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1.
人力资源管理正日益成为企业核心竞争力的重要元素之一。科学理解人力资源管理的含义及内容,充分认识人力资源管理对企业发展的重要影响,是应对全球化挑战、提高企业竞争力的前提条件。 相似文献
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涂层混凝土在应力腐蚀条件下氯离子渗透性能的变化是一个新的课题。本文利用自行设计的加载设备对混凝土保护涂层及涂层涂刷次数等不同情况下的氯离子渗透性进行了研究。研究表明,保护涂层减小了混凝土在应力腐蚀环境作用下抗弯强度的损失。同时也提高了混凝土的抗氯离子渗透性,而且随着保护涂层刷涂次数的增加这种优越性越明显。 相似文献
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介绍了常用的复合标的中标形式和矩阵博弈理论,论述了复合标的的组成及现实意义,研究了最佳报价公式和最优报价策略,结合复合标底和矩阵博弈论的最优报价模型,推导了误差矩阵对个体报价的影响,研究了投标人报价的策略.最后,结合实例验证了此种方法是一种有效的工程投标方法,对工程领域具有很强的针对性和实用性. 相似文献
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Pt/Ti bottom electrodes were fabricated on SiO2/Si substrates by magnetron dual-facing-target sputtering system. Lead zirconate titanate(PZT) thin films were deposited on Pt/Ti/ SiO2/Si substrates by radio frequency (RF) magnetron sputtering system. The thickness of PZT thin films which were deposited for 5 h was about 800 nm. XRD spectra show that PZT thin films deposited in Ar ambience and rapid-thermal-annealed for 20 min at 700 ℃ have good crystallization behavior and perovskite structure. AFM micrographs show that mean diameter of crystallites is 70 nm and surface structures of PZT thin films are uniform and dense. Raw mean, root mean square roughness and mean roughness of PZT thin films are 34.357 nm, 2.479 nm and 1.954 nm respectively. As test frequency is 1 kHz, dielectric constant of PZT thin films is 327.6. Electric hysteresis loop shows that coercive field strength, residual polarization strength and spontaneous polarization strength of PZT thin films are 50 kV/cm, 10 μC/cm2 and 13 μC/cm2 respectively. 相似文献
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Based on planar Si dual-base transistor conception, a novel mesa dual-base heterojunction bipolar transistor （ HBT） is designed and fabricated. Molecule beam extension, selective wet chemical etching, common contact photolithography and metal lift-off technique are adopted in the process. The device has particular and distinct voltage-controlled negative differential resistance （NDR） and photo-controlled NDR. The highest peak-to-vally current rate of the voltage-controlled NDR is larger than 148 and the peak current varies with the increase of collector voltage. The device features high speed and high frequency characteristics derived from HBT and intrinsic bistability and self-latching characteristics due to NDR. A single dual-base HBT can be seen as an integration of NDR device, HBT and photoconductive device. Compared with common HBT,the groove is the key factor producing NDR. 相似文献
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The resonant tunneling diode (RTD) is an ultra-highspeed and ultra-high frequency quantum-transport deviceaccompanied with negative differential resistance (NDR)I-Vcharacteristic originating fromresonant tunneling effect .The core structure of RTDis doubl… 相似文献
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齐海涛 《体育科技文献通报》2014,(7):76-77,121
本文利用文献资料法、理论分析法和专家访谈法,结合视频拍摄的功能和体育教学过程的特点,对视频拍摄法在大学体育教学中的应用进行了理论分析,得出视频拍摄法在大学体育教学中应用具有可行性,如果视频拍摄法得到合理应用可以促进学生运动表象的形成、帮助纠正学生的动作,调动学生学习的积极性,增强体育学习的乐趣,提高体育教学效果。 相似文献
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A kind of undercoat for resistor with high temperature and humidity resistance was obtained by modifying epoxy resin with proper nano-SiO2 added at 80 ℃. The structure, thermal stability, humidity resistance, and morphological characteristics of the modified epoxy resin undercoat were studied by electrical tests, infrared spectra (IR) analysis, and scanning electron microscopy (SEM). The results show that more compact and steady inter-crosslinked network structures are formed in the modified epoxy resin undercoat added with nano-SiO2, which greatly improves the performance of modified epoxy resin undercoat. The undercoat with nano-SiO2 of about 2.71%, kept for six months at room temperature without flocculating and aggregating, is of good stability, and the surface of painted resistor is uniform, tight and without air holes on it. The varying ratio of resistance with such undercoat painted is less than one in a thousand after high temperature and humidity resistance tests. 相似文献
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A kind of modified epoxy resins was obtained by condensation of epoxy resin with silicic acid tetraethyl ester(TEOS) and nano-SiO2. The reactions were performed with hydrochloric acid as a catalyst at 63℃. The structure, thermal stability and morphological characteristics of the modified epoxy resins were studied through infrared spectra (FF-IR) analysis, thermogravimetric (TG) analysis and scanning electron microscopy respectively. It has been found from the IR and TG study that modified epoxy resins have greater thermal stability than epoxy resins, and its thermal stability has been improved by the formation of inter-crosslinked network structure. The modified epoxy resins exhibit heterogeneous morphology and heterogeneity increases with more TEOS feeding, which in turn confirms the formation of inter-crosslinked network structure in modified epoxy resins. 相似文献
10.
High resistance thin film chip resistors(0603 type) were studied,and the specifications are as follows:1 k? with tolerance about ±0.1% after laser trimming and temperature coefficient of resistance(TCR) less than ±15×10-6/℃.Cr-Si-Ta-Al films were prepared with Ar flow rate and sputtering power fixed at 20 standard-state cubic centimeter per minute(sccm) and 100 W,respectively.The experiment shows that the electrical properties of Cr-SiTa-Al deposition films can meet the specification requirements of 0603 type thin film chip resistors when the deposition time was about 11 min and deposition films were annealed at 500 ℃ for 120 min.The morphologies of Cr-Si-TaAl film surfaces were examined by scanning electron microscopy(SEM).The analysis suggests that Ta and Al may be distributed in CrSi2 film with mixed form of several structures(e.g.,bridge-like,capillary-like or island-like structures),and such a structure distribution is responsible for high film resistance and low TCR of Cr-Si-Ta-Al film. 相似文献