Transition Temperature of Bi_2Sr_2CaCu_2O_(8+x) Superconducting Films Prepared from Commercial Precursors

This paper have made a systematic study of the superconducting Bi-2212 phase transition temperature, which has a transition temperature (Tc) around 80-93 K, and depends on precise control of synthesis conditions, mainly including heat treatment parameters, oxygen partial pressure, and annealing temperature. Partial melting of the sample during preparation helps to raise its Tc. To elucidate the origin of this strong effect, the samples were heated with different melting process. The rapid changes in Tc valu...     

Microstructure of electrochemical micromachining using inert metal mask

Electrochemical micromachining (EMM) has been gaining popularity as an alternative method to fabricate microstructure. A method of EMM is proposed to produce microhole array or micro-dimple array, in which a patterned inert metal mask (platinum plate) is closely attached to workpiece (anode), not bonded to the anode. When voltage is applied across the anode and the cathode over which electrolyte flows at a high speed, the patterns in the mask are transferred to the anode, and microstructures are produced. A mathematical model to describe the actual machining process is established. By considering the effect of nonlinear electrolyte, the parametric finite element method is adopted to simulate and numerically analyze the erosion process. Some experiments are performed to verify the proposed model.     

灵活性住宅类型

欧洲受到当今全球性生态和经济的挑战,可持续性和适应性的建筑结构设计概念再次变得愈发重要。此外,个性化的要求、人口结构的变化、民族的多样化以及向灵活工作方式的过渡也激发了对适应性住房需求的日益增长。自20世纪80年代末以来,灵活住宅的范围在欧洲显著扩大,并产生了多种类型：从功能开放的楼层平面、活动墙体的楼层平面以及各种组合类型,到前卫的空间场景、实验性高科技适应结构以及开放功能计划的建筑类型。建立起一种实现灵活性之方法的框架,并介绍了几个具有创新性的案例。     

氧气驱动万托林治疗小儿哮喘的疗效分析

目的:探讨氧气驱动万托林治疗小儿哮喘的临床疗效.方法:选取我院2009年7月至2010年7月收治的120例支气管哮喘患儿为研究对象,该组患儿均在常规治疗的基础上采用氧气驱动万托林治疗,分析该组患儿的疗效、治疗前后肺功能和炎症的改善情况.结果:该组患儿显效76例,好转34例,总有效率为91.7%.治疗后肺功能指标用力肺活量(FVC)、第1s用力呼气容积(FEV1)、用力呼气流量(PEFR)及炎症指标白细胞介素6(IL-6)、肿瘤坏死因子(TNF-α)均较治疗前显著改善,P<0.05.结论:氧气驱动万托林可明显缓解哮喘患儿的临床症状,改善肺功能和炎症,值得临床推广.     

Replication of polypyrrole with photonic structures from butterfly wings as biosensor

Polypyrrole (PPy) with photonic crystal structures were synthesized from Morpho butterfly wings using a two-step templating process. In the first step photonic crystal SiO₂ butterfly wings were synthesized from Morpho butterfly wings and in the second step the SiO₂ butterfly wings were used as templates for the replication of PPy butterfly wings using an in situ polymerization method. The SiO₂ templates were then removed from the PPy butterfly wings using a HF solution. The hierarchical structures down to the nanometer level, especially the photonic crystal structures, were retained in the final PPy replicas, as evidenced directly by field-emission scanning electron microscope (FE-SEM) and transmission electron microscopy (TEM). The optical properties of the resultant PPy replicas were investigated using reflectance spectroscopy and the PPy replicas exhibit brilliant color due to Bragg diffraction through its ordered periodic structures. The preliminary biosensing application was investigated and it was found that the PPy replicas showed a much higher biological activity compared with PPy powders through their response to dopamine (DA), probably due to the hierarchical structures as well as controlled porosity inherited from Morpho butterfly wings. It is expected that our strategy will open up new avenues for the synthesis of functional polymers with photonic crystal structures, which may form applications as biosensors.     

