专业用SONY TC-D5M立体声盒带录音机对磁带的选择

<正> 随着盒带录音机及磁带质量的日益提高,盒带录音机及盒带已进入专业领域。极为轻便、质量优良的 SONY TC-D5M 便携录音机,是目前在电视和电影领域受欢迎而使用较多的一种机型。但在工作中能否真正发挥好这种录音机的质量水平,并录制出理想的使人满意的声音,重要的是选择性能优良、适合这种录音机使用的磁带。尽管该机有Ⅰ型盒式常规氧化铁带、Ⅱ型盒式氧化铬(CrO_2)带、Ⅲ     

缩合剂1,3-二环己基碳二亚胺(DCC)在有机合成中的应用

N,N′-二环己基碳二亚胺(DCC)是酯化、酰胺化等反应常用的一种脱水剂,采用DCC脱水缩合,反应条件温和,合成收率通常较高.综述了DCC作为脱水剂在合成酯、酰胺、磷酰胺等方面的研究工作.     

DCC装置原料优化摸索分析

DCC装置开工以后,目标产品乙烯、丙烯收率一直与设计值偏差较大。为摸索常压渣油、加氢尾油等DCC装置原料的配比对DCC装置产品分布的影响,对DCC装置进行了原料优化摸索。原料优化期间,将DCC装置的原料配比先后调整为:m (常渣)/m (尾油)=85/115、105/105、115/95,综合分析各原料配比下的产品分布情况,发现在当前催化剂活性下,DCC装置原料配比以m (常压渣油)/m(加氢尾油)为105/105即1∶1时最优,丙烯及乙烯收率达到峰值,异丁烯收率达三种原料配比中的最高值,目标产品收率最高。     

2.2Mt/a催化裂解装置的降本增效措施分析

DCC装置作为大榭石化三期馏分油项目的重要装置,自2016年6月9日投料以来一直是大榭石化的主要效益点所在,因此,在DCC装置推行并落实降本增效措施对增加企业效益有着重要意义。从增产乙烯丙烯、提高装置生产负荷、高附加值产品开发等方面阐述DCC装置的降本增效措施。     

一种控制活性的新方法

Scripps研究学院的专家组不使用自动催化剂就可以加速反应。据Skaggs化学生物学院的主任和教授JuliusRebek，Jr．称在二聚纳米胶囊剂的存在下进行反应可以得到自动放大。纳米胶囊剂可以胶囊化适当尺寸和形状的分子，并抑制其反应。在Rebek的实验中，螯合分子为反应物之一的环己基碳化二亚胺（DCC）。当DCC分子与对甲苯甲酸和对乙基苯胺混合时，它们反应会形成一种酰胺和尿素分子。但当DCC分子首先与纳米胶囊化剂反应时，起初反应进行得相当缓慢，因为纳料胶囊化可以有效地降低溶液中DCC的浓度。但是一段时间以后反应会加快，因为反…     

中国海油在海南建大型精细化工项目

总投资约50亿元、年产200万吨的中罔海油海南精细化工（DCC）项目已在该省东方工业区破土动工。DCC项目由中国海油全资子公司一中海石油炼化有限责任公司负责项目投资建设。     

世界香料香精市场一个月详报

2005年8月25日 指数：8月份，DCC食品香精指数跳至6923，而日化香精指数则下滑至9174。DCC食品香精指数达到了自2000年1月以来的最高点。     

基于神经网络算法对DCC装置的大数据高阶优化

结合集团公司提出的加快建设数字化工厂的设想,利用过程工业大数据高阶优化对DCC装置进行诊断分析,搭建软件模型,论述现有数据建模方法,提升潜力并优化工艺控制,达到降本增效的目的。最后,探讨过程工业大数据高阶优化的特点和挑战,实现业务价值的提升。     

世界香料香精市场一个月详报

2006年1月25日 指数：本月，DCC日化香精指数有大幅跳升，主要是由于檀香木油的价格失控。同样因为一个产品——薄荷脑，使得1月份DCC食品香精指数也上升不少。     

沙特Aramco和日住友将用中石化DCC技术多产烯烃

沙特Aramco和日本住友化学公司已选定Stone ＆ LWebster公司提供的深度催化裂化（DCC）技术，用于沙特阿拉伯Rabigh地区多产烯烃流化催化裂化（HOFCC）项目。该技术由中国石化石油化工科学研究院开发。Stone ＆ Webster是Shaw集团公司的下属公司，是中国以外唯一的DCC技术供应商。     

