AIM:To provide a specifi c review and meta-analysis of the available evidence for continuous wound infusion of local anaesthetic agents following midline laparoto-my for major colorectal surgery. METHODS: Medline, Emb...AIM:To provide a specifi c review and meta-analysis of the available evidence for continuous wound infusion of local anaesthetic agents following midline laparoto-my for major colorectal surgery. METHODS: Medline, Embase, trial registries, conference proceedings and article reference lists were searched to identify randomised, controlled trials of continuous wound infusion of local anaesthetic agents following colorectal surgery. The primary outcomes were opioid consumption, pain visual analogue scores (VASs), return to bowel function and length of hospital stay. Weighted mean difference were calculated for continuous outcomes. RESULTS: Five trials containing 542 laparotomy wounds were eligible for inclusion. There was a sig- nificant decrease in post-operative pain VAS at rest on day 3 (weighted mean difference: -0.43; 95% CI: -0.81 to -0.04; P = 0.03) but not on post-operative day 1 and 2. Local anaesthetic infusion was associated with a signifi cant reduction in pain VAS on movement on all three post-operative days (day 1 weighted mean difference: -1.14; 95% CI: -2.24 to -0.041; P = 0.04, day 2 weighted mean difference: -0.97, 95% CI: -1.91to -0.029; P = 0.04, day 3 weighted mean difference: -0.61; 95% CI: 1.01 to -0.20; P = 0.0038). Local an- aesthetic wound infusion was associated with a signifi - cant decrease in total opioid consumption (weighted mean difference: -40.13; 95% CI: -76.74 to -3.53; P = 0.03). There was no signifi cant decrease in length of stay (weighted mean difference: -20.87; 95% CI: -46.96 to 5.21; P = 0.12) or return of bowel function (weighted mean difference: -9.40; 95% CI: -33.98 to 15.17; P = 0.45). CONCLUSION: The results of this systematic re- view and meta-analysis suggest that local anaesthetic wound infusion following laparotomy for major color- ectal surgery is a promising technique but do not pro- vide conclusive evidence of benefi t. Further research is required including cost-effectiveness analysis.展开更多
This paper attempts to analyze geothermy revealed by the sounding data at 8 h and 20 h every day from China Meteorological Administration and the data counted per minute such as the wellhead temperature,the electromag...This paper attempts to analyze geothermy revealed by the sounding data at 8 h and 20 h every day from China Meteorological Administration and the data counted per minute such as the wellhead temperature,the electromagnetic disturbance,the ground tilt and so of water level instrument in Sanxing of Chengdu with the method of information digitization.The result shows the recognizable differentiation of the change process before and after the earthquake,provides an analytic method for the improvement of earthquake prediction or prevention,and shows the feasible further research and the wide application prospect.展开更多
Over the past two decades, numerous ports located in China have participated in port integration strategies, thus influencing the entire port system. The current research is initiated in order to examine the nature of...Over the past two decades, numerous ports located in China have participated in port integration strategies, thus influencing the entire port system. The current research is initiated in order to examine the nature of port integration in China, including associated temporal pathways, spatial patterns and dynamics. Results indicate that port integration in China has been characterized by a significant increase at the turn of the 21 st century, comprising thirteen distinguishable pathways typified by differing dynamics, particularly between the northern and southern ports. Pathways were found to include 44 seaports and river ports, chiefly concentrated in the Bohai Rim, Yangtze(Changjiang) River Delta, Beibu Gulf and the southeastern Fujian, thus representing significant spatial regions. Categorically larger seaports have become the primary beneficiaries of port integration. Integration cases were divided into four categories based upon quantified dynamic magnitude including the government-driven mode, market-driven mode, government/market-driven mode and strategic alliance, and into five further categories based upon spatial extent including port internal integration, jurisdictional port integration, port integration across neighbor region, regional port integration and hub-feeder port integration. Results suggest that several factors have effectively driven port integration in China, including legislative tools and spatial planning, optimization of shoreline resources and port functionality, and port competition with the same hinterland.展开更多
This paper discussed the stability of model of an age structured population systems,proved that the equilibrium solution systems is globally asymptotically stable.
