China is one of the world’s major agricultural countries. About 80% of its annual water consumption is used for fanning undertakings. On the other hand, China is a country deficient in water resources and in particul...China is one of the world’s major agricultural countries. About 80% of its annual water consumption is used for fanning undertakings. On the other hand, China is a country deficient in water resources and in particular, the water shortage is embarrassingly serious in the north. So the current development of water-saving agriculture (WSA) is a way of easing the strain between the supply and demand of water. This article expounds the WSA’s status in the development of the national economy, its research and implementation, and suggests an institutional system of WSA to be established in this country.展开更多
With the deepening of economic globalization and increasingly fierce competition of trade liberalization in WTO member countries,the effect of traditional trade protection measures is gradually weakening or even remov...With the deepening of economic globalization and increasingly fierce competition of trade liberalization in WTO member countries,the effect of traditional trade protection measures is gradually weakening or even removed. In recent years,Technical Barriers to Trade( TBT)as a category of nontariff barriers to trade,are the widely divergent measures that countries use to regulate markets,protect their consumers,or preserve their natural resources( among other objectives),but they also can be used( or perceived by foreign countries) to discriminate against imports in order to protect domestic industries. These directly or indirectly lead to gradual rise of trade friction of China's pork export. This paper analyzed background and significance of measures for TBT of pork export,current situations of researches on TBT both at home and abroad,and came up with new ideas and viewpoints for further strengthening measures for TBT of pork export.展开更多
Purpose: In this contribution we continue our investigations related to the activity index (A/) and its formal analogs. We try to replace the AI by an indicator which is better suited for policy applications. Desig...Purpose: In this contribution we continue our investigations related to the activity index (A/) and its formal analogs. We try to replace the AI by an indicator which is better suited for policy applications. Design/methodology/approach: We point out that fluctuations in the value of the AI for a given country and domain are never the result of that country's policy with respect to that domain alone because there are exogenous factors at play. For this reason we introduce the F-measure. This F-measure is nothing but the harmonic mean of the country's share in the world's publication output in the given domain and the given domain's share in the country's publication output.Findings: The F-measure does not suffer from the problems the AI does Research limitations: The indicator is not yet fully tested in real cases R&D policy management: In policy considerations, the AI should better be replaced by the F-measure as this measure can better show the results of science policy measures (which the AI cannot as it depends on exogenous factors). Originality/value: We provide an original solution for a problem that is not fully realized by policy makers.展开更多
The wide distribution of saline-alkali land in China is a restrictive factor for the sustainable development of agriculture.Saline-alkaline soil inhibits the growth and development of crops,reducing its yield and qual...The wide distribution of saline-alkali land in China is a restrictive factor for the sustainable development of agriculture.Saline-alkaline soil inhibits the growth and development of crops,reducing its yield and quality.In this article,we summarized the germination status,physiological characteristics,response mechanisms and mitigation measures of different crops under saline-alkali stress in recent years,aiming to provide important reference for the study of saline-alkali tolerance mechanism in crops,cultivation of crop varieties tolerant to salts and alkalis and improvement of the utilization rate of saline-alkali land,and put forward suggestions for future development trend of saline-alkali land crops and mitigation measures.展开更多
The internal control and risk managementof drug research and development enterprises directlyaffects the survival and development of enterprises.With the development of information technologyand the integration with t...The internal control and risk managementof drug research and development enterprises directlyaffects the survival and development of enterprises.With the development of information technologyand the integration with the global economy,pharmaceutical companies are able to achieve moreachievements in development while facing increasingcompetitive pressures. Finance is a pivotal spine of acompany’s development. If the internal control andrisk management of a company are not complete andcomprehensive, the enterprise will inevitably turn intoa crisis. Therefore, it is necessary to strengthen theanalysis of the problems in the internal control andrisk management of drug research and developmententerprises, and propose corresponding solutions.展开更多
Objectives:The study aimed to the multicenter application of a nursing workload measurement scale in the internal medicine and surgery adults hospitalization units.Methods:The study design was a multicenter,observatio...Objectives:The study aimed to the multicenter application of a nursing workload measurement scale in the internal medicine and surgery adults hospitalization units.Methods:The study design was a multicenter,observational,and descriptive study.A multicenter application of the MIDENF®nursing workload measurement scale was carried out,which consists of 21 items,and covers the four nursing functions(patient care items,teaching,manager,and researcher),in units of hospitalization of adults of internal medicine and surgery of four different hospitals.Each item contains one or more of the nursing interventions of Nursing Interventions Classification(NIC)and has an assigned time,after comparing the real time it takes to perform each intervention with the North American Nursing Diagnosis Association(NANDA)standardized time.The study was carried out during nine months of the year 2020,measuring two days each month in the three work shifts(morning,evening,and night)to all patients admitted on the days of measurement in the indicated units.Results:The descriptive and inferential analysis of 11,756 completed scales,5,695 in general surgery and 6,061 in internal medicine,showed a greater care load for the two units during the morning shift(227,034 min in general surgery,261,835 min in internal medicine),especially in the items of“self-care”,“medication”,“common invasive procedures”,“fluid therapy”,and“patient and family support”,while the managerial function was similar during the three work shifts in the two units studied,getting values between 57,348 and 62,901min.In the analysis by shift and unit,statistical significance was obtained both for the total workload and the four nursing functions(P<0.001).Conclusions:It is shown that the use of validated scales with the standardized language of nursing functions,adapted to the units,provides objective information to adjust the nursing staff to the real situation of care in any hospital and unit where it is applied,improving quality and patient safety.