Physical-chemical properties of phosphorous gypsum, proportion and cemented mechanism of slurry with gypsum as aggregate were studied to remove the harms of gypsum pile, combining with difficult problems of excessive ...Physical-chemical properties of phosphorous gypsum, proportion and cemented mechanism of slurry with gypsum as aggregate were studied to remove the harms of gypsum pile, combining with difficult problems of excessive mined-out gobs, enormous ore body under roadway and low recovery ratio of Yongshaba Mine, Kaiyang Phosphor Mine Group, Guizhou Province, China. An appropriate backfill system and craflwork were designed, using shattering milling method to crush gypsum, double-axles mixing and strong activation mixing way to mix slurry, cemented slurry and mullock backfill alternately process. The results show that gypsum is fit for backfilling afterwards by adding fly ash, though it is not an ideal aggregate for fine granule and coagulate retardation. The suggested dosage (the mass ratio of cement to fly ash to gypsum) is 1:1:6-1:1:8 with mass fraction of solid materials 60%-63%. Slurry is transported in suspend state with non-plastic strength, and then in concretion state after backfilling. The application to mine shows the technology is feasible, and gypsum utilization ratio is up to 100%. Transportation and backfill effect is very good for paste-like slurry and drenching cemented slurry into mullock, and the compressive strength and recovery ratio are 2.0 MPa and 82.6%, respectively, with the maximum subsidence of surface only 1.307 mm. Furthermore, the investment of system is about 7 × 10^6 yuan (RMB), only 1/10 of that of traditional paste backfill system.展开更多
The fundamental research and industry, trials of the third generation automobile steel QP980 were introduced in this paper, including chemical ingredient, mechanical properties, microstructure, forming limit and basic...The fundamental research and industry, trials of the third generation automobile steel QP980 were introduced in this paper, including chemical ingredient, mechanical properties, microstructure, forming limit and basic perform- ance parameters. The application of QP steel of the B-pillar was researched, and the QP980, DP600 and hot forming steel were compared in the aspect of formability, safety and cost. The resuhs showed that the QP980 replacing DP600 steel single piece carl reduce the weight by 2.4 kg. The security and performance is basically the same as that of hot forming steel using 22MnB5, and the cost is reduced by 30 %.展开更多
In order to provide a new way for waste cooking oil(WCO) resource utilization, several diester derivatives were obtained from WCO through a three-step chemical modifications, viz.: transesterification, epoxidation and...In order to provide a new way for waste cooking oil(WCO) resource utilization, several diester derivatives were obtained from WCO through a three-step chemical modifications, viz.: transesterification, epoxidation and oxirane ring opening with carboxylic acids. The effects of the chain length of side chain groups on the viscosity, acid value, low temperature fluidity, thermo-oxidative stability, tribological properties and surface tension of diester derivatives were investigated. The results showed that increasing the chain length of side chain groups had a positive influence on the viscosity, viscosity index, acid value, pour point, friction coefficient and wear scar diameter along with a negative influence on the oxidation onset temperature, volatile loss, insoluble deposit, maximum non-seizure load and surface tension. These diester derivatives exhibited improved physicochemical and tribological properties that make themselves promising environmentally friendly biolubricant basestocks.展开更多
Polyaniline(PANI) nanofiber was synthesized by interfacial polymerization utilizing the interface between HC1 and CCl4. The hybrid type supercapacitors (PLi/C) based on Li-doping polyaniline and activated carbon e...Polyaniline(PANI) nanofiber was synthesized by interfacial polymerization utilizing the interface between HC1 and CCl4. The hybrid type supercapacitors (PLi/C) based on Li-doping polyaniline and activated carbon electrode were fabricated and compared with the redox type capacitors (PLi/PLi) based on two uniformly Li-doping polyaniline electrodes. The electrochemical performances of the two types of supercapacitors were characterized in non-aqueous electrolyte. PLi/C supercapacitors have a wider effective energy storage potential range and a higher upper potential. At the same time, the PLi/C supercapacitor exhibits a specific capacity of 120.93 F/g at initial discharge and retains 80% after 500 cycles. The ohmic internal resistance (REs) of PLi/C supercapacitor is 5.0 Ω, which is smaller than that of PLi/PLi capacitor (5.5 Ω). Moreover, it can be seen that EtgNBF4 organic solution is more suitable for using as organic electrolyte of PLi/C capacitor compared with organic solution containing LiPFr.展开更多