The spatial distribution of urban population can reflect significantly urban functions and development status. Shenyang, as a typical old industrial city in China, has experienced considerable changes in spatial distr...The spatial distribution of urban population can reflect significantly urban functions and development status. Shenyang, as a typical old industrial city in China, has experienced considerable changes in spatial distribution of population in the process of urban transformation, resulting in the change of urban spatial structure. Based on the sub-district data of Chinese national population censuses in 1982, 1990 and 2000, this study simulates the evolution pattern of spatial distribution of urban population in Shenyang City. Using statistical method and exploratory spatial data analysis (ESDA), we found that the population distribution, on the whole, has presented a balanced and decentralized trend since the 1980s, which characterizes with Chinese suburbanization. Furthermore, based on the investigation of the pattern of population distribution, it is concluded that the negative exponential model fitted the distribution best, and population concentration in the inner suburb kept increasing gradually, meanwhile, the spatial structure of population distribution has presented a polycentric feature since the 1980s. The parameters of the model show that population in the urban core concentrate significantly all the time. The increase of population in the inner suburb influences the population distribution pattern more and more importantly, but the concentration intensity of population cores in inner suburb is still low.展开更多
Objective: This study was done to compare between the effect of preoperative radiotherapy and postoperative radiotherapy in treatment of resectable rectal carcinoma. The primary endpoints are local recurrence rate, o...Objective: This study was done to compare between the effect of preoperative radiotherapy and postoperative radiotherapy in treatment of resectable rectal carcinoma. The primary endpoints are local recurrence rate, overall survival (OS) and disease free survival (DFS). The secondary endpoints are to evaluate down-staging, treatment toxicity, and ability to do sphincter preservation, aiming at choosing the optimal treatment modality. Methods: This study included 100 patients with resectable rectal carcinoma who presented to Surgical Gastro Entrology Center and Clinical Oncology and Nuclear Medicine Department, Mansoura University during the period between January 2007 and September 2009. The included patients were randomized in two groups; group h 50 patients received preoperative radiotherapy and group Ih 50 patients received post- operative radiotherapy. Concurrent 5-fluorouracil-based chemotherapy was given to all patients. Two major types of surgery were done: abdomino-perineal resection with a permanent colostomy and low anterior resection with colorectal or coloanal anastomosis. Results: Preoperative radiotherapy resulted in pathologic complete response in 3 patients. T down-staging occurred in 18 out of 50 patients (36%) with statistically significant difference (P = 0.008). N down-staging occurred in 10 out of 24 patients. Sphincter preservation was more in group I. Delayed wound healing was the most common postoperative complication in group I with no significant difference. After a median follow up of 18 months, local recurrence rate and distant metastasis were higher in group I1. The 2-year disease free survival was 72% and 60% in group I and II respectively with no statistically significant difference between both groups. Conclusion: This study concluded that preoperative radiotherapy is better than postoperative radiotherapy as regard local control, sphincter preservation with higher disease free survival and overall survival. No difference in treatment toxicity between both groups.展开更多
Urbanization process to change the pattern of population distribution in rural areas to strengthen the flow of farmers in the city and rural areas; national industrial structural adjustment, the gradual decline in per...Urbanization process to change the pattern of population distribution in rural areas to strengthen the flow of farmers in the city and rural areas; national industrial structural adjustment, the gradual decline in per capital income of farmers; yearly increase in medical costs, making the farmers a serious shortage of personal medical capacity, Disease caused by poverty, due to illness back to poverty "phenomenon is obvious. Based on the historical background of the development of rural medical security, based on the perspective of "supply" of modem medical service, this paper analyzes the economic factors and policies of the farmers' "difficult to see medical treatment", and the data analysis is carried out according to the latest social data. Factors, and put forward the corresponding improvement measures.展开更多
Port of Igoumenitsa in Greece is one of the most important Ports in European Union and enjoys a privileged position being located at the starting point of Egnatia Motorway The Port is one of the largest passenger port...Port of Igoumenitsa in Greece is one of the most important Ports in European Union and enjoys a privileged position being located at the starting point of Egnatia Motorway The Port is one of the largest passenger ports in the East Mediterranean Sea basin, which, handles around 1,000,000 passengers per year for international destinations. The paper investigates current waste management and disposal options for ship generated waste and the associated impact of the waste for port. Data about the ship traffic were provided by the Port Authority and about the amount and characteristics of the wastes by the contractors for the disposal of the ship generated waste. It was concluded that all vessels should be encouraged to use the reception facilities and should pursue a waste reduction strategy and the port authority to provide adequate recycling facility. An electronic recording data system has to be adopted for better evaluation of the performance of the system. This system must record the deliveries for every ship in the port, the amount and the type of wastes are generated. Also must provide information about the maximum storage capacity of waste on board and about management of waste treatment options by the ships.展开更多
