共析钢经表面研磨处理后微观组织的演化

利用表面研磨处理(SMAT)在共析钢上制备出具有纳米晶体结构的表面层,并利用X射线衍射和透射电镜分析了纳米表面层的微观组织结构及其演变.结果表明:原始组织为层片状铁素体 渗碳体两相复合组织的共析钢经过SMAT后,铁素体晶粒由于位错产生、位错缠结形成位错胞,然后分割晶粒使铁素体细化至纳米尺度,而渗碳体在强烈塑性变形下,经历弯曲、断裂,最终分解成体心立方铁素体和底心正交的石墨.     

A Project Risk Ranking Approach Based on Set Pair Analysis

Set Pair Analysis （SPA） is a new methodology to describe and process system uncertainty. It is different from stochastic or fuzzy methods in reasoning and operation, and it has been applied in many areas recently. In this paper, the application of SPA in risk ranking is presented, which includes review of risk ranking, introduction of Connecting Degree （CD） that is a key role in SPA., Arithmetic and Tendency Grade （TG） of CDs, and a risk ranking approach proposed. Finally a case analysis is presented to illustrate the reasonability of this approach. It is found that this approach is very convenient to operate, while the ranking result is more comprehensible.     

机械合金化工艺对Fe-Ni合金显微结构的影响

对机械合金化制备的Fe-Ni粉体利用X射线衍射(XRD)进行分析，得到了不同Ni含量和不同球磨时间Fe-Ni纳米晶的XRD谱．实验表明，w(Ni)=10％和20％时，Ni溶入Fe晶格，分别在球磨20h和50h后形成单一的a(bcc)相；w(Ni)=50％时，其先后经历了γ(fcc)→←a(bcc)正逆转变，在球磨120h后最终形成单一γ(fcc)相．无论是a(bcc)相还是γ(fcc)相．它们的固溶度均比块体Fe-Ni合金显著提高．w(Ni)=35％时，则始终是两相共存．对试样的XRD谱采用3种不同的方法测定了Fe-Ni粉体的晶粒尺寸和显微畸变，发现经球磨20h后，不同Ni含量的粉体均呈纳米结构，并随球磨时间延长，Fe-Ni纳米晶的晶粒尺寸下降而显微畸变上升．     

An improved form of the ELMS algorithm

1.INTRODUCTION Adaptiveechocancellersarewidelyemployedintele conferencingsystemsinordertocompensateforthe impairmentinthequalityduotoundesiredechoesre sultingfromcouplingbetweenloudspeakerandmicro phone.Inastereophonicenvironment,thefunda mentalproblemofechocancellationisthatgiventhe inputtotheloudspeakersandtheoutputofthemicro phonesinthereceivingroom,theechopathcannot bedetermineduniquely[3,8,9].Theproblemisdueto thecorrelationbetweenthestereosignals.Asare sult,anyadaptivetechniqueusedi…     

Dynamic characteristics of the planetary gear train excited by time-varying meshing stiffness in the wind turbine

Wind power has attracted increasing attention as a renewable and clean energy. Gear fault frequently occurs under extreme environment and complex loads. The time-varying meshing stiffness is one of the main excitations. This study proposes a 5 degree-of-freedom torsional vibration model for the planetary gear system. The influence of some parameters (e.g., contact ratio and phase difference) is discussed under different conditions of a single teeth pair and double pairs of teeth. The impact load caused by the teeth face fault, ramped load induced by the complex wind conditions, and the harmonic excitation are investigated. The analysis of the time-varying meshing stiffness and the dynamic meshing force shows that the dynamic design under different loads can be made to avoid resonance, can provide the basis for the gear fault location of a wind turbine, and distinguish the fault characteristics from the vibration signals.     

Nanoengineering of amino - functionalized mesoporous silica nanospheres as nanoreactors

Selective functionalization of mesoporous silica nanospheres (MSNs) is crucial for nanoengineering of MSNs. Herein, we have combined “surface-protected etching strategy” and “cationic surfactant assisted etching strategy” to prepare functionalized MSNs with externally attached amino groups. The externally attached NH2 groups endow the catalysts with excellent catalytic performance for nitroaldol reaction between nitromethane and benzaldehyde. In addition, those NH2-MSNs can also be used to support gold nanoparticles, which display very good catalytic performance for reduction of 4-nitrophenol. It can be envisioned that the synthesis protocol developed in this work could also be extended to nanoengineered MSNs, which provides opportunities for nanoreactors design.     

