浅谈时事政治在高中政治教学中的应用

时事政治是当前国内外发生的热点,引人注目,且有重大意义的新闻。时事政治作为政治教学内容的补充,与思想政治教学结合,全面反映了当前国内外政治形势。时事政治作为一个新鲜的时政热点,其对推动学生积极主动学习政治有着一定的影响,对政治教学有着一定的影响。文章基于时事政治的必要性,提出当前我国高中政治教学中时事政治教学存在的问题,同时,阐述如何将时事政治融入高中政治教学。     

三相软开关PWM变流器电流极性检测与电流补偿方法

A novel software implementation for current polarity detection and current compensation is presented. For a three-phase zero-voltage soft-switching （ZVS） PWM converter based on phase and amplitude control （PAC）, when saw-tooth carriers with alternate positive and negative slopes are adopted, the positive or negative slopes are chosen according to the phase current polarity. Since polarity reversal causes current distortion, current at the instant of reversal should be compensated for. Based on the characteristic of unity power factor converter in rectification and regeneration modes, a software implementation for current polarity detection is proposed. Distortion of current zero-crossing caused by using saw-tooth carriers with alternate positive and negative slopes is analyzed, and the relevant compensation method is proposed. Experimental study with a 1.5 kW device shows that phase current has a small harmonic content and power factor is high both in rectification and regeneration modes.     

新型高精度数控恒流源的设计

针对传统数控恒流源恒流校正方法复杂、调整时间较长等缺点,利用PWM技术设计了一种新型的高精度数控恒流源.该恒流源以SoC单片机C8051F020为主控芯片,采用负反馈闭环控制的方法,由PWM信号实时调整输出设定的电流.测试结果表明,该恒流源在输出电流10mA-4A范围内,控制精度为1mA,电流输出值与设定值的相对误差小于0.1%,具有精度高、控制简单、响应快、自适应能力强等特点.     

教育与学生当下的幸福感探究

针对目前学生幸福感缺失的现实,分析其原因在于家庭＂望子成龙＂心切、学校应试教育固存、自我幸福能力匮乏、社会传统观念规约等。认为教育关涉学生当下幸福,要做到使家庭教育蕴育学生当下幸福、学校教育惠育学生当下幸福、学生自我教育智育当下幸福。     

半导体激光器恒流驱动电路的研制

阐述了大功率半导体激光器恒流源的设计方法.该恒流源采用功率MOSFET作电流控制元件,运用负反馈原理稳定输出电流.应用结果表明该恒流源对激光器安全可靠,输出电流的短期稳定度达到1×10-5.     

中高压软启动控制器的设计

直接启动电动机会产生很强的冲击电流,降低了电动机的使用寿命,对电网也会造成很大的冲击.设计一种限流PI调节降压式软启动,该软启动以TMS320 F28335为控制核心,通过在同步信号作用下,采集电动机启动时电流、电压信号,对晶闸管触发角移相的控制实现电动机启动电压和电流的调节,电动机启动过程中的参数可以根据电动机不同负...     

A 155 Mbps laser diode driver with automatic power and extinction ratio control

An integrated laser diode driver(LDD) driving an edge-emitting laser diode was designed and fabricated by 0.35 μm BiCMOS technology. This paper proposes a scheme which combines the automatic power control loop and temperature com-pensation for modulation current in order to maintain constant extinction ratio and average optical power. To implement tem-perature compensation for modulation current,a novel circuit which generates a PTAT current by using the injecting base current of a bipolar transistor in saturation region,and alternates the amplifier feedback loop(closed or not) to control the state of the current path is presented. Simulation results showed that programmed by choice of external resistors,the IC can provide modu-lation current from 5 mA to 85 mA with temperature compensation adjustments and independent bias current from 4 mA to 100 mA. Optical test results showed that clear eye-diagrams can be obtained at 155 Mbps,with the output optical power being nearly constant,and the variation of extinction ratio being lower than 0.7 dB.     

高校科研信息化的基本现状和发展方向

科研信息化是高校教育信息化进程中的一项重大举措,当前我国高校科研信息化,尚处于探索阶段,在实践中普遍存在着一些问题和现象。该文在对当前高校科研信息化基本现状分析的基础上,提出了未来高校科研创新管理的发展方向。     

浅析农村教师队伍现状及改善措施

本从三个方面就我国现阶段农村教师队伍存在的突出问题进行了分析。即：农村教师整修业务素质水平不高；社会经济地位低，教师队伍不稳定；师德意识淡薄。在此基础上，结合自己的实践认识，提出了改善农村教师队伍现状的必要性及相对应的积极措施。同时指出改善农村教师队伍现状的重要意义。     

交流负载高频电流驱动放大器的设计与实现

交流负载高频电流驱动放大器采用光耦及LED采集PLC输出的直流信号,实现光电隔离及输入状态显示,控制双向可控硅BTA16导通驱动大电流交流负载工作。该放大器已获实用新型专利权,并转让给企业投入生产和使用。企业应用结果表明,该产品通用性强,性能可靠,接线方便规范,有效发挥了驱动电流放大作用,提高了设备抗干扰能力,降低了机电设备开发成本。     