The issues of reducing CO_2 levels in the atmo-sphere, sustainably utilizing natural mineral resources,and dealing with indus trial waste offer challenging opportunities for sustainable development in energy and the e...The issues of reducing CO_2 levels in the atmo-sphere, sustainably utilizing natural mineral resources,and dealing with indus trial waste offer challenging opportunities for sustainable development in energy and the environment. The latest advances in CO_2 mineralization technology involving natural minerals and industrial waste are summarized in this paper, with great emphasis on the advancement of fundamental science, economic evaluation, and engineering applications. We discuss several lead-ing large-scale CO_2 mineralization methodologies from a techn ical and engineering-science perspective. For each technology option, we give an overview of the technical parameters, reaction pathway, reactivity, procedural scheme, and laboratorial and pilot devices. Furthermore, we present a discussion of each technology based on experimental results and the literature. Finally, current gaps in knowledge are identified in the conclusion, and an overview of the challenges and opportunities for future research in this field is provided.展开更多
A paste-like self-flowing pipeline transportation backfilling technology with coal gangue as aggregate is proposed to remove the potential damage caused by coal gangue piles. As well, the difficult problems of recover...A paste-like self-flowing pipeline transportation backfilling technology with coal gangue as aggregate is proposed to remove the potential damage caused by coal gangue piles. As well, the difficult problems of recovering high quality safety coal pillars and deep mining of the Suncun Coal Mine (SCM), Xinwen Coal Group, Shandong are resolved. The physical-chemical properties of coal gangue, optimized proportion of materials, backfilling system and craft in the SCM were studied in the laboratory and then an industrial test was carried out on high quality coal pillars under a town. The results show that finely crushed kaolinized and fresh gangue with granularity less than 5 mm can be used as aggregate with fly ash to replace part of the cement and a composite water reducer as an additive, accounting for 1.0%-1.5% of the total amount of cement and fly ash. The recommended proportion is l(cement):4(fly ash): 15(coal gangue), with a mass fraction of 72%-75%, rheoiogical paste-like properties and a strength of more than 0.7 MPa at 7 d. The sequence of adding cement, fly ash, water reducer and then coal gangue ensures that the suspended state of the slurry, reducing the wear and jam of pipelines. The working face is advancing continuously by the alternating craft of building block walls with coal gangue and backfilling mined-out gobs with paste-like slurry. The recovery rate is as high as 90% with a backfilling cost of 36.9 YuarffL good utilization of coal gangue and no subsidence on the surface. This technology provides a good theoretical basis and application experience for coal mines, cement backfilling with paste-like slurry.展开更多
Geoengineering (also called climate engineering), which refers to large-scale intervention in the Earth's climate system to counteract greenhouse gas-induced warming, has been one of the most rapidly growing areas ...Geoengineering (also called climate engineering), which refers to large-scale intervention in the Earth's climate system to counteract greenhouse gas-induced warming, has been one of the most rapidly growing areas of climate research as a potential option for tackling global warming. Here, we provide an overview of the scientific background and research progress of proposed geoengineering schemes. Geo- engineering can be broadly divided into two categories: solar geoengineering (also called solar radiation management, or SRM), which aims to reflect more sunlight to space, and carbon dioxide removal (CDR), which aims to reduce the CO2 content in the atmosphere. First, we review different proposed geoengineering methods involved in the solar radiation management and carbon dioxide removal schemes. Then, we discuss the fundamental science underlying the climate response to the carbon dioxide removal and solar radiation management schemes. We focus on two basic issues: 1) climate response to the reduction in solar irradiance and 2) climate response to the reduction in atmospheric COe. Next, we introduce an ongoing geoengineering research project in China that is supported by National Key Basic Research Program. This research project, being the first coordinated geoengineering research program in China, will systematically investigate the physical mechanisms, climate impacts, and risk and governance of a few targeted geoengineering schemes. It is expected that this research program will help us gain a deep understanding of the physical science underlying geoengineering schemes and the impacts of geoengineering on global climate, in particular, on the Asia monsoon region.展开更多
The electric double layer with the transmission of particles was presented based on the principle of electrochemistry.In accordance with this theory,the cavitation catalysis removal mechanism of ultrasonic-pulse elect...The electric double layer with the transmission of particles was presented based on the principle of electrochemistry.In accordance with this theory,the cavitation catalysis removal mechanism of ultrasonic-pulse electrochemical compound machining(UPECM) based on particles was proposed.The removal mechanism was a particular focus and was thus validated by experiments.The principles and experiments of UPECM were introduced,and the removal model of the UPECM based on the principles of UPECM was established.Furthermore,the effects of the material removal rate for the main processing parameters,including the particles size,the ultrasonic vibration amplitude,the pulse voltage and the minimum machining gap between the tool and the workpiece,were also studied through UPECM.The results show that the particles promote ultrasonic-pulse electrochemical compound machining and thus act as the catalyzer of UPECM.The results also indicate that the processing speed,machining accuracy and surface quality can be improved under UPECM compound machining.展开更多
