The construction of advanced laboratories for precision instruments, such as electron microscopes, involves unique challenges that are influenced by the specific environmental conditions required for optimal functiona...The construction of advanced laboratories for precision instruments, such as electron microscopes, involves unique challenges that are influenced by the specific environmental conditions required for optimal functionality. These include mitigating interference from magnetic fields and vibrations, which are critical for maintaining the precision and accuracy of the instruments used. This study aims to offer enhanced project management strategies and detailed construction solutions that address the environmental and technical needs specific to electron microscopy labs, thereby facilitating effective lab operations and extending the lifecycle of high-end precision instruments. Case studies of existing laboratory constructions, onsite investigations, and comprehensive reviews of the technical and environmental requirements provide the basis for a best practice for constructing sophisticated electron microscopy labs. The approach integrates both pre-construction planning and post-construction adjustments to create optimal operational environments. The findings suggest that successful lab constructions are those that incorporate thorough onsite assessments, strategic location choices, and the use of advanced construction materials and techniques specifically designed to counteract environmental challenges like magnetic and vibration interferences. Actionable guidelines for both planning and executing the construction of electron microscope labs highlighted in this tutorial are intended as an important resource to troubleshoot or upgrade existing lab facilities and to consult in preparation of future lab construction projects.展开更多
With the rapid development of globalization and information technology,intellectual property has been one of the key drivers of economic growth,and the construction of intellectual property system has become an import...With the rapid development of globalization and information technology,intellectual property has been one of the key drivers of economic growth,and the construction of intellectual property system has become an important criterion for measuring the quality of business environment.This article is intended to explore the current status of intellectual property system construction in China,the challenges,and its relationship with the business environment,to propose the corresponding countermeasures and suggestions.The study finds that the legal system of intellectual property in China is gradually improving,and judicial and administrative protection are continuously strengthened.However,the challenges still remain such as frequent infringements,rights hard to protect and insufficient international cooperation.These issues not only affect the legitimate rights and interests of innovation entities,but also for the market fairness and the level of the business environment.Therefore,this article proposes that strengthening the perfection of the intellectual property legal system,enhancing intellectual property services and support capabilities,strengthening international cooperation and exchanges,and accelerating the cultivation of composite talents.It aims to provide theoretical references for the construction of intellectual property system and the optimization of the business environment,promote the high-quality development of economy and enhance the global competitiveness of the country.展开更多
Yunnan is one of the most typical mountalnous provinces in western Chi-na. For the geographical features of mountalnous areas accounting for most parts and fIatIand areas accounting for smal parts, the contradiction b...Yunnan is one of the most typical mountalnous provinces in western Chi-na. For the geographical features of mountalnous areas accounting for most parts and fIatIand areas accounting for smal parts, the contradiction between farmIand protection and construction guarantee is very prominent. In the first half of 2011, Yunnan Province estabIished creativeIy the strategy of "protecting farmIand in fIat-Iand areas and constructing mountalnous cities" (hereinafter referred to as the strat-egy of "constructing mountalnous cities"), which was almed at protecting effectiveIy the Iimited and high quality arabIe Iand resources in fIatIand area and providing new construction area for new type of urbanization and industrialization, so as to achieve win-win situation between arabIe Iand protection and urbanization deveIopment. Im-pIementing this strategy in Yunnan Province is feasibIe, malnIy in the Iarge deveIop-ment potentials in the gentIe gradient between 8° to 25°. The gentIe sIope area be-tween 8° to 25° occupies 51% of the total Iand area in Yunnan Province, which is almost 140 times of the area of urban construction Iand in Yunnan in 2009. The surrounding areas of fIatIand or maln town in most counties (cities, regions) dis-tribute with different sizes of Iow hiI s and gentIe sIopes, thus mountalnous construc-tion Iand reserves are abundant, which benefits for impeI ing the strategy of "con-structing mountalnous cities" in the Iight of Iocal conditions.展开更多
In this study, we reported the repaid construction of a molecular marker linkage map of rice (Oryza sativa L.). An F-2 population from the cross between Annong S-1 and Nanjing 11 was used to construct a genetic linkag...In this study, we reported the repaid construction of a molecular marker linkage map of rice (Oryza sativa L.). An F-2 population from the cross between Annong S-1 and Nanjing 11 was used to construct a genetic linkage map of rice. Total of 142 newly screened AFLP markers and 30 anchor markers (25 SSR markers and 5 RFLP markers) were mapped on the 12 chromosomes covering 1537.4 cM of rice genome. The average interval between these markers was 9.0 cM. The total work which usually was finished in more than one year was finished within only 3 months by one person. This is the first plant AFLP map developed in China. A new thermosensitive genic male sterile gene in rice, tms5, was Egged and mapped onto chromosome 2 during the development of the linkage map.展开更多
