Hydrothermal Chemistry Involved in Developing Practical Y Type Zeolite Catalysts

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Mechanism of C2+ oxygenate synthesis on Rh catalysts

This paper examines the reaction pathways and the nature of active sites for CO hydrogenation in general and C₂₊ oxygenate synthesis over Rh catalysts in particular.     

Layered lithium cobalt nitrides: A new class of lithium intercalation compounds

Lithium cobalt nitrides Li_3−2xCo_xN (0.1 ≤ x ≤ 0.44) have been prepared and investigated as negative electrode in the 1/0.02 V potential window. The evolution of the unit cell parameters and unit cell volume with the Co content show a solid solution behaviour. Whatever the Co content, all these nitrides are electroactive with a single step around 0.6 V/0.7 V for the discharge and charge processes, respectively. The electrochemical behaviour observed is typical of a Li intercalation compound and involves the Co²⁺/Co⁺ redox couple in the interlayer plane combined with the reversible accommodation of Li⁺ ions in the cation vacancies located in Li₂N⁻ layers. XRD experiments performed after discharge, charge and cycling tests clearly indicate the hexagonal layered structure of the host lattice is maintained. This intercalation process explains the excellent capacity retention found after 50 cycles. A specific capacity of 180 mAh g⁻¹ at C/20 and 130 mAh g⁻¹ at C/5 rate (100 mA cm⁻²) is achieved for Li_2.23Co_0.39N. ac impedance measurements have allowed to characterize the kinetics of the reaction.     

基于gt-power软件的某汽车排气系统消声器改进

通过gt-power软件对发动机某一转速下排气系统尾管噪声进行仿真。提出几种消声器改进方案,选出最佳方案。在该方案基础上,分析几种因素变化对消声器性能影响,选出较为理想的参数。最终使功率损失、插入损失等指标达到较好的水平,解决了尾管噪声过高的问题。得出了穿孔管,插入管长度,扩张腔体积对消声性能影响较大的结论。     

Identification of Specific Variations in a Non-Motile Strain of Cyanobacterium Synechocystis sp. PCC 6803 Originated from ATCC 27184 by Whole Genome Resequencing

Cyanobacterium Synechocystis sp. PCC 6803 is a widely used model organism in basic research and biofuel biotechnology application. Here, we report the genomic sequence of chromosome and seven plasmids of a glucose-tolerant, non-motile strain originated from ATCC 27184, GT-G, in use at Guangzhou. Through high-throughput genome re-sequencing and verification by Sanger sequencing, eight novel variants were identified in its chromosome and plasmids. The eight novel variants, especially the five non-silent mutations might have interesting effects on the phenotype of GT-G strains, for example the truncated Sll1895 and Slr0322 protein. These resequencing data provide background information for further research and application based on the GT-G strain and also provide evidence to study the evolution and divergence of Synechocystis 6803 globally.     

KDR基因遗传变异对贝伐珠单抗一线治疗晚期非小细胞肺癌患者临床疗效的影响

目的: 本研究旨在探讨激酶插入区受体（KDR）基因遗传变异对贝伐珠单抗联合化疗治疗晚期非小细胞肺癌（NSCLC）患者疗效的影响。方法:本研究纳入135例一线接受贝伐珠单抗治疗的NSCLC患者,收集外周血及活检癌组织标本分别用来进行基因分型及表达测定。多态性位点的基因型和其他变量的相关性通过logistic回归模型进行分析。基因型和预后的单变量分析用Kaplan-Meier生存分析方法,并通过Cox风险比例模型对其他变量进行校正。结果:在KDR的标记多态性位点中,只发现了V297I位点的临床意义。V297I位点位于该基因的编码区,在研究人群的基因分布频率为：CC型99例（73.33%）,CT型33例（24.44%）,TT型3例（2.23%）,最小等位基因频率为0.14,三种基因型分布频率符合哈迪温伯格平衡（P=0.898）。后期比较将TT型和CT型患者合并,对不同基因型患者进行疗效分析发现：CT/TT基因型患者和野生型CC型患者的客观缓解率（ORR）分别为41.67%和47.47%（P=0.549）。CT/TT和CC基因型患者的中位无进展生存期（mPFS）分别为6.2和8.6个月,差异具有统计学意义（P=0.003）。在总生存期（OS）方面,两种基因型患者的中位总生存期（mOS）分别为18.9和21.5个月,差异具有统计学意义（P=0.017）。对无进展生存期（PFS）构建多变量的Cox模型校正之后发现CT/TT基因型对PFS的影响仍然具有统计学意义（OR=1.95,P=0.019）。另外,进一步在68例癌组织标本的表达分析中发现,CT/TT基因型患者相对于野生型的CC型患者,癌组织中KDR的表达明显较高,且差异具有统计学意义（P<0.01）。结论:在接受贝伐珠单抗治疗的非小细胞肺癌患者中,KDR基因V297I位点可能通过影响KDR基因的表达从而影响贝伐珠单抗一线治疗非小细胞肺癌患者的疗效。     

