妙用蓝牙30元组建无线网

蓝牙技术大家再熟悉不过了,我们今天的主题是“用蓝牙适配器组建局域网”,这可不是一个寻常的组网方式哦^-^下面就让我们一同来探讨一下。     

Design and Implementation of an Extended Collectives Library for Unified Parallel C

Unified Parallel C(UPC) is a parallel extension of ANSI C based on the Partitioned Global Address Space(PGAS) programming model,which provides a shared memory view that simplifies code development while it can take advantage of the scalability of distributed memory architectures.Therefore,UPC allows programmers to write parallel applications on hybrid shared/distributed memory architectures,such as multi-core clusters,in a more productive way,accessing remote memory by means of different high-level language constructs,such as assignments to shared variables or collective primitives.However,the standard UPC collectives library includes a reduced set of eight basic primitives with quite limited functionality.This work presents the design and implementation of extended UPC collective functions that overcome the limitations of the standard collectives library,allowing,for example,the use of a specific source and destination thread or defining the amount of data transferred by each particular thread.This library fulfills the demands made by the UPC developers community and implements portable algorithms,independent of the specific UPC compiler/runtime being used.The use of a representative set of these extended collectives has been evaluated using two applications and four kernels as case studies.The results obtained confirm the suitability of the new library to provide easier programming without trading off performance,thus achieving high productivity in parallel programming to harness the performance of hybrid shared/distributed memory architectures in high performance computing.     

Working without accumulation membrane in flow field-flow fractionation

Nonideal interaction of sample with the separation device is a difficulty found in chromatographic methods as well as in field-flow fractionation. However, in field-flow fractionation (FFF), greater flexibility in the choice of carrier solution composition is possible, thus reducing the need of a wide choice of surface chemistry when nonideal sample interaction is to be minimized. The use of an ultrafiltration membrane as the surface for the accumulation wall is common practice in flow field-flow fractionation. Typical membranes in use are laminates of a skin membrane onto a backing material such as woven polyester. At this point, only a limited choice of membrane chemistries is available. Many membranes have been developed for protein applications as membranes are widely used in the pharmaceutical industries. While these membranes work well for protein applications, flow field-flow fractionation is applicable to polymeric particulate as well as protein samples. Thus, sample interaction with the membrane surface is possible with nonprotein applications and these interactions can induce significant secondary effects on retention ratio and affect instrumental reliability. Also, the woven texture of membranes may detrimentally affect the FFF separation. For these reasons, the study of flow field-flow fractionation using a flat, smooth surface of controlled chemistry is of relevance. We present here the results of a new, membraneless channel that uses a bare frit as the accumulation wall and that is intended for analysis of micrometer-sized particles only. Selectivity results are comparable to those obtained with the membrane, while relative sample recovery indicates that the best quantitative performance can be obtained without the membrane. Moreover, neither sample immobilization nor losses through the frit occur when operating membraneless. On the other hand, first experimental evidence of a certain level of frit surface activity suggests that optimization of experimental conditions is required.     

Fabrication and characterization of microwell array chemical sensors

Microwell arrays have been fabricated on the distal face of coherent fiber-optic bundles. A typical microwell array comprises approximately 3,000 individual optical fibers that were etched chemically. Individual microwells were 1 to 14-microm deep with approximately 22-microm widths and were filled partially with a chemical sensing (polymer + dye) layer to produce a microwell array sensor (MWAS). MWASs were fabricated using a technically expedient, photoinitiated polymerization reaction whereby a approximately 2 to 10-microm thick pH-sensitive or O2-sensitive sensing layer was immobilized inside each microwell. The pH-sensing layer comprised fluorescein isothiocyanate-dextran conjugate immobilized in a photopolymerizable poly(vinyl alcohol) membrane. The O2-sensing layer comprised a ruthenium metal complex entrapped in a gas-permeable photopolymerizable siloxane membrane. pH and PO2 were quantitated by acquiring luminescence images using an epifluorescence microscope/charge-coupled device imaging system. The pH-sensitive MWAS displayed a pKa of approximately 6.4 and a response time of approximately 2.5 s. The O2-sensitive MWAS behaved according to a nonlinear Stern-Volmer model with a maximum I0/I of approximately 4 and a response time of approximately 2.5 s. MWASs are advantageous in that suitably sized samples such as single biological cells can be co-localized with the sensing matrix in individual microwells.     

