A Possible Reaction Pathway to Fabricate a Half‐Metallic Wire on a Silicon Surface

Based on first‐principles electronic structure calculations and molecular dynamics simulations, a possible reaction pathway for fabricating half‐metallic Mo‐borine sandwich molecular wires on a hydrogen‐passivated Si(001) surface is presented. The molecular wire is chemically bonded to the silicon surface and is stable up to room temperature. Interestingly, the essential properties of the molecular wire are not significantly affected by the Si substrate. Furthermore, their electronic and magnetic properties are tunable by an external electric field, which allows the molecular wire to function as a molecular switch or a basic component for information storage devices, leading to applications in future molecular electronic and spintronic devices.     

燃气涡轮无气膜动叶的内流流场和气热耦合计算

为了详细设计涡轮动叶冷却结构,采用内流三维流场计算对内部的流动细节进行设计,并将全三维气热耦合计算作为冷却结构最终方案的详细设计。计算结果表明,当调整第三腔隔板倾斜时,可以有效地控制第三腔流动,降低第三腔位置的高温;由于第二腔根部冷气流动雷诺数较低,导致第二腔温度较高。通过将肋形式由60°平行肋改为60V型肋能够将最大温度降低10K。三维云图以及流线图可以看出,高温区随着结构的改变而改变。     

屯留井田煤层气井排采主控因素研究

为提高煤层气井的产能,分析煤层气排采机理和排采阶段,并从地质构造、顶底板岩性、压裂液及井网部署等方面,探讨影响屯留井田煤层气井排采的主要因素。研究认为褶皱对煤层气井的排采效果影响较大,裂隙和顶底板也对煤层气排采有一定影响;采用压裂工艺对煤储层强化改造中,活性水+氮气压裂液体系助排效果优于活性水压裂,而清洁压裂液助排效果最差;研究区煤储层特征决定了屯留井田煤层气井难以获得高产量,但可能产气时间较长。同时研究认为,研究区煤层气井井网宜采用排间距200 m×250 m的小井网结构,且井位布置应与主裂缝延伸方向(东北方向)平行。     

Effects of Melt Thermal-Rate Treatment on Fe-Containing Phases in Hypereutectic Al-Si Alloy

In this paper, effects of melt thermal-rate treatment (MTRT) on Fe-containing phases in hypereutectic Al-Si alloy were investigated. Results show that MTRT can refine microstructures and improve castability, mechanical properties, wear characteristics, and corrosion resistance of Fe-containing Al-Si alloy. When Al-15Si-2.7Fe alloy is treated with MTRT by 1203 K (930 °C) melt: coarse primary Si and plate-like Fe-containing phase both can be refined to small blocky morphology, and the long needle-like Fe-containing phase disappears almost entirely; ultimate tensile strength and elongation are 195 MPa and 1.8 pct, and increase by 12.7 and 50 pct, respectively; and the wear loss and coefficient of friction decrease 7 to 17 and 24 to 30 pct, respectively, compared with that obtained with conventional casting technique. Corrosion resistance of the alloy treated with MTRT by 1203 K (930 °C) melt is the best, that is it has the lowest i _corr value and the highest E _corr value. Besides, effects of MTRT on Al-15Si-xFe (x = 0.2, 0.7, 1.7, 3.7, 4.7) alloys were also studied, MTRT can only refine microstructure and improve mechanical properties of Al-15Si alloy with 0.7 to 3.7 pct Fe content greatly in the present work.     

Pressure-sketch: a tablet-based design system in immersive VR

Virtual Reality - Sketch design is generally a feasible concept within virtual reality (VR). However, VR controllers suffer from a fundamental problem that limits operability and immersion, which...     

Optimization of biodegradation of polycyclic aromatic sulfur heterocycles in soil using response surface methodology

Abstract

This paper uses response surface methodology based on the Box-Behnken design to investigate the influence of substrate concentration, inoculation quantity and temperature on the biodegradation of polycyclic aromatic sulfur hydrocarbons in oil-contaminated soil by Pseudomonas sp. LKY-5. Substrate concentration is identified as the most important factor through the analysis of variance. The maximum degradation of PASHs can be achieved at the conditions of substrate concentration of 75.77?ml/kg, inoculation quantity of 20.4% and temperature of 30?°C.     

Dr．COM认证环境下Internet接入共享与仿真

为了满足企业内、外网之间灵活访问的需求,设计了一个改进的Internet接入共享方案,基于路由和远程访问服务和网络地址转换技术,成功实现了Dr．COM宽带认证环境下主机和移动终端的网络接入共享,并在VMware虚拟机上仿真某企业网络．改进后的方案,无需购置专用硬件路由器,具有成本低、软硬件可扩充性强、组网灵活等优点,尤其适用于中小型企业,并为工程技术人员研究In—ternet接入提供了有益参考．     

高强阻燃维纶混纺织物的热性能研究

采用高强阻燃维纶短纤维混纺股线制作成织物,测试该织物的导热性能和耐热性能。结果表明,添加高强阻燃维纶的织物可在220℃之内保证织物一定的力学性能和尺寸稳定性。     

复凝聚法制备山核桃油微胶囊的研究

以改性乳清分离蛋白聚阳离子及阿拉伯树胶聚阴离子为壁材,采用复凝聚法在山核桃油表面形成包覆结构,利用转谷氨酰胺酶进行固定化,冷冻干燥脱水获得微胶囊成品.根据微胶囊包油率,对制备条件和固化条件进行评价.结果表明,最佳制备条件为:山核桃油添加量为0.6mL,改性乳清分离蛋白添加量20mL,阿拉伯树胶添加量为6％,pH4.5,搅拌速度为300r/min.最佳固化条件为:固化pH6.0,固化时间为10h,固化温度为10℃,转谷氨酰胺酶添加量为25U/g阿拉伯树胶.最终包油率可达84.15％.在贮藏过程中,微胶囊化后的核桃油可有效的抑制山核桃油过氧化值升高.     

一种新的等温扩增技术检测阪崎肠杆菌

目的:建立一种新型阪崎肠杆菌快速筛选检测方法——交叉引物恒温扩增结合免疫金标检测方法。方法:针对阪崎肠杆菌16S-23S rDNA间区序列设计特异性引物及探针,建立交叉引物等温扩增法,利用免疫金标试纸条对结果进行检测。用18株阪崎肠杆菌及其他36株近源菌进行特异性试验;通过定量DNA、纯菌液计数、添加干扰菌检测进行灵敏度验证。结果:建立方法具有很好的特异性;增菌液检测灵敏度为10~1CFU/mL,DNA检测灵敏度为10~0fg/test。结论:建立的交叉引物恒温扩增结合免疫金标检测方法特异性好、灵敏度高,不需要复杂仪器,对口岸快速筛查、基层或偏远经济不发达地区顺利开展检测具有实际意义。