According to the particularity of towns' construction in the southwestern mountainous areas of Yunnan Province, this study has built constructive land suit- ability evaluation index system which is different to flat ...According to the particularity of towns' construction in the southwestern mountainous areas of Yunnan Province, this study has built constructive land suit- ability evaluation index system which is different to flat area. Then this study deter- mined single evaluation factors index and comprehensive suitability index using "ex- treme conditions method" and "suitability index method", and analyzed and assessed the constructive land suitability on each evaluation unit polygons and its suitability level by using GIS software. Taking Lianghe County of Dehong Dai-Jingpo Au- tonomous Prefecture as an example to evaluate land suitability in Lianghe County's main towns around the gentle slope, the results show, in the evaluation area, the area of land suitable for construction and unsuitable for construction respectively ac- count 73.58% and 26.42%. And first-class, second and third-class of land suitable for construction should be composited at the ratio of about 11:49:40. The suitability evaluation index system and method developed in this paper is applicable for evalu- ating the construction land suitability in mountainous areas of southwest Yunnan Province, and will provide theoretical and technical support for land policy measures which strengthen the protection of farmland and promote the scientific development of urbanization in Yunnan Province and even similar mountainous areas of the whole China.展开更多
In 2011, Yunnan provincial committee and government proposed the strat- egy of constructing mountainous cities in order to protect farmlands and guarantee crop safety, which makes full use of hills and gentle-slopes a...In 2011, Yunnan provincial committee and government proposed the strat- egy of constructing mountainous cities in order to protect farmlands and guarantee crop safety, which makes full use of hills and gentle-slopes and transforms land use pattern. However, social and economic development performs unevenly in Yun- nan, supplemented by varied geographical conditions, so that constructing mountain- ous cities should proceed as per local conditions. The research proposed the con- trol of constructing mountainous cities provided crop safety under the principle of farmland protection and measured the quantities of demanded construction lands ac- cording to science of population prediction and ekistics, based on which the control scales of constructing mountainous cities were determined by multiplying basic farm- land coefficient and the area of newly increased construction lands. The research is of significance for guiding the construction of mountainous cities and avoiding the occupation of construction lands on farmlands.展开更多
This paper expounds the practical necessity of constructing diversified rural food safety supervision system as follows: it is the necessary requirements of guaranteeing people's health and life safety; it is an i...This paper expounds the practical necessity of constructing diversified rural food safety supervision system as follows: it is the necessary requirements of guaranteeing people's health and life safety; it is an important component of governmental function of social management and the logical extension of administrative responsibilities; it is the basis of maintaining order of rural society and constructing harmonious society. The main problems existing in the supervision of rural food safety are analyzed as follows: first, the legislative work of rural food safety lags behind to some extent; second, the supervision of governmental departments on rural food safety is insufficient; third, the industrial supervision mechanism of rural food security is not perfect; fourth, the role of rural social organizations in supervising food safety is limited; fifth, the farmers' awareness of food safety supervision is not strong. Based on these problems, the targeted strategies of constructing diversified rural food safety supervision system are put forward as follows: accelerate the legislation of rural food safety, and ensure that there are laws to go by; give play to the dominant role of government, and strengthen administrative supervision on rural food safety; perfect industrial convention of rural food safety, and improve industrial supervision mechanism; actively support the fostering of social organizations, and give play to the role of supervision of organizations; cultivate correct concept of rights and obligations of farmers, and form awareness of food safety supervision.展开更多
The construction of rural residents' living style is the fundamental significance of building the new socialist countryside. With the deep development of the urban and rural, rural residents' living style has change...The construction of rural residents' living style is the fundamental significance of building the new socialist countryside. With the deep development of the urban and rural, rural residents' living style has changed profoundly on the labour, consumption, entertainment, marriage and family, etc., and the differences of living style between the urban and rural are becoming smaller and smaller. Therefore, this paper suggested to promote the rural residents to build the scientific, cultural and healthy modern life style, and put forward the rational development thoughts.展开更多
The theory of quantum error correcting codes is a primary tool for fighting decoherence and other quantum noise in quantum communication and quantum computation. Recently, the theory of quantum error correcting codes ...The theory of quantum error correcting codes is a primary tool for fighting decoherence and other quantum noise in quantum communication and quantum computation. Recently, the theory of quantum error correcting codes has developed rapidly and been extended to protect quantum information over asymmetric quantum channels, in which phase-shift and qubit-flip errors occur with different probabilities. In this paper, we generalize the construction of symmetric quantum codes via graphs (or matrices) to the asymmetric case, converting the construction of asymmetric quantum codes to finding matrices with some special properties. We also propose some asymmetric quantum Maximal Distance Separable (MDS) codes as examples constructed in this way.展开更多