The u Mhlatuzana, u Mbilo and a Manzimnyama river catchments located on the eastern seaboard of the Kwa Zulu-Natal province, South Africa, form the core of urbanization and industrialization, contributing the only nat...The u Mhlatuzana, u Mbilo and a Manzimnyama river catchments located on the eastern seaboard of the Kwa Zulu-Natal province, South Africa, form the core of urbanization and industrialization, contributing the only natural freshwater inflows to the Bayhead Canal portion of the Durban Harbour. In this study, seasonal discharges and physico–chemical water properties were used to quantitatively determine the material mass transport capacity of the river systems on the basis of hydrographic inputs and chemical loading from the surrounding land use sectors.The mass transport of the total dissolved solids(TDS),ammonia(NH_4), phosphorous(P), aluminum(Al), calcium(Ca), copper(Cu), chromium(Cr), mercury(Hg), potassium(K), magnesium(Mg), sodium(Na), nickel(Ni), lead(Pb), sulphur(S) and vanadium(V) was determined for each river. Results indicated that land use, seasonality and river flow were significant determinants for the material loading in the rivers and the receiving port waters. The spatio-temporal distribution patterns of chemical fluxes indicated that industrial activity associated with the a Manzimnyama canal contributed the most, with regards to TDS, NH_4, Ca, K, Mg, Na, S and V, loading in both wet and dry seasons, as well as Al, Cu, Hg and Pb during the dry season. Similarly, industrial activity associated with the u Mbilo/u Mhlatuzana Canal at the lower reaches accounted for the highest P, Al, Cu and Pb fluxes in the wet season alone. Fluxes of these parameters are used to explain theobserved elemental concentrations and patterns of the receiving port waters of the Bayhead Canal.展开更多
The production of chemicals from biomass is a very challenging process due to its diverse chemical composition. Lignin, cellulose and hemicellulose are the three main biopolymers of wood biomass, with cell walls &pla...The production of chemicals from biomass is a very challenging process due to its diverse chemical composition. Lignin, cellulose and hemicellulose are the three main biopolymers of wood biomass, with cell walls &plant origin. Lignin has been chosen for the present studies due to its range of different linkages and structures. The present work involved a computational study of the most dominant lignin dimers and their vibrational structures, based on the Density Functional Theory method. Full geometry optimization of the compartments used the StoBe code with cluster model and non-local functional (RPBE) approach. The calculations of the vibrational frequencies were performed with harmonic approximations as well as an anharmonicity fit in the Morse potential function, as implemented in the StoBe code. In the case oflignin, the calculations included three different precursors based on: coumaryl alcohol, coniferyl alcohol and sinapyl alcohol. To represent the cellulose and hemicellulose derivatives, selected aldopentoses and aldohexoses (arabinose, xylose, glucose, galactose, and mannose) were considered. Presented here are the theoretical investigations for a variety of biomass derived compounds, to give the possibility of obtaining a theoretical VBD (Vibrations Basis Database) for experimental spectra interpretation. Such a database could be further used in the preliminary composition assessment of biomass derived substrates, which will be discussed here in more detail.展开更多
Standardization theory is viewed as an element of standardization education. This paper defines the discipline of standardization based on advancements in standardization theory, examines the relationship between the ...Standardization theory is viewed as an element of standardization education. This paper defines the discipline of standardization based on advancements in standardization theory, examines the relationship between the discipline of standardization and standardization education, and predicts trends in standardization.展开更多
Objective:Triple-negative breast cancer(estrogen receptor-negative,progesterone receptor-negative and Her2-negative) can be classified into two subtypes:basal and non-basal phenotype.And the basal phenotype is associa...Objective:Triple-negative breast cancer(estrogen receptor-negative,progesterone receptor-negative and Her2-negative) can be classified into two subtypes:basal and non-basal phenotype.And the basal phenotype is associated with poor outcome.The purpose of this study was to figure out the differences of clinicopathological characters and related factors of prognosis between these two subtypes.Methods:Immunohistochemical staining was performed for the CK5/6,CK17 basal markers and EGFR on biopsy samples from 40 triple-negative patients and the clinicopathology features of these samples were investigated.Results:Seventy percent of the patients were diagnosed as the basal phenotype.Compared with the non-basal phenotype,the basal phenotype lesions were significantly larger in diameter with a high nuclear grade.In the node-negative group the basal phenotype clearly showed the same clinicopathological differences.There was statistically significant concordance among all three antibodies.Conclusion:Expression of basal markers identifies a biologically and clinically distinct subgroup of TN tumors,justifying the use of basal markers to define the basal or the non-basal phenotype.It is important to help the doctor deciding the therapeutic strategy for patient with triple-negative breast cancer.展开更多
