To meet the increasing demand on the quality and co st of precision components for the semiconductor industries, extensive studies on high efficiency and precision machining of ceramic materials have been conducted ov...To meet the increasing demand on the quality and co st of precision components for the semiconductor industries, extensive studies on high efficiency and precision machining of ceramic materials have been conducted over the past several years. It is found that the effects of grinding pressure and rotational speed of spindle in the machining for the ceramic materials are v ery significant on the quality of the grinding process. In order to achieve stab le grinding conditions for improved performance, a new grinding control scheme i n which the grinding pressure is maintained constant throughout the grinding pro cess was carried out in the present study. The surface quality of ground ceramics depends on the mechanism of material remo val in the vertical grinding process. For grinding of Si 3N 4 and glass under the condition of constant pressure, increasing pressure enhances material remova l rate, and at the same time causes more machining-induced microcracks on the g round surfaces. Along with the analysis of tangential forces, specific grinding energy, and the micro observations on ground surfaces, it can be found that low pressure and high wheel speed should be selected to high efficiently remove cera mics in ductile mode in the vertical grinding. From the theoretically analytical and measured grinding temperatures in the vert ical grinding of ceramics, it is found that the analytical temperature profile w ithε= 55% has the same trend with the measured one. The measured temperature is higher that the analytical one at the beginning stage of grinding process, whic h might be contributed to the unstable grinding condition of this stage. The gri nding temperatures in the vertical grinding of ceramics under a constant are not high enough for glassy phase formation, and may not reduce surface fracture as expected. However, the temperature in dry grinding may cause thermal damage to t he resin bond diamond wheel, thereby resulting in low quality workpiece surface.展开更多
Following slack-based inefficiency measurement method and Luenberger productivity index, this paper decomposes industrial environmental TFP index by input factors and output to estimate the sources of China＇s industr...Following slack-based inefficiency measurement method and Luenberger productivity index, this paper decomposes industrial environmental TFP index by input factors and output to estimate the sources of China＇s industrial environmental TFP. Results indicate that （1） China＇s industrial environmental TFP increased between 2001 and 2007 but declined in 2008 under the effect of global financial crisis; （2） input utilization productivity contributes 1/3 to industrial environmental TFP and pollution treatment productivity contributes about 2/3, which means that pollution treatment will effectively increase industrial environmental TFP; （3） capital utilization productivity contributes I/6 to input productivity and labor utilization productivity contributes about 5/6, which means that progress of labor production technologies is an effective means to increase industrial environmental TFP; （4） COD treatment productivity contributes roughly 2/3 to pollution treatment productivity, and S02 treatment productivity contributes about 1/3, which shows that priority on COD treatment will more effectively increase industrial environmental TFP.展开更多
In order to objectively and reasonably evaluate the actual and potential value of cultivated land, both social and ecological values are introduced into the classification and grading index system of cultivated land b...In order to objectively and reasonably evaluate the actual and potential value of cultivated land, both social and ecological values are introduced into the classification and grading index system of cultivated land based on the viewpoint of sustainable development, after considering the natural and economic values of cultivated land. Index system construction of the sustainable utilization of cultivated land should follow the principles of economic viability, social acceptability, and ecological protection. Classification of cultivated land should take into account the soil fertility of cultivated land. Then, grading of cultivated land is carried out from the practical productivity (or potential productivity) of cultivated land. According to the existing classification index system of cultivated land, the soil, natural and environmental factors in plains, mountains and hills are mainly modified in the classification index system of cultivated land. And index systems for the cultivated land classification in plains, mountains and hills are set up. The grading index system of cultivated land is established based on the economic viability (economic value), social acceptability (social value) and protection of cultivated land (ecological value). Quantitative expression of cultivated land grading index is also carried out.展开更多
