物理方法改性在塑料改性中的应用

介绍了物理改性剂如玻璃纤维、橡胶、碳酸钙、滑石粉、云母粉等在塑料改性中的应用,以及对塑料性能的主要影响     

9Cr-1Mo-V-Nb-N钢管的热处理工艺的优化

采用单因素比较试验法和正交试验法对9Cr-1Mo-V-Nb-N钢厚壁无缝钢管热处理工艺参数进行了优化研究,通过16个力学性能指标的多指标综合量化评估法得到了优化的热处理工艺参数.结果表明,优化工艺的正火温度为1055℃±15℃,回火温度765℃±15℃.经优化工艺处理后的厚壁管其力学性能显著提高.     

Peroxyacetic Acid Oxidation of Olefins and Alkanes Catalyzed by a Dinuclear Manganese(IV) Complex with 1,4,7-trimethyl-1,4,7-triazacyclononane

Natural terpenes, (−)-limonene and (+)-carvone, can be epoxidized by peroxyacetic acid (PAA) at room temperature if a dinuclear manganese(IV) complex with 1,4,7-trimethyl-1,4,7-triazacyclononane (L), [Mn₂L₂O₃] [PF₆]₂, is used as a catalyst. The total yield of the epoxides based on the consumed olefins are 97 and 95%, respectively. A kinetic study of the dec-1-ene and cyclohexane oxygenations including the investigation of their simultaneous competitive oxidation was carried out. The olefin epoxidation rate does not depend on dec-1-ene concentration and the dec-1-ene concentration does not affect the rate of cyclohexane oxidation. The cyclohexane oxidation rate is proportional to the alkane concentration. The kinetic analysis led to the conclusion that two species X ₁ and X ₂ are generated in the system, and there is no their mutual interconversion. The rate equation for the dec-1-ene epoxidation was proposed: W = k ₊₁[cat][PAA], where cat is the initial manganese complex or its derivative, and the constant was determined: k ₊₁ = 3.5 mol⁻¹ dm³ s⁻¹. Species X ₁ is apparently an effectively epoxidizing manganese peroxo derivative whereas species X ₂ is an alkane hydroxylating manganese oxo complex.     

Stress, seen from outside

This article draws from the vast literature on stress in nursing and discusses the preoccupation that researchers and specialists have with this area. It asks the reader to take a moment to reflect on the types of stressful situations that nurses face on a daily basis. The authors focus on the potential tensions that can ensue following exposure to stress and the resulting psychosomatic, psychological, behavioral and organizational consequences. The authors challenge legislators, governments, administrators, members of the multidisciplinary team and nursing organizations to tackle the issue of stress in nursing and make it a priority. Research conducted during the last 20 years provides overwhelming evidence that nurses work in a high-stress environment. The sources of stress vary and their consequences are significant. However, it is recognized that certain personal factors such as type "A" personality can influence the way nurses deal with stress. Ultimately, the authors conducted their literature review with the aim of proposing anti-stress strategies.     

Extreme-ultraviolet Mo/Si multilayer mirrors deposited by radio-frequency-magnetron sputtering

Mo/Si multilayer mirrors with a high reflectance at normal incidence in the 130-135-? spectral region have been deposited by rf magnetron sputtering. A new and quick technique was used to calibrate the deposition rates. Characterization by transmission electron microscopy (TEM) and grazing-incidence x-ray diffraction (XRD) indicated good thickness control of the deposition process and low interface roughness. However, the TEM and, indirectly, the XRD reflectance measurements, indicated that the interfaces are asymmetric. A brief review discussing the origin of the modulation of the Bragg peak intensities in the XRD reflectance is given. An analytical formula was derived for periodic multilayers that describes the effect of asymmetric interfaces on the amplitude of the Bragg peak modulation. Theoretically, in XRD reflectance measurements, any asymmetry in the interdiffusion of the Mo-Si interfaces results in a decrease of the usual amplitude modulation of the Bragg peaks. Extreme-ultraviolet (XUV) reflectance measurements were also made with synchrotron radiation on a new high-resolution reflectometer. The near-normal-incidence peak reflectances measured at λ = 134 ? were ~ 59% for the best multilayer mirrors. Good fits to both XRD and XUV reflectance measurements have been obtained with a model that allows for interface asymmetry.     

铍的连接技术研究进展

作为最轻的金属之一铍具有许多优异性能，因而在电子工业、航天航空和国防工业广泛应用。对铍的连接技术，如钎焊、扩散焊、熔化焊等焊接方法现状进行了分析，并介绍了具体连接方法，提出了存在的问题和解决办法，有助于提高铍的连接质量。     

低热膨胀磷酸盐陶瓷材料Ca_(1-X)Ba_XZr_4(PO_4)_6的合成

Ca1-XBaXZr4 (PO4 ) 6(0 X 1.0 ,简称CBZP)属于NZP族磷酸盐陶瓷材料 ,它是新的一类低热膨胀陶瓷材料。本文采用共沉淀法合成了CBZP超细粉体 ,研究了共沉淀法反应机理和粉体分散性并对粉体进行了热重 -差热分析及X射线衍射分析。实验结果表明 ,反应过程的pH应控制在 7～ 11之间 ,共沉淀物用乙醇进行分散后 ,可得到粒径为 1.6～ 1.8μm、分布均匀、无硬团聚体的CBZP超细粉体 ;煅烧后所得到的超细粉体具有确定的晶型     

支持向量机训练算法综述

本文介绍统计学习理论中最年轻的分支——支持向量机的训练算法，主要有三大类：以 SVMlight为代表的分解算法、序贯分类方法和在线训练法，比较了各自的优缺点，并介绍了 其它几种算法及多类分类算法．最后指出了支持向量机具体实现的方向及其在模式识别、数 据挖掘、系统辨识与控制等领域中的应用．     

试论高校新校区建设与校园文化的融合

当前许多在建新校区的高校面临着同样的问题:高校新校区如何创建特色鲜明、品味高 雅的校园文化。本文认为在新校园建设过程中应理念先行、精心建设,注重校园文化的传承与 创新,促进新校区建设与校园文化的融合。     

Design, synthesis, and in vitro antifungal activity of 1-[(4-substituted-benzyl)methylamino]-2-(2,4-difluorophenyl)-3-(1H-1,2,4-triazol-1-yl)propan-2-ols

As part of our studies focused on the design of 1‐[((hetero)aryl‐ and piperidinylmethyl)amino]‐2‐phenyl‐3‐(1H‐1,2,4‐triazol‐1‐yl)propan‐2‐ols as antifungal agents, we report the development of new extended benzylamine derivatives substituted at the para position by sulfonamide or retrosulfonamide groups linked to alkyl or aryl chains. These molecules have broad‐spectrum antifungal activities not only against Candida spp., including fluconazole‐resistant strains, but also against a filamentous species (A. fumigatus). Concerning fluconazole resistance, selected compounds exhibit the capacity to overcome CDR and ERG11 gene upregulation and to maintain antifungal activity despite a recognized critical CYP51 substitution in C. albicans isolates. Synthesis, investigation of the mechanism of action by sterol analysis in a C. albicans strain, and structure–activity relationships (SARs) are reported.