DCC／DMAP法合成二茂铁基苯甲酸胆甾醇酯

倒重氮法合成两类二茂铁基苯甲酸，继而研究以N，N-二环己基碳二亚胺（DCC）作脱水剂，用4-二甲胺基吡啶（DMAP）作除水促进剂，胆甾醇与间、对-二茂铁苯甲酸反应合成液晶材料间、对-二茂铁基苯甲酸胆甾醇酯的方法。研究结果表明，该方法反应条件比较温和，用DMAP作除水促进剂时，胆甾醇酯产率比较高。高效酰化催化剂法是十分有效的酰化方法，在合成胆甾醇酯液晶中可较大幅度地提高产品的产率与纯度，简化操作，降低反应毒性。     

水杨酸苄酯合成新方法研究

在以水杨酸和苄醇为原料催化合成水杨酸苄酯的实验中,考察了对甲苯磺酸、浓硫酸和N,N-二环己基碳二亚胺(DCC)、4-二甲氨基吡啶(DMAP)等几种催化剂的应用。结果表明,在室温条件下,DCC、DMAP的催化活性较高。同时考察了反应时间、醇酸比、催化剂用量、反应温度对合成水杨酸苄酯产率的影响。实验结果表明,当反应时间为3.5h,水杨酸与甲醇的质量比为1.2:1(mol/mol),反应温度为25℃时,水杨酸甲酯的收率可达到82.5%。     

Inulin polysaccharide having pendant amino acids: Synthesis and characterization

Inulin polysaccharide was esterified with N-protected α-amino acids (N,N′-di-benzylocarbonyl-L -lysine and N-benzylocarbonyl-glycine) under a mild condition (room temperature) and within short reaction times (6 h). The esterification reactions were conducted in the presence of dicyclohexylcarbodiimide and 4-(dimethylamino)pyridine as a catalyst. The optimal reaction time (6 h) was determined by monitoring the concentration of free carboxylic acid of the N-protected amino acids during the reaction. The degree of substitution per fructose unit was 0.95 for inulin-lysine and 1.01 for inulin-glycine. The resulting biopolymer was deprotected by catalytic transfer hydrogenation method using 1,4-cyclohexadiene as an effective hydrogen donor. The structures, molecular weight, and thermal properties of the amino acid esters of inulin were determined by Fourier transform infrared spectroscopy, ¹H and ¹³C NMR, UV, viscosity, and dicyclohexylcarbodiimide. This new modified inulin polysaccharide would have the potential as a biomaterial for biomedical applications. © 1998 John Wiley & Sons, Inc. J. Appl. Polym. Sci. 70: 953–963, 1998     

SDH DCC管理信息通信的协议栈

本文介绍ＳＤＨＤＣＣ协议栈各层的主要内容和特征，特别是面向目标的应用层ＣＭＩＳＥ、ＲＯＳＥ、ＡＣＳＥ，网络层的路由参数以及数据键路层的ＬＡＰＤ。并给出了各层ＰＤＵ间的对应关系。最后举出两种网络单元中协议栈配置的实例。     

催化裂化汽油的下行床催化转化

以循环下行床为反应器,催化裂化汽油为原料,在工业催化裂化(FCC)催化剂和催化裂解(DCC)催化剂作用下,研究了催化裂化汽油的催化转化过程。实验结果表明,在下行床反应器中,催化裂化汽油中的烯烃能显著降低,主要转化为低碳烯烃产品,同时得到富含芳烃的液体产品,副产干气和焦炭量很低。催化裂化汽油在FCC催化剂和DCC催化剂上表现出不同的反应机理。FCC催化剂孔道大,可以发生双分子裂化反应和单分子裂化反应,而DCC催化剂孔道小,以单分子裂化反应机理为主,同时DCC催化剂低碳烯烃选择性更高。     