In typical Wi-Fi based indoor positioning systems employing fingerprint model,plentiful fingerprints need to be trained by trained experts or technician,which extends labor costs and restricts their promotion.In this ...In typical Wi-Fi based indoor positioning systems employing fingerprint model,plentiful fingerprints need to be trained by trained experts or technician,which extends labor costs and restricts their promotion.In this paper,a novel approach based on crowd paths to solve this problem is presented,which collects and constructs automatically fingerprints database for anonymous buildings through common crowd customers.However,the accuracy degradation problem may be introduced as crowd customers are not professional trained and equipped.Therefore,we define two concepts:fixed landmark and hint landmark,to rectify the fingerprint database in the practical system,in which common corridor crossing points serve as fixed landmark and cross point among different crowd paths serve as hint landmark.Machinelearning techniques are utilized for short range approximation around fixed landmarks and fuzzy logic decision technology is applied for searching hint landmarks in crowd traces space.Besides,the particle filter algorithm is also introduced to smooth the sample points in crowd paths.We implemented the approach on off-the-shelf smartphones and evaluate the performance.Experimental results indicate that the approach can availably construct WiFi fingerprint database without reduce the localization accuracy.展开更多
With the mine exploitation depth getting deeper and deeper, the mine heat-harm turns into another natural disaster after the five disasters, which are the roof, the gas, the fire, the dust and the flood disaster. Comp...With the mine exploitation depth getting deeper and deeper, the mine heat-harm turns into another natural disaster after the five disasters, which are the roof, the gas, the fire, the dust and the flood disaster. Compared with other researches on prevention and cure against the heat-harm, the research on prevention and cure against the heat-harm in constructing mine are less. Referring to the experience of prevention and cure against the heat-harm home and 'abroad, analyzing the characteristic of cooling in the constructing mine, and based on the ground former freezing equipments and the modified mine temporary cooling equipments, the paper proposed four technical projects. By comparing with the four technical projects, the second project is preponderant both in technology and economy and can solve the heat-harm of the constructing mine, which is proved by the forecast and calculation. The project can be widely applied in de-temperature tasks of high temperature and heat-harm mines during the mine constructing period and in the exploiting preparing phase.展开更多
A teaching model based on constructivism is proposed in this paper. The model contains five teaching steps, e.g. interpretation teaching, questioning- dialogue, knowledge and skills teaching, discussion- collaboration...A teaching model based on constructivism is proposed in this paper. The model contains five teaching steps, e.g. interpretation teaching, questioning- dialogue, knowledge and skills teaching, discussion- collaboration and field training. Practice proves that it can effectively improve the training efficiency of the training of English guides of stone inscription relics and enhance their interpretation quality and English skills.展开更多
The European Union(EU)seeks to build a Europe fit for the digital age.For this purpose,the EU has accelerated the process of catching up with digital technology and issued a number of legal and regulatory documents to...The European Union(EU)seeks to build a Europe fit for the digital age.For this purpose,the EU has accelerated the process of catching up with digital technology and issued a number of legal and regulatory documents to establish a digital governance rule regime with EU characteristics.This paper analyzes the EU’s path towards the construction of digital governance rules.This path is composed of three aspects,i.e.,strict digital supervision,differentiation of the free market,and multi-stakeholder governance.This three-step path has intrinsic logical implications.That is,strict digital supervision is applied to defend the EU’s unified market and values;differentiation of the free market takes the principle of adequate protection as the core to make the EU an exporter of rules;multi-stakeholder governance brings multiple stakeholders together in the governance to deal with the ethical anomie that arises during the use of big data.By setting up a series of digital governance rules,the EU seeks to achieve rule dominance to gain regulatory power for global digital governance.However,due to multiple constraints,there is a long way to go,and there are obstacles in the way.展开更多
The construction of extraterrestrial bases has become a new goal in the active exploration of deep space.Among the construction techniques,in situ resource-based construction is one of the most promising because of it...The construction of extraterrestrial bases has become a new goal in the active exploration of deep space.Among the construction techniques,in situ resource-based construction is one of the most promising because of its good sustainability and acceptable economic cost,triggering the development of various types of extraterrestrial construction materials.A comprehensive survey and comparison of materials from the perspective of performance was conducted to provide suggestions for material selection and optimization.Thirteen types of typical construction materials are discussed in terms of their reliability and applicability in extreme extraterrestrial environment.Mechanical,thermal and optical,and radiation-shielding properties are considered.The influencing factors and optimization methods for these properties are analyzed.From the perspective of material properties,the existing challenges lie in the comprehensive,long-term,and real characterization of regolith-based construction materials.Correspondingly,the suggested future directions include the application of high-throughput characterization methods,accelerated durability tests,and conducting extraterrestrial experiments.展开更多
In order to study the constructing technology of virtual production line, the structure model of virtual production line was presented, and the object oriented technique was used to establish its basic classes and re...In order to study the constructing technology of virtual production line, the structure model of virtual production line was presented, and the object oriented technique was used to establish its basic classes and relevant models, including solid model, behavior model and object oriented Petri net based control model, and based on this, the constructing of virtual production line was realized. The application proved that the virtual production line had many good characteristics, such as visualization, interaction, multi layer and reusability, and it's an efficient tool of analyzing and modