水产品中创伤弧菌ddPCR定量方法的建立

选取创伤弧菌单拷贝基因met为靶基因,设计引物探针,建立对创伤弧菌准确定量的微滴式数字聚合酶链式反应(droplet digital polymerase chain reaction,ddPCR)方法,并进行特异性、灵敏度和重复性实验,同时与实时PCR(real-time PCR)方法进行比较。结果显示,所建立的ddPCR方法可以快速、高效地检测出创伤弧菌,细菌纯培养物中其定量限可达323拷贝数/mL,检测限可达61拷贝数/mL,人工污染牡蛎样品中能最低能检测到1.13×102拷贝数/g的目标菌。对人工污染样品中目标菌的检测,ddPCR的定量结果约为平板计数结果的1.4倍,比real-time PCR方法的检测更加稳定准确。本研究建立的ddPCR检测方法能快速准确、特异、灵敏地定量检测创伤弧菌。     

功率超声作用下水平连铸装置的设计及试验研究

为了提高水平连铸坯的使用性能，设计了一套带有功率超声系统的线坯水平连续铸造装置，并选择键合线用Al1Si合金作为试验材料在此装置上进行了模拟试验。采用光学显微镜分析了所得到的铸坯凝固组织，观察了铸坯的表面质量，并且对铸坯进行了力学性能测量。结果表明，功率超声作用下，铸坯的凝固组织得到细化，表面质量得到改善，当经功率为1000W的超声波处理后，合金抗拉强度和伸长率分别比未超声处理的合金提高了20．5％和37．5％。     

立体光造形技术的精度论述

论述立体光造形技术中零件的精度问题，从ＣＡＤ模型精度，切片过程中的切片精度，激光固化光敏树脂过程的制造精度，以及后固化过程中零件的尺寸精度等各个主要方面进行了深入的探讨。     

超声场对Al-1%Si合金水平连铸坯显微组织及力学性能的影响

对直径为10 mm的Al-1%Si合金水平连铸过程施加超声处理后,铸坯的表面质量得到了改善,凝固组织得到了细化,力学性能得到了提高.当超声功率达到1000 W时,表面粗糙度由未施加超声波时的40 μm降为10 μm;平均晶粒度由94.1 μm降为31.2μm;抗拉强度、延伸率和硬度分别提高了20.5%、37.5%和23.9%;同时,Si元素在α(Al)基体中分布的均匀性得到了提高,晶界偏析得到了抑制,析出的Si相形貌由条状变为颗粒状.     

Return just your search: privacy-preserving homoglyph search for arbitrary languages

Searchable encryption is an effective way to ensure the security and availability of encrypted outsourced cloud data. Among existing solutions, the keyword exact search solution is relatively inflexible, while the fuzzy keyword search solution either has a high index overhead or suffers from the false-positive. Furthermore, no existing fuzzy keyword search solution considers the homoglyph search on encrypted data. In this paper, we propose an efficient privacy-preserving homoglyph search scheme supporting arbitrary languages (POSA, in short). We enhance the performance of the fuzzy keyword search in three aspects. Firstly, we formulate the similarity of homoglyph and propose a privacy-preserving homoglyph search. Secondly, we put forward an index build mechanism without the false-positive, which reduces the storage overhead of the index and is suitable for arbitrary languages. Thirdly, POSA returns just the user’s search, i.e., all returned documents contain the search keyword or its homoglyph. The theoretical analysis and experimental evaluations on real-world datasets demonstrate the effectiveness and efficiency of POSA.     

VKSE-MO: verifiable keyword search over encrypted data in multi-owner settings

Searchable encryption (SE) techniques allow cloud clients to easily store data and search encrypted data in a privacy-preserving manner, where most of SE schemes treat the cloud server as honest-but-curious. However, in practice, the cloud server is a semi-honest-but-curious third-party, which only executes a fraction of search operations and returns a fraction of false search results to save its computational and bandwidth resources. Thus, it is important to provide a results verification method to guarantee the correctness of the search results. Existing SE schemes allow multiple data owners to upload different records to the cloud server, but these schemes have very high computational and storage overheads when applied in a different but more practical setting where each record is co-owned by multiple data owners. To address this problem, we develop a verifiable keyword search over encrypted data in multi-owner settings (VKSE-MO) scheme by exploiting the multisignatures technique. Thus, our scheme only requires a single index for each record and data users are assured of the correctness of the search results in challenging settings. Our formal security analysis proved that the VKSE-MO scheme is secure against a chosen-keyword attack under a random oracle model. In addition, our empirical study using a real-world dataset demonstrated the efficiency and feasibility of the proposed scheme in practice.     

Monte Carlo simulation of electron mobility in strained Si DG-FETs with TB bandstructure calculation

A low dimensional tight-binding (TB) based bandstructure calculation program is developed for double-gate MOSFETs (DG-FETs) to model the effects of channel orientation, transverse electric field, stress, and geometry-induced quantum confinement. Electron mobility in the strained channel is then evaluated using the Monte Carlo (MC) method, based on the calculated bandstructure. It is concluded that electron mobility is enhanced by the splitting of conduction band valleys and the change of electron effective mass, as a function of layer thickness, crystal orientation and stress in strained Si DG-FETs.     

掺加CAN和粉体的流态混凝土耐久性分析

在普通混凝土中掺加适量的减水剂和粉体等外加剂，可以改善混凝土的使用性能。通过室内试验，总结出流态混凝土配制技术，该混凝土180d的干缩值仅为2．663×10^-4mm；同时测定的氯离子扩散系数及通电量说明其具有较好的耐久性。为混凝土向环保化、流态化、高强化、高效化发展起到促进作用。     

A direct solution method for carrier transport using Markov process representation

A direct solution method for semi-classical carrier transport problems by representing the transport process as a Markov process (also known as Continuous-Time Markov chain) is introduced to evaluate the carrier mobility in semiconductors. Comparison of the results from our direct method to conventional Monte Carlo method shows that this method outperforms the Monte Carlo method in both computational efficiency and accuracy.