展开更多
Proper selection of machines and equipment used in underground coal mining significantly influence the increase of their durability and reliability. The paper describes new, created in Poland devices to determine and ...Proper selection of machines and equipment used in underground coal mining significantly influence the increase of their durability and reliability. The paper describes new, created in Poland devices to determine and evaluate the mechanical properties of the carbon (workability) whose co-founder is the author of this paper. These devices reflect the nature of the work of a plough and drum cutter-loader. It is presented their construction, operating principles as well as innovation and originality of used solutions. The devices are certified by enabling them to work in conditions of real mines, as a device intended for use in potentially explosive atmospheres. These devices have been awarded medals and diplomas at many International Fairs and Technological Innovation Exhibitions.展开更多
An active measurement method and its principle was introduced consideringthe low success rate,special difficulty,and long measurement time of the direct gas pressuremeasurement currently used in coal roadways.The tech...An active measurement method and its principle was introduced consideringthe low success rate,special difficulty,and long measurement time of the direct gas pressuremeasurement currently used in coal roadways.The technology of drilling,boreholesealing depth,borehole sealing length,sealing control of the measuring process,compensatorycomputation of gas loss quantity and other key techniques were discussed.Finally,based on the latest instrument the authors developed,a series of experiments of directgas pressure measurement in the coal roadways of the Jincheng and Tongchuanmine district,were carried out.The experimental results show that active gas pressuremeasurement technique has advantages as follows:(1) the application scope of direct gaspressure measurement technique is wide and it does not have the restriction of coalhardness,coal seam fissure and other conditions;(2) the measured results are credible,which can be tested by the same gas pressure value acquired from a different borehole inthe same place;(3) the measurement process is convenient and quick,it takes about 2 to3 days to acquire the gas pressure value in a coal seam.展开更多
Due to the difficulty and weakness of current stress measurement methods in deep soft rock, a new rheological stress recovery method of the determination of the three-dimensional(3D) stress tensor is proposed. It is s...Due to the difficulty and weakness of current stress measurement methods in deep soft rock, a new rheological stress recovery method of the determination of the three-dimensional(3D) stress tensor is proposed. It is supposed that rock stresses will recovery gradually with time and can be measured by embedding transducers into the borehole. In order to explore the applicability and accuracy of this method, analytical solutions are developed for stress measurement with the rheological stress recovery method in a viscoelastic surrounding rock, the rheological properties of which are depicted as both the Burger's model and a 3-parameter solid model. In such conditions, explicit analytical expressions for predicting time-dependent pressures on the transducer are derived. A parametric analysis is then adopted to investigate the influences of the grout solidification time and the mechanical properties of the grout layer. The results indicate that this method is suitable for stress measurement in deep soft rock, the characteristics of which are soft, fractured and subjected to high geo-stress.展开更多
The Mechanism of Enterprise-university-research institute (EURI) Binding is a market-oriented strategic alliance as the government and industry associations and intermediary organs for auxiliary forces complement, in ...The Mechanism of Enterprise-university-research institute (EURI) Binding is a market-oriented strategic alliance as the government and industry associations and intermediary organs for auxiliary forces complement, in which enterprises play the leading role and which combines the efforts of enterprises, universities and research institutes. It is the advanced development of enterprise- university-research institute binding cooperation. The development of technology and social economy continue to offer new challenges for higher education. Under this situation, many universities in Tianjin area actively develop their superiority and cooperate with enterprise and research department, trying their best to explore various enterprise- university-research institute binding ways to quicken the pace of technology innovation and transfer in order to make the school's track wider and wider. According to the situation of Tianjin area, this text introduces the cases of mechanism of enterprise-university- research binding about this area's universities and comes up with safeguard measures on the base of analyzing other areas' mechanism of enterprise-university-research institute binding, combining with educational economy and management theory.展开更多
