AZ61镁合金热压缩变形组织研究

在gleeble 1500D热模拟试验机上以应变速率为0.01 s-1和1s-1,变形温度为350℃和400℃,对AZ61镁合金热压缩变形,并对变形试样显微组织进行了研究。结果表明:热变形过程中发生了不同程度的动态再结晶,得到不完全再结晶组织。变形温度和应变速率对再结晶程度、再结晶晶粒尺寸均匀性有明显影响;以较低的温度配合高的应变速率,热变形后发生再结晶晶粒均匀细小;变形温度高且应变速率高时,发生动态再结晶的区域变小,再结晶晶粒尺寸偏大且极不均匀,低温高速热变形有利于获得均匀细小的再结晶组织。     

Recent Advances of Spatial Self‐Phase Modulation in 2D Materials and Passive Photonic Device Applications

Optical nonlinearity in 2D materials excited by spatial Gaussian laser beam is a novel and peculiar optical phenomenon, which exhibits many novel and interesting applications in optical nonlinear devices. Passive photonic devices, such as optical switches, optical logical gates, photonic diodes, and optical modulators, are the key compositions in the future all‐optical signal‐processing technologies. Passive photonic devices using 2D materials to achieve the device functionality have attracted widespread concern in the past decade. In this Review, an overview of the spatial self‐phase modulation (SSPM) in 2D materials is summarized, including the operating mechanism, optical parameter measurement, and tuning for 2D materials, and applications in photonic devices. Moreover, some current challenges are also proposed to solve, and some possible applications of SSPM method are predicted for the future. Therefore, it is anticipated that this summary can contribute to the application of 2D material‐based spatial effect in all‐optical signal‐processing technologies.     

均匀化退火对Al－Mg－Li（01420）合金加工性能及力学性能的影响

通过对０１４２０合金的均匀化退火，研究了均匀化制度对合金热加工性能和力学性能的影响。结果表明：均匀化制度对合金性能的影响很大，均匀化不足或过烧都会使合金热轧开裂和塑性降低。经过４７５℃×４８ｈ退火后，主合金元素Ｍｇ的分布均匀，合金可获得最好的综合性能。     

非线性理论在计算机视觉中的应用

针对目前计算机视领域中普遍存在的大量非线性问题以及此带来的鲁棒必差、效率低等问题，结合目前比较新的解决非线性问题的方法，诸如同伦法、吴方法以及Ａｄｏｍａｉｎ方法等，对一系列计算机视觉中的非线性问题给出了比较满意的解答。     

卷钢专用平台箱的三维建模及有限元分析

目的 针对国内外采用集装箱方式装载卷钢的现状及存在的问题,初步设计一种20 ft(1 ft=0.3048 m)卷钢专用平台箱(内部尺寸为5.9 m×2.35 m×2.393 m,门宽为2.342 m,门高为2.28 m),并分析其力学性能.方法 利用SolidWorks软件建立平台箱的三维模型,通过对其在调车冲击工况下的载荷和约束进行分析,利用Ansys Workbench软件建立有限元模型,并进行平台箱强度有限元计算.结果 得到该平台箱在最不利工况下的等效应力和位移情况.其中,卷钢支架支撑面和角件内侧壁部位出现了应力集中现象,最大工作应力值为234.01 MPa,不超出结构钢材料的许用应力(246 MPa);最薄弱环节的最大变形量为1.0572 mm,在允许范围内.结论 仿真结果表明该平台箱满足结构强度要求.     

变温LPCVD沉积氮化硅薄膜的均匀性优化

以低压化学气相沉积(LPCVD)热壁立式炉为实验平台,由二氯硅烷和氨通过LPCVD工艺合成氮化硅薄膜,利用降温成膜提高氮化硅薄膜的膜厚均匀度.基于气体碰撞理论建立了氮化硅薄膜沉积速率与反应气体浓度的关系式.分析比较了LPCVD炉内不同升温速率沉积氮化硅薄膜的表面性能.发现在变温沉积阶段,选择合适的降温速率是实现薄膜沉积...     

催化重整装置进料/产物换热器泄漏的检测及判断

介绍了三种检测及判断催化重整装置进料/产物换热器泄漏的方法及原理,并在某工业装置上加以运用的情况.其中芳烃含量法是根据产物分离罐底物料和重整汽油芳烃含量变化来判断;转化率比较法是根据特定环烷烃的转化率来判断;示踪剂法是在原料中注入苯酚,再根据产物分离罐底物料中是否存在苯酚来判断.     

Genome-Wide Association Study Identifies a Rice Panicle Blast Resistance Gene,Pb2, Encoding NLR Protein

Rice blast is one of the main diseases in rice and can occur in different rice growth stages. Due to the complicated procedure of panicle blast identification and instability of panicle blast infection influenced by the environment, most cloned rice resistance genes are associated with leaf blast. In this study, a rice panicle blast resistance gene, Pb2, was identified by genome-wide association mapping based on the panicle blast resistance phenotypes of 230 Rice Diversity Panel 1 (RDP1) accessions with 700,000 single-nucleotide polymorphism (SNP) markers. A genome-wide association study identified 18 panicle blast resistance loci (PBRL) within two years, including 9 reported loci and 2 repeated loci (PBRL2 and PBRL13, PBRL10 and PBRL18). Among them, the repeated locus (PBRL10 and PBRL18) was located in chromosome 11. By haplotype and expression analysis, one of the Nucleotide-binding domain and Leucine-rich Repeat (NLR) Pb2 genes was highly conserved in multiple resistant rice cultivars, and its expression was significantly upregulated after rice blast infection. Pb2 encodes a typical NBS-LRR protein with NB-ARC domain and LRR domain. Compared with wild type plants, the transgenic rice of Pb2 showed enhanced resistance to panicle and leaf blast with reduced lesion number. Subcellular localization of Pb2 showed that it is located on plasma membrane, and GUS tissue-staining observation found that Pb2 is highly expressed in grains, leaf tips and stem nodes. The Pb2 transgenic plants showed no difference in agronomic traits with wild type plants. It indicated that Pb2 could be useful for breeding of rice blast resistance.     

不同地应力下的地下硐室动态特征分析

采用FLAC3D对地震动荷载作用下不同地应力状态的地下岩体硐室的动态特性进行了初步分析。分析结果表明,地震荷载作用下,硐室位移随地应力侧压系数的增加明显减小,地应力侧压系数λ<1时的硐室位移量值随侧压系数的变化幅度明显大于地应力侧压系数λ>1时的情况;当侧压系数λ<1,随剪切波入射角的变化,硐室测量点位移响应先增加后减小;而当侧压系数λ>1,随剪切波入射角的增加,硐室测点位移先减小后增加,同时随地应力侧压系数的增加有减小的趋势。