重写系统和的合流性

在实际应用中,常常使用多个重写系统。本文主要讨论重写系统和的合流性,并给出了一个重写系统和具有合流性的充分条件。     

非谐调π空间可测场的分类

讨论π空间可测场的谐调性问题。给出非谐调可测场的等价条件，进而对非谐调可测场进行分类，并对各类可测场给出相应的刻划。最后给出一个例子。     

Synthesis and structural characterization of novel,fluorinated poly(phthalazinone ether)s containing perfluorophenylene moieties

The synthesis and structural characterization of a series of novel, fluorinated poly(phthalazinone ether)s containing perfluorophenylene moieties are described. The monomers, 4‐(4′‐hydroxyaryl)phthalazin‐1(2H)‐ones ( 2a – 2d ), were conveniently and efficiently synthesized from phenols and phthalic anhydride in two steps via 2‐(4′‐hydroxybenzoyl)benzoic acids, which were first obtained by the Friedel–Crafts reaction in good yields and with high stereoselectivity and were then converted into 2a – 2d by fusion with hydrazine. All the polymers were prepared by nucleophilic aromatic substitution (S_NAr) polycondensation between the compounds perfluorobiphenyl and 4‐(4′‐hydroxyaryl)phthalazin‐1(2H)‐ones ( 2a ‐ 2d ). The resulting fluorinated polymers were readily soluble in common organic solvents (e.g., CHCl₃, tetrahydrofuran, dimethylformamide, dimethyl sulfoxide, N‐methylpyrrolidone, etc.) at room temperature. Their weight‐average molecular weights and the polydispersities ranged from (7.96–18.25) × 10³ to 1.31–2.71, respectively. Their glass‐transition temperatures varied from 213 to 263 °C. They were all stable up to 390 °C both in air and in argon. The 5% weight‐loss temperatures of these polymers in air and argon ranged from 393–487 to 437–509 °C, respectively. Wide‐angle X‐ray diffraction studies indicated they were all amorphous and could be attributed to the presence of kink nonplanar moiety, phenyl phthalazinone along the polymer backbone. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 925–932, 2004     

爆磁压缩发生器通过脉冲变压器对脉冲形成线充电的理论分析

 将爆磁压缩等效为电流源的方法，对爆磁压缩发生器通过脉冲变压器对脉冲形成线充电进行了理论分析，得出爆磁压缩发生器在负载上产生电流波形（简称负载电流）为直线情况和任意电流波形情况下充电电流和充电电压的表达式。分析表明变压器耦合互感与负载电流随时间变化增长率是脉冲形成线充电的两个重要参数，脉冲形成线第一个充电电压峰值与变压器的耦合互感和负载电流波形斜率成正比，负载电流波形斜率的变化可以改变充电电压峰值的时间，斜率不断增加可以延长第一个充电电压峰值时间，从而可能增加充电电压的幅值，提高爆磁压缩发生器能量的利用效率。     

喷气Z箍缩内爆等离子体的雪铲模型

 在喷气Z pinch内爆等离子体研究中，雪铲模型是一种常用的、比较简单的物理模型。根据实验中提供的电流波形，负载线质量和初始半径，可以通过雪铲模型来估算内爆到心的时刻。根据一维运动方程和不同构形下的解析解以及部分实验结果相结合，讨论了雪铲模型的适用范围。数值计算的内爆时间和实验（Gamble II, Double EAGLE, BLACKJACK 5）测量值符合得较好。结果表明，雪铲模型在喷气Z pinch实验的负载优化设计研究中是很有参考价值的方法。     

Investigation of Scale Exponents of Complete and Incomplete Aggregation-Annihilation Processes

The complete and incomplete aggregation-annihilation processes are investigated with the method of generating function, and the scale exponents are obtained exactly. We find that the scale exponents of incomplete aggregation-annihilation process are different from the previous exponents obtained by different methods. The time dependence of the total number of clusters and the total mass of clusters are analytically obtained.     

Detection of failure sites by focused ion beam and nano-probing in the interconnect of three-dimensional stacked circuit structures

Focused ion beam (FIB) and nano-probing were applied for failure analysis of three-dimensional stacked circuits with copper through-silicon-vias between the stacked chips. The failure analysis was done after high temperature storage and thermal cycling tests. Passive voltage contrast in FIB allowed to pinpoint the open sites. FIB cross-sections showed the presence of opens at the bottom of the copper vias. The failure cause was suspected to be an interlayer particle, which was confirmed by optical profilometry. Nano-probing was used on another sample to pinpoint the failure location through the measurement of the local resistance within the daisy chains. The failure was traced out to be related with surface contamination.     

SYNTHESIS OF LIGHT OLEFINS FROM SYNGAS VIA DIMETHYLETHR——A NEW TECHNIQUE PROCESS

A new route named as SDTO method for the synthesis of lightolefins from syngas has been proposed.That is to convert syngas todimethylether and then to convert dimethylether to light olefins.The catalystsfor the two conversion reactions have been developed.For the first reaction,the catulySt was synthesized by the combination of methanol synthesis catalystwith γ-Al_2O_3or zeolites which possesses both metallic and acidic functions.Thecatalyst for the second reaction was modified SAPO-34 molecular sieve.Thevariables of the reactions have also been investigated.The results from theserial connection of the two conversion steps without any separation show thatthe yield of C_2~-C_4~- olefins Could be>100g/(m~3 syngas).     

高峰值功率重频脉冲固体激光器

综述了高峰值功率重频脉冲固体激光器的发展现状，对其中的Ｑ开关、腔倒空、锁模等窄脉冲技术和放大技术进行了分析，展示了高峰值功率重频脉冲固体激光器的发展前景。     

Statistical computer-aided design for microwave circuits

A useful methodology for microwave circuit design is presented. A statistical technique known as Design of Experiments is used in conjunction with computer-aided design (CAD) tools to obtain simple mathematical expressions for circuit responses. The response models can then be used to quantify response trade-offs, optimize designs, and minimize circuit variations. The use of this methodology puts the designer's intelligence back into design optimization while making “designing for circuit manufacturability” a more systematic and straightforward process. The method improves the design process, circuit performance, and manufacturability. Two design examples are presented in context to the new design methodology