Existing quantitative migration studies are mainly at the inter-region or inter-province level for lacking of detailed geo-referenced migration data.Meanwhile,few of them integrate explorative spatial data analysis an...Existing quantitative migration studies are mainly at the inter-region or inter-province level for lacking of detailed geo-referenced migration data.Meanwhile,few of them integrate explorative spatial data analysis and spatial regression model into migration analysis.Based on aggregated registered floating population data from 2005 to 2008,the phenomena that population floating to Yiwu City in Zhejiang Province is analyzed at the provincial and county levels.The spatial layout of Yiwu's pull forces is proved as a V-shaped pattern excluding Sichuan Province based on map visualization method.Using the migration ratio in 2007 as an explanatory variable,two models are compared using ordinary least square,spatial error model and spatial lag model methods for county-level data in Jiangxi and Anhui provinces.The model with migration stock provides an improved fitting over the model without migration stock according to the model fitting results.The floating population flocking into Yiwu City from Jiangxi is determined mostly by migration stock while the determinant factors are migration stock and distance to Yiwu City for Anhui.The distance-decay effect is true for migration flow from Anhui to Yiwu City while the distance rule is not confirmed in Jiangxi with the best fitting model.The correlation between per capita net income of rural labor forces and migration ratio is not significant in Jiangxi and significant but at the 0.1 level only in Anhui.Further analysis shows that the distance,income and man-land ratio are important factors to explain population floating at earlier stage.However,as the dynamic population floating process evolves,the determinant factor would be migration stock.展开更多
The pioneer technical policy carried out by Federal State Institution "Novorossiysk Maritime Port Administration" in mutual cooperation with the Southern Scientific Centre of Russian Academy of Sciences on control a...The pioneer technical policy carried out by Federal State Institution "Novorossiysk Maritime Port Administration" in mutual cooperation with the Southern Scientific Centre of Russian Academy of Sciences on control and management of ballast waters and ecosystem monitoring of marine environment in areas of ballast water discharge provides the task of complex approach for minimization of risk of introduction of biologically negative invaders by marine transport and preservation of biodiversity of the Black Sea.展开更多
On January 19,National Bureau of Statistics announced that births in 2015 were 16.55 million,a slight drop of 320 000 compared to 2014.How should we consider the reduction of births after implementation of the selecti...On January 19,National Bureau of Statistics announced that births in 2015 were 16.55 million,a slight drop of 320 000 compared to 2014.How should we consider the reduction of births after implementation of the selective two-child policy?展开更多
Based on the population and economic data of the Wumeng Mountain Area from 2000 to 2020,this study explored the imbalanced spatiotemporal patterns of population and economy in the area using methods such as the geogra...Based on the population and economic data of the Wumeng Mountain Area from 2000 to 2020,this study explored the imbalanced spatiotemporal patterns of population and economy in the area using methods such as the geographic concentration,gravity model,imbalance index,and inconsistency index.The study also analyzed the influencing factors using geodetectors and spatiotemporal geographically weighted regression models.The results show four key aspects of this phenomenon.(1)The spatial distributions of the population and economic geographic concentrations deviate from their ideal distributions.The population distribution shows a spatial pattern of being higher in the northeast and lower in the southwest,while the economic distribution shows a spatial pattern of being higher in the south and lower in the north.(2)The population and economic gravity centers have shifted toward the northeast and south relative to the geometric center of the mountain area,respectively,and the economic center has shifted more than the population center.(3)The degree of imbalance between the population and economic distributions is decreasing,but regional development disparities still exist.The region with inconsistent spatial distributions between population and economy remains stable,showing a"north high,south low"pattern,with an increase in the number of counties dominated by the economy and reductions in the numbers of counties in other categories.(4)Economic power,social consumption level,industrial structure,urban development level,government regulation capacity,and health care infrastructure are the main factors affecting the inconsistent distributions of population and economy in Wumeng Mountain Area,and the effects of these factors are reflected in the promotion of economic development.展开更多
