光还原法制备Ag/Bi2WO6可见光催化剂及其性能研究

利用离子液体辅助醇热法制备了具有较高活性的Bi_2WO_6可见光催化剂,并进一步采用光还原法将Ag纳米粒子负载到Bi_2WO_6催化剂表面.利用Ag良好的导电性以及表面plasma效应,有效增强了催化剂的可见光吸收,降低了光生载流子复合的几率,显著提高了污染物降解的光催化活性.同时确定了最佳Ag含量和反应条件.     

Drug susceptibility of PCA in WBB6F1-W/Wv mice

Our previous study revealed that passive cutaneous anaphylaxis (PCA) can be produced in congenitally mast cell-deficient WBB6F1-W/W^v (abbreviated as W/W^v) mice on sensitization with undiluted or slightly diluted allogeneic and xenogeneic antisera but not on sensitization with allogeneic monoclonal immunoglobulin (Ig)E and IgG1 antibodies regardless of the antibody concentration [1]. In view of these findings, the present study was conducted to characterize PCA in this strain from its drug susceptibilities using mast cell-bearing WBB6F1-+/+ (abbreviated as +/+) and B6D2F1 mice as references. PCA in W/W^v mice mediated by a low dilution (1  4) of hyperimmune serum to bovine serum albumin of the B6D2F1 mouse origin was markedly suppressed by CV-6209, an antagonist of platelet-activating factor (PAF), but not by antihistamines such as cyproheptadine and oxatomide. In contrast, PCA in +/+ and B6D2F1 mice mediated by a high dilution (1  128) of the anti-serum (virtually by IgG1 antibody) was nearly completely suppressed by antihistamines but not by CV-6209. A remarkable difference between PCA in W/W^v and reference mice was also observed in the susceptibility to monoclonal anti mouse granulocyte (Gr-1) antibody PCA in W/W^v mice was potently suppressed by the 1- to 3-day pretreatment with this antibody but that in references was not at all. Putting these present results together with the previous finding that anti-granulocyte antibody greatly reduces circulatory Gr-1⁺ leukocytes, 1 to 3 days after the treatment [2], it is highly probable that PCA in W/W^v mice mediated by some antibody isotypes other than IgE and IgG1 is produced by PAF mainly released from Gr-1⁺ cells, while IgG1 antibody-mediated PCA in mast cell-bearing reference mice is evoked by histamine derived from mast cells. PCA homologous to that in W/W^v mice could also be produced in the reference mice on sensitization with undiluted or slightly diluted antiserum, when generalized blueing due to excess IgG1 antibody was removed by the oxatomide treatment be fore the antigen challenge. Received 10 December 1997; received after revision 2 February 1998; accepted 23 February 1998     

基于IPv6技术的CNGI驻地网设计

通过一个IPv6驻地网的建设,利用IPv6的过渡机制,提供了校园网用户IPv6接入服务,真正实现了IPv4网络和kOv6网络之间的互联互通,为在校园网全面开展IPv6的组网和研究积累了经验.     

从IPv4向IPv6过渡的技术方案浅析

随着Internet的迅速发展，IPv6必将替代IPv4，但二者又会长期共存，文章对IPv4到IPv6转换常用的3种技术方案进行了分析和研究，使其得到平稳过渡。     

Dawson结构磷钨酸的制备、表征及催化绿色合成乙酸正丁酯工艺研究

制备了H6P2W18O62.13H2O催化剂,并通过FT-IR、UV-Vis、TG-DSC对催化剂进行表征.以乙酸正丁酯合成反应为探针考察催化剂的催化性能.研究了磷钨酸用量、醇酸比、反应时间和反应温度对反应的影响,并提出可能的催化机理.结果表明,最优的反应条件是:催化剂用量为0.72%(按反应体系总质量计算),醇酸比为2.0︰1.0,反应时间为2.0 h,反应温度为125℃,在此条件下酯化率可达96.83%.     

IPv4向IPv6过渡的几种技术探讨

IPv4向IPv6转换过渡过程中需要面临的问题,并对常见的过渡技术进行了分析。     

Antagonistic effect of 6-hydroxydopamine (6-OHDA) on generation of immunosuppressive protein of stress in the rat

Neonatal rats were injected with 6-hydroxydopamine (6-OHDA) for chemical sympathectomy. The rats were treated with restraint stress when they grew up to 56 d. It has-been found that the generation of immunosuppressive protein of stress (ISPS) is significantly reduced, suggesting that peripheral sympathetic nerve plays an important role in mediating the generation of ISPS.     

谷胱甘肽过氧化物酶模拟物6-CySeCD对过氧化氢诱导小鼠成纤维细胞损伤的保护作用

考察不同剂量的H2O2作用于小鼠成纤维细胞(NIH3T3)后,细胞脂质过氧化、存活率、DNA片段化的变化情况,并研究谷胱甘肽过氧化物酶(GPX)的模拟物6A,6B-环己胺-6A′,6B′-硒桥联-β-CD(6-CySeCD)抗H2O2诱导小鼠成纤维细胞损伤的能力.结果表明:H2O2对NIH3T3细胞有严重损伤;6-CySeCD能有效保护细胞,防止紫外线引起的损伤.     

在Na3AlF6-AlF3-CaF2-LiF-Al2O3体系中低温铝电解

研究了Ｎａ３ＡｌＦ６－ＡｌＦ３－ＣａＦ２－ＬｉＦ－Ａｌ２Ｏ３熔盐体系的物化性质，包括液相线温度、电导率和密度，并选择体系中的低分子比电解质在１００Ａ垂直排铝式电解槽上进行了电解制铝。