新法合成环己烯

在一水硫酸氢钠存在下,将环己醇小心加热40min制得环己烯,其收率达62.8%。     

8407钢与4Cr5MoSiV1钢纵横向热疲劳性能研究

采用自约束热疲劳试验方法,在相同的热处理条件下,对比研究了8407,4Cr5MoSiV1钢的纵横向热疲劳特性,观察分析了两种钢的热 形貌及深度,并选择典型试样进行扫描电镜分析,结果表明,8507钢比4Cr5MoSiV1钢的碳化物颗粒较小,而且分布均匀,从而表现出较好的热疲劳性能,尤其是4Cr5MoSiV1钢的横纵向热疲劳性能差异较8407钢大,即8407钢的各向同性要优于4Cr5MoSiV1钢,与两种钢的横纵向冲击韧性的比值相对应。     

[Co(2，3tri)(pz)Cl]2+体系配合物水解-重排机理研空

本文提出了一个「Ｃｏ（三元胺）（二元胺）Ｃｌ」＾２＋型的配合物及其异构体的重排机理模型,它包含了所有异构体间的转换关系,这一模型表面式异构体在重排过程中的重要性,利用对映异构体旋光性质及其可能的变化提出了可能存在一与经典模式不同的中间体假设。     

[Co(2，6-二胺基甲基吡啶)(1，2-二胺基丙烷)Cl]ZnCl4体系配合物的合成及一异构体的晶体结构

用过氧化物法合成了 [Co(bamp) (cmen)Cl]ZnCl4(bamp =2 ,6 -二胺基甲基吡啶 ;cmen =1 ,2 -二胺基丙烷 ) ]中的两个经式异构体 ,解析了其中一个异构体阳离子的晶体结构为m1 .晶体学参数 :单斜晶系 ,空间群C2 /c,a =2 .0 1 2 0(6 )nm ,b =0 .940 8(3)nm ,c =2 .0 5 2 1 (6 )nm ,β =92 .0 45 (6 )° ,V =3.882 2(1 9)nm3,Dc =1 .786 g/cm3,Z =8,F0 0 0 =2 1 0 4,μ(MoKα) =2 7.83cm-1,R =0 .0 42 6 ,RW=0 .1 0 38.配合物离子中Co3 为六配位 .晶胞中含 4个配合物离子 ,对映体的比例为 1 :1     

一种基于有色Petri网的知识库验证方法

以有色Petri网为基础,在经过了必要的功能扩充后,针对知识验证的主要内容,建立了有色Petri网的知识表示模型,提出了一种简洁有效的、基于有色Petri网的知识库验证方法,并给出了相应的判定准则,最后给出了一个说明知识表示模型和知识验证准则的实例。     

基于CMAC神经网络的泵控马达调速系统控制性能

提出了一种基于ＣＭＡＣ神经来控制泵马达调速系统的方法,该方法对液压系统时变和动特性差的缺点能加以补偿和改善。通过仿真研究证明了这种方法的有效性。     

Ferroelectric phase transition in relaxor ferroelectric single crystals 0.76PMN-0.24PT

The features of the single crystals 0.76PMN-0.24PT in dietectric, ferroetectric, pyroetectric properties and domain structures indicate that they are located between typical ferroetectrics and normal ones. The unpoled crystals present a transitional domain configuration between microdomains and typical macrodomains while the crystals on (001) cuts undergo fietd-induced phase transition under poling, showing two special temperature points T_d andT _m during the succedent heating procedure. The dietectric constant starts to decrease drastically at T_d during cooling, or the transformation from induced macrodomain to transitional domain takes place atT _d during heating. Ferroetectric-paraetectric phase transition or depolarization continues within the whole temperature range ofT _d-T _m, where ferroetectric phase in the form of transitional macrodomains coexists with paraetectric phase. Then the crystals macroscopically transoform into paraetectric phase containing ferroetectric microdomains at a temperature aboveT _m. However, owing to the influence of crystallite orientation on fietd-induced phase transition, the temperatureT _d does not appear in the same temperature-etectric fietd history in multicrystal ceramics with the same composition as the above single crystals.     

Characteristics of atmospheric aerosol optical depth variation over China in recent 30 years

This note retrieves the annual and monthly mean 0.75 μm aerosol optical depth (AOD) by using the daily direct solar radiation and sunshine duration data of 47 solar stations from 1961 to 1990. The characteristic of AOD variation over China in recent 30 years was analyzed. The results indicate that AOD increased obviously over China from 1961 to 1990. AOD increased most rapidly over the east part of Southwest China, the middle-and-lower reaches of the Yangtze River and the Tibetan Plateau. The increasing trend of AOD is also relatively distinct in North China, the Shandong Peninsula, east part of Qinghai Province, and coastal areas of Guangdong Province. However, in most parts of Northwest China and Northeast China, the increase of AOD is less significant, while in the west part of the Xinjiang Uygur Autonomous Region and some parts of Yunnan Province, AOD shows decreasing tendency. Generally, AOD reaches its maximum in spring and the minimum appears in summer. As to the linear trend, the maximum occurs in spring but the minimum in winter. Among the 47 stations selected in this note, the largest three stations of AOD are Chengdu, Chongqing and Nanchong, respectively, which all lie in the Sichuan Basin, and the smallest value of AOD occurs in Jinghong located in Yunnan Province.     

The two-step monsoon changes of the last deglaciation recorded in tropical Maar Lake Huguangyan, southern China

The concentrations of biogenic silica, total organic carbon, total nitrogen and total hydrogen inferred from the sediments of tropical Maar Lake Huguangyan, southern China, provide a climate record of the last déglaciation with century resolution. The records fully demonstrate the existence of the two-step shape of the last déglaciation in tropic East Asia, and they point out noticeable differences between the low and high latitudes in the Northern Hemisphere. Thus, the Boiling first warming at the last deglaciation in the low latitude may have preceded that of the high latitude, whereas the cooling of the Younger Dryas occurred synchronously in the two regions. These results likely suggest that the links between the low and high latitude climates in the Northern Hemisphere during this period are complexity.     

2-连通图中X-最长圈下界估计

给一个图G,XV(G),G[X]为G的X生成子图,r为正整数。定义α(X)=max｛｜S｜｝S是G[X]的顶点独立集｝,αk(X)=min｛∑ki=1d(vi)｜｛v1,v2,…,vk｝是G[X]的顶点独立集},NCk(X)=min｛｜Uki=1N(vi)｜｛v1,…,vk是G[x]的独点独立集}(k≥2)．我们得到结论;对—任意的n阶2-连通图G(n≥3),xG,且α3(X)≥n+r≥n+2,则存在一个包含X的顶点数为min｛｜X｜,[X]+NC,+2+e(n+r)(X)-α(X)}的圈,ε(i)=3〔1-3i〕-1-3i.该结论推广了H.J.Broersma在文献[1]中的结果．