基于.NET的设备管理系统的设计与实现

阐述了基于ASP．NET的设备管理系统的设计与实现。系统根据企业的实际需要,利用先进的网络平台,采用B／S体系结构,将数据挖掘技术、网络安全防护技术等结合起来,实现企业设备的智能化管理,极大地提高企业设备的管理水平。     

软切换技术在变频与工频切换中的应用

在变频器从变频和工频切换中,工频旁路运行是变频器的一种重要运行方式,变频器与工频电源之间切换禾当会引起很大的电流冲击和严重的电磁干扰。提出了变频器与工频电源之间的软切换概念,论述了软切换的原理及其实现方法,使用PSCAD／EMTDC电磁暂态仿真软件对几种切换方式的仿真结果表明,变频调速系统的软切换方式有效地避免了过大的冲击电流,保证了电动机转速的平稳过渡。     

STS教育思想的特点及在《科学·化学》中的渗透

STS教育是科学教育改革中兴起的强调理解科学、技术和社会三者关系的一种新的科学教育思想。其宗旨是普及STS知识,培养具有科学素质的公民,使人们形成一种科学、科技与社会可持续发展的新的价值意识——STS意识。基于小学教师培养的高师《科学·化学》课程改革应当在教材建设和教学实践等方面充分体现和渗透STS教育思想,使其具有时代性和社会功能价值。     

ICL7129的自动量程转换控制

利用双积分单片A／D转换器ICL7129自身的特殊结构特点,加极简单的外围电路即可构成一个两个量程自动转换的数字仪表．叙述其电路原理及实用的电路．     

少数民族社区农户参与旅游发展问题研究

论文以洱源县梨园村旅游业发展为案例,对在旅游开发的过程中,由于缺乏良好的制度安排和利益分配机制,许多社区农户没有公平的参与机会,无法从中获益,但所有的农户共同承担着旅游业发展的环境和社会成本。旅游业的发展使农户中产生了严重的贫富差距,引发了农户之间的矛盾与分化。因此,社区旅游中,如果没有居民的有效参与,农户无法享受到旅游业的积极影响,无法脱贫致富,直接的结果是社区农户的社会分层日益明显,长远而言,社区旅游无法实现真正的可持续发展,不利于实现社区的稳定与和谐。     

基于嵌入式技术网络测试仪的研究及设计

本文就网络发展现状进行分析,重点研究了嵌入式技术,C8051F340处理器和TCP/IP协议。提出了一种基于嵌入式技术的网络终端测试仪的设计。     

In-package P/G planes analysis and optimization based on transmission matrix method

Power integrity （PI） has become a limiting factor for the chip＇s overall performance, and how to place in-package decoupling capacitors to improve a chip＇s PI performance has become a hot issue. In this paper, we propose an improved transmission matrix method （TMM） for fast decoupling capacitance allocation. An irregular grid partition mechanism is proposed, which helps speed up the impedance computation and complies better with the irregular power/ground （P/G） plane or planes with many vias and decoupling capacitors. Furthermore, we also ameliorate the computation procedure of the impedance matrix whenever decoupling capacitors are inserted or removed at specific ports. With the fast computation of impedance change, in-package decoupling capacitor allocation is done with an efficient change based method in the frequency domain. Experimental results show that our approach can gain about 5× speedup compared with a general TMM, and is efficient in restraining the noise on the P/G plane.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in flue gas emissions from municipal solid waste incinerators in China

Polychlorinated dibenzo-p-dioxins and furalls(PCDD/Fs)emissions in flue gas from two types of municipal solid waste incinerators(MSWIs)most commonly used in China were investigated in this study.The selected incinerators include two grate-type MSWIs:MSWl-A(350 t/d)and MSWI-B(150 t/d),and two fluidized bed MSWIs:MSWI-C(400 t/d) and MSWI-D (400 t/d),which are all equipped with semi-dry lime scrubber and bag filter except MSWI-D equipped with cyclone and wet scrubber(WS)as air pollutant conffol device(APCD).Results indicated that the emission concentration and the international toxic equivalents(I-TEQs)of the PCDD/Fs from the stacks were in the range of 1.210～10.273 ng/Nm3 and 0.019～0.201 ngI-TEQ/Nm3,respectively.They were greatly lower than the emission regulation standard of PCDD/FS in China(1.0 ng I-TEQ/Nm3).However,only the PCDD/Fs emission Ievel from MSWI-C Was below 0.1 ng I-TEQ/Nm3.Although the homologue profiles were distinct,the contributions of the 2,3,7,8-subsituted congenem to the total I-TEQ were similar among all the investigated MSWIs.Two major 2,3,7,8-substituted congeners,2,3,4,7,8-PeCDF and 1,2,3,7,8-PeCDD,account for 47% and 9%(average values)of the total I-TEQ values,respectively.The correlation between PCDD/Fs levels and composition of flue gas Was also discussed.     

Polychlorinated dibenzo-p-dioxins and dibenzofurans in flue gas emissions from municipal solid waste incinerators in China

Polychlorinated dibenzo-p-dioxins and furans （PCDD/Fs） emissions in flue gas from two types of municipal solid waste incinerators （MSWIs） most commonly used in China were investigated in this study. The selected incinerators include two grate-type MSWIs： MSWI-A （350 t/d） and MSWI-B 050 t/d）, and two fluidized bed MSWIs： MSWI-C （400 t/d） and MSWI-D （400 t/d）, which are all equipped with semi-dry lime scrubber and bag filter except MSWI-D equipped with cyclone and wet scrubber （WS） as air pollutant control device （APCD）. Results indicated that the emission concentration and the international toxic equivalents （I-TEQs） of the PCDD/Fs from the stacks were in the range of 1.210-10.273 ng/Nm^3 and 0.019-0.201 ng I-TEQ/Nm^3, respectively. They were greatly lower than the emission regulation standard of PCDD/Fs in China （1.0 ng I-TEQ/Nm^3）. However, only the PCDD/Fs emission level from MSWI-C was below 0.1 ng I-TEQ/Nm^3. Although the homologue profiles were distinct, the contributions of the 2,3,7,8-subsituted congeners to the total I-TEQ were similar among all the investigated MSWIs. Two major 2,3,7,8-substituted congeners, 2,3,4,7,8-PeCDF and 1,2,3,7,8-PeCDD, account for 47% and 9% （average values） of the total I-TEQ values, respectively. The correlation between PCDD/Fs levels and composition of flue gas was also discussed.     

地塞米松诱导小鼠腭裂动物模型的建立

目的:探讨地塞米松诱导小鼠腭裂动物模型的建立方法。方法:采用一次性腹腔注射地塞米松的方法,建立腭裂模型鼠。取孕12.5d、13.5d、14.5d、15.5d、16.5d胚胎头部,石蜡包埋,6μm切片,HE染色,观察腭发育过程腭突的变化。结果:妊娠第11.5d一次性给予地塞米松(Dex)1mL(用量为50mg/Kg)可诱发小鼠产生腭裂。模型组腭突体积瘦小,不能在中线区接触融合,以致不能与腭突上方的鼻中隔接触融合,胎鼠出现腭裂。结论:妊娠第11.5d一次性给予小鼠足量地塞米松,可成功建立腭裂动物模型。为研究腭裂形成原因及分子机制提供了一个较好的模型。