Copolymerization of ethylene/1-octene was carried out in toluene withvarious concentrations of comonomer in the feed using Et(Ind)_2ZrCl_2/MAO (methyl alu-minoxane) as catalyst. It was found that with the increase of ...Copolymerization of ethylene/1-octene was carried out in toluene withvarious concentrations of comonomer in the feed using Et(Ind)_2ZrCl_2/MAO (methyl alu-minoxane) as catalyst. It was found that with the increase of 1-octene concentration in thefeed the content of 1-octene in the copolymer increases, while the density, melting point,crystallinity and intrinsic viscosity of copolymer decrease. A copolymer with very lowdensity, containing 11.5 mol% of 1-octene (VLLDPE) can be produced with this catalystsystem. The effect of temperature and zirconium aluminum mole ratio of the catalyst onthe copolymerization was also investigated. The results of ^(13)C NMR determination of thecopolymer showed that the 1-octene units in the copolymer are principally isolated.展开更多
Objective:To achieve the effective construction of NICU nursing quality evaluation indes and promote the necessany inprovement of the success rate of treatment of citially ill newborns.Methods:The "structure-proc...Objective:To achieve the effective construction of NICU nursing quality evaluation indes and promote the necessany inprovement of the success rate of treatment of citially ill newborns.Methods:The "structure-process-outcome"mnodel was used to constuct the necessary logical relationship for NICU ursing quality evaluation icators.Then the NICU rursing qality evaluation indeses were initilly establisbed and defined accordingly.After that,the consultation scoring method was used to cary out the two rouds of questionnaire consultation,which was divided,deleted,and modified in the process.The second round of quality assessment indicators for critical neooatal care were used as research results.The establishment of the corresponding judgment matrix and the determination of the weighting relationship of each ervaluation indes were realized Resulis:Forty-eight experts from 12 tertiary care children's hospitals in 9 provinces and cities in China participated in the questiomaire consultation Aifter the work.the resulting quality asessment indicators for crical neonatal care were ageed upo by all the eaperts Sixty-seven quality indicators for cntical neonatal care(18 process indicators)were evaluated based on the Structure Process-Outcome(SPO)model.The necessary definitional work was achieved for the first round of questionnaire comsulations(1 evaluation indicator,19 structural indicators,30 outcome idicators).In the first round of questionnaire consultations,eight evaluation indicators were deleted,one evaluation indicator was split,four ervaluatiom indicators were aded,and four indicators were added.Iwo evaluation indicators were combined In the second round of questiornaine consultation,5 evalunion indicators were removed,resulting in a more complete quality of care for critially ill Dewbons.Conchusion:Based on the"sucuerprces-ouatone"model the 58 indiators for evaluating the quality of tertiary NICU care were fully obtained The unanimous approval of the consaling egets provides a solid foundiation for the later stages oflreatmnent of citically i neonates.展开更多
文摘To meet the increasing demand on the quality and co st of precision components for the semiconductor industries, extensive studies on high efficiency and precision machining of ceramic materials have been conducted over the past several years. It is found that the effects of grinding pressure and rotational speed of spindle in the machining for the ceramic materials are v ery significant on the quality of the grinding process. In order to achieve stab le grinding conditions for improved performance, a new grinding control scheme i n which the grinding pressure is maintained constant throughout the grinding pro cess was carried out in the present study. The surface quality of ground ceramics depends on the mechanism of material remo val in the vertical grinding process. For grinding of Si 3N 4 and glass under the condition of constant pressure, increasing pressure enhances material remova l rate, and at the same time causes more machining-induced microcracks on the g round surfaces. Along with the analysis of tangential forces, specific grinding energy, and the micro observations on ground surfaces, it can be found that low pressure and high wheel speed should be selected to high efficiently remove cera mics in ductile mode in the vertical grinding. From the theoretically analytical and measured grinding temperatures in the vert ical grinding of ceramics, it is found that the analytical temperature profile w ithε= 55% has the same trend with the measured one. The measured temperature is higher that the analytical one at the beginning stage of grinding process, whic h might be contributed to the unstable grinding condition of this stage. The gri nding temperatures in the vertical grinding of ceramics under a constant are not high enough for glassy phase formation, and may not reduce surface fracture as expected. However, the temperature in dry grinding may cause thermal damage to t he resin bond diamond wheel, thereby resulting in low quality workpiece surface.