碳纳米管纱作为填料应用于硝基芳烃污水处理（英文）

碳纳米管纱(CNTY)因具有优异的力学强度、化学稳定性、热稳定性和高比表面积而成为去除废水中有机污染物的潜在材料。本文将CNTY用于含2,4-二硝基甲苯(DNT)的污水处理。CNTY对DNT的吸附能力与文献报道值作对比研究,同时探讨吸附动力学。采用SEM-EDX、HRTEM、Raman与XPS表征CNTY吸附DNT前后的尺寸、表面形貌及表面化学。结果表明,经CNTY对DNT污水处理后的水质达到实验室无离子水级纯度。CNTY对DNT吸附符合Freundlich吸附等温线,Freundlich参数由K/nF为55.0 mg/g(L/mg)1,指数1/n为0.737得到,表明其比活性炭吸附性弱,但更易再生。CNTY比活性炭的吸附性速率更快,遵循拟二级动力学模型。CNTY吸附DNT引起D、G常偏移,归因于CNTs与DNT间电子受体和供体效应。     

复合材料--一种采用机织物的现代化材料

在与建筑构件相关的领域 ,尤其是在交通和车辆制造部门 ,对重量轻而性能高的材料需求不断增加。复合材料的主要组分通常是由高性能纤维制成的纱线和织物。在需要轻质建筑的领域———无论是汽车、桥梁、建筑、运输集装箱行业还是作为加固件 ,所提出的方案中越来越多地采用纤维复合材料。在过去几年中 ,即使在要求用最轻部件提供最安全保护的安全部门 ,机织物复合材料也被证明是最佳的解决方案。新的应用领域正在不断得到开发。尤其在交通和交通建筑部门 ,复合材料具有很多优势。重量减轻的结果是 :消耗更少的能量而产生更大的工作载荷。1　…     

随时随地冲浪用好网络收藏夹

无论你使用什么浏览器,收藏夹的调用还是不变的。面对多地点或者多台电脑的情况下,IE收藏夹又不能同步,是不是很不方便呢？而且当系统崩溃或遇到病毒时,辛苦收藏的网址将面临丢失的危险。既然如此不方便,那么我们还是抛弃IE收藏夹吧。可以通过“网络收藏夹”（网络书签）采替代收藏同步的功能,它是通过将用户收藏的网址保存在网络服务器上实现“网络收藏”功能的,这样就不必担心系统崩溃、中毒等情况导致收藏夹丢失的现象发生了。     

土耳其德里内尔拱坝在最大可信地震下的动力稳定性分析

本文讨论了位于土耳其东北部克鲁赫河上正在建设中的高250m德里内尔拱坝。该拱坝建基面开挖施工已于2005年完成，大坝混凝土已经开始浇筑，预计将于2010年完成大坝混凝土浇筑。建成后，该坝混凝土总方量为330万m3，将是土耳其最高的拱坝，也是世界上最高的拱坝之一。本文详细讨论了大坝的抗震设计。重现期为10000年的安全评估地震的峰值加速度为0.35g。在该地震作用下，坝体中上部将出现沿水平施工缝的裂缝，带有键槽的灌浆横缝也将张开。于是，大坝顶部由于开裂而形成的混凝土坝块可能向水库方向发生位移，本文研究了该混凝土坝块可能出现的最大位移和转动位移。     

Characterization of mesoporous rice husk ash (RHA) and adsorption kinetics of metal ions from aqueous solution onto RHA

The present study deals with the characterization of low-cost rice husk ash (RHA) for its various physico-chemical properties and adsorption characteristics of metal ions. The average particle size of RHA was 150.47mum. Proximate analysis showed the presence of high amount of ash in RHA. Bulk density and the heating value of RHA were 104.9kg/m(3) and 9.68MJ/kg, respectively. The pore size distribution results showed that the RHA was predominantly mesoporous. The BET surface area was 36.44m(2)/g. The average pore diameter by BET was 42.603A. The BJH pore area showed 80% of the pore area due to the mesopores. The polar groups present on the RHA surface imparted considerable cation exchange capacity to it. RHA was found to be an effective adsorbent for the removal of cadmium (Cd(II)), nickel (Ni(II)) and zinc (Zn(II)) metal ions from aqueous solutions. The pH(0) approximately 6.0 is found to be the optimum for the removal of individual cations from the aqueous solutions by RHA at an optimum dose of 10kg/m(3). The kinetics of adsorption showed that the metal ions adsorption on RHA is a gradual process with quasi-equilibrium being attained in 5h. The pseudo-second-order kinetics represents the equilibrium data well. The effective diffusion coefficient of the cations onto the RHA is of the order of 10(-13)m(2)/s.