DanHong Injection inhibits the development of primary abdominal aortic aneurysms in apoE knockout mice

Clinical observations indicate that DanHong Injection （DHI） can increase blood flow and reduce various syndromes in patients with cardiovascular disease. How- ever, it still needs to define the function of DHI and the involved mechanisms in details, such as the protective effect on the development of primary abdominal aortic aneurysms （AAAs）. In this study, we determined whether DHI is able to inhibit AAA in apoE knockout （apoE-/-） mice. Thirty apoE-/- male mice on high-fat diet （0.5 % cholesterol, 21% fat） were randomly divided into two groups and received i.p. injection of saline （100 μL/day） and DHI （100 μL/day）, respectively, for 16 weeks. At the end of experiment, we determined the development of atherosclerosis in en face aorta and aneurysms,pathological morphology of arterial wall, and serum lipid levels. We also determined the expression of monocyte chemoattractant protein-1 （MCP-1）, MMP-2, and MMP-9 mRNA in aortic wall using real-time RT-PCR. Our results indicated that high-fat diet induced the development of AAAs in apoE-/- mice, but the induction was totally blocked by DHI （P 〈 0.01）. The result of staining of abdominal aortic cross sections showed that DHI main- tained the collagen content in arterial wall, thereby pre- venting the animals from the development of AAA. Although DHI had little effect on serum total- and LDL- cholesterol levels, it reduced the expression of MCP-1, MMP-2, and MMP-9 mRNA in aortic wall （P 〈 0.01）. Taken together, our study suggests that DHI can inhibit the high-fat diet-induced AAA formation. The inhibitory effects may be related to the maintenance of the collagen content and inhibition of expression of AAA-related genes. Our study may suggest a new application of DHI in clinics.     

A second generation human haplotype map of over 3.1 million SNPs

We describe the Phase II HapMap, which characterizes over 3.1 million human single nucleotide polymorphisms (SNPs) genotyped in 270 individuals from four geographically diverse populations and includes 25-35% of common SNP variation in the populations surveyed. The map is estimated to capture untyped common variation with an average maximum r2 of between 0.9 and 0.96 depending on population. We demonstrate that the current generation of commercial genome-wide genotyping products captures common Phase II SNPs with an average maximum r2 of up to 0.8 in African and up to 0.95 in non-African populations, and that potential gains in power in association studies can be obtained through imputation. These data also reveal novel aspects of the structure of linkage disequilibrium. We show that 10-30% of pairs of individuals within a population share at least one region of extended genetic identity arising from recent ancestry and that up to 1% of all common variants are untaggable, primarily because they lie within recombination hotspots. We show that recombination rates vary systematically around genes and between genes of different function. Finally, we demonstrate increased differentiation at non-synonymous, compared to synonymous, SNPs, resulting from systematic differences in the strength or efficacy of natural selection between populations.     

Genome-wide detection and characterization of positive selection in human populations

With the advent of dense maps of human genetic variation, it is now possible to detect positive natural selection across the human genome. Here we report an analysis of over 3 million polymorphisms from the International HapMap Project Phase 2 (HapMap2). We used 'long-range haplotype' methods, which were developed to identify alleles segregating in a population that have undergone recent selection, and we also developed new methods that are based on cross-population comparisons to discover alleles that have swept to near-fixation within a population. The analysis reveals more than 300 strong candidate regions. Focusing on the strongest 22 regions, we develop a heuristic for scrutinizing these regions to identify candidate targets of selection. In a complementary analysis, we identify 26 non-synonymous, coding, single nucleotide polymorphisms showing regional evidence of positive selection. Examination of these candidates highlights three cases in which two genes in a common biological process have apparently undergone positive selection in the same population:LARGE and DMD, both related to infection by the Lassa virus, in West Africa;SLC24A5 and SLC45A2, both involved in skin pigmentation, in Europe; and EDAR and EDA2R, both involved in development of hair follicles, in Asia.     

Principle and Realization Method of Tunnel Deformation Detection Based on Image Recognition and Data Transmission Technology

<正>To detect the deformation of the tunnel structure based on image sensor networks is the advanced study and application of spatial sensor technology.For the vertical settlement of metro tunnel caused by internal and external stress after its long period operation,the overall scheme and measuring principle of tunnel deformation detection system is introduced. The image data acquisition and processing of detection target are achieved by the cooperative work of image sensor,ARM embedded system.RS485 communication achieves the data transmission between ARM memory and host computer.The database system in station platform analyses the detection data and obtains the deformation state of tunnel inner wall,which makes it possible to early-warn the tunnel deformation and take preventive measures in time.