电源线滤波器对电子设备EMC影响分析

针对电子设备在电磁兼容(Electromagnetic Compatibility,EMC)测试中遇到的问题,从电源线滤波器内部电路入手,分析了电源线滤波器对电子设备EMC性能的影响。描述了如何根据电子设备内部电路、使用条件,尤其是输入端电路特性,对电源线滤波器的阻抗特性、插入损耗等参数进行正确选择。对于影响电子设备EMC性能的电源线滤波器的安装方法进行了分析、讨论,列举了2个实际测试例子,并对整改措施进行描述和分析。     

3dB带状线电桥的研究与设计

首先对90°电桥进行了分析。提出一种特殊结构的宽带3dB电桥的设计方案。该方案可使电桥方向性更好、制作工艺更加简便,其带宽可达到9～11GHz,可以承受较大的功率容量,体积小,新式结构使其实现了低插损、高方向性和宽频带,并且易生产、易调试。实测结果和仿真结果基本吻合,验证了研究结果的一致性。     

开关电源输入EMI滤波器设计与仿真

开关电源中常用EMI滤波器抑制共模干扰和差模干扰。三端电容器在抑制开关电源高频干扰方面有良好性能。文中在开关电源一般性能EMI滤波器电路结构基础上,给出了使用三端电容器抑制高频噪声的滤波器结构。并使用PSpice软件对插入损耗进行仿真,给出了仿真结果。     

Dynamic and kinetic modeling of isotopic transient responses for CO insertion on Rh and Mn–Rh catalysts

Isotopic transient tracer techniques have been employed to study heterogeneous hydroformylation on Rh/SiO₂ and Mn–Rh/SiO₂. Pulse injection of D₂ and allowed tracing of the deuterium and CO incorporation pathway into the aldehyde product. The d₁- and d₂-propionaldehyde responses showed a double-peak, or two-hump, response to the D₂ pulse, while showed a single-hump response to the pulse. Analysis of the product responses to the D₂ pulse in CO/H₂/C₂H₄ and CO/H₂/C₂H₄/C₂H₅CHO suggests that the first hump of the d₁- and d₂-propionaldehyde responses was due to rapid H/D exchange with adsorbed propionaldehyde via enol intermediates. The decay of the second hump was due to reaction of adsorbed acyl with spillover hydrogen/deuterium. The response was due to CO insertion followed by acyl hydrogenation. Compartment modeling of the product responses from the and D₂ pulse inputs allowed determination of residence times of adsorbed intermediates, surface coverages of adsorbed intermediates, and the elementary rate constants for acyl hydrogenation and CO insertion. Elementary rate constants for acyl hydrogenation determined from this study were consistent with the value calculated by transition state theory (TST). The addition of Mn promoter to Rh/SiO₂ increased coverages of , , and and shifted the rate-limiting step for propionaldehyde formation. Acyl hydrogenation is the rate-limiting step on Rh/SiO₂ while CO insertion and acyl hydrogenation are both kinetically significant on Mn–Rh/SiO₂.