Fault diagnosis of complex chemical process based on multi-scale ADCRC feature learning

The time series and multi-scale characteristics of complex industrial process data are always important factors affecting the performance of fault diagnosis. In this study, a new fault diagnosis model based on multi-scale attention dilated causal residual convolution (ADCRC) is proposed. Aiming at the temporal nature of industrial data, the ADCRC module is developed to extract time series features, in which the ADCRC module is composed of dilated causal convolution (DCC), attention mechanism (AM), and residual connection, DCC is used to extract time series features, AM adjusts the weight of features according to attention distribution to obtain more important feature information, and residual connection is used to enhance the training accuracy of model. For the multi-scale characteristics of original data, MS-ADCRC model based on ADCRC module is developed for multi-scale feature extraction, in which multiple ADCRC modules extract multi-scale features of data in parallel. Finally, the proposed MS-ADCRC model is tested on the Tennessee-Eastman data set. Compared with other existing models, the results show that the proposed MS-ADCRC model has more advantages in fault diagnosis feature learning.     

三洋新力电子照相机简介

概述了三洋/新力电子照相机的整机概念及其包括的摄像机、放像机与音频单元等组成部分的原理。     

Potential Dental Biofilm Inhibitors: Dynamic Combinatorial Chemistry Affords Sugar-Based Molecules that Target Bacterial Glucosyltransferase

We applied dynamic combinatorial chemistry (DCC) to find novel ligands of the bacterial virulence factor glucosyltransferase (GTF) 180. GTFs are the major producers of extracellular polysaccharides, which are important factors in the initiation and development of cariogenic dental biofilms. Following a structure-based strategy, we designed a series of 36 glucose- and maltose-based acylhydrazones as substrate mimics. Synthesis of the required mono- and disaccharide-based aldehydes set the stage for DCC experiments. Analysis of the dynamic combinatorial libraries (DCLs) by UPLC-MS revealed major amplification of four compounds in the presence of GTF180. Moreover, we found that derivatives of the glucose-acceptor maltose at the C1-hydroxy group act as glucose-donors and are cleaved by GTF180. The synthesized hits display medium to low binding affinity (K_D values of 0.4–10.0 mm ) according to surface plasmon resonance. In addition, they were investigated for inhibitory activity in GTF-activity assays. The early-stage DCC study reveals that careful design of DCLs opens up easy access to a broad class of novel compounds that can be developed further as potential inhibitors.     

陶瓷直接凝固注模（DCC）成型

直接凝固注模式型（ＤＣＣ）是一种陶瓷净尺寸胶态成型方法，ＤＣＣ成型的坯体具有成型密度高，密度及组分分布均匀，不含或只含少量有机物等特点，本文了ＤＣＣ成型的原理、成型过程及特点。     

Degradable cationic clarifiers based on ester bonds for treating wastewater produced from polymer flooding

Polymer-contained oily sludge is inevitably produced when the oily wastewater produced from polymer flooding (OWPF) is treated by a cationic polymer clarifier, and it severely affects oilfield production. This study designed a novel degradable cationic clarifier (DCC) based on the ester bond and prepared it in light of the poly(β-amino ester) used in the area of generic material delivery. First, the copolymer of N-[3-(dimethylamino) propyl] methacryamide (DMAPMA) and diallylamine (PDMAPMA-NH) were synthesized by radical copolymerization. Then, the DCC was prepared by Michael addition between PDMAPMA-NH and poly(ethylene glycol) diacrylate. The synthesis conditions of DCC were investigated, and a DCC with excellent flocculant performance and good degradability was successfully prepared. At 70°C, both the degradations of DCC and the water-insoluble polymer complex formed by DCC and the polymer used for polymer flooding can be completed in 10 h, which is beneficial for the self-disappearance of the polymer-contained oily sludge. The flocs formed by DCC were observed at different times, and the results confirmed that the flocs can change to an oil film and that the polymer-contained oily sludge cannot exist for a long time. This study provides inspiration for OWPF treatment and expands the new application for poly(β-amino ester).     