DCC Technology and Its Commercial Experience

DCC is a new technology derived from FCC for propylene production. The propylene yields can reach 23m% with paraffinic feed and around 17m% with intermediate base feed. A portion of DCC cracked naphtha recycled in a commercial unit resulted in a propylene yield increment of 3.5m% at some expense of naphtha. The total BTX in the 75 - 150℃ naphtha fraction was 57. 6v%, in which toluene and xylenes were 21.9v% and 30.3v%, respectively. DCC catalyst consists of a modified mesopore zeolite with pentasil structure for primary product of naphtha range to undergo secondary cracking for producing light olefins. A series of DCC catalysts was formulated for various objectives, such as maximum propylene, maximum isoolefins, and metal tolerance for residual oil processing, etc. Seven commercial units have been put into production since 1990 inside and outside China, in which three of them were revamped from existing FCCUs, and the other four were grassroots units including a 750kt/a unit in TPI Company, Thailand. Currently, the TPI unit is running in full design capacity with about 40m% of atmospheric residual oil in the feedstock. Although the feedstock is much heavier than design, the propylene yield still keeps around the design value. The commercial experiences of some units are presented.     

森吉米尔20辊可逆冷轧机交流控制系统

全交流S120控制系统应用于森吉米尔20辊轧机,实现速度、直接张力控制.介绍了森吉米尔20辊轧机的特点,传动系统在驱动控制图中实现卷径计算、直接张力控制、加减速补偿及摩擦补偿的控制方法.采用高精度、快速响应的数字式速度控制,使该轧机的张力系统具有先进、可靠、精度高等特点,张力波动小,满足用户对张力的高精度要求.     

Experimental Investigation of the Steam Condensation Phenomena due to a Multi-hole Sparger

KAERI has performed a series of steam condensation tests to assess the performance of a unit cell sparger that will be used in the APR1400 reactor. A simplified I-sparger was used for the steady state steam condensation tests to study the characteristics of the condensation phenomena due to a multi-hole sparger and to provide test data for a code development and verification. A range of steam mass fluxes for the steady state condensation tests were selected to define the transition region from the condensation oscillation regime to the stable condensation regime. Condensation loads and a variation of the frequencies of the pressure waves due to a steam condensation are analyzed. In addition, the local temperature distribution near the sparger discharge holes is discussed and a condensation regime map for a multi-hole sparger has been suggested.     

基于MCQRDDC的负荷概率预测模型

针对具有约束性的复合分位数回归网络(monotone composite quantile regression neural network, MCQRNN)无法较好地分析负荷数据之中的时序信息和内在规律的问题,本研究融合MCQRNN以及膨胀因果卷积网络(dilated causal convolutional networks, DCC),提出了一种新的分位数回归模型MCQRDCC (monotone composite quantile regression dilated causal convolutional networks),该模型将输入划分为分位点输入与非约束输入,使该模型的输出随分位点的增大而增大,以此解决分位数交叉的问题.同时,使用DCC的结构,使该模型充分地分析负荷数据之中的序列信息,使得预测结果更加符合真实负荷的变化趋势.此外, MCQRNN使用指数函数对约束权重矩阵和隐藏层权重进行转化,会影响反向传播时权重的调整,本研究使用ReLU函数代替指数函数可以解决这个问题,以此提高预测的精度.使用真实的负荷数据进行实验,实验结果表明, MCQRDCC能有效地提高预测...     

Diagnosable evaluation of DCC linear congruential graphs under the PMC diagnostic model

A DCC (disjoint consecutive cycles) linear congruential graph G(F, n) consists of n nodes and is generated by a set of linear functions F with special properties. It was proved that G(F, n) is a 2t-regular graph and has connectivity 2t, where t=|F| and 1?t?p-1 (n=2^p for some integer p). For a multiprocessor system, its diagnosability is critical to measure the performance. In this paper, we study the diagnosability of G(F,2^p) under the precise and pessimistic diagnosis strategies based on the PMC (Preparata, Metze, and Chien) diagnostic model. It is proved that G(F,2^p) is 2t-diagnosable and (4t-5)/(4t-5)-diagnosable under the two diagnosis strategies, respectively, where p?3 and 2?t?p-1. In addition, the diagnosability of DCC linear congruential graphs is compared with that of BC (bijective connection) graphs.