Electrochemical drilling inclined holes using wedged electrodes

This paper presents electrochemical machining of inclined holes using wedge-shaped electrodes. Numerical simulation has been carried out to study the initial flow fields of the machining area with and without the wedged tip at different machining inclination angles. Experiments were conducted consequently to study the machining characteristics affected by each flow field distribution mentioned above. Theoretical and experimental analyses indicate that inclined hole machining using wedged electrodes distributes the electrolyte flow more uniformly and hence leads to a more stable machining process. Wedged electrodes could be used in electrochemical drilling to efficiently drill high-quality holes with large inclination angles.     

Vacuum-based preservation of surgical specimens: An environmentally-safe step towards a formalin-free hospital

Formalin as a fixative has no practical substitutes, but is toxic and potentially carcinogenic, so caution of its use in hospitals and elsewhere is mandatory. In our hospital, preservation of surgical specimens into formalin to be transferred to pathology labs was replaced by under-vacuum sealing (UVS) tissues into plastic bags and preservation at 4 °C until transfer. Data analysis showed UVS processing to be superior in terms of staff satisfaction and of gross anatomic preservation; no problems in terms of technical feasibility or histopathologic preservation were encountered. Formalin was confined to pathology labs while its use on hospital premises was vastly reduced.     

Multi‐Atomic Layers of Metallic Aluminum for Ultralong Life Lithium Storage with High Volumetric Capacity

Metallic aluminum (Al) have been explored as potential anode materials for lithium storage because of its high theoretical capacity (993 mAh g^–1) and low voltage plateaus. Al possesses high electric conductivity, low cost and environmental friendliness. Unfortunately, Al suffers from huge volume change (>100%) during the lithiation/delithiation process, which inevitably results in the pulverization of electrode and rapid capacity decay during cycling processes. To circumvent above issues, a simple but efficient strategy is demonstrated to fabricate free‐standing multi‐atomic layers of metallic Al by harnessing the good ductility of Al under pressure. The resultant multi‐atomic Al layers are ultrathin, ≈3 nm, and have a large aspect ratio. Such unique features enable multi‐atomic Al nanosheets to construct uniform and compact films with graphene. Thus, the hybrid films with different ratios are achieved, in which the notorious volume change of metallic Al can be efficiently circumvented via the good flexibility of graphene, and the density of whole electrode can be significantly enhanced. As a consequence, the optimized multi‐atomic Al layers‐graphene (AlL‐G) film exhibits a very high volumetric capacity of 1089 mAh cm^–3, high‐rate capability and ultralong cycle life up to 20 000 cycles for lithium storage.     

Large-area,high-quality self-assembly electron transport layer for organic optoelectronic devices

We propose a self-assembly method for forming large-area high-quality solution-processed titanium oxide (TiO₂) films as efficient electron transport layer for organic solar cells. The self-assembled solution-processed TiO₂ layers are highly ordered and significantly improved in surface morphology over commonly-used spin-coating process resulting in better charge collection and significant material saving. When incorporated into polymer solar cells, the TiO₂ device shows enhanced performance. Furthermore, we demonstrate the TiO₂ can form large-area films, and achieve very uniform and improved device performances. Consequently, the self-assembled TiO₂ films can be efficient and low-cost electron transport layer potentially for large-area organic optoelectronics.     

Improved low-distortion sigma-delta ADC with DWA for WLAN standards

An improved low distortion sigma-delta ADC(analog-to-digital converter) for wireless local area network standards is presented.A feed-forward MASH 2-2 multi-bit cascaded sigma-delta ADC is adopted;however,this work shows a much better performance than the ADCs which have been presented to date by adding a feedback factor in the second stage to improve the performance of the in-band SNDR(signal to noise and distortion ratio),using 4-bit ADCs in both stages to minimize the quantization noise.Data weighted ...