The "Hu Line" has been regarded as one of the greatest geographical discoveries in China because it reveals the significant spatial relationship between human activity and natural environment. The spatial ev...The "Hu Line" has been regarded as one of the greatest geographical discoveries in China because it reveals the significant spatial relationship between human activity and natural environment. The spatial evolution of population on both sides of the "Hu Line" has had important implications for both urbanization and regional development and has attracted widespread attention during the dramatic economic and social changes since the implementation of reform and opening-up policy in China in 1978. Using Geographical Information System(GIS) techniques, this paper studied the stability of the "Hu Line" and the spatial patterns of population growth on each side by constructing a spatial database of China's census data from 1982 to 2010. The findings are as follows:(1) In the last 30 years, the "Hu Line" has remained relatively stable, but a new tendency of population change has begun to emerge. The population ratio either side, namely, the southeast half(SEH) and the northwest half(NWH), of the "Hu Line" remains at roughly 94:6(SHE : NWH). Noteworthy, the proportion of population in the SEH of the "Hu Line" has been decreasing slightly, while that in the NWH has been increasing slightly, as the latter has benefited from its higher rate of natural population growth.(2) The spatial patterns of population growth on both sides of the "Hu Line" were quite different. The degree of population concentration in the SEH increased faster than the NWH. Regions with a negative population growth rate have rapidly expanded; these were mainly located in the south of the "Qinling Mountains-Huaihe River belt" and northeastern China. Meanwhile, regions with a fast population growth rate were mainly concentrated in the Yangtze River Delta, the Pearl River Delta, and the Beijing-Tianjin metropolitan area. Thus, the spatial pattern of population growth in the SEH presented a concentration pattern that could be called "Matthew effect pattern".(3) The spatial pattern of population growth in the NWH could be regarded as the "Relative Balance pattern." In the NWH, the population growth rate was positive and the degree of population concentration was very low. There were many minority populations located in the NWH that usually lived in a dispersed pattern but had a higher rate of natural population growth due to the preferential population policy. There were also some regions with a negative rate of population growth in the NWH, which were mainly located close to the "Hu Line" and the Ancient Silk Road.(4) In the future, the spatial patterns of population growth on both sides of the "Hu Line" may continue to evolve. For the SEH, the capacity to attract more people to small and medium-sized cities and towns should be enhanced. For the NWH, the emphasis should be placed on promoting urbanization and enhancing population agglomeration in its major cities.展开更多
Wavelet denoising is an effective approach to extract fault features from strong background noise.It has been widely used in mechanical fault detection and shown excellent performance.However,traditional thresholds ar...Wavelet denoising is an effective approach to extract fault features from strong background noise.It has been widely used in mechanical fault detection and shown excellent performance.However,traditional thresholds are not suitable for nonstationary signal denoising because they set universal thresholds for different wavelet coefficients.Therefore,a data-driven threshold strategy is proposed in this paper.First,the signal is decomposed into different subbands by wavelet transformation.Then a data-driven threshold is derived by estimating the noise power spectral density in different subbands.Since the data-driven threshold is dependent on the noise estimation and adapted to data,it is more robust and accurate for denoising than traditional thresholds.Meanwhile,sliding window method is adopted to set a flexible local threshold.When this method was applied to simulation signal and an inner race fault diagnostic case of dedusting fan bearing,the proposed method has good result and provides valuable advantages over traditional methods in the fault detection of rotating machines.展开更多
A three-dimensional (3D) numerical model is established and validated for cooling performance optimization between a high-level water collecting natural draft wet cooling tower (HNDWCT) and a usual natural draft w...A three-dimensional (3D) numerical model is established and validated for cooling performance optimization between a high-level water collecting natural draft wet cooling tower (HNDWCT) and a usual natural draft wet cooling tower (UNDWCT) under the actual operation condition at Wanzhou power plant, Chongqing, China. User defined functions (UDFs) of source terms are composed and loaded into the spray, fill and rain zones. Consider- ing the conditions of impact on three kinds of corrugated fills (Double-oblique wave, Two-way wave and S wave) and four kinds of fill height (1.25 m, 1.5 m, 1.75 m and 2 In), numerical simulation of cooling performance are analysed. The results demonstrate that the S wave has the highest cooling efficiency in three fills for both towers, indicating that fill characteristics arc crucial to cooling performance. Moreover, the cooling performance of the HNDWCT is far superior to that of the UNDWCT with fill height increases of 1.75 m and above, because the air mass flow rate in the fill zone of the HNDWCT improves more than that in the UNDWCT, as a result of the rain zone resistance declining sharply for the HNDWCT. In addition, the mass and heat transfer capacity of the HNDWCT is better in the tower centre zone than in the outer zone near the tower wall under a uniform fill layout. This behaviour is inverted for the UNDWCT, perhaps because the high-level collection devices play the role of flow guiding in the inner zone. Therefore, when non-uniform fill layout optimization is applied to the HNDWCT, the inner zone increases in height from 1.75 m to 2 m, the outer zone reduces in height from 1.75 m to 1.5 m, and the outlet water temperature declines approximately 0.4 K compared to that of the uniform layout.展开更多
