radius is examined. Accident modification functions developed in different countries have important similarities. The functions diverge with respect to accident rate in the sharpest curves.     

烷基糖苷的合成及表面性能测定

以葡萄糖、月桂醇为原料，利用直接法合成了十二烷基葡萄苷，采用正交实验法，优选出反应最佳工艺条件：反应温度，１１５℃；反应压力，２．６７ｋＰａ；反应时间，４．０ｈ，催化剂与葡萄糖质量比０．００７：１，月桂醇与葡萄物质的量比５：１，利率 １５８．７％。并测定了产品的表面张力和起泡性质。     

Plasma-controlled chemistry in plasma reforming of methane

Plasma is receiving attention as a prospective tool for the reforming process of obtaining synthesis gas and hydrogen. Although many reports on plasma-induced reforming have been introduced, detailed correlations between the reaction paths and plasma parameters remain unclear. Therefore, to figure out the relative role and dominance of plasma-controlled chemistry in the reforming process, we investigate diverse reaction paths in reforming CH₄. The arc column length is proposed as a universal process parameter of the plasma-reforming process, and a rationale to support the proposition is provided As a result, the dependence of the reforming process on the arc column length is explained. Three different reaction regimes, defined according to the arc column length and plasma chemistry in each regime, are addressed. The arc column length controls the thermal environment of the reaction and activates different reaction pathways depending on its length. This concept of control also enables the discovery of efficient ways of reforming. The increase in thermal efficiency by controlling the arc column reveals possibilities for optimizing the plasma-induced reforming process.     

导引刚性平面两位置的曲柄摇杆机构极限位置处综合法

本文介绍了一种刚体导引的曲柄摇杆机构几何综合法。该方法不但使连杆实现给定的两个位置，而且在该两位置摇杆具有运动间歇，机构自锁和预知急回性能等特性。     

双环戊二烯酚型树脂的合成及其结构表征

在８０￣１４０℃下ＤＣＰＤ与苯酚（或烷基酚）经催化反应合成ＤＣＰＤ酚型树脂。研究了反应温度，反应时间，催化剂用量、ＤＣＰＤ与酚的配比等条件对合成ＤＣＰＤ酚树脂的影响。经红外光谱及核磁共振光谱表征了ＤＣＰＤ酚树脂的化学结构。     

可溶性导电高分子的合成与研究

研究了导电高分子聚 - 3 -庚基噻吩及单体 3 -庚基噻吩的合成 ,对高分子性能进行测试和分析     

Copolymerization of Styrene with Bis(4-methacryloylmethylphenyl) Sulphide

Abstract

A new monomer was prepared in the reaction of bis(4-chloromethylphenyl)sulphide with potassium salt of methacrylic acid. The monomer was characterized by elementary analysis, IR, ^{1 >}H-NMR and ¹³C-NMR analyses. After determination of the structure, studies on its solubility with common as well as vinyl solvents such as styrene, methyl methacrylate, butyl acrylate, acrylonitrile, and divinylbenzene were carried out. Besides, a hardening system for styrene solutions of bis(4-methacryloylmethylphenyl)sulphide (BMMPhS) was chosen. Combinations of the following components: benzoyl peroxide, methyl ethyl ketone peroxide, N,N-dimethylaniline, and cobalt naphthenate were used for hardening. Polymerization of the following styrene solutions of BMMPhS: 50,40,30, 20 and 10% was performed. The obtained copolymers were tested for mechanical properties like: Young's modulus, tensile strength, elongation at break, hardness of Shore's and Brinnell's methods. For the chosen copolymers, thermal properties were determined.     

摩托车发动机气门机构的分析与综合

本文以摩托车发动机气门机构为研究对象 ,在已知平底从动件升程的条件下 ,通过对升程曲线进行“预光顺”和“精光顺” ,然后进行运动学和动力学计算 ,为摩托车气门机构的设计提供依据。     

微生物和酶在香料生产中的应用

介绍了微生物和酶在香料生产中的应用情况。认为值得进一步开展此项工作的研究。     

2,4—二烯醛类及2—烯醛类香料的合成方法研究

本文通过对2，4-二烯醛类及2-烯醛类香料的四种合成路线的概述，总结出其较合理的合成方法。并对此两类香料的可应用种类及其香型做了阐述。