Multi-walled carbon nanotubes （MWNTs） were wet-milled in the presence of ammonia and cationic surfactant and then used as reinforcements to prepare Ni-P-MWNTs composite coatings by electroless plating. The tribologi...Multi-walled carbon nanotubes （MWNTs） were wet-milled in the presence of ammonia and cationic surfactant and then used as reinforcements to prepare Ni-P-MWNTs composite coatings by electroless plating. The tribological performances of the composite coatings under dry condition were investigated in comparison with 45 steel and conventional Ni-P coating, Micrographs show that short MWNTs with uniform length and open tips were obtained through the wet-milling process. The results of wear test reveal that the Ni-P-MWNTs composite coatings posses much better friction reduction and anti-wear performances when compared with 45 steel and Ni-P coating. Within the MWNTs content range of 0.74%-1.97%, the friction coefficient and the volume wear rate of the composite coatings decrease gradually and reach the minimum values of 0.08 and 6.22x10-15 m3/（N.m）, respectively. The excellent tribological performances of the composite coatings can be attributed to the introduction of MWNTs, which play both roles of reinforcements and solid lubricant during the wear process.展开更多
In order to obtain the earth pressure coefficient at rest (K0) at higher consolidation pressures during secondary compression, a series of K0 tests for saturated reconstituted clay were conducted. The results indicate...In order to obtain the earth pressure coefficient at rest (K0) at higher consolidation pressures during secondary compression, a series of K0 tests for saturated reconstituted clay were conducted. The results indicate that the measured K0 in secondary compression can be described by equations related to internal friction angle, secondary compression coefficient, compression index, recompression index, and sediment time. Effects of consolidation pressures and sediment time on K0 during secondary compression can be attributed to cementation (part of cohesion) increase and internal friction angle decrease. Cementation increase leads to nonlinear variation for K0 and internal friction angle decrease results in increase of K0. K0 computed by equations associated with internal friction angle is overestimated at apparent lower consolidation pressures with different sediment time, which agrees with the measured values well at apparent higher consolidation pressures.展开更多
This paper theoretically analyzes the lock-in mechanism of labor division for developing countries when they stick to static comparative advantages and the internal mechanism of cultivating dynamic comparative advanta...This paper theoretically analyzes the lock-in mechanism of labor division for developing countries when they stick to static comparative advantages and the internal mechanism of cultivating dynamic comparative advantages. Through empirical analysis, this paper finds that China, while sharing the benefits of globalization, showcases the lock-in effect regarding its status in the international labor division chain. The analysis finds that in its participation in globalization, the net barter terms of trade ~BTT） and factorial terms of trade for China are deteriorating, and the income terms of trade are seriously overvalued, resulting in a series of contradictions, such as scanty returns for enterprises, slow income growth, increasing trade frictions, and intensified environmental and resource pressures. The paper analyzes rapidly changing factors in China＇s comparative advantages and characteristics of the changes in industries where China possesses comparative advantages. According to changes in different types of industries at different stages, this paper puts forward suggestions on direction and policies for cultivating dynamic comparative advantages.展开更多
Economic globalization is the core of information technology, information technology is the core of e-commerce. E-commerce is as an important part of inlbrnaation technology in recent years when China has been booming...Economic globalization is the core of information technology, information technology is the core of e-commerce. E-commerce is as an important part of inlbrnaation technology in recent years when China has been booming. For a large number of SMEs, human resources, capital, technology and information are in a relatively weak position, in addition, in recent years, changes in the external environment in which small and medium enterprises are also reflected in： international trade friction increase, RMB such as the increasing appreciation of the exchange rate increase, it raises the cost of export products. Under the new situation, how to find space for development, how to implement e-commerce strategy, clutches the huge growth opportunities given the times, to keep pace with the times, in an invincible position in the competitive market environment, many small and medium enterprises become China＇ s urgent problems.展开更多
基金Project (JPPT-115-5-1759) supported by the National Defense Science and Technology Industry Committee of China Project (20090162120080) supported by Research Fund for the Doctoral Program of Higher Education of ChinaProject (2010FJ3012) supported by the Program of Science and Technology of Hunan Province, China
文摘Multi-walled carbon nanotubes （MWNTs） were wet-milled in the presence of ammonia and cationic surfactant and then used as reinforcements to prepare Ni-P-MWNTs composite coatings by electroless plating. The tribological performances of the composite coatings under dry condition were investigated in comparison with 45 steel and conventional Ni-P coating, Micrographs show that short MWNTs with uniform length and open tips were obtained through the wet-milling process. The results of wear test reveal that the Ni-P-MWNTs composite coatings posses much better friction reduction and anti-wear performances when compared with 45 steel and Ni-P coating. Within the MWNTs content range of 0.74%-1.97%, the friction coefficient and the volume wear rate of the composite coatings decrease gradually and reach the minimum values of 0.08 and 6.22x10-15 m3/（N.m）, respectively. The excellent tribological performances of the composite coatings can be attributed to the introduction of MWNTs, which play both roles of reinforcements and solid lubricant during the wear process.
基金Projects(50534040, 50974117) supported by the National Natural Science Foundation of ChinaProject(20110491489) supported by China Postdoctoral Science FoundationProject(2011QNA03) supported by Fundamental Research Funds for Central Universities, China
文摘In order to obtain the earth pressure coefficient at rest (K0) at higher consolidation pressures during secondary compression, a series of K0 tests for saturated reconstituted clay were conducted. The results indicate that the measured K0 in secondary compression can be described by equations related to internal friction angle, secondary compression coefficient, compression index, recompression index, and sediment time. Effects of consolidation pressures and sediment time on K0 during secondary compression can be attributed to cementation (part of cohesion) increase and internal friction angle decrease. Cementation increase leads to nonlinear variation for K0 and internal friction angle decrease results in increase of K0. K0 computed by equations associated with internal friction angle is overestimated at apparent lower consolidation pressures with different sediment time, which agrees with the measured values well at apparent higher consolidation pressures.
文摘This paper theoretically analyzes the lock-in mechanism of labor division for developing countries when they stick to static comparative advantages and the internal mechanism of cultivating dynamic comparative advantages. Through empirical analysis, this paper finds that China, while sharing the benefits of globalization, showcases the lock-in effect regarding its status in the international labor division chain. The analysis finds that in its participation in globalization, the net barter terms of trade ~BTT） and factorial terms of trade for China are deteriorating, and the income terms of trade are seriously overvalued, resulting in a series of contradictions, such as scanty returns for enterprises, slow income growth, increasing trade frictions, and intensified environmental and resource pressures. The paper analyzes rapidly changing factors in China＇s comparative advantages and characteristics of the changes in industries where China possesses comparative advantages. According to changes in different types of industries at different stages, this paper puts forward suggestions on direction and policies for cultivating dynamic comparative advantages.
文摘Economic globalization is the core of information technology, information technology is the core of e-commerce. E-commerce is as an important part of inlbrnaation technology in recent years when China has been booming. For a large number of SMEs, human resources, capital, technology and information are in a relatively weak position, in addition, in recent years, changes in the external environment in which small and medium enterprises are also reflected in： international trade friction increase, RMB such as the increasing appreciation of the exchange rate increase, it raises the cost of export products. Under the new situation, how to find space for development, how to implement e-commerce strategy, clutches the huge growth opportunities given the times, to keep pace with the times, in an invincible position in the competitive market environment, many small and medium enterprises become China＇ s urgent problems.