Objective: To investigate the effect of anti-infective reconstituted bone xenograft as a primary graft to repair a segmental with severe contamination. Methods: A canine model of contaminated defect of 1.5 cm in size ...Objective: To investigate the effect of anti-infective reconstituted bone xenograft as a primary graft to repair a segmental with severe contamination. Methods: A canine model of contaminated defect of 1.5 cm in size in the radius was used, in which anti-infective reconstituted bone xenograft or reconstituted bone xenograft was implanted as a primary graft followed by internal fixation. The effectiveness of the two grafting materials in repairing a contaminated segmental defect was compared. Results: The animals which had received implant of anti-infective reconstituted bone xenograft should largely healed defects 6 months after operation while the defects implanted with reconstituted bone xenograft remained unrepaired with bone infection. Conclusions: Besides its strong osteoinductive and osteoconductive activity, anti-infective reconstituted bone xenograft is highly antibacterial and can be used as a primary graft to repair the severely contaminated segmental defect.展开更多
文摘AIM:To provide a specifi c review and meta-analysis of the available evidence for continuous wound infusion of local anaesthetic agents following midline laparoto-my for major colorectal surgery. METHODS: Medline, Embase, trial registries, conference proceedings and article reference lists were searched to identify randomised, controlled trials of continuous wound infusion of local anaesthetic agents following colorectal surgery. The primary outcomes were opioid consumption, pain visual analogue scores (VASs), return to bowel function and length of hospital stay. Weighted mean difference were calculated for continuous outcomes. RESULTS: Five trials containing 542 laparotomy wounds were eligible for inclusion. There was a sig- nificant decrease in post-operative pain VAS at rest on day 3 (weighted mean difference: -0.43; 95% CI: -0.81 to -0.04; P = 0.03) but not on post-operative day 1 and 2. Local anaesthetic infusion was associated with a signifi cant reduction in pain VAS on movement on all three post-operative days (day 1 weighted mean difference: -1.14; 95% CI: -2.24 to -0.041; P = 0.04, day 2 weighted mean difference: -0.97, 95% CI: -1.91to -0.029; P = 0.04, day 3 weighted mean difference: -0.61; 95% CI: 1.01 to -0.20; P = 0.0038). Local an- aesthetic wound infusion was associated with a signifi - cant decrease in total opioid consumption (weighted mean difference: -40.13; 95% CI: -76.74 to -3.53; P = 0.03). There was no signifi cant decrease in length of stay (weighted mean difference: -20.87; 95% CI: -46.96 to 5.21; P = 0.12) or return of bowel function (weighted mean difference: -9.40; 95% CI: -33.98 to 15.17; P = 0.45). CONCLUSION: The results of this systematic re- view and meta-analysis suggest that local anaesthetic wound infusion following laparotomy for major color- ectal surgery is a promising technique but do not pro- vide conclusive evidence of benefi t. Further research is required including cost-effectiveness analysis.
文摘This paper attempts to analyze geothermy revealed by the sounding data at 8 h and 20 h every day from China Meteorological Administration and the data counted per minute such as the wellhead temperature,the electromagnetic disturbance,the ground tilt and so of water level instrument in Sanxing of Chengdu with the method of information digitization.The result shows the recognizable differentiation of the change process before and after the earthquake,provides an analytic method for the improvement of earthquake prediction or prevention,and shows the feasible further research and the wide application prospect.
基金Under the auspices of National Natural Science Foundation of China(No.41171108)Key Program of Chinese Academy of Sciences(No.KZZD-EW-06-02)Exploratory Forefront Project for the Strategic Science Plan in IGSNRR,CAS(No.2012QY004)
文摘Over the past two decades, numerous ports located in China have participated in port integration strategies, thus influencing the entire port system. The current research is initiated in order to examine the nature of port integration in China, including associated temporal pathways, spatial patterns and dynamics. Results indicate that port integration in China has been characterized by a significant increase at the turn of the 21 st century, comprising thirteen distinguishable pathways typified by differing dynamics, particularly between the northern and southern ports. Pathways were found to include 44 seaports and river ports, chiefly concentrated in the Bohai Rim, Yangtze(Changjiang) River Delta, Beibu Gulf and the southeastern Fujian, thus representing significant spatial regions. Categorically larger seaports have become the primary beneficiaries of port integration. Integration cases were divided into four categories based upon quantified dynamic magnitude including the government-driven mode, market-driven mode, government/market-driven mode and strategic alliance, and into five further categories based upon spatial extent including port internal integration, jurisdictional port integration, port integration across neighbor region, regional port integration and hub-feeder port integration. Results suggest that several factors have effectively driven port integration in China, including legislative tools and spatial planning, optimization of shoreline resources and port functionality, and port competition with the same hinterland.
文摘This paper discussed the stability of model of an age structured population systems,proved that the equilibrium solution systems is globally asymptotically stable.