文摘Following slack-based inefficiency measurement method and Luenberger productivity index, this paper decomposes industrial environmental TFP index by input factors and output to estimate the sources of China＇s industrial environmental TFP. Results indicate that （1） China＇s industrial environmental TFP increased between 2001 and 2007 but declined in 2008 under the effect of global financial crisis; （2） input utilization productivity contributes 1/3 to industrial environmental TFP and pollution treatment productivity contributes about 2/3, which means that pollution treatment will effectively increase industrial environmental TFP; （3） capital utilization productivity contributes I/6 to input productivity and labor utilization productivity contributes about 5/6, which means that progress of labor production technologies is an effective means to increase industrial environmental TFP; （4） COD treatment productivity contributes roughly 2/3 to pollution treatment productivity, and S02 treatment productivity contributes about 1/3, which shows that priority on COD treatment will more effectively increase industrial environmental TFP.
基金Supported by the Key Project of Chinese Ministry of Education ( 108098)the National Natural Science Foundation of China ( 40671078,40771088)the Dangui Plan of Huazhong Normal University
文摘In order to objectively and reasonably evaluate the actual and potential value of cultivated land, both social and ecological values are introduced into the classification and grading index system of cultivated land based on the viewpoint of sustainable development, after considering the natural and economic values of cultivated land. Index system construction of the sustainable utilization of cultivated land should follow the principles of economic viability, social acceptability, and ecological protection. Classification of cultivated land should take into account the soil fertility of cultivated land. Then, grading of cultivated land is carried out from the practical productivity (or potential productivity) of cultivated land. According to the existing classification index system of cultivated land, the soil, natural and environmental factors in plains, mountains and hills are mainly modified in the classification index system of cultivated land. And index systems for the cultivated land classification in plains, mountains and hills are set up. The grading index system of cultivated land is established based on the economic viability (economic value), social acceptability (social value) and protection of cultivated land (ecological value). Quantitative expression of cultivated land grading index is also carried out.
文摘Copolymerization of ethylene/1-octene was carried out in toluene withvarious concentrations of comonomer in the feed using Et(Ind)_2ZrCl_2/MAO (methyl alu-minoxane) as catalyst. It was found that with the increase of 1-octene concentration in thefeed the content of 1-octene in the copolymer increases, while the density, melting point,crystallinity and intrinsic viscosity of copolymer decrease. A copolymer with very lowdensity, containing 11.5 mol% of 1-octene (VLLDPE) can be produced with this catalystsystem. The effect of temperature and zirconium aluminum mole ratio of the catalyst onthe copolymerization was also investigated. The results of ^(13)C NMR determination of thecopolymer showed that the 1-octene units in the copolymer are principally isolated.
文摘Objective:To achieve the effective construction of NICU nursing quality evaluation indes and promote the necessany inprovement of the success rate of treatment of citially ill newborns.Methods:The "structure-process-outcome"mnodel was used to constuct the necessary logical relationship for NICU ursing quality evaluation icators.Then the NICU rursing qality evaluation indeses were initilly establisbed and defined accordingly.After that,the consultation scoring method was used to cary out the two rouds of questionnaire consultation,which was divided,deleted,and modified in the process.The second round of quality assessment indicators for critical neooatal care were used as research results.The establishment of the corresponding judgment matrix and the determination of the weighting relationship of each ervaluation indes were realized Resulis:Forty-eight experts from 12 tertiary care children's hospitals in 9 provinces and cities in China participated in the questiomaire consultation Aifter the work.the resulting quality asessment indicators for crical neonatal care were ageed upo by all the eaperts Sixty-seven quality indicators for cntical neonatal care(18 process indicators)were evaluated based on the Structure Process-Outcome(SPO)model.The necessary definitional work was achieved for the first round of questionnaire comsulations(1 evaluation indicator,19 structural indicators,30 outcome idicators).In the first round of questionnaire consultations,eight evaluation indicators were deleted,one evaluation indicator was split,four ervaluatiom indicators were aded,and four indicators were added.Iwo evaluation indicators were combined In the second round of questiornaine consultation,5 evalunion indicators were removed,resulting in a more complete quality of care for critially ill Dewbons.Conchusion:Based on the"sucuerprces-ouatone"model the 58 indiators for evaluating the quality of tertiary NICU care were fully obtained The unanimous approval of the consaling egets provides a solid foundiation for the later stages oflreatmnent of citically i neonates.
