聚砜/磺化聚砜共混及离子交换膜C3H6/C3H8渗透性能的研究

以聚砜和磺化聚砜为膜材料制备了聚砜／磺化聚砜共混膜，共混膜与金属盐溶液进行离子交换得到含不同阳离子的离子交换膜，测试了两种膜对C3H6及C3H8的渗透分离性能；讨论了磺酸基团（－SO3^-）、金属离子及共混膜的离子交换当量IEC对气体渗透性能的影响；着重分析了膜内金属离子与C3H6的络合作用及C3H6和C3H8在离子交换膜内的传递行为。     

CH4—C2H6—C3H8和N2—CH4—C3H8三元混合物汽—液相平衡

对含有N_2、CH_4、C_2H_0和C_3H_8的混合物体系的相平衡、热力学性质进行了实验研究,并对其热力学关联式的精度进行了检验。本文报告了压力在20～120巴和温度个在200K条件下三元体系的许多T-p-x-y实验结果,并与由普遍化状态方程计算的结果作了比较。     

H3C与Cisco交换机互联解决方案分析与探讨

交换式局域网组建的核心问题是交换机互连,通常在第一次组建网络时采用同一厂商的网络设备,可是在后期旧网改造及升级时,经常会使用不同厂商设备,这样就存在不同厂商设备互联的问题。因此,深入讨论主要的网络设备厂商H3C和Cisco交换机互联时可能出现的问题,进行理论分析,提出解决方案,并总结出不同厂商网络设备互联的思路。     

CHF3/C6H6等离子体中的基团分析

在一个微波电子回旋共振等离子体化学气相沉积系统中，测量了CHF3、C6H6及其混合气体放电的质谱和发射光谱图，分析了等离子体中主要基团的分布及其产生的途径，研究了放电功率和流量对主要基团密度的影响，以及它们与氟化非晶碳薄膜沉积速率和键结构之间的关联。结果表明，提高微波功率会增加CHx、CFx等成膜基团的密度，有利于加大沉积速率；而增加CHF3的进气量则会加大F原子基团的密度，这是由于它控制了薄膜的氟化程度。     

Synthesis of Macroscopic Zr（C6H5PO3）2 Tubes

A new method of infiltration-diffusion is used to synthesize macroscopic α-Zr（C6H5PO3）2 （α-ZrBP） tube. Compared to the routine method, no HF was used and a fiberlike product with several millimeters in length was obtained. SEM （scanning electronic microscopy） result indicates that these fibers are tubes. The wall of the tubes is composed of the flake of α-ZrBP overlapped with each other. As we know, it is the first report on the synthesis of millimeter-scale supramolecular assembly of α-ZrBP.     

Intercalation of Graphite in the Ternary Systems C–HNO3–R (R = H2O, CH3COOH, H3PO4 , H2SO4)

The reactions between highly oriented pyrolytic graphite and HNO₃–R (R = H₂O, CH₃COOH, H₃PO₄, H₂SO₄) solutions were studied by x-ray diffraction and potentiometry. The results demonstrate that the nature of component R has a crucial effect on the intercalation process and phase composition of the reaction products. The ability to form ternary graphite intercalation compounds (GICs) depends on the acidity of R. It is shown that CH₃COOH, a weak protic Brönsted acid (pK = 4.76), does not form cointercalation compounds when graphite is treated chemically or electrochemically in HNO₃–CH₃COOH solutions. H₃PO₄, a weak Brönsted acid (pK = 2.12) forms ternary intercalation compounds. Stage II–IV ternary GICs with HNO₃ and H₃PO₄ (d _i = 8.05 Å) were for the first time synthesized and investigated. H₂SO₄, a strong Brönsted acid (pK = –2.8), forms stage I cointercalation compounds (I _c = 8.02 Å), independent of the HNO₃ content (5–95 wt %) of the oxidizing mixture. The potential of the HNO₃–H₂SO₄ solutions was found to be E _Ag/AgCl = 1.39 V, independent of the HNO₃ : H₂SO₄ ratio. The main relationships in the ternary systems were shown to be similar to those for the formation of binary GICs with acids. There is a perfect correlation between the redox potential of the HNO₃–R (R = H₂O, CH₃COOH, H₃PO₄, H₂SO₄) solutions and the stage index of the resulting GIC. The concentration ranges of GIC formation in nonaqueous HNO₃ solutions were extended substantially. The behavior of stage I–IV graphite nitrates in different solvents (H₂O, CH₃COOH, H₃PO₄, and H₂SO₄) was studied. Based on the experimental results, mechanisms of the processes in the systems studied were proposed.     

