剖析半悬挂减速机故障的产生与对策

介绍了半悬挂减速机的工作原理，分析其故障原因，实施相应的解决对策。     

Characterizing the deformation behavior of Tertiary sandstones

Tertiary sandstones possess deformational behavior different from hard rocks, especially the relatively larger amount of volumetric dilation during shearing. Such excess dilation contributes to the increase of crown settlement during tunnel excavation and accounts for several cases of tunnel squeezing within Tertiary sandstones. Therefore, the deformation behavior of Tertiary sandstones sampled from more than 13 formations was studied. To distinguish the volumetric deformation induced by hydrostatic stress or by shear stress as well as to decompose the elastic and the plastic components of strains, special experimental techniques, including pure shear tests and cycles of loading–unloading were applied.The experimental results reveal that the deformation of Tertiary sandstone exhibits the following characteristics: (1) significant amount of shear dilation, especially elastic shear dilation; (2) non-linear elastic and plastic deformation; (3) plastic deformation occurs prior to the failure state. Furthermore, features of plastic deformation were inferred from experimental results and, as a result, the geometry of plastic potential surface and the hardening rule were accordingly determined. A constitutive model, involving nonlinear elastic/plastic deformation and volumetric deformation induced by shear stress, is proposed. This proposed model simulates the deformational behavior for the shear-dilation-typed rocks reasonably well. Furthermore, tests on the versatility of the proposed model, including varying hydrostatic stress and stress paths, indicate that the proposed model is capable of predicting deformational behavior for various conditions.     

水培花卉与室内装饰

水培花卉是当今室内摆花应用的大趋势。它具有省工、省肥、省水、轻便卫生、无污染等优点,应用前景诱人。本文总结了水培花卉的特点及其在室内绿化中的功能,提出了水培花卉在日常栽培、管理和室内装饰中应注意的问题。     

HotSpot: a compact thermal modeling methodology for early-stage VLSI design

This paper presents HotSpot-a modeling methodology for developing compact thermal models based on the popular stacked-layer packaging scheme in modern very large-scale integration systems. In addition to modeling silicon and packaging layers, HotSpot includes a high-level on-chip interconnect self-heating power and thermal model such that the thermal impacts on interconnects can also be considered during early design stages. The HotSpot compact thermal modeling approach is especially well suited for preregister transfer level (RTL) and presynthesis thermal analysis and is able to provide detailed static and transient temperature information across the die and the package, as it is also computationally efficient.     

精铸件结构优化设计实践

以6种典型的精密铸件为例，利用“6个千方百计”原则对产品结构进行优化设计，同时辅助有限元分析对优化结果进行再验证。通过减少大平面、避免深长孔、采用加强筋等优化措施，有效地避免了夹砂、鼓包、跑火、缩孔、裂纹等铸造缺陷，实现了少无切削和减轻铸件质量。     

Solid Modeling Error : Analysis and Compensation

ＳｏｌｉｄＭｏｄｅｌｉｎｇＥｒｏｒ：ＡｎａｌｙｓｉｓａｎｄＣｏｍｐｅｎｓａｔｉｏｎ①ＸｕＺｈｉｇａｎｇＨｕａｎｇＫｅｚｈｅｎｇＡｉＸｉｎｇＳｈａｎＬｉａｎｙｅＣｏｌｅｇｅｏｆＭｅｃｈａｎｉｃａｌＥｎｇｉｎｅｅｒｉｎｇ，ＳｈａｎｄｏｎｇＵｎｉｖｅｒｓｉ...     

Effects of NH3 plasma passivation on N-channelpolycrystalline silicon thin-film transistors

The NH₃-plasma passivation has been performed on polycrystalline silicon (poly-Si) thin-film transistors (TFT's), It is found that the TFT's after the NH₃-plasma passivation achieve better device performance, including the off-current below 0.1 pA/μm and the on/off current ratio higher than 10⁸, and also better hot-carrier reliability than the H₂-plasma devices. Based on optical emission spectroscopy (OES) and secondary ion mass spectroscopy (SIMS) analysis, these improvements were attributed to not only the hydrogen passivation of the defect states, but also the nitrogen pile-up at SiO₂/poly-Si interface and the strong Si-N bond formation to terminate the dangling bonds at the grain boundaries of the polysilicon films. Furthermore, the gate-oxide leakage current significantly decreases and the oxide breakdown voltage slightly increases after applying NH₃-plasma treatment. This novel process is of potential use for the fabrication of TFT/LCD's and TFT/SRAM's     

Molecular recognition of diketide substrates by a beta-ketoacyl-acyl carrier protein synthase domain within a bimodular polyketide synthase

BACKGROUND: Modular polyketide synthases (PKSs) are large multifunctional proteins that catalyze the biosynthesis of structurally complex bioactive products. The modular organization of PKSs has allowed the application of a combinatorial approach to the synthesis of novel polyketides via the manipulation of these biocatalysts at the genetic level. The inherent specificity of PKSs for their natural substrates, however, may place limits on the spectrum of molecular diversity that can be achieved in polyketide products. With the aim of further understanding PKS specificity, as a route to exploiting PKSs in combinatorial synthesis, we chose to examine the substrate specificity of a single intact domain within a bimodular PKS to investigate its capacity to utilize unnatural substrates. RESULTS: We used a blocked mutant of a bimodular PKS in which formation of the triketide product could occur only via uptake and processing of a synthetic diketide intermediate. By introducing systematic changes in the native diketide structure, by means of the synthesis of unnatural diketide analogs, we have shown that the ketosynthase domain of module 2 (KS2 domain) in 6-deoxyerythronolide B synthase (DEBS) tolerates a broad range of variations in substrate structure, but it strongly discriminates against some others. CONCLUSIONS: Defining the boundaries of substrate recognition within PKS domains is crucial to the rationally engineered biosynthesis of novel polyketide products, many of which could be prepared only with great difficulty, if at all, by direct chemical synthesis or semi-synthesis. Our results suggest that the KS2 domain of DEBS1 has a relatively relaxed specificity that can be exploited for the design and synthesis of medicinally important polyketide products.     

一种新型分层式双循环冷却系统

设计并研制出一种新型分层式双循环冷却水系统，用于冷却激光器，效果良好     

双层辉光离子渗镀钽

介绍了一种新型离子渗镀钽的工艺方法。较好解决了渗镀钽时供给活性钽粒子的总是比方法工艺简单，操作方便，效率高。为充分利用和节约使用昂贵的钽探索了一条实用可行的途径。