基金Under the auspices of Knowledge Innovation Programs of Chinese Academy of Sciences (No. KZCX2-YW-342, KZCX2-YW-321-04)National Natural Science Foundation of China (No. 40635030)
文摘The spatial distribution of urban population can reflect significantly urban functions and development status. Shenyang, as a typical old industrial city in China, has experienced considerable changes in spatial distribution of population in the process of urban transformation, resulting in the change of urban spatial structure. Based on the sub-district data of Chinese national population censuses in 1982, 1990 and 2000, this study simulates the evolution pattern of spatial distribution of urban population in Shenyang City. Using statistical method and exploratory spatial data analysis (ESDA), we found that the population distribution, on the whole, has presented a balanced and decentralized trend since the 1980s, which characterizes with Chinese suburbanization. Furthermore, based on the investigation of the pattern of population distribution, it is concluded that the negative exponential model fitted the distribution best, and population concentration in the inner suburb kept increasing gradually, meanwhile, the spatial structure of population distribution has presented a polycentric feature since the 1980s. The parameters of the model show that population in the urban core concentrate significantly all the time. The increase of population in the inner suburb influences the population distribution pattern more and more importantly, but the concentration intensity of population cores in inner suburb is still low.
文摘Objective: This study was done to compare between the effect of preoperative radiotherapy and postoperative radiotherapy in treatment of resectable rectal carcinoma. The primary endpoints are local recurrence rate, overall survival (OS) and disease free survival (DFS). The secondary endpoints are to evaluate down-staging, treatment toxicity, and ability to do sphincter preservation, aiming at choosing the optimal treatment modality. Methods: This study included 100 patients with resectable rectal carcinoma who presented to Surgical Gastro Entrology Center and Clinical Oncology and Nuclear Medicine Department, Mansoura University during the period between January 2007 and September 2009. The included patients were randomized in two groups; group h 50 patients received preoperative radiotherapy and group Ih 50 patients received post- operative radiotherapy. Concurrent 5-fluorouracil-based chemotherapy was given to all patients. Two major types of surgery were done: abdomino-perineal resection with a permanent colostomy and low anterior resection with colorectal or coloanal anastomosis. Results: Preoperative radiotherapy resulted in pathologic complete response in 3 patients. T down-staging occurred in 18 out of 50 patients (36%) with statistically significant difference (P = 0.008). N down-staging occurred in 10 out of 24 patients. Sphincter preservation was more in group I. Delayed wound healing was the most common postoperative complication in group I with no significant difference. After a median follow up of 18 months, local recurrence rate and distant metastasis were higher in group I1. The 2-year disease free survival was 72% and 60% in group I and II respectively with no statistically significant difference between both groups. Conclusion: This study concluded that preoperative radiotherapy is better than postoperative radiotherapy as regard local control, sphincter preservation with higher disease free survival and overall survival. No difference in treatment toxicity between both groups.
文摘Urbanization process to change the pattern of population distribution in rural areas to strengthen the flow of farmers in the city and rural areas; national industrial structural adjustment, the gradual decline in per capital income of farmers; yearly increase in medical costs, making the farmers a serious shortage of personal medical capacity, Disease caused by poverty, due to illness back to poverty "phenomenon is obvious. Based on the historical background of the development of rural medical security, based on the perspective of "supply" of modem medical service, this paper analyzes the economic factors and policies of the farmers' "difficult to see medical treatment", and the data analysis is carried out according to the latest social data. Factors, and put forward the corresponding improvement measures.
文摘Port of Igoumenitsa in Greece is one of the most important Ports in European Union and enjoys a privileged position being located at the starting point of Egnatia Motorway The Port is one of the largest passenger ports in the East Mediterranean Sea basin, which, handles around 1,000,000 passengers per year for international destinations. The paper investigates current waste management and disposal options for ship generated waste and the associated impact of the waste for port. Data about the ship traffic were provided by the Port Authority and about the amount and characteristics of the wastes by the contractors for the disposal of the ship generated waste. It was concluded that all vessels should be encouraged to use the reception facilities and should pursue a waste reduction strategy and the port authority to provide adequate recycling facility. An electronic recording data system has to be adopted for better evaluation of the performance of the system. This system must record the deliveries for every ship in the port, the amount and the type of wastes are generated. Also must provide information about the maximum storage capacity of waste on board and about management of waste treatment options by the ships.