Sintering of 6H(α)-SiC and 3C(β)-SiC powders with B4C and C additives

The sintering behavior of three fine industrial SiC powders (two 6H()-type and one 3C()-type) has been comparatively investigated. The powders were pressureless sintered with B₄C and C additives between 1950°C and 2250°C in a high temperature dilatometer with flowing Ar atmosphere. The densification and shrinkage rate curves, polytype content, and grain growth were correlated with physical and chemical characteristics of starting powders. One of 6H()-type powders presented good sinterability only after extensive milling, even though it presented small average particle size, narrow particle size distribution and high specific surface area. The main difference in densification behavior among powders was the narrower shrinkage rate curve of -SiC powder, with its maximum shifted to higher temperature. Grain growth and phase transformation simultaneously occurred. In -SiC, 6H polytype partially transformed to 4H. This transformation was favored by aluminum impurity and resulted in a microstructure with more elongated grains. In -SiC, 3C transformed mainly to 6H, 15R and 4H, introducing many stacking faults which resulted in elongated SiC grains.     

液体闪烁计数法绝对测量~3H、~(14)C活度

本文介绍液体闪烁计数法绝对测量~3H、~(14)C活度的装置,测量结果和比对情况。甄别电压外推到零时的计数率随光电倍增管阳极电流而改变,当阳极电流的倒数趋于零时,计数率趋于被测源的活度。放置~3H、~(14)C溶液和闪烁体的瓶子是半球形的石英瓶或低钾玻璃瓶,底部直接耦合到光电倍增管的阴极上。在半球面的外部,涂TiO_2作为反射层。测量~3H的效率达86％,~(14)C的效率达91％。测量~3H、~(14)C活度的合成不确定度分别为0.80％和0.30％。     

Synthesis and characterization of a new organic sulphate, [2,3-(CH3)2C6H3NH3]HSO4·H2O

Crystals of a new hybrid compound C₈H₁₂N⁺, HSO₄^?·H₂O were synthesized in aqueous solution and characterized by X-ray diffraction and IR absorption spectroscopy. This compound crystallizes in the orthorhombic non-centrosymmetrical space group P2₁2₁2₁ and an unit cell with a = 5.74(2) Å, b = 9.17(2) Å, c = 21.34(4) Å, V = 1124(6) Å³, and Z = 4. Its crystal structure is a packing of alternated inorganic and organic layers parallel to (a,b) planes. The different components are connected by a bi-dimensional network of strong OH…O and NH…O hydrogen bonds. Then, in order to detect phase transitions and watch changes in the conductivity behaviour, investigations by DTA–TG and differential scanning calorimetry (DSC) and electrical conductivity measurements were carried out.     

3D C/C复合材料的热膨胀性能

通过测定热膨胀系数(CTE),分析了不同密度以及高温处理前后热解炭基三维编织炭/炭复合材料(3DC/C复合材料)的热膨胀行为,并与PAN基炭纤维以及热解炭的热膨胀性能作了比较。结果表明:PAN基炭纤维在1200℃以后,出现明显的负膨胀。从室温到100℃,C/C复合材料呈负膨胀状态,CTE与密度成正比;从100℃到1000℃,C/C复合材料的CTE-温度曲线基本遵循热解炭基体的热膨胀规律变化;超过1000℃以后,CTE-温度曲线出现峰值,表明热解炭的膨胀受纤维的限制。复合材料的热膨胀行为由纤维和基体二者决定。     

激活温度对C—H,C—O和C—H—O体系低压金刚石生长条件的影响

激活温度和衬底温度是低压人造金刚石制备过程中的两个重要的温度参数，激活温度决定着制备过程中一些重要激活粒子如超平衡氢原子和超平衡氧原子等浓度，而衬底温度对能否 生长金刚石也有重要作用。采用合理的理论计算可以预测温度对金刚石生长条件的影响。本研究采用非平衡力学硝模型计算了Ｃ－Ｈ、Ｃ－Ｏ和Ｃ－Ｈ－Ｏ体系不同激活温度下的金刚石生长相图，研究了激活温度和衬底温度对金刚石生长区的影响规律。本研究结果将对金刚     

