喷丸对23Co14Ni12Cr3Mo超高强度钢 表面性能的影响

针对23Co14Ni12Cr3Mo超高强度钢材料，研究喷丸强化对其表面性能的影响。采用扫描电镜、白光干涉仪等设备，分析喷丸强化对试样表面形貌、粗糙度、硬度、残余应力、元素含量等的影响。结果表明:喷丸强化后，试样表面留有大量弹坑，产生明显塑性变形；表面粗糙度增大，算术平均粗糙度为1.33 μm；硬度显著增大，最表层硬度由喷丸前的HV 476增加至HV 497，硬化层深度约150 μm；试样表层的残余压应力值由375 MPa增加至475 MPa，最大残余压应力值约518 MPa，位于距表面50 μm深度处，喷丸形成的残余压应力层深度约为134 μm；喷丸后试样中C、Si、Cr等各元素的质量分数均略有增加。喷丸在一定程度上改善了23Co14Ni12Cr3Mo钢材料的表面性能，有利于提高其疲劳抗力和耐腐蚀性。     

Studies on urethane–allophanate networks based on hydroxyl‐terminated polybutadiene: Modeling of network parameters and correlation to mechanical properties

Hydroxyl‐terminated polybutadiene (HTPB)‐based allophanate–urethane networks were prepared by reacting HTPB with di‐isocyanates, such as toluene–di‐isocyanate (TDI), isophorone–di‐isocyanate (IPDI), and 4,4′‐di(socyanatocyclohexyl)methane (H₁₂MDI) at stoichiometric ratios (r‐values) ranging from 1.0 to 1.5. The networks were characterized for mechanical and swell properties. The network parameters, such as “X,” which is the fraction of urethane groups involved in the allophanate formation, and effective chain length (L_x) were calculated from experimental crosslink density values determined from swell data, using α‐model equations developed by Marsh. Excellent linear correlations were obtained between mechanical properties and the calculated network parameters. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 2986–2994, 2006     

Synthesis,characterization and side chains crystallization of comb-like poly(<Emphasis Type="Italic">p</Emphasis>-<Emphasis Type="Italic">n</Emphasis>-alkylstyrene)s

A series of comb like poly(p-n-alkylstyrene)s with linear alkyl groups, containing even numbers of carbon atoms from 12 up to 22 were synthesized by radical polymerization and characterized by FTIR, ¹H NMR, TGA, TVA DSC, and WAXS. All polymers were obtained in good yields and were soluble in organic solvents as chloroform, dichloromethane or tetrahydrofuran and insoluble in methanol; they are stable up to temperatures near 300 °C. On the other hand, the alkylic side chains of all series are able to crystallize in a paraffinic phase in which the melting temperature and enthalpy increase with the methylene number of the n-alkyl chain.     

LED驱动器的优化设计

本文在分析目前LED驱动器存在的一些问题的基础上，以Intersil公司高功率LED驱动器ISL78100为例，说明了LED驱动器应用中应考虑的一些设计参数，包括电路结构以及元器件的选择等，最后提出了有效解决功耗和系统可靠性问题的方法。     

基于Salvo的嵌入式直流伺服电机控制系统

本文探讨一种采用中低档微处理器的嵌入式直流伺服电机控制系统,该系统用户软件设计采用嵌入式实时操作系统Salvo,系统功能扩展和裁剪方便,可移植到各个应用领域。     

钛酸锶铋介电陶瓷中MgO掺杂研究

本文研究了锶铋钛陶瓷中ＭｓＯ的掺杂效应，发现ＭｇＯ对材料的相结构和介电性能产生很大影响，随ＭｇＯ含量的增加，材料介电温度稳定性提高．作者根据Ｋ．Ｌｉｃｈｔｅｎｅｃｈｅｒ规则以及元素替代效应，讨论了ＭｇＯ相、材料体内元素替代以及电荷施受主补偿对材料缺陷机构和介电性能的影响．     

受主杂质Mn对（Ba,Pb）TiO3系高温PTC热敏陶瓷的影响

本文研究了(Ba,Pb)TiO_3系高温PTC半导体陶瓷中半导化与其烧结工艺、铅空位、钡空位和施、受主杂质等相互之间的关系。着重分析讨论了引入受主杂质Mn对材料的半导化的影响,并采用复合缺陷模型自洽地解释了实验现象。     

Adjuvant chemotherapy for patients with resected Dukes' C and high-risk B2 colon cancer with fluorouracil and levamisole

Carcinoma of the large bowel is the second leading cause of cancer mortality in Singapore. Although the great majority of patients are discovered at a stage where resection with curative intent is possible, almost half of the patients afflicted will die of it. The combination of 5-fluorouracil + levamisole used in patients with curatively resected high risk Dukes B2 and all Dukes' C colon cancers has been shown to reduce cancer recurrence rate and improve overall survival. Since 1990 adjuvant chemotherapy has been recommended for this group of patients. This report describes patients treated in Singapore, their toxicities and their outcome. A total of 341 patients were treated between 1990 and 1996. Treatment compliance was 71.8%. Toxicity was moderate with mainly grade 1-2 nausea and vomiting, diarrhoea, stomatitis, alopecia, and neutropenia. There was 1 treatment-related death. Median recurrence-free interval was 81 months and median survival was not reached at 90 months. This regimen is tolerable. Until further randomised reports comparing 5-fluorouracil + levamisole to other combinations are available, this combination chemotherapy is recommended to patients after surgical resection of the high risk Dukes' B2 and Dukes' C colon cancer to reduce cancer recurrence and improve overall survival.