基金Under the auspices of National Natural Science Foundation of China(No.41001314)Youth Science Funds of State Key Laboratory of Resources and Environmental Information System,Chinese Academy of Sciences(No.KA11040101)National Key Technology R&D Program of China(No.2012BAI32B07)
文摘Existing quantitative migration studies are mainly at the inter-region or inter-province level for lacking of detailed geo-referenced migration data.Meanwhile,few of them integrate explorative spatial data analysis and spatial regression model into migration analysis.Based on aggregated registered floating population data from 2005 to 2008,the phenomena that population floating to Yiwu City in Zhejiang Province is analyzed at the provincial and county levels.The spatial layout of Yiwu's pull forces is proved as a V-shaped pattern excluding Sichuan Province based on map visualization method.Using the migration ratio in 2007 as an explanatory variable,two models are compared using ordinary least square,spatial error model and spatial lag model methods for county-level data in Jiangxi and Anhui provinces.The model with migration stock provides an improved fitting over the model without migration stock according to the model fitting results.The floating population flocking into Yiwu City from Jiangxi is determined mostly by migration stock while the determinant factors are migration stock and distance to Yiwu City for Anhui.The distance-decay effect is true for migration flow from Anhui to Yiwu City while the distance rule is not confirmed in Jiangxi with the best fitting model.The correlation between per capita net income of rural labor forces and migration ratio is not significant in Jiangxi and significant but at the 0.1 level only in Anhui.Further analysis shows that the distance,income and man-land ratio are important factors to explain population floating at earlier stage.However,as the dynamic population floating process evolves,the determinant factor would be migration stock.
文摘The pioneer technical policy carried out by Federal State Institution "Novorossiysk Maritime Port Administration" in mutual cooperation with the Southern Scientific Centre of Russian Academy of Sciences on control and management of ballast waters and ecosystem monitoring of marine environment in areas of ballast water discharge provides the task of complex approach for minimization of risk of introduction of biologically negative invaders by marine transport and preservation of biodiversity of the Black Sea.
文摘On January 19,National Bureau of Statistics announced that births in 2015 were 16.55 million,a slight drop of 320 000 compared to 2014.How should we consider the reduction of births after implementation of the selective two-child policy?
基金The National Natural Science Foundation Project(41261039).
文摘Based on the population and economic data of the Wumeng Mountain Area from 2000 to 2020,this study explored the imbalanced spatiotemporal patterns of population and economy in the area using methods such as the geographic concentration,gravity model,imbalance index,and inconsistency index.The study also analyzed the influencing factors using geodetectors and spatiotemporal geographically weighted regression models.The results show four key aspects of this phenomenon.(1)The spatial distributions of the population and economic geographic concentrations deviate from their ideal distributions.The population distribution shows a spatial pattern of being higher in the northeast and lower in the southwest,while the economic distribution shows a spatial pattern of being higher in the south and lower in the north.(2)The population and economic gravity centers have shifted toward the northeast and south relative to the geometric center of the mountain area,respectively,and the economic center has shifted more than the population center.(3)The degree of imbalance between the population and economic distributions is decreasing,but regional development disparities still exist.The region with inconsistent spatial distributions between population and economy remains stable,showing a"north high,south low"pattern,with an increase in the number of counties dominated by the economy and reductions in the numbers of counties in other categories.(4)Economic power,social consumption level,industrial structure,urban development level,government regulation capacity,and health care infrastructure are the main factors affecting the inconsistent distributions of population and economy in Wumeng Mountain Area,and the effects of these factors are reflected in the promotion of economic development.
基金National Natural Science Foundation of China,No.41271174Key Project of National Natural Science Foundation of China,No.71433008
文摘The "Hu Line" has been regarded as one of the greatest geographical discoveries in China because it reveals the significant spatial relationship between human activity and natural environment. The spatial evolution of population on both sides of the "Hu Line" has had important implications for both urbanization and regional development and has attracted widespread attention during the dramatic economic and social changes since the implementation of reform and opening-up policy in China in 1978. Using Geographical Information System(GIS) techniques, this paper studied the stability of the "Hu Line" and the spatial patterns of population growth on each side by constructing a spatial database of China's census data from 1982 to 2010. The findings are as follows:(1) In the last 30 years, the "Hu Line" has remained relatively stable, but a new tendency of population change has begun to emerge. The population ratio either side, namely, the southeast half(SEH) and the northwest half(NWH), of the "Hu Line" remains at roughly 94:6(SHE : NWH). Noteworthy, the proportion of population in the SEH of the "Hu Line" has been decreasing slightly, while that in the NWH has been increasing slightly, as the latter has benefited from its higher rate of natural population growth.(2) The spatial patterns of population growth on both sides of the "Hu Line" were quite different. The degree of population concentration in the SEH increased faster than the NWH. Regions with a negative population growth rate have rapidly expanded; these were mainly located in the south of the "Qinling Mountains-Huaihe River belt" and northeastern China. Meanwhile, regions with a fast population growth rate were mainly concentrated in the Yangtze River Delta, the Pearl River Delta, and the Beijing-Tianjin metropolitan area. Thus, the spatial pattern of population growth in the SEH presented a concentration pattern that could be called "Matthew effect pattern".(3) The spatial pattern of population growth in the NWH could be regarded as the "Relative Balance pattern." In the NWH, the population growth rate was positive and the degree of population concentration was very low. There were many minority populations located in the NWH that usually lived in a dispersed pattern but had a higher rate of natural population growth due to the preferential population policy. There were also some regions with a negative rate of population growth in the NWH, which were mainly located close to the "Hu Line" and the Ancient Silk Road.(4) In the future, the spatial patterns of population growth on both sides of the "Hu Line" may continue to evolve. For the SEH, the capacity to attract more people to small and medium-sized cities and towns should be enhanced. For the NWH, the emphasis should be placed on promoting urbanization and enhancing population agglomeration in its major cities.