Laser display technology is the most promising display technology in the market and is widely used in many fields. However, laser speckle has been troubling the application and expansion of this technology in some fie...Laser display technology is the most promising display technology in the market and is widely used in many fields. However, laser speckle has been troubling the application and expansion of this technology in some fields. In order to better evaluate the speckle, speckle measurement methods must be studied. In this study, a dynamic measurement method for laser speckles is proposed according to the optical superposition characteristics of speckle, which can reduce the influence of non-coherent factors on the speckle measurement results. The feasibility of the dynamic speckle measurement method is verified by designing an experimental scheme.展开更多
As natural ecosystems provide the material basis and fundamental support for regional sustainable devel-opment,the sustainability of natural ecosystems is an important prerequisite and a viable approach for the achiev...As natural ecosystems provide the material basis and fundamental support for regional sustainable devel-opment,the sustainability of natural ecosystems is an important prerequisite and a viable approach for the achievement of regional sustainable development.It is also the final criteria to assess whether sustainable development paradigm is successful.Along with the increasing impacts of human activities on natural ecosystems,the evaluation of regional ecological sustainability has become one of the key issues for research on macro ecology and sustainable development.Based on different unit of indicators,this study firstly groups the evaluation frameworks of regional ecological sus-tainability into three major types:comprehensive index evaluation with dimensionless unit,monetary valuation,and biophysical quantity measurement.We then discuss and compare these types in terms of basic principles,scope of ap-plications,advantages and shortcomings.Finally,drawn on the discussion about characteristics of ecological sustain-ability,we outline the current trend and future directions of regional ecological sustainability evaluation,for instance,transition from sustainable development evaluation to sustainability science,integration of goal-oriented and problem-solving approaches,combination of spatial pattern analysis and ecological sustainability evaluation,and en-hancement of ecological sustainability evaluation at landscape scale.展开更多
This study explored and reviewed the logistic regression (LR) model, a multivariable method for modeling the relationship between multiple independent variables and a categorical dependent variable, with emphasis on m...This study explored and reviewed the logistic regression (LR) model, a multivariable method for modeling the relationship between multiple independent variables and a categorical dependent variable, with emphasis on medical research. Thirty seven research articles published between 2000 and 2018 which employed logistic regression as the main statistical tool as well as six text books on logistic regression were reviewed. Logistic regression concepts such as odds, odds ratio, logit transformation, logistic curve, assumption, selecting dependent and independent variables, model fitting, reporting and interpreting were presented. Upon perusing the literature, considerable deficiencies were found in both the use and reporting of LR. For many studies, the ratio of the number of outcome events to predictor variables (events per variable) was sufficiently small to call into question the accuracy of the regression model. Also, most studies did not report on validation analysis, regression diagnostics or goodness-of-fit measures;measures which authenticate the robustness of the LR model. Here, we demonstrate a good example of the application of the LR model using data obtained on a cohort of pregnant women and the factors that influence their decision to opt for caesarean delivery or vaginal birth. It is recommended that researchers should be more rigorous and pay greater attention to guidelines concerning the use and reporting of LR models.展开更多
The reduction of molecular nitrogen(N_(2))to ammonia(NH_(3))under mild conditions is one of the most promising studies in the energy field due to the important role of NH_(3)in modern industry,production,and life.The ...The reduction of molecular nitrogen(N_(2))to ammonia(NH_(3))under mild conditions is one of the most promising studies in the energy field due to the important role of NH_(3)in modern industry,production,and life.The photocatalytic reduction of N_(2)is expected to achieve clean and sustainable NH_(3)production by using clean solar energy.To date,the new photocatalysts for photocatalytic reduction of N_(2)to NH_(3)at room temperature and atmospheric pressure have not been fully developed.The major challenge is to achieve high light-absorption efficiency,conversion efficiency,and stability of photocatalysts.Herein,the methods for measuring produced NH_(3)are compared,and the problems related to possible NH_(3)pollution in photocatalytic systems are mentioned to provide accurate ideas for measuring photocatalytic efficiency.The recent progress of nitrogen reduction reaction(NRR)photocatalysts at ambient temperature and pressure is summarized by introducing charge transfer,migration,and separation in photocatalytic NRR,which provides a guidance for the selection of future photocatalyst.More importantly,we introduce the latest research strategies of photocatalysts in detail,which can guide the preparation and design of photocatalysts with high NRR activity.展开更多
Academic evaluations such as tenure/promotion applications and society fellowship nominations rely heavily on bibliometric measures of each candidate’s research impact, including their research citations. This articl...Academic evaluations such as tenure/promotion applications and society fellowship nominations rely heavily on bibliometric measures of each candidate’s research impact, including their research citations. This article first reviews existing evaluation criteria such as the h-index and<em> q</em>-most-citations, and then proposes a weighted w-index which minimizes shortcomings in existing single-number measures. The w-index consists of three factors<span style="white-space:nowrap;">—</span>3 most cited first-author publications, 3 most cited publications as the corresponding/last author, and 3 additional most cited publications as a co-author, but does not allow double counting of these publications.展开更多