三相电子节能灯负载中线电流的测试及分析

文中提出了一个在大面积集中使用电子节能灯时值得注意的中线电流太大的问题,通过对三相四线制中线电流的数值及波形的测试,分析了电流大的原因及由此可引发的几种危害,提出了选择中线的原则。     

一体化电子式电流电压互感器研究

A high-performance current and voltage measurement system has been developed in power system.The system is composed of two parts:one current measurement element and one voltage measurement element.A Rogowski coil and a capacitive voltage divider are used respectively for the line current and voltage measurements.Active electronic components are used to modulate signal,and power supply for these components is drawn from power line via an auxiliary current transformer,Measurement signal is transmitted y optical fibers,which is resistant to electromagnetic induction and noise,With careful design and the use of digital signal processing technology,the whole system can meet 0.5% accuracy for metering and provides large dynamic range coupled with good accuracy for protective relaying use.     

过去时、完成体与现时关联

现时关联是否是英语动词完成体所具有的内在语义特征,这一直是国内外语言学界争论的焦点之一。过去时和完成体中都存在现时关联的现象;但现时关联是完成体固有的语义特征,而过去时中的现时关联只在一定的语境中体现出来;现时关联与语用含义是两种不同范畴,但都有着密切的联系。     

The development of gender differences in affective expression and in the relationship between mood and achievement-related self-judgments

In this study, 434 children and adolescents completed the Control-,Agency-, and Means-ends beliefs Interview (CAMI). Moreover, we asked for current mood-state and achievement-related affect after success and failure at school. There was no gender difference in achievement-related affective expression in children (9 and 10 years old), but there was a substantial difference in adolescents (15 and 16 years old), boys reporting less affect than girls. A different pattern emerged for the impact of affect on achievement-related beliefs. Again, children did not show any gender difference. In adolescents, however, boys' current mood-state was related to agency beliefs to a higher extent than girls' current mood state. Thus, boys, in comparison to girls, may develop inhibition of affective expression, but over the same span, they continue to base agency beliefs on their current mood-state whereas girls do not.     

工作于临界模式的SEPIC拓扑的分析和设计

应用于DC-DC变换器的传统拓扑中SEPIC(Single-Ended Primary Inductance Converter)拓扑既可以用于升压又可以用于降压,并且输出电压为正电压,具有启动时限制浪涌电流、较小输入电流纹波和低电磁干扰(Electromagnetic Interference,EMI),具有谐波小等优点,但针对SEPIC拓扑的详细分析和建模相对较少,文中针对工作于电流临界模式(Critical Current Mode,CRM)的SEPIC线路进行了详细的分析,并对理论等式进行了详细推导,给出了简化的设计步骤,最后根据要求对SEPIC变换器进行了设计,并给出了仿真波形.     

On Consultation and Beginner Educational Psychologists

In this article, we describe some of our purposes and processes when introducing consultation as a comprehensive model of service delivery to course members in their programme of initial professional education. We also note some of the impacts from this model, both in the course modules and the placement experiences. While it is written from the perspective of course tutors, we hope that this account may trigger useful thoughts for readers-about their own initial training, about their current model of practice, about their current professional development or even their current contribution to initial training.     

企业团队建设中的三大误区

鉴于团队在当前企业竞争中的极端重要性，本对我国企业团队建设的现状进行了探讨和分析，指出了当前团队建设中的三大误区。     

中小学教师休闲活动的误区、成因及建议

随着中国经济快速增长与进步,21世纪的中国正在步入一个前所未有的休闲时代.如何提高休闲质量成为目前的一个重要议题.就中小学教师而言,他们在休闲活动中还存在一些误区,比如,认为休闲就是浪费时间,休闲活动方式单一,存在失范休闲行为和跟风休闲.这些误区形成的原因主要在于概念理解、工作压力、活动条件限制等方面的问题.要提高中小学教师对休闲活动的认识,提高休闲活动的质量,学校必须减轻他们的工作压力,社区要加强文化建设,教师自身要提升休闲活动素养.     

净现值法和内含报酬率法的比较分析及理性选择

在投资项目评价中，净现值法和内含报酬率法是考虑资金时间价值的两种方法。净现值法在理论及计算技术上要比内含报酬率法更完善，但在实际工作中，应用内含报酬率法的企业又明显地多于应用净现值法的企业。在互斥投资项目决策中，当这两个方法出现矛盾的结论时，应理性选择净现值作为投资项目的评价指标。     

中小学校长培训问题与改进策略

当前校长培训存在的两方面问题,必须通过改革现有的培训方式来解决。培训要有效益有质量,就必须逐步建立起科学的培训管理,并以合理的培训评估为导向。校长培训应走一个管理和评估相结合的模式,其中校长培训管理模式可以规划为培训项目的开发管理和培训项目的实施,并进一步加强培训评估,系统规范校长培训工作。