Magnesia induced coagulation of aqueous PZT powder suspensions for direct coagulation casting

Coagulation characteristics of poly(acrylate) dispersed PZT powder suspensions by MgO coagulating agent have been studied. The PZT powder suspensions undergoes coagulation at MgO concentrations much lower than the equivalent amount to react with the dispersant indicating a major shift in the coagulation mechanism from the corresponding alumina powder suspensions. Unlike in alumina powder suspensions, the Mg²⁺ ions generated from the MgO reacts with the ammonium poly(acrylate) adsorbed on particle surface that result in cross-linking of PZT particles by Mg²⁺ through the ammonium poly(acrylate) molecules. The particle bridging induces faster coagulation of the slurry cast in a mould as required for an ideal DCC process. The compressive strength and stability against oscillatory stresses of the wet-coagulated bodies increased with increase in number of cross-links between the particles. The PZT green bodies prepared by the DCC process sintered to near theoretical density and the MgO added as coagulating agent (～0.1 wt%) had only minor influence on its piezoelectric characteristics.     

陶瓷直接凝固注模成型（DCC）原理及应用

直接凝固注模成型是一种崭新的净尺寸陶瓷成型概念，其基本过程是通过酶催化底物的化学反应改变，ｐＨ值至等电点（ＩＥＰ）或增加盐离子浓度，使双电层稳定的陶瓷浓悬浮体实现原位凝固，得到均匀，无密度梯度的坯体，然后干燥（无需脱脂）烧结致密化，本文详细讨论了这种成型工艺的原理和应用研究成果。     

重油性质对油煤浆表观黏度的影响

以催化裂解油浆(DCC)、山东渣油(SDR)、中低温煤焦油重馏分(TAR)和塔河渣油(THR)为研究对象,考察了不同条件下油煤浆表观黏度变化规律,研究了油煤浆的流体性质和黏温特性,探讨了制浆过程中不同性质重油对煤的适应性。结果表明:不同性质的重油组分差距较大,THR与TAR中饱和脂肪烃含量低,含有大量氢键缔合结构。分析结果表明THR中沥青质的分子母核结构更大,重油胶质体系稳定性差,极易缩聚,在升温过程中容易结焦。煤粉浓度为30%条件下,随剪切速率提高,DCC,SDR和TAR油煤浆体系黏度下降幅度均小于10%,这与三种重油均呈牛顿流体性质有关。添加煤粉增强了THR剪切稀化的能力,黏度下降高达26.80%。四种重油配制的不同浓度油煤浆体系lnμ与1/T线性关系良好,相关系数R²>0.98。在相同温度和煤浆浓度条件下,THR油煤浆体系黏度>SDR油煤浆体系黏度>TAR油煤浆体系黏度>DCC油煤浆体系黏度。SDR与TAR配制的油煤浆黏度适中,且在输送过程中受温度波动影响较小,油煤浆稳定性较高,是比较适宜的制浆原料。     

基于短时平均幅度和HMM的语音识别系统研究

为克服现行语音识别精度不高的缺点,充分利用资源,改进语音识别效率,研究了基于音频波段特征分析的声音检测与分辨方法。方法以不同人对同一字的发音样本中的音频段信号为主要检测组分,研究不同样本的语音特征区别,使用MNP21声音传感器采集音频信号并进行分析。针对不同人的发音样本体系,提出了使用音频波段检测的思路。基于短时平均幅度优化获得音频信号,进而用隐马尔可夫模型进行识别,设计了语音识别系统。实验结果表明：每人采集10组样本训练,针对五人的不同样本进行多次语音区分,准确率达到100%。     

Thiol esters of 2-mercaptoethanol and 3-mercapto-1,2-propanediol

2-Mercaptoethanol and 3-mercapto-1,2-propanediol are selectively S-acylated by fatty acids with dicyclohexylcarbodiimide (DCC) catalyzed by 4-dimethylaminopyridine. Since reaction of such thiols with acid halides produces mixtures of S- and O-acylated materials, the procedure using DCC is more efficient. Such thiol esters are valuable as substrates in the study of lipase activity, using Ellman's Reagent in a continuous spectrophotometric assay. This selective synthesis will facilitate the study of fatty acid residues that are less available. Rearrangement of S- to O-acylated compounds occurs only slowly under the conditions of the lipase assay and should not significantly affect activity measurements. Using DCC, it is possible to sequentially esterify 2-mercaptoethanol to form unsymmetrical diesters.