This paper presents the sequence of activities to improve the thermal hydraulic analysis of the IEA-R1 research reactor to operate in safe conditions after power upgrade from 2 to 5 MW and core size reduction from 30 ...This paper presents the sequence of activities to improve the thermal hydraulic analysis of the IEA-R1 research reactor to operate in safe conditions after power upgrade from 2 to 5 MW and core size reduction from 30 to 24 fuel assemblies. A realistic analysis needs the knowledge of the actual operation conditions (heat flow, flow rates) beyond the geometric data and the uncertainties associated with manufacturing and measures. A dummy fuel assembly was designed and constructed to measure the actual flow rate through the core fuel assemblies and its pressure drop. First results showed that the flow distribution over the core is nearly uniform. Nevertheless, the values are below than the calculated ones and the core bypass flow rate is greater than those estimated previously. Based on this, several activities were performed to identify and reduce the bypass flow, such as reduction of the flow rate through the sample irradiators, closing some unnecessary secondary holes on the matrix plate, improvement in the primary flow rate system and better fit of the core components on the matrix plate. A sub-aquatic visual system was used as an important tool to detect some bypass flow path. After these modifications, the fuel assemblies flow rate increased about 13%. Additional tests using the dummy fuel assembly were carried out to measure the internal flow distribution among the rectangular channels. The results showed that the flow rate through the outer channels is 10% - 15% lower than the internal ones. The flow rate in the channel formed between two adjacent fuel assemblies is an estimated parameter and it is difficult to measure because this is an open channel. A new thermal hydraulic analysis of the outermost plates of the fuel assemblies takes into account all this information. Then, a fuel design modification was proposed with the reduction of 50% in the uranium quantity in the outermost fuel plates. In order to avoid the oxidation of the outermost plates by high temperature, low flow rate, a reduction of 50% in the uranium density in the same ones was shown to be adequate to solve the problem.展开更多
BACKGROUND Quality of life(QoL)outcomes are a focal endpoint of cancer treatment strategies.AIM To externally validate the Moroccan Arabic version of the European Organization for Research and Treatment of Cancer(EORT...BACKGROUND Quality of life(QoL)outcomes are a focal endpoint of cancer treatment strategies.AIM To externally validate the Moroccan Arabic version of the European Organization for Research and Treatment of Cancer(EORTC)QoL Questionnaire(QLQ)for colorectal cancer(CRC)patients(CR29).METHODS Both Moroccan Arabic modules of QLQ-CR29 and QLQ-C30 were administered to Moroccan CRC.Psychometric properties were retested by measuring Cronbach’s alpha coefficient for reliability and Intraclass correlation coefficient(ICC)to examine test-retest reproducibility.The multitrait-scaling analysis was performed to demonstrate the validity of the instrument and known-groups comparison was used to test the score’s ability to discriminate between different groups of patients.RESULTS In total,221 patients were included in our study and 34 patients completed the questionnaire twice.The Urinary Frequency scale and Stool Frequency scale had good internal consistency with alpha Cronbach coefficients of 0.79 and 0.83 respectively,while the same coefficients were moderately lower for the Blood and Mucus in Stool scale(0.61)and the Body Image scale(0.67).The ICCs ranged from 0.88 to 1 indicating good to excellent reproducibility.In multitrait scaling analyses,the criterion for item convergent and divergent validity was satisfactory.The known-group comparison showed statistically significant differences between patients according to age,gender,stoma status,tumor location,and radiotherapy.CONCLUSION The Moroccan Arabic version of the EORTC QLQ-CR29 is a valid and reliable tool that can be used safely for research and clinical purposes in Moroccan CRC patients.展开更多
The clearance of the hemisphere dynamic pressure motor is small and difficult to measure, the measurement method of micro clearance is studied. The shortcomings of the original measurement method are analyzed, and a c...The clearance of the hemisphere dynamic pressure motor is small and difficult to measure, the measurement method of micro clearance is studied. The shortcomings of the original measurement method are analyzed, and a clearance measuring device for the hemisphere dynamic pressure motor is designed, which improves the measurement efficiency and stability.展开更多
This article describes research needs for sustainable buildings as defi ned in a July 2009 National Science Foundationsponsored workshop.This workshop brought together building researchers with researchers in the area...This article describes research needs for sustainable buildings as defi ned in a July 2009 National Science Foundationsponsored workshop.This workshop brought together building researchers with researchers in the areas of distributed renewable energy and multifunctional materials to engage their expertise and identify overlapping research needs and opportunities.An overview of sustainable building design provided the broad context for discussion.This overview was followed by focused presentations in building control systems,advanced building envelopes,and systems and process integration.In addition,presentations on distributed renewable energy and multi-functional materials supported the participants in outlining and generating research needs that connect the topic areas.The primary outcome from this part of the workshop was the identifi cation of key sustainable building research needs in:transformative measurements;passive strategies;regional solutions and living labs;systems integration;storage and cascades;adoption of international advances;and implementation and market transformation.These needs,along with associated technical challenges and potential impacts,are described in this paper to guide sustainable building research.展开更多
文摘China is one of the world’s major agricultural countries. About 80% of its annual water consumption is used for fanning undertakings. On the other hand, China is a country deficient in water resources and in particular, the water shortage is embarrassingly serious in the north. So the current development of water-saving agriculture (WSA) is a way of easing the strain between the supply and demand of water. This article expounds the WSA’s status in the development of the national economy, its research and implementation, and suggests an institutional system of WSA to be established in this country.
