论城市多民族和谐社区的构建——以南京七家湾、评事街社区为例

七家湾与评事街社区为南京七家湾地区典型的回族与汉族杂居的城市社区。在这两个社区的发展过程中,回族与汉族形成了良好的互动关系,几十年来未出现民族纠纷,遂成为民族团结,社区和谐发展的典范。通过对这两个社区现状的调研,典型事例的分析与探讨,揭示了城市多民族杂居社区中各民族相处的互动关系,为构建和谐的多民族社区提供范例。     

Exome sequencing identifies recurrent somatic RAC1 mutations in melanoma

We characterized the mutational landscape of melanoma, the form of skin cancer with the highest mortality rate, by sequencing the exomes of 147 melanomas. Sun-exposed melanomas had markedly more ultraviolet (UV)-like C>T somatic mutations compared to sun-shielded acral, mucosal and uveal melanomas. Among the newly identified cancer genes was PPP6C, encoding a serine/threonine phosphatase, which harbored mutations that clustered in the active site in 12% of sun-exposed melanomas, exclusively in tumors with mutations in BRAF or NRAS. Notably, we identified a recurrent UV-signature, an activating mutation in RAC1 in 9.2% of sun-exposed melanomas. This activating mutation, the third most frequent in our cohort of sun-exposed melanoma after those of BRAF and NRAS, changes Pro29 to serine (RAC1(P29S)) in the highly conserved switch I domain. Crystal structures, and biochemical and functional studies of RAC1(P29S) showed that the alteration releases the conformational restraint conferred by the conserved proline, causes an increased binding of the protein to downstream effectors, and promotes melanocyte proliferation and migration. These findings raise the possibility that pharmacological inhibition of downstream effectors of RAC1 signaling could be of therapeutic benefit.     

Genome-wide association study of prostate cancer in men of African ancestry identifies a susceptibility locus at 17q21

In search of common risk alleles for prostate cancer that could contribute to high rates of the disease in men of African ancestry, we conducted a genome-wide association study, with 1,047,986 SNP markers examined in 3,425 African-Americans with prostate cancer (cases) and 3,290 African-American male controls. We followed up the most significant 17 new associations from stage 1 in 1,844 cases and 3,269 controls of African ancestry. We identified a new risk variant on chromosome 17q21 (rs7210100, odds ratio per allele = 1.51, P = 3.4 × 10(-13)). The frequency of the risk allele is ～5% in men of African descent, whereas it is rare in other populations (<1%). Further studies are needed to investigate the biological contribution of this allele to prostate cancer risk. These findings emphasize the importance of conducting genome-wide association studies in diverse populations.     

Ultrathin compound semiconductor on insulator layers for high-performance nanoscale transistors

Over the past several years, the inherent scaling limitations of silicon (Si) electron devices have fuelled the exploration of alternative semiconductors, with high carrier mobility, to further enhance device performance. In particular, compound semiconductors heterogeneously integrated on Si substrates have been actively studied: such devices combine the high mobility of III-V semiconductors and the well established, low-cost processing of Si technology. This integration, however, presents significant challenges. Conventionally, heteroepitaxial growth of complex multilayers on Si has been explored-but besides complexity, high defect densities and junction leakage currents present limitations in this approach. Motivated by this challenge, here we use an epitaxial transfer method for the integration of ultrathin layers of single-crystal InAs on Si/SiO(2) substrates. As a parallel with silicon-on-insulator (SOI) technology, we use 'XOI' to represent our compound semiconductor-on-insulator platform. Through experiments and simulation, the electrical properties of InAs XOI transistors are explored, elucidating the critical role of quantum confinement in the transport properties of ultrathin XOI layers. Importantly, a high-quality InAs/dielectric interface is obtained by the use of a novel thermally grown interfacial InAsO(x) layer (~1?nm thick). The fabricated field-effect transistors exhibit a peak transconductance of ~1.6?mS?μm(-1) at a drain-source voltage of 0.5?V, with an on/off current ratio of greater than 10,000.     

电子产品多物理场耦合仿真方法研究

多物理场耦合涉及机械、电磁、流体、热、声等学科,对产品性能有直接影响。针对电子产品,研究其共同属性、基本场及耦合模式、各场间耦合关系,提出一种面向电子产品的多场耦合协同仿真方法和仿真框架,并以机架式服务器为例,提出了协同仿真流程和内容,并采用Pro/E、FLOTHERM和FLUENT等软件进行了多场耦合仿真,特别是气—声耦合的噪声分析。仿真结果验证了多场耦合协同仿真方法,对预测和优化产品性能具有一定指导意义。     

IPv6下协同入侵检测系统的设计与实现

以IPv6协议为基础,设计并实现了一个Snort和iptables相协同的入侵检测系统.给出了协同入侵检测系统的思想,并结合这种想法,在传统的入侵检测和防火墙的基础上,设计了协同入侵检测的总体框架.实验结果表明,该系统具有较好的检测率.     

化学气相合成AIN超细粒子过程模型研究

基于化学气相(CVD)合成超细粒子过程的反应、成核、生长和凝并,考虑CVD反应器中的轴向温度分布,建立了CVD反应器中描述超细粒子粒度及分布的一维过程模型。针对AlCl_3-NH_3-N_2体系化学气相合成AlN超细粒子的过程,研究了AlN粒子形成过程特征和操作参数对其粒度及分布的影响。CVD反应器中的轴向温度分布严重影响AlN粒子合成过程中的化学反应速率、成核速率和生长速率;AlN超细粒子的粒度随AlCl_3浓度的减小和总流量的增加而减小,其粒度分布宽度则随总流量的增加而增大。     

基于模糊综合评判的作战指挥辅助决策系统效能评估

针对部队作战指挥辅助决策系统效能评估问题,提出了评估的指标体系,采用现代系统评估理论的层次分析法确定了评价指标的权重,建立了模糊综合评判模型,并通过对具体的实例的计算分析,验证了该模型的有效性。     

某立交曲线匝道桥事故分析

某预应力混凝土立交匝道桥在施工尚未完成时,在圆形墩柱柱身出现肉眼可见的环状裂缝,部分裂缝宽度在１ｍｍ以上,柱顶附近已局部破坏。本文对此匝道桥进行了计算,分析了事故的原因。     

口服胰岛素缓释微球的制备

用液中干燥法制备胰岛素的丙烯酸树脂缓释微球，利用扫描电镜和紫外光谱考察了内相聚合物浓度和搅拌速度对微球粒径和药物包封率的影响，结果表明，随着搅拌速度的增加和内相聚合物浓度的减小，微球粒径减小，药物包封率有所增加。此外，温度、投药量、分散剂对成球有一定的影响。最后，对缓释微球中胰岛素含量进行了测定。