化学二氧化锰中试研究

采用碳酸锰沉淀热解法进行300t/a化学二氧化锰（CMD）中试开发研究,就生产中的一些问题做了叙述,介绍了中试产品的各项技术指标。硫酸锰溶液除杂后主要金属杂质为0.1mg/L,中间产品碳酸锰的振实密度达到2.18g/cm3;产品的振实密度达到1.86g/cm3。     

Comparison of wound culture and bronchial lavage in the severely burned child: implications for antimicrobial therapy

BACKGROUND: The relationship of the burn wound flora to microbial pathogens in the tracheobronchial tree has important implications for antimicrobial therapy in the severely burned patient. Management of septic complications is bolstered by surveillance quantitative wound cultures (QWC) and bronchial lavage fluid (BLF) cultures. OBJECTIVES: To compare the organisms present in BLF with those found in QWC and to determine if QWC can predict BLF results. DESIGN: Results of BLF cultures from all patients who underwent bronchial lavage from January 1, 1996, to December 31, 1996, at our institution were compared with QWC data from the same date. Criteria for a positive match included an identical antibiotic susceptibility pattern and biotype. Match rates were calculated qualitatively and quantitatively. RESULTS: In 30 (48%) of the 62 BLF cultures, there was a match between the organism identified in the BLF and the QWC. When strict quantitative criteria were applied, the match rate was only 9 (14%) of 62. Burn size and inhalation injury had no significant effect on match rate. CONCLUSIONS: Whereas the microbial pathogens were similar in the QWC and BLF, linear regression showed no value of QWC in predicting BLF culture results. The difference between qualitative and quantitative match rates suggests cross-colonization between the burn wound and tracheobronchial tree, but little to no cross-infection. The QWC and BLF cultures must be performed independently in determining antimicrobial specificity in the burned patient.     

Kinetics and mechanisms of chemical reactions in nonequilibrium-plasma etching of silicon and silicon compounds

Plasma-chemical etching of silicon and silicon compounds is reviewed. It is shown that present data indicates that fluorine atoms and molecules are the main particles responsible for etching of silicon and that atomic fluorine is the main active particle for etching of silicon dioxide. Insufficient data exists to establish the contribution of charged and excited states to the etching of silicon and its compounds but oxygen atoms and molecules are seen to have a strong influence and fluorocarbon radicals can passivate the surface by forming polymer films.     

Ni纳米管的电化学模板法制备及表征

本文采用一种简单而有效的电化学方法在硫酸铵体系中利用氧化铝模板(AAO)成功制备出规则有序的Ni的管状纳米阵列.使用这种方法可获得外径约为70nm,内径约为50nm的Ni纳米管.对所得的Ni纳米管进行了扫描电镜(SEM)、透射电镜(TEM)、选区电子衍射图(SAED)和X射线衍射(XRD)分析,结果表明:该方法制备的Ni纳米管高度有序,大小均一,其形貌受控于氧化铝模板的结构,外径与模板的孔径相等.     

湘西苗族头面部的体质形态测量分析

为探讨湘西苗族头面部的体质特征，对湘西苗族头面部42项指标进行活体测量，得到了头面部42项体质指标的平均测量值和相关指数，并对各体质指数进行了分型。通过与国内其他10个民族头面部的体质特征进行比较，表明湘西苗族头面部体质有其独特的民族特征。     

Matlab/Simulink在电力电子技术教学中的应用

在电力电子技术课程教学中,有许多电路需要画波形图进行分析,而这些波形图往往非常复杂,只靠板书既费时费力,图形不够规范,又看不到动态情况,教学效果非常不理想.Matlab/Simulink动态仿真工具为解决此类问题提供了一个很好的的途径.本文介绍了MATLAB/Simulink仿真软件的特点和功能,并以三相桥式全控整流电路为例对其进行了建模和仿真分析.结果表明,利用该软件辅助电力电子教学,不仅建模简单、直观,更改参数方便,交互性较强,能动态显示仿真波形,节约课堂时间,而且可提高学生学习的兴趣,增强学生对相关理论知识的理解.     

基于小波系数能量差值的音频“零数字”水印算法

提出了一种基于小波系数能量差值的音频“零数字”水印算法。对原始音频信号进行小波分解，通过选取适当的阈值，根据逼近系数分量和细节系数分量的能量差值与阈值的大小关系，实现对水印信息的“嵌入”和提取；在提取过程中结合线性伸缩恢复来消除时间轴上线性伸缩带来的影响。实验结果表明，该算法对多种音频文件的操作和攻击，如低通滤波、重采样、重量化、回声干扰、MPEG编码等均具有良好的鲁棒性。     

一种交流伺服系统的多输出辅助开关电源设计

介绍了用于现代交流伺服控制系统的多路输出辅助开关电源的设计与制作,根据电流连续模式反激开关电源的工作原理对电源设计和提高电源品质的措施进行了详细分析和讨论。基于原理分析和实验调试制作了样机,在数控机床用永磁同步电机伺服控制器上的应用表明电源设计满足伺服系统辅助电源的各项设计要求。     

无创胃液隐血检测传感器的设计

基于胶囊内窥镜与隐血检测原理,提出了一种能够智能识别胃液隐血(GOB)信息的智能电子胶囊,设计了基于胶体金免疫原理的胃液隐血检测传感器,该传感器主要包括隐血检测模块与隐血识别模块,隐血检测模块特异性针对人体血红蛋白.在离体状态下对传感器样机进行了原理性实验.结果表明:该胃液隐血检测传感器能够较好地识别血红蛋白浓度为6-1 800 mg/L的胃液隐血.整个系统结构设计简单、可靠,为早期胃癌的普查初筛提供了一个新的思路.