基金Supported by Science and Technology Program Project of General Administration of Quality Supervision,Inspection and Quarantine of the People's Republic of China(2014IK242)Science and Technology Planning Project of Sichuan Province(2014ZR0118)Key Science and Technology Self-Funded Project of Sichuan Province in 2013(2013ZRZ008)
文摘With the deepening of economic globalization and increasingly fierce competition of trade liberalization in WTO member countries,the effect of traditional trade protection measures is gradually weakening or even removed. In recent years,Technical Barriers to Trade( TBT)as a category of nontariff barriers to trade,are the widely divergent measures that countries use to regulate markets,protect their consumers,or preserve their natural resources( among other objectives),but they also can be used( or perceived by foreign countries) to discriminate against imports in order to protect domestic industries. These directly or indirectly lead to gradual rise of trade friction of China's pork export. This paper analyzed background and significance of measures for TBT of pork export,current situations of researches on TBT both at home and abroad,and came up with new ideas and viewpoints for further strengthening measures for TBT of pork export.
文摘Purpose: In this contribution we continue our investigations related to the activity index (A/) and its formal analogs. We try to replace the AI by an indicator which is better suited for policy applications. Design/methodology/approach: We point out that fluctuations in the value of the AI for a given country and domain are never the result of that country's policy with respect to that domain alone because there are exogenous factors at play. For this reason we introduce the F-measure. This F-measure is nothing but the harmonic mean of the country's share in the world's publication output in the given domain and the given domain's share in the country's publication output.Findings: The F-measure does not suffer from the problems the AI does Research limitations: The indicator is not yet fully tested in real cases R&D policy management: In policy considerations, the AI should better be replaced by the F-measure as this measure can better show the results of science policy measures (which the AI cannot as it depends on exogenous factors). Originality/value: We provide an original solution for a problem that is not fully realized by policy makers.
基金Tiemenguan Science and Technology Project of the Second Division of Xinjiang Production and Construction Corps(2019NYGG13)XPCC People’s Practical Livelihood Matter Project of"Improving the Level of Agricultural Science and Technology".
文摘The wide distribution of saline-alkali land in China is a restrictive factor for the sustainable development of agriculture.Saline-alkaline soil inhibits the growth and development of crops,reducing its yield and quality.In this article,we summarized the germination status,physiological characteristics,response mechanisms and mitigation measures of different crops under saline-alkali stress in recent years,aiming to provide important reference for the study of saline-alkali tolerance mechanism in crops,cultivation of crop varieties tolerant to salts and alkalis and improvement of the utilization rate of saline-alkali land,and put forward suggestions for future development trend of saline-alkali land crops and mitigation measures.
文摘The internal control and risk managementof drug research and development enterprises directlyaffects the survival and development of enterprises.With the development of information technologyand the integration with the global economy,pharmaceutical companies are able to achieve moreachievements in development while facing increasingcompetitive pressures. Finance is a pivotal spine of acompany’s development. If the internal control andrisk management of a company are not complete andcomprehensive, the enterprise will inevitably turn intoa crisis. Therefore, it is necessary to strengthen theanalysis of the problems in the internal control andrisk management of drug research and developmententerprises, and propose corresponding solutions.
