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141.
“团队项目训练法”是充分利用各种市场资源,按照市场营销工作实际,让学生自组团队、自寻商机、自设项目,理论联系实际分析营销环境.对真实对象进行市场营销方案设计、实施、评估,亲历市场营销的完整过程,以此进一步掌握理论,训练技能,提高能力。介绍了重庆科技学院对市场营销专业本科生运用“团队训练法”进行实践教学的做法及效果。 相似文献
142.
143.
目前,金融危机已对全球实体经济产生了巨大的冲击,2008年世界经济已明显放缓,下行风险逐步加大,前景更加不确定。中国经济虽一支独秀,但毫无疑问也会受到外部因素冲击从而影响国内经济发展,以投资和外向型贸易为特点的中国经济急需新技术和高科技领域经济增长来改变现有传统经济增长模式,而LED行业就是这样的代表性行业。本论文立足于当前世界金融危机整体发展局势,重点分析了当前金融危机对LED行业的影响,并对江西LED行业发展的整体环境及发展趋势进行了探讨和分析。 相似文献
144.
145.
何庆复 《武汉理工大学学报(材料科学英文版)》2009,24(3):428-431
Behaviour of hardening and serration yield of a Fe-Ni-Cr alloy under isothermal cycling (ISC) and out-phase TMF was studied
on the basis of varied hysteresis loops. Cycling hardening and serrated yielding for ISC depend on the temperature and the
total strain range, stronger hardening with serrated yielding at higher strain range under ISC at 600 °C, but no hardening
and serrated yielding occurred under ISC at 800 °C. Stronger hardening with stress serration occurred at the thermal path
going to the lowest temperature, no stress serration occurred at the highest temperature under the out-phase. The hardening
also depends on the total strain range, higher total strain range with lower cycling temperature resulted in a stronger hardening
and remarkable serration yielding behavior. Weaker hardening without serrated yielding occurred at near 800 °C may due to
an obvious cycling stress drop under out-phase TMF. Change in the shape of the hysteresis loops also expresses the degree
of the damage of the tested alloy under out-phase and ISC. 相似文献
146.
章桥新 《武汉理工大学学报(材料科学英文版)》2009,24(6):871-874
Silver powder was fabricated by spray pyrolysis, using 2%–20% AgNO3 solution, 336–500 mL/h flux of AgNO3 solution, 0.28–0.32 MPa flux of carrier gas and in the 620–820 °C temperature range. The effects of furnace set temperature,
concentration of AgNO3 aqueous solution, flux of AgNO3 aqueous solution as well as carrier gas on the morphology and particle size distribution of silver powder, were investigated.
The experimental results showed that with the high concentration of AgNO3 aqueous solution, the average grain size of silver decreased with the increasing of furnace set temperature. But the gain
size distribution was not homogenous, the discontinuous grain growth occurred. With the low concentration of AgNO3 aqueous solution, the higher furnace set temperature made the nano sliver grains sintered together to grow. Nano silver powder
about 100 nm was fabricated by spray pyrolysis, using 2wt% AgNO3 solutions, 336 mL/h flux of AgNO3 aqueous solution, 0.32 MPa flux of carrier gas at 720 °C furnace set temperature. 相似文献
147.
研究了PAN浸渍树脂对锌(Ⅱ)离子的吸附特性。结果表明,对Zn(Ⅱ)吸附的最佳pH为6.0;其吸附动力学实验数据与二级动力学模型相吻合,表明化学吸附过程为速率控制步骤。 相似文献
148.
AADL 测试模型的构造研究 总被引:1,自引:0,他引:1
目前,结构分析和设计语言AADL在任务关键嵌入式系统领域有着良好的应用.为了保障任务关键软件的质量,文章提出基于AADL测试模型对AADL设计模型进行测试,以发现设计模型中存在的错误.研究给出了体现系统拓扑结构的AADL测试模型的形式定义及由AADL构造该测试模型的算法,基于该测试模型可以对AADL设计模型中构件交互的输入、输出端口序列和连接的正确性进行测试,并以飞行控制系统的AADL设计模型为例,阐释了研究成果. 相似文献
149.
Poly(vinyl alcohol)/Hydroxylapatite (PVA/HA) composite hydrogel was prepared with poly(vinyl alcohol) and hydroxylapatite
as raw materials, using the method of repeated freezing and thawing. The morphologies of PVA/HA composite hydrogel were observed
by means of high-accuracy 3D profiler and scanning electron microscope (SEM). The compressive elastic modulus and the stress
relaxation characteristics of PVA/HA composite hydrogel were measured using the flat-head cylinder indenter. The friction
and wear tests between PVA/HA composite hydrogel and bovine knee articular cartilage were performed on the micro-tribometer.
The worn morphologies of PVA/HA composite hydrogel were observed with environmental scanning electron microscope (ESEM). The
results showed that PVA/HA composite hydrogel has the cross-link network microstructure which is similar to that of the natural
bovine knee articular cartilages. With the increase of freezing-thawing cycles and the HA content, the degree of cross-link
and the crystallization of PVA/HA composite hydrogel both increase, the elastic modulus increases evidently, the rate of stress
relaxation is improved and the value of balance stress decreases. The friction coefficient decreases with the increase of
the freezing-thawing cycles and the HA content. The more the freezing-thawing cycles are, the earlier the friction coefficient
reaches the stable balance value. The friction deformation depth between PVA/HA composite hydrogel and bovine knee articular
cartilage is inversely proportional to freezing-thawing cycles and the HA content. The main wear mechanisms of PVA/HA composite
hydrogel are plastic flowing and adhesive flaking. The wear severity degree decreases with the increase of freezing-thawing
cycles and the HA content.
Supported by Key Program of the National Natural Science Foundation of China (Grant No. 50535050), Program for New Century
Excellent Talents in University (Grant No. NCET-06-0479) and Natural Science Foundation of Jiangsu Province (Grant No. BK2005403) 相似文献
150.
The overall behavior of concrete depends on its meso structures such as aggregate shape, interface status, and mortar matrix
property. The two key meso structure characters of concrete, bond status of interface and nonlinear property of matrix, are
considered in focus. The variational structure principle is adopted to establish the macro-meso constitutive law of concrete.
Specially, a linear reference composite material is selected to make its effective behavior approach the nonlinear overall
behavior of concrete. And the overall property of linear reference composite can be estimated by classical estimation method
such as self-consistent estimates method and Mori-Tanaka method. This variational structure method involves an optimum problem
ultimately. Finally, the macro-meso constitutive law of concrete is established by optimizing the shear modulus of matrix
of the linear reference composite. By analyzing the constitutive relation of concrete established, we find that the brittleness
of concrete stems from the imperfect interface and the shear dilation property of concrete comes from the micro holes contained
in concrete.
Supported by the National Natural Science Foundation of China (Grant Nos. 50679022, 90510017, 50539090) and National Basic
Research Program of China (Grant No. 2007CB714104) 相似文献