In this paper, the teaching of course Three-dimensional Animation Foundation is designed mainly based on teaching content modularization and scaffolding teaching model. The modularized content design for Three-dimensi...In this paper, the teaching of course Three-dimensional Animation Foundation is designed mainly based on teaching content modularization and scaffolding teaching model. The modularized content design for Three-dimensional Animation Foundation is specifically expounded, and also the ideas for developing the scaffolding teaching model are analyzed. How to integrate the scaffolding teaching model into course teaching is introduced in details. Finally, new methods for guiding students to think independently in course teaching and improve students' self-awareness and self-learning ability are proposed.展开更多
With the globalization of English, the macro and micro cultures of the users of English around the world interact intensively. Considering these conditions, the local and global cultural interface seems an important i...With the globalization of English, the macro and micro cultures of the users of English around the world interact intensively. Considering these conditions, the local and global cultural interface seems an important issue which needs to be clarified in the materials and books used for learning English. Thus, the focus of this study was to explore the language learning policy of the new Iranian English course book at high schools, Prospect 1, recently published and taught for a year in Iran, in light of globalization and culture. This qualitative study was conducted through carrying out semi-structured interviews. The participants of this study were 30 teachers of Ministry of Education, who had the experience of teaching Prospect I for a year and they were mostly chosen from Mashhad and the rest from other cities of Khorasan province, Iran. The interview contained four main questions which were posed to the teachers. The findings of the study indicate that the language learning policy of Iran need to pay more attention to the learners' intercultural communicative competence because it mainly attempts at teaching English language focusing on the home culture in the Iranian context. The article ends with some pedagogical implications and more recommendations for developing research studies.展开更多
A dynamic cooperation model of multi-agent is established by combining reinforcement learning with distributed artificial intelligence(DAI),in which the concept of individual optimization loses its meaning because of ...A dynamic cooperation model of multi-agent is established by combining reinforcement learning with distributed artificial intelligence(DAI),in which the concept of individual optimization loses its meaning because of the dependence of repayment on each agent itself and the choice of other agents.Utilizing the idea of DAI,the intellectual unit of each robot and the change of task and environment,each agent can make decisions independently and finish various complicated tasks by communication and reciprocation between each other.The method is superior to other reinforcement learning methods commonly used in the multi-agent system.It can improve the convergence velocity of reinforcement learning,decrease requirements of computer memory,and enhance the capability of computing and logical ratiocinating for agent.The result of a simulated robot soccer match proves that the proposed cooperative strategy is valid.展开更多
The purpose of research study was to develop a theoretical relativistic framework for research in open and flexible learning environment because it is a new dimension in the field of education. Developing a theoretica...The purpose of research study was to develop a theoretical relativistic framework for research in open and flexible learning environment because it is a new dimension in the field of education. Developing a theoretical relativistic framework for any research study is first and prime step in walking on the track to reach the distinction set by the researcher. Open and flexible learning is a new trend in education, enriched with ICT-use as a basic demand of the 21st century generation in all parts of the globe. So, it requires a theoretical framework for its initiation, implementation, development and evaluation which is relatively developed and advanced from the existing framework. In any research study the literature review is carried out in order to develop, build or construct a theoretical framework. The researcher of the study has observed while attending the international conference on ODL (AAOU, 2013) that most of the studies require theoretical underpinning for ICT-use in education. The researcher assume that being a new trend in education to use ICT for teaching learning purpose; it requires conceptual clarity and theoretical background of the user and researcher, because, without theory the practice is wastage of money, time and energy and it becomes ineffective and requires relatively new conceptual development. So, the problem stated by the researcher for the study was: Developing theoretical relativistic framework for research in open and flexible learning: A new trend in educational research. The objective of the study was integrating the interrelated concepts to build a pnemonological network for identifying the constructs in ICT-rich open and flexible learning environment. The study was significant because it provided theoretical background for conducting research in ICT-use for teaching and learning through open and flexible systems; whether blended or online learning and training. The methodology used by the researcher was qualitative and interpretive because there were reviewing of literature and meta-analysis for building the framework. The data were analyzed and interpreted by the researcher for the findings and drawing conclusions. On the basis of conclusions the researcher has made suggestions and recommendations for conducting research in open and flexible learning environment by using this theoretical relativistic framework. The framework was named as Virtual Learning Environment Framework (VLEF).展开更多
基金Project(2006BAB02A03)supported by the National Key Technology Research and Development ProgramProject(08MX16)supported by Mittal Scientific and Technological Innovation Projects of Central South University during 2008
文摘Physical-chemical properties of phosphorous gypsum, proportion and cemented mechanism of slurry with gypsum as aggregate were studied to remove the harms of gypsum pile, combining with difficult problems of excessive mined-out gobs, enormous ore body under roadway and low recovery ratio of Yongshaba Mine, Kaiyang Phosphor Mine Group, Guizhou Province, China. An appropriate backfill system and craflwork were designed, using shattering milling method to crush gypsum, double-axles mixing and strong activation mixing way to mix slurry, cemented slurry and mullock backfill alternately process. The results show that gypsum is fit for backfilling afterwards by adding fly ash, though it is not an ideal aggregate for fine granule and coagulate retardation. The suggested dosage (the mass ratio of cement to fly ash to gypsum) is 1:1:6-1:1:8 with mass fraction of solid materials 60%-63%. Slurry is transported in suspend state with non-plastic strength, and then in concretion state after backfilling. The application to mine shows the technology is feasible, and gypsum utilization ratio is up to 100%. Transportation and backfill effect is very good for paste-like slurry and drenching cemented slurry into mullock, and the compressive strength and recovery ratio are 2.0 MPa and 82.6%, respectively, with the maximum subsidence of surface only 1.307 mm. Furthermore, the investment of system is about 7 × 10^6 yuan (RMB), only 1/10 of that of traditional paste backfill system.
文摘The fundamental research and industry, trials of the third generation automobile steel QP980 were introduced in this paper, including chemical ingredient, mechanical properties, microstructure, forming limit and basic perform- ance parameters. The application of QP steel of the B-pillar was researched, and the QP980, DP600 and hot forming steel were compared in the aspect of formability, safety and cost. The resuhs showed that the QP980 replacing DP600 steel single piece carl reduce the weight by 2.4 kg. The security and performance is basically the same as that of hot forming steel using 22MnB5, and the cost is reduced by 30 %.
基金the financial support from the Natural Science Foundation of Chongqing(Project No.cstc2014jcyj A90013)
文摘In order to provide a new way for waste cooking oil(WCO) resource utilization, several diester derivatives were obtained from WCO through a three-step chemical modifications, viz.: transesterification, epoxidation and oxirane ring opening with carboxylic acids. The effects of the chain length of side chain groups on the viscosity, acid value, low temperature fluidity, thermo-oxidative stability, tribological properties and surface tension of diester derivatives were investigated. The results showed that increasing the chain length of side chain groups had a positive influence on the viscosity, viscosity index, acid value, pour point, friction coefficient and wear scar diameter along with a negative influence on the oxidation onset temperature, volatile loss, insoluble deposit, maximum non-seizure load and surface tension. These diester derivatives exhibited improved physicochemical and tribological properties that make themselves promising environmentally friendly biolubricant basestocks.
基金Project(2008AA03Z207) supported by the National High-Tech Research and Development Program of China
文摘Polyaniline(PANI) nanofiber was synthesized by interfacial polymerization utilizing the interface between HC1 and CCl4. The hybrid type supercapacitors (PLi/C) based on Li-doping polyaniline and activated carbon electrode were fabricated and compared with the redox type capacitors (PLi/PLi) based on two uniformly Li-doping polyaniline electrodes. The electrochemical performances of the two types of supercapacitors were characterized in non-aqueous electrolyte. PLi/C supercapacitors have a wider effective energy storage potential range and a higher upper potential. At the same time, the PLi/C supercapacitor exhibits a specific capacity of 120.93 F/g at initial discharge and retains 80% after 500 cycles. The ohmic internal resistance (REs) of PLi/C supercapacitor is 5.0 Ω, which is smaller than that of PLi/PLi capacitor (5.5 Ω). Moreover, it can be seen that EtgNBF4 organic solution is more suitable for using as organic electrolyte of PLi/C capacitor compared with organic solution containing LiPFr.
基金finance support of the Ministry of Science and Technology (State Key Research Plan, 2013BAC12B00)the National Natural Science Foundation of China (21336004 and 51254002)
文摘The issues of reducing CO_2 levels in the atmo-sphere, sustainably utilizing natural mineral resources,and dealing with indus trial waste offer challenging opportunities for sustainable development in energy and the environment. The latest advances in CO_2 mineralization technology involving natural minerals and industrial waste are summarized in this paper, with great emphasis on the advancement of fundamental science, economic evaluation, and engineering applications. We discuss several lead-ing large-scale CO_2 mineralization methodologies from a techn ical and engineering-science perspective. For each technology option, we give an overview of the technical parameters, reaction pathway, reactivity, procedural scheme, and laboratorial and pilot devices. Furthermore, we present a discussion of each technology based on experimental results and the literature. Finally, current gaps in knowledge are identified in the conclusion, and an overview of the challenges and opportunities for future research in this field is provided.
基金Projects 2006BAB02A03 supported by the National Key Technology Research and Development ProgramProjects 2006BA02B05 by the 11th Five Year Key Program for Science and Technology Development of China
文摘A paste-like self-flowing pipeline transportation backfilling technology with coal gangue as aggregate is proposed to remove the potential damage caused by coal gangue piles. As well, the difficult problems of recovering high quality safety coal pillars and deep mining of the Suncun Coal Mine (SCM), Xinwen Coal Group, Shandong are resolved. The physical-chemical properties of coal gangue, optimized proportion of materials, backfilling system and craft in the SCM were studied in the laboratory and then an industrial test was carried out on high quality coal pillars under a town. The results show that finely crushed kaolinized and fresh gangue with granularity less than 5 mm can be used as aggregate with fly ash to replace part of the cement and a composite water reducer as an additive, accounting for 1.0%-1.5% of the total amount of cement and fly ash. The recommended proportion is l(cement):4(fly ash): 15(coal gangue), with a mass fraction of 72%-75%, rheoiogical paste-like properties and a strength of more than 0.7 MPa at 7 d. The sequence of adding cement, fly ash, water reducer and then coal gangue ensures that the suspended state of the slurry, reducing the wear and jam of pipelines. The working face is advancing continuously by the alternating craft of building block walls with coal gangue and backfilling mined-out gobs with paste-like slurry. The recovery rate is as high as 90% with a backfilling cost of 36.9 YuarffL good utilization of coal gangue and no subsidence on the surface. This technology provides a good theoretical basis and application experience for coal mines, cement backfilling with paste-like slurry.
基金supported by National Key Basic Research Program of China (2015CB953601)National Natural Science Foundation of China (41422503, 41276073)+1 种基金the Fundamental Research Funds for the Central Universities (2015XZZX00405)Zhejiang University K. P. Chao's High Technology Development Foundation
文摘Geoengineering (also called climate engineering), which refers to large-scale intervention in the Earth's climate system to counteract greenhouse gas-induced warming, has been one of the most rapidly growing areas of climate research as a potential option for tackling global warming. Here, we provide an overview of the scientific background and research progress of proposed geoengineering schemes. Geo- engineering can be broadly divided into two categories: solar geoengineering (also called solar radiation management, or SRM), which aims to reflect more sunlight to space, and carbon dioxide removal (CDR), which aims to reduce the CO2 content in the atmosphere. First, we review different proposed geoengineering methods involved in the solar radiation management and carbon dioxide removal schemes. Then, we discuss the fundamental science underlying the climate response to the carbon dioxide removal and solar radiation management schemes. We focus on two basic issues: 1) climate response to the reduction in solar irradiance and 2) climate response to the reduction in atmospheric COe. Next, we introduce an ongoing geoengineering research project in China that is supported by National Key Basic Research Program. This research project, being the first coordinated geoengineering research program in China, will systematically investigate the physical mechanisms, climate impacts, and risk and governance of a few targeted geoengineering schemes. It is expected that this research program will help us gain a deep understanding of the physical science underlying geoengineering schemes and the impacts of geoengineering on global climate, in particular, on the Asia monsoon region.
