冷藏汽车制冷方式及其特点

冷藏汽车在易腐食品产、贮、运、销中起着重要的作用,文中分析了我国食品冷藏链的现状,介绍了冷藏车的发展概况,阐述了冷藏汽车在食品链中的作用和地位,系统论述了冷藏汽车的各种制冷方式及其特点,介绍了冷藏汽车的技术状况。提出了发展我国冷藏车的建议,对我国冷藏车的设计与运行管理具有一定的参考价值。     

The persistence of HIV-1 spreading in MSM population in China

In this work, we develop and analyze mathematical models for the dynamics about the evolution of HIV/AIDS in men who have sex with men in China. We focus on the analyses of the basic reproduction number $R_0$ and the persistence of infection. Through simulations we also find that the interventions including antiviral therapy, condom using and potential vaccinations play very important roles in the HIV/AIDS spreading in MSM population in China.     

粗糙海面高功率微波传输特性矩量法分析

应用蒙特卡罗方法实现了粗糙海面的仿真与模拟,建立了基于双积分方程的高功率微波（HPM）近海面传输特性矩量法计算模型。模型采用光滑窗函数对均匀平面波进行调制,把均匀平面波入射调制为锥形波,消除了粗糙海面突然被截断而引起的边缘效应的影响;重新推导了锥形波入射下的基尔霍夫近似公式,并在满足基尔霍夫近似的条件下,通过对比分析,验证了模型的正确性;采用模型计算分析了不同海面几何参数和海水媒质参数对HPM近海面传输系数的影响。结果表明:粗糙海面的均方根高度对HPM传输系数影响明显,均方根高度越大,传输系数越小,能量分布越均匀;另外随着海水介电常数实部和虚部的增加,传输系数均有所增加,并且实部的影响更明显。     

A new type of minimal thinness with respect to the stationary Schrödinger operator and its applications

In this paper we define a new type of minimal thinness with respect to the stationary Schrödinger operator at a fixed Martin–Sch boundary point of a cylinder. We also discuss some criteria for it.     

碱性离子液体催化下一锅三组分合成螺环吲哚衍生物

在碱性离子液体[H3N+CH2CH2OH][CH3COO]催化作用下,由靛红、丙二腈,氰乙酸乙酯和β-二酮三组分"一锅法"合成了一系列螺环吲哚类化合物,产物的结构通过1H NMR,IR和MS表征.该方法条件温和,操作简单,后处理方便,反应时间短,对环境友好,且催化剂廉价易得.     

碱性离子液体催化下一锅三组分合成螺环1,3-二氧代茚满吡喃衍生物

在碱性离子液体[Bmim][OH]催化作用下,以茚三酮、丙二腈和β二酮/β萘酚/8-羟基喹啉等为原料合成了一系列螺环1,3-二氧代茚满吡喃类化合物,产物的结构通过1H NMR,IR和MS表征.该方法条件温和,操作简单,后处理方便,反应时间短,对环境友好,且催化剂可以方便的回收,且循环使用4次其催化活性并没有显著降低.     

A novel ultrathin single-crystalline Bi2O3 nanosheet wrapped by reduced graphene oxide with improved electron transfer for Li storage

Journal of Solid State Electrochemistry - Two-dimensional (2D) metal oxides have been of great interest owning to their particular properties such as rapid electron transfer capability. Herein, we...     

Notes on certain quotient images of paracompact locally compact spaces

We continue to study the characterizations of paracompact locally compact spaces under certain quotient mappings, and discuss the relationships among them, which expand the results on certain quotient images of paracompact locally compact spaces. This revised version was published online in June 2006 with corrections to the Cover Date.     

强1-星紧空间的性质

探讨强1-星紧与可数紧、feebly紧、伪紧和DFCC之间的关系，给出它在具有分离性（Q）的T1空间类中的特征．     

富硒酵母中硒的连续浸提原子荧光法形态分析

采用连续浸提、氢化物发生一原子荧光法测定研究了富硒酵母中硒的赋存形态。结果表明，富硒酵母中不同形态的硒所占比例从高到低顺序为：碱溶态，水溶态，盐溶态，醇溶态，残渣态；酵母硒中有机态硒达78％以上，主要以碱溶态形式存在。