文摘Objectives:The study aimed to the multicenter application of a nursing workload measurement scale in the internal medicine and surgery adults hospitalization units.Methods:The study design was a multicenter,observational,and descriptive study.A multicenter application of the MIDENF®nursing workload measurement scale was carried out,which consists of 21 items,and covers the four nursing functions(patient care items,teaching,manager,and researcher),in units of hospitalization of adults of internal medicine and surgery of four different hospitals.Each item contains one or more of the nursing interventions of Nursing Interventions Classification(NIC)and has an assigned time,after comparing the real time it takes to perform each intervention with the North American Nursing Diagnosis Association(NANDA)standardized time.The study was carried out during nine months of the year 2020,measuring two days each month in the three work shifts(morning,evening,and night)to all patients admitted on the days of measurement in the indicated units.Results:The descriptive and inferential analysis of 11,756 completed scales,5,695 in general surgery and 6,061 in internal medicine,showed a greater care load for the two units during the morning shift(227,034 min in general surgery,261,835 min in internal medicine),especially in the items of“self-care”,“medication”,“common invasive procedures”,“fluid therapy”,and“patient and family support”,while the managerial function was similar during the three work shifts in the two units studied,getting values between 57,348 and 62,901min.In the analysis by shift and unit,statistical significance was obtained both for the total workload and the four nursing functions(P<0.001).Conclusions:It is shown that the use of validated scales with the standardized language of nursing functions,adapted to the units,provides objective information to adjust the nursing staff to the real situation of care in any hospital and unit where it is applied,improving quality and patient safety.
文摘Proper selection of machines and equipment used in underground coal mining significantly influence the increase of their durability and reliability. The paper describes new, created in Poland devices to determine and evaluate the mechanical properties of the carbon (workability) whose co-founder is the author of this paper. These devices reflect the nature of the work of a plough and drum cutter-loader. It is presented their construction, operating principles as well as innovation and originality of used solutions. The devices are certified by enabling them to work in conditions of real mines, as a device intended for use in potentially explosive atmospheres. These devices have been awarded medals and diplomas at many International Fairs and Technological Innovation Exhibitions.
基金Supported by National Basic Research Program of China(2005cb221504)National Key Technologies R & D Program of China(2006BAK03B01)
文摘An active measurement method and its principle was introduced consideringthe low success rate,special difficulty,and long measurement time of the direct gas pressuremeasurement currently used in coal roadways.The technology of drilling,boreholesealing depth,borehole sealing length,sealing control of the measuring process,compensatorycomputation of gas loss quantity and other key techniques were discussed.Finally,based on the latest instrument the authors developed,a series of experiments of directgas pressure measurement in the coal roadways of the Jincheng and Tongchuanmine district,were carried out.The experimental results show that active gas pressuremeasurement technique has advantages as follows:(1) the application scope of direct gaspressure measurement technique is wide and it does not have the restriction of coalhardness,coal seam fissure and other conditions;(2) the measured results are credible,which can be tested by the same gas pressure value acquired from a different borehole inthe same place;(3) the measurement process is convenient and quick,it takes about 2 to3 days to acquire the gas pressure value in a coal seam.
基金supported by the National Basic Research Program of China (No.2014CB046904)the National Natural Science Foundation of China (Nos.41130742 and 11302242)
文摘Due to the difficulty and weakness of current stress measurement methods in deep soft rock, a new rheological stress recovery method of the determination of the three-dimensional(3D) stress tensor is proposed. It is supposed that rock stresses will recovery gradually with time and can be measured by embedding transducers into the borehole. In order to explore the applicability and accuracy of this method, analytical solutions are developed for stress measurement with the rheological stress recovery method in a viscoelastic surrounding rock, the rheological properties of which are depicted as both the Burger's model and a 3-parameter solid model. In such conditions, explicit analytical expressions for predicting time-dependent pressures on the transducer are derived. A parametric analysis is then adopted to investigate the influences of the grout solidification time and the mechanical properties of the grout layer. The results indicate that this method is suitable for stress measurement in deep soft rock, the characteristics of which are soft, fractured and subjected to high geo-stress.
文摘The Mechanism of Enterprise-university-research institute (EURI) Binding is a market-oriented strategic alliance as the government and industry associations and intermediary organs for auxiliary forces complement, in which enterprises play the leading role and which combines the efforts of enterprises, universities and research institutes. It is the advanced development of enterprise- university-research institute binding cooperation. The development of technology and social economy continue to offer new challenges for higher education. Under this situation, many universities in Tianjin area actively develop their superiority and cooperate with enterprise and research department, trying their best to explore various enterprise- university-research institute binding ways to quicken the pace of technology innovation and transfer in order to make the school's track wider and wider. According to the situation of Tianjin area, this text introduces the cases of mechanism of enterprise-university- research binding about this area's universities and comes up with safeguard measures on the base of analyzing other areas' mechanism of enterprise-university-research institute binding, combining with educational economy and management theory.
