催化裂化条件下甲醇与烃的相互作用研究

为进一步研究甲醇作为催化裂化部分进料的反应过程,对催化裂化条件下甲醇和烃的相互作用规律进行考察。采用脉冲一微反装置分别对甲醇与单体烃及混合烃共同进料的反应过程进行研究。实验结果表明：甲醇与单环芳烃可进行甲基化反应,但该反应只在芳烃比例大时明显。甲醇与烷烃、环烷烃虽互不反应,但具有一定的相互作用;该作用使得产物烯烃的选择性降低,异构烷烃的选择性增加。甲醇与催化汽油的相互作用与二者的比例及反应温度都有一定的关系。该研究初步论述了甲醇与烃的相互作用,为甲醇作为催化裂化部分进料过程的进一步研究提供参考。     

裂解碳五选择性加氢研究

将裂解C5馏分资源经选择性加氢、醚化,合成了高辛烷值汽油调和组分。为满足醚化催化剂的要求,进行了蒸汽裂解C5双烯烃选择性加氢工艺研究,对裂解C5双烯烃选择性加氢催化剂进行了评价,考察了反应压力、空速、反应温度、氢烯摩尔比对双烯烃选择性加氢的影响,得出适宜工艺条件为:反应压力0.5～1.5 MPa,温度45～80℃,空速10～2．0 h-1 ,氢烯摩尔比大于1.1。     

贺兰山西麓中生代构造反转及意义

通过对小松山断裂特征的再分析和对顺层断层特征的观察研究发现,发育于贺兰山北段西麓的小松山“推覆”构造实际上是一个滑覆构造。该区于晚侏罗世之后发生大规模构造反转,贺兰山沉积特征及玄武岩环境指示该区是一大陆裂谷斜坡,在中生代早中期并不存在大规模的东西向挤压应力环境。滑覆面之下的三叠系—中上侏罗统的褶皱变形及顺层剪切是这种滑覆引起的局部构造变形,与鄂尔多斯地块西部发育的典型的东西向逆冲形成明显对比,值得重视。     

中原油田岩石可钻性与声波时差关系研究

选取中原油田的大量岩心，采用常规岩石力学测试方法测定了岩石的可钻性、声波测试方法测定了岩石和岩屑声波时差，通过对测得的岩石可钻性级值和声波时差进行回归拟合，得出了中原油田岩石可钻性与声波时差的关系式。现场应用表明，该关系式较好地反映了中原油田地层岩石可钻性与声波时差的关系，可以在优选钻头时作为参考或直接应用。     

Dramatic Tuning of the Topological Hall Effect in AxRhO2 (A = K,Rb, and Cs) Crystals by Electron Concentration or Cation

Topological Hall effect, being an unconventional anomalous Hall effect, is originated from the real-space Berry curvature caused by the nontrivial topological spin textures in materials. Manipulations of nontrivial magnetic structure and related topological Hall effect are very important for the study of the chiral magnet. Herein, it is experimentally observed that the significant topological Hall conductivity σ_xy in antiferromagnetic K_0.5RhO₂ can reach 3.5% of ν = 1 quantum conductivity below 20 K. Furthermore, by adjusting the concentration of K-cation different from 0.5 in K_xRhO₂ or substituting the K cations by Rb or Cs to form Rb_0.5RhO₂ or Cs_0.5RhO₂, it is observed that the topological Hall effect is much weakened or even disappeared. This evolution, verified by the theoretical calculations, is attributed to the unstable ground state of the non-coplanar spin structure in K_xRhO₂ (x = 0.4 and 0.6) and Cs_0.5RhO₂. The significantly tunable topological Hall effect in A_xRhO₂ makes it prospective on logical/sensor devices of spintronics.     

全光纤电流互感器λ/4波片制作工艺

根据全光纤电流互感器（FOCT）的光路结构及其工作原理,分析了/4波片的制作效果对FOCT的影响,研究了/4波片的制作工艺,得出了影响波片制作效果的主要因素。通过选择合适的材料和工艺方法,获得了性能优异的全光纤/4波片。试验结果表明:该方法制作的波片提高了FOCT的性能,使其满足了0.2 S级测量用电子式电流互感器的准确度要求。     

LED节能灯的安规要求

根据CTL发布的DSH 0743决议,归纳了LED节能灯测试标准中的要求,主要包含对灯头、防触电、灯头温升、绝缘材料、异常状态、结构的考核,以及灯的光生物学安全考核。     

A 0D Lead‐Free Hybrid Crystal with Ultralow Thermal Conductivity

Organic–inorganic hybrid materials are of significant interest owing to their diverse applications ranging from photovoltaics and electronics to catalysis. Control over the organic and inorganic components offers flexibility through tuning their chemical and physical properties. Herein, it is reported that a new organic–inorganic hybrid, [Mn(C₂H₆OS)₆]I₄, with linear tetraiodide anions exhibit an ultralow thermal conductivity of 0.15 ± 0.01 W m^?1 K^?1 at room temperature, which is among the lowest values reported for organic–inorganic hybrid materials. Interestingly, the hybrid compound has a unique 0D structure, which extends into 3D supramolecular frameworks through nonclassical hydrogen bonding. Phonon band structure calculations reveal that low group velocities and localization of vibrational energy underlie the observed ultralow thermal conductivity, which could serve as a general principle to design novel thermal management materials.     

一种虚拟机系统下关于多级安全的强制访问控制框架II:实现

This paper is a continuation of our last paper [1] which describes the theory of Virt-BLP model. Based on Virt-BLP model, this paper implements a mandatory access control (MAC) framework applicable to multi-level security (MLS) in Xen. The Virt-BLP model is the theoretical basis of this MAC framework, and this MAC framework is the implementation of Virt-BLP model. Our last paper focuses on Virt-BLP model, while this paper concentrates on the design and implementation of MAC framework. For there is no MAC framework applicable to MLS in virtual machine system at present, our MAC framework fills the blank by applying Virt-BLP model to Xen, which is better than current researches to guarantee the security of communication between virtual machines (VMs). The experimental results show that our MAC framework is effective to manage the communication between VMs.     

Learning-based ventricle detection from cardiac MR and CT images

The objective of this work is to investigate the issue of automatically detecting regions of interest (ROI's) in medical images. It is assumed that the regions to be detected can be roughly segmented by a threshold based on a likelihood measure of the ROI, First, an analysis of the global histogram is used to compute a preliminary threshold that is likely near the optimal one. The histogram analysis is motivated by the analytical result of a bell image intensity model proposed in this work. Then, the preliminary threshold is used to segment the input image, resulting in an attention map, which contains an attention region that approximates the ROI as well as many spurious ones. Due to the nonoptimality of the preliminary threshold, it can happen that the attention region contains a part of, or more regions than, the ROI. Learning takes place in two stages: (1) learning for automatic selection of the preliminary threshold value and (2) learning for automatically selecting the ROI from the attention map while dynamically tuning the threshold according to the learned-likelihood function. Experiments have been conducted to approximately locate the endocardium boundaries of the left and right ventricles from gradient-echo magnetic resonance (MR) images. Cardiac computed tomography (CT) images have also been used for testing. The boundary of the segmented region provided by this algorithm is not very accurate and is meant to be used for further fine tuning based on other application-specific measures