基金supported by the National Natural Science Foundation of China(Grant No.51275384)the Key project of National Natural Science Foundation of China(Grant No.51035007)+1 种基金the National Basic Research Program of China("973"Project)(Grant No.2011CB706805)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant No.20110201130001)
文摘Wavelet denoising is an effective approach to extract fault features from strong background noise.It has been widely used in mechanical fault detection and shown excellent performance.However,traditional thresholds are not suitable for nonstationary signal denoising because they set universal thresholds for different wavelet coefficients.Therefore,a data-driven threshold strategy is proposed in this paper.First,the signal is decomposed into different subbands by wavelet transformation.Then a data-driven threshold is derived by estimating the noise power spectral density in different subbands.Since the data-driven threshold is dependent on the noise estimation and adapted to data,it is more robust and accurate for denoising than traditional thresholds.Meanwhile,sliding window method is adopted to set a flexible local threshold.When this method was applied to simulation signal and an inner race fault diagnostic case of dedusting fan bearing,the proposed method has good result and provides valuable advantages over traditional methods in the fault detection of rotating machines.
基金financially supported by the National Major Projects of China(Grant No.2014ZX07406002-2)
文摘A three-dimensional (3D) numerical model is established and validated for cooling performance optimization between a high-level water collecting natural draft wet cooling tower (HNDWCT) and a usual natural draft wet cooling tower (UNDWCT) under the actual operation condition at Wanzhou power plant, Chongqing, China. User defined functions (UDFs) of source terms are composed and loaded into the spray, fill and rain zones. Consider- ing the conditions of impact on three kinds of corrugated fills (Double-oblique wave, Two-way wave and S wave) and four kinds of fill height (1.25 m, 1.5 m, 1.75 m and 2 In), numerical simulation of cooling performance are analysed. The results demonstrate that the S wave has the highest cooling efficiency in three fills for both towers, indicating that fill characteristics arc crucial to cooling performance. Moreover, the cooling performance of the HNDWCT is far superior to that of the UNDWCT with fill height increases of 1.75 m and above, because the air mass flow rate in the fill zone of the HNDWCT improves more than that in the UNDWCT, as a result of the rain zone resistance declining sharply for the HNDWCT. In addition, the mass and heat transfer capacity of the HNDWCT is better in the tower centre zone than in the outer zone near the tower wall under a uniform fill layout. This behaviour is inverted for the UNDWCT, perhaps because the high-level collection devices play the role of flow guiding in the inner zone. Therefore, when non-uniform fill layout optimization is applied to the HNDWCT, the inner zone increases in height from 1.75 m to 2 m, the outer zone reduces in height from 1.75 m to 1.5 m, and the outlet water temperature declines approximately 0.4 K compared to that of the uniform layout.
基金ThisarticleissupportedbytheappointedresearchfundsofthePLA (No .96L0 5 2 ) .
文摘Objective: To investigate the effect of anti-infective reconstituted bone xenograft as a primary graft to repair a segmental with severe contamination. Methods: A canine model of contaminated defect of 1.5 cm in size in the radius was used, in which anti-infective reconstituted bone xenograft or reconstituted bone xenograft was implanted as a primary graft followed by internal fixation. The effectiveness of the two grafting materials in repairing a contaminated segmental defect was compared. Results: The animals which had received implant of anti-infective reconstituted bone xenograft should largely healed defects 6 months after operation while the defects implanted with reconstituted bone xenograft remained unrepaired with bone infection. Conclusions: Besides its strong osteoinductive and osteoconductive activity, anti-infective reconstituted bone xenograft is highly antibacterial and can be used as a primary graft to repair the severely contaminated segmental defect.