基金supported by the National Natural Science Foundation of China (No.62076160)the Natural Science Foundation of Shanghai (No.21ZR1424700)。
文摘Laser display technology is the most promising display technology in the market and is widely used in many fields. However, laser speckle has been troubling the application and expansion of this technology in some fields. In order to better evaluate the speckle, speckle measurement methods must be studied. In this study, a dynamic measurement method for laser speckles is proposed according to the optical superposition characteristics of speckle, which can reduce the influence of non-coherent factors on the speckle measurement results. The feasibility of the dynamic speckle measurement method is verified by designing an experimental scheme.
基金Under the auspices of National Natural Science Foundation of China (No.40635028,40801066)State Key Laboratory of Earth Surface Processes and Resource Ecology of China (No.2008-KF-04)
文摘As natural ecosystems provide the material basis and fundamental support for regional sustainable devel-opment,the sustainability of natural ecosystems is an important prerequisite and a viable approach for the achievement of regional sustainable development.It is also the final criteria to assess whether sustainable development paradigm is successful.Along with the increasing impacts of human activities on natural ecosystems,the evaluation of regional ecological sustainability has become one of the key issues for research on macro ecology and sustainable development.Based on different unit of indicators,this study firstly groups the evaluation frameworks of regional ecological sus-tainability into three major types:comprehensive index evaluation with dimensionless unit,monetary valuation,and biophysical quantity measurement.We then discuss and compare these types in terms of basic principles,scope of ap-plications,advantages and shortcomings.Finally,drawn on the discussion about characteristics of ecological sustain-ability,we outline the current trend and future directions of regional ecological sustainability evaluation,for instance,transition from sustainable development evaluation to sustainability science,integration of goal-oriented and problem-solving approaches,combination of spatial pattern analysis and ecological sustainability evaluation,and en-hancement of ecological sustainability evaluation at landscape scale.
文摘This study explored and reviewed the logistic regression (LR) model, a multivariable method for modeling the relationship between multiple independent variables and a categorical dependent variable, with emphasis on medical research. Thirty seven research articles published between 2000 and 2018 which employed logistic regression as the main statistical tool as well as six text books on logistic regression were reviewed. Logistic regression concepts such as odds, odds ratio, logit transformation, logistic curve, assumption, selecting dependent and independent variables, model fitting, reporting and interpreting were presented. Upon perusing the literature, considerable deficiencies were found in both the use and reporting of LR. For many studies, the ratio of the number of outcome events to predictor variables (events per variable) was sufficiently small to call into question the accuracy of the regression model. Also, most studies did not report on validation analysis, regression diagnostics or goodness-of-fit measures;measures which authenticate the robustness of the LR model. Here, we demonstrate a good example of the application of the LR model using data obtained on a cohort of pregnant women and the factors that influence their decision to opt for caesarean delivery or vaginal birth. It is recommended that researchers should be more rigorous and pay greater attention to guidelines concerning the use and reporting of LR models.
基金Taishan Scholars Program of Shandong Province,Grant/Award Number:tsqn201812068Higher School Youth Innovation Team of Shandong Province,Grant/Award Number:2019KJA013+1 种基金The Opening Fund of State Key Laboratory of Heavy Oil Processing,Grant/Award Number:SKLOP202002006National Natural Science Foundation of China,Grant/Award Number:51872173。
文摘The reduction of molecular nitrogen(N_(2))to ammonia(NH_(3))under mild conditions is one of the most promising studies in the energy field due to the important role of NH_(3)in modern industry,production,and life.The photocatalytic reduction of N_(2)is expected to achieve clean and sustainable NH_(3)production by using clean solar energy.To date,the new photocatalysts for photocatalytic reduction of N_(2)to NH_(3)at room temperature and atmospheric pressure have not been fully developed.The major challenge is to achieve high light-absorption efficiency,conversion efficiency,and stability of photocatalysts.Herein,the methods for measuring produced NH_(3)are compared,and the problems related to possible NH_(3)pollution in photocatalytic systems are mentioned to provide accurate ideas for measuring photocatalytic efficiency.The recent progress of nitrogen reduction reaction(NRR)photocatalysts at ambient temperature and pressure is summarized by introducing charge transfer,migration,and separation in photocatalytic NRR,which provides a guidance for the selection of future photocatalyst.More importantly,we introduce the latest research strategies of photocatalysts in detail,which can guide the preparation and design of photocatalysts with high NRR activity.
文摘Academic evaluations such as tenure/promotion applications and society fellowship nominations rely heavily on bibliometric measures of each candidate’s research impact, including their research citations. This article first reviews existing evaluation criteria such as the h-index and<em> q</em>-most-citations, and then proposes a weighted w-index which minimizes shortcomings in existing single-number measures. The w-index consists of three factors<span style="white-space:nowrap;">—</span>3 most cited first-author publications, 3 most cited publications as the corresponding/last author, and 3 additional most cited publications as a co-author, but does not allow double counting of these publications.
文摘This paper presents the sequence of activities to improve the thermal hydraulic analysis of the IEA-R1 research reactor to operate in safe conditions after power upgrade from 2 to 5 MW and core size reduction from 30 to 24 fuel assemblies. A realistic analysis needs the knowledge of the actual operation conditions (heat flow, flow rates) beyond the geometric data and the uncertainties associated with manufacturing and measures. A dummy fuel assembly was designed and constructed to measure the actual flow rate through the core fuel assemblies and its pressure drop. First results showed that the flow distribution over the core is nearly uniform. Nevertheless, the values are below than the calculated ones and the core bypass flow rate is greater than those estimated previously. Based on this, several activities were performed to identify and reduce the bypass flow, such as reduction of the flow rate through the sample irradiators, closing some unnecessary secondary holes on the matrix plate, improvement in the primary flow rate system and better fit of the core components on the matrix plate. A sub-aquatic visual system was used as an important tool to detect some bypass flow path. After these modifications, the fuel assemblies flow rate increased about 13%. Additional tests using the dummy fuel assembly were carried out to measure the internal flow distribution among the rectangular channels. The results showed that the flow rate through the outer channels is 10% - 15% lower than the internal ones. The flow rate in the channel formed between two adjacent fuel assemblies is an estimated parameter and it is difficult to measure because this is an open channel. A new thermal hydraulic analysis of the outermost plates of the fuel assemblies takes into account all this information. Then, a fuel design modification was proposed with the reduction of 50% in the uranium quantity in the outermost fuel plates. In order to avoid the oxidation of the outermost plates by high temperature, low flow rate, a reduction of 50% in the uranium density in the same ones was shown to be adequate to solve the problem.
文摘BACKGROUND Quality of life(QoL)outcomes are a focal endpoint of cancer treatment strategies.AIM To externally validate the Moroccan Arabic version of the European Organization for Research and Treatment of Cancer(EORTC)QoL Questionnaire(QLQ)for colorectal cancer(CRC)patients(CR29).METHODS Both Moroccan Arabic modules of QLQ-CR29 and QLQ-C30 were administered to Moroccan CRC.Psychometric properties were retested by measuring Cronbach’s alpha coefficient for reliability and Intraclass correlation coefficient(ICC)to examine test-retest reproducibility.The multitrait-scaling analysis was performed to demonstrate the validity of the instrument and known-groups comparison was used to test the score’s ability to discriminate between different groups of patients.RESULTS In total,221 patients were included in our study and 34 patients completed the questionnaire twice.The Urinary Frequency scale and Stool Frequency scale had good internal consistency with alpha Cronbach coefficients of 0.79 and 0.83 respectively,while the same coefficients were moderately lower for the Blood and Mucus in Stool scale(0.61)and the Body Image scale(0.67).The ICCs ranged from 0.88 to 1 indicating good to excellent reproducibility.In multitrait scaling analyses,the criterion for item convergent and divergent validity was satisfactory.The known-group comparison showed statistically significant differences between patients according to age,gender,stoma status,tumor location,and radiotherapy.CONCLUSION The Moroccan Arabic version of the EORTC QLQ-CR29 is a valid and reliable tool that can be used safely for research and clinical purposes in Moroccan CRC patients.
文摘The clearance of the hemisphere dynamic pressure motor is small and difficult to measure, the measurement method of micro clearance is studied. The shortcomings of the original measurement method are analyzed, and a clearance measuring device for the hemisphere dynamic pressure motor is designed, which improves the measurement efficiency and stability.
文摘This article describes research needs for sustainable buildings as defi ned in a July 2009 National Science Foundationsponsored workshop.This workshop brought together building researchers with researchers in the areas of distributed renewable energy and multifunctional materials to engage their expertise and identify overlapping research needs and opportunities.An overview of sustainable building design provided the broad context for discussion.This overview was followed by focused presentations in building control systems,advanced building envelopes,and systems and process integration.In addition,presentations on distributed renewable energy and multi-functional materials supported the participants in outlining and generating research needs that connect the topic areas.The primary outcome from this part of the workshop was the identifi cation of key sustainable building research needs in:transformative measurements;passive strategies;regional solutions and living labs;systems integration;storage and cascades;adoption of international advances;and implementation and market transformation.These needs,along with associated technical challenges and potential impacts,are described in this paper to guide sustainable building research.