Thermodynamics of the System InCl3–HCl–H2O at 25° C

A comprehensive equation for the thermodynamic properties of the system at 25°C in the ion-interaction (Pitzer) equation form is generated on the basis of a very recent and comprehensive array of electrochemical-cell measurements of the HCl activity, together with older published measurements of the activity of InCl₃ in mixtures with 0.02 molal HCl. Alternate equations with and without explicit consideration of the ion pair InCl²⁺ as a separate species are tested. Excellent agreement is obtained on either formulation between calculated and measured activities, although considerable uncertainty remains concerning the standard potential for the in electrode.     

3C认证与电磁兼容

从2002年5月1日起我国开始实行新的强制性产品认证制度,并将于2003年8月1日(原定于2003年5月1日,现因故推迟到8月1日)起强制执行。新的国家强制性产品认证标志名称为“中国强制认证”(ChinaCompulsory Certification),英文缩写为“CCC”,所以也常被人们称作3C认证。这一认证制度是我国为应对入世而按照国际通行规则建立起来的一种全新的产品市场准入制度。 所谓强制性产品认证制度是各国政府主管部门为保护广大消费者人身安全、保护动植物生命安全,保护环境、保护国家安全,依照法律法规实施的一种对产品是否符合国家强制标准、技术法规的合格评定制度。主要是通过制定强制性产品认证的产品目录和强制性产品认证程序规定,对列入《目录》中的产品实施强制性的检测和审核。凡列入强制性产品认证目录内的产品,未获得指定机构的认证程序规定,未按规定加施认证标志,不得进口、不得出厂销售和在经营服务场所使用。发达国家为了保护本国的政治利益和经济利益,都通过政府法令的形式对产品实行强制认证。 我国自1978年恢复国际标准化组织的成员国地位以     

H3LIS331DL运动传感器

意法半导体(STMicroelectronics,简称ST)近日推出全球首个能够检测三个轴向的超高加速度和低功耗的运动传感器。汽车行车记录仪(俗称黑匣子)、医疗监护设备、运动装备对空间和功耗的限制非常严格,     

H C Starck公司推出新型铁基合金粘接剂

H C Starck公司推出了商标为AMPERSINTRMAP的新型铁基合金粘接剂。H C Starck公司方面表示：这种合金粘接剂在原子级别上进行了充分的合金化,可被应用于制作高性能的硬质合金,使用这种新型铁基合金粘接剂制作的硬质合金与使用纯钻粘接剂制作的硬质合金相比性能相当甚至更好,并且这种新型铁基合金粘接剂有利于环境保护和劳动保护。     

a—C：H薄膜组成及结构

含氢非晶碳(a-CH)薄膜主要由SP3C、SP2C和H 3种"元素"组成,在它们的三元相图中,a-CH薄膜具有特定的组成区域.由于IR分析法对SP3C/SP2C分析存在着系统误差,因而导致所得结构偏离该组成域.通过对IR法的结果分析发现,SP3C含量偏高,SP2C含量偏低;a-CH薄膜中SP2C主要以非质子化形式存在,其含量可高达67%;质子化的SP2C仅占Sp2C总量的10%左右.a-CH薄膜是受到较高约束的空间立体网络结构.     

High-Pressure Reactions in the CeCo3–H2 and GdNi3–H2Systems

Reactions in the CeCo₃–H₂and GdNi₃–H₂systems were studied at hydrogen pressures of up to 0.2 GPa. Using hydrogen absorption–desorption isotherms, the compositions of the high-pressure hydrides were determined to be CeCo₃H_6.8(–70°C) and GdNi₃H_5.1(–50°C). According to x-ray diffraction studies, high-pressure hydrogen absorption to above the stoichiometry CeCo₃H₄is accompanied by insignificant volume changes. In the GdNi₃–H₂system, the hydride phase amorphizes at high hydrogen contents.     

3C绿色变电站的实践

根据电网实际情况和技术发展现状,结合建设和运行需求,积极应用新技术、新设备、新材料和新工艺,将智能、高效、可靠、绿色等理念融入到电网工程建设中,促进绿色电网的建设和发展。