基金Project(51275116)supported by the National Natural Science Foundation of ChinaProject(2012ZE77010)supported by the Aero Science Foundation of ChinaProject(LBH-Q11090)supported by the Postdoctoral Science Research Development Foundation of Heilongjiang Province,China
文摘The electric double layer with the transmission of particles was presented based on the principle of electrochemistry.In accordance with this theory,the cavitation catalysis removal mechanism of ultrasonic-pulse electrochemical compound machining(UPECM) based on particles was proposed.The removal mechanism was a particular focus and was thus validated by experiments.The principles and experiments of UPECM were introduced,and the removal model of the UPECM based on the principles of UPECM was established.Furthermore,the effects of the material removal rate for the main processing parameters,including the particles size,the ultrasonic vibration amplitude,the pulse voltage and the minimum machining gap between the tool and the workpiece,were also studied through UPECM.The results show that the particles promote ultrasonic-pulse electrochemical compound machining and thus act as the catalyzer of UPECM.The results also indicate that the processing speed,machining accuracy and surface quality can be improved under UPECM compound machining.
基金the National Research Foundation(NRF)for financial support during this study
文摘The u Mhlatuzana, u Mbilo and a Manzimnyama river catchments located on the eastern seaboard of the Kwa Zulu-Natal province, South Africa, form the core of urbanization and industrialization, contributing the only natural freshwater inflows to the Bayhead Canal portion of the Durban Harbour. In this study, seasonal discharges and physico–chemical water properties were used to quantitatively determine the material mass transport capacity of the river systems on the basis of hydrographic inputs and chemical loading from the surrounding land use sectors.The mass transport of the total dissolved solids(TDS),ammonia(NH_4), phosphorous(P), aluminum(Al), calcium(Ca), copper(Cu), chromium(Cr), mercury(Hg), potassium(K), magnesium(Mg), sodium(Na), nickel(Ni), lead(Pb), sulphur(S) and vanadium(V) was determined for each river. Results indicated that land use, seasonality and river flow were significant determinants for the material loading in the rivers and the receiving port waters. The spatio-temporal distribution patterns of chemical fluxes indicated that industrial activity associated with the a Manzimnyama canal contributed the most, with regards to TDS, NH_4, Ca, K, Mg, Na, S and V, loading in both wet and dry seasons, as well as Al, Cu, Hg and Pb during the dry season. Similarly, industrial activity associated with the u Mbilo/u Mhlatuzana Canal at the lower reaches accounted for the highest P, Al, Cu and Pb fluxes in the wet season alone. Fluxes of these parameters are used to explain theobserved elemental concentrations and patterns of the receiving port waters of the Bayhead Canal.
文摘The production of chemicals from biomass is a very challenging process due to its diverse chemical composition. Lignin, cellulose and hemicellulose are the three main biopolymers of wood biomass, with cell walls &plant origin. Lignin has been chosen for the present studies due to its range of different linkages and structures. The present work involved a computational study of the most dominant lignin dimers and their vibrational structures, based on the Density Functional Theory method. Full geometry optimization of the compartments used the StoBe code with cluster model and non-local functional (RPBE) approach. The calculations of the vibrational frequencies were performed with harmonic approximations as well as an anharmonicity fit in the Morse potential function, as implemented in the StoBe code. In the case oflignin, the calculations included three different precursors based on: coumaryl alcohol, coniferyl alcohol and sinapyl alcohol. To represent the cellulose and hemicellulose derivatives, selected aldopentoses and aldohexoses (arabinose, xylose, glucose, galactose, and mannose) were considered. Presented here are the theoretical investigations for a variety of biomass derived compounds, to give the possibility of obtaining a theoretical VBD (Vibrations Basis Database) for experimental spectra interpretation. Such a database could be further used in the preliminary composition assessment of biomass derived substrates, which will be discussed here in more detail.
基金supported by the Foundation for Scientific Research Program of AQSIQ's (Grant No. 2007QK30)the CNIS's Program on Basic Research Fund (Grant No.51076S-1467) Study on Feasibility of Establishing the Discipline of StandardizationCNIS's Program on Basic Research Fund (Grant No. 520806s-1648) New Standardization methods under the industrial cluster pattern
文摘Standardization theory is viewed as an element of standardization education. This paper defines the discipline of standardization based on advancements in standardization theory, examines the relationship between the discipline of standardization and standardization education, and predicts trends in standardization.
基金Supported by a grant from the National Natural Science Foundation of Hubei Province (No.2009CDB063)
文摘Objective:Triple-negative breast cancer(estrogen receptor-negative,progesterone receptor-negative and Her2-negative) can be classified into two subtypes:basal and non-basal phenotype.And the basal phenotype is associated with poor outcome.The purpose of this study was to figure out the differences of clinicopathological characters and related factors of prognosis between these two subtypes.Methods:Immunohistochemical staining was performed for the CK5/6,CK17 basal markers and EGFR on biopsy samples from 40 triple-negative patients and the clinicopathology features of these samples were investigated.Results:Seventy percent of the patients were diagnosed as the basal phenotype.Compared with the non-basal phenotype,the basal phenotype lesions were significantly larger in diameter with a high nuclear grade.In the node-negative group the basal phenotype clearly showed the same clinicopathological differences.There was statistically significant concordance among all three antibodies.Conclusion:Expression of basal markers identifies a biologically and clinically distinct subgroup of TN tumors,justifying the use of basal markers to define the basal or the non-basal phenotype.It is important to help the doctor deciding the therapeutic strategy for patient with triple-negative breast cancer.
文摘In this paper, the teaching of course Three-dimensional Animation Foundation is designed mainly based on teaching content modularization and scaffolding teaching model. The modularized content design for Three-dimensional Animation Foundation is specifically expounded, and also the ideas for developing the scaffolding teaching model are analyzed. How to integrate the scaffolding teaching model into course teaching is introduced in details. Finally, new methods for guiding students to think independently in course teaching and improve students' self-awareness and self-learning ability are proposed.
文摘With the globalization of English, the macro and micro cultures of the users of English around the world interact intensively. Considering these conditions, the local and global cultural interface seems an important issue which needs to be clarified in the materials and books used for learning English. Thus, the focus of this study was to explore the language learning policy of the new Iranian English course book at high schools, Prospect 1, recently published and taught for a year in Iran, in light of globalization and culture. This qualitative study was conducted through carrying out semi-structured interviews. The participants of this study were 30 teachers of Ministry of Education, who had the experience of teaching Prospect I for a year and they were mostly chosen from Mashhad and the rest from other cities of Khorasan province, Iran. The interview contained four main questions which were posed to the teachers. The findings of the study indicate that the language learning policy of Iran need to pay more attention to the learners' intercultural communicative competence because it mainly attempts at teaching English language focusing on the home culture in the Iranian context. The article ends with some pedagogical implications and more recommendations for developing research studies.
文摘A dynamic cooperation model of multi-agent is established by combining reinforcement learning with distributed artificial intelligence(DAI),in which the concept of individual optimization loses its meaning because of the dependence of repayment on each agent itself and the choice of other agents.Utilizing the idea of DAI,the intellectual unit of each robot and the change of task and environment,each agent can make decisions independently and finish various complicated tasks by communication and reciprocation between each other.The method is superior to other reinforcement learning methods commonly used in the multi-agent system.It can improve the convergence velocity of reinforcement learning,decrease requirements of computer memory,and enhance the capability of computing and logical ratiocinating for agent.The result of a simulated robot soccer match proves that the proposed cooperative strategy is valid.
文摘The purpose of research study was to develop a theoretical relativistic framework for research in open and flexible learning environment because it is a new dimension in the field of education. Developing a theoretical relativistic framework for any research study is first and prime step in walking on the track to reach the distinction set by the researcher. Open and flexible learning is a new trend in education, enriched with ICT-use as a basic demand of the 21st century generation in all parts of the globe. So, it requires a theoretical framework for its initiation, implementation, development and evaluation which is relatively developed and advanced from the existing framework. In any research study the literature review is carried out in order to develop, build or construct a theoretical framework. The researcher of the study has observed while attending the international conference on ODL (AAOU, 2013) that most of the studies require theoretical underpinning for ICT-use in education. The researcher assume that being a new trend in education to use ICT for teaching learning purpose; it requires conceptual clarity and theoretical background of the user and researcher, because, without theory the practice is wastage of money, time and energy and it becomes ineffective and requires relatively new conceptual development. So, the problem stated by the researcher for the study was: Developing theoretical relativistic framework for research in open and flexible learning: A new trend in educational research. The objective of the study was integrating the interrelated concepts to build a pnemonological network for identifying the constructs in ICT-rich open and flexible learning environment. The study was significant because it provided theoretical background for conducting research in ICT-use for teaching and learning through open and flexible systems; whether blended or online learning and training. The methodology used by the researcher was qualitative and interpretive because there were reviewing of literature and meta-analysis for building the framework. The data were analyzed and interpreted by the researcher for the findings and drawing conclusions. On the basis of conclusions the researcher has made suggestions and recommendations for conducting research in open and flexible learning environment by using this theoretical relativistic framework. The framework was named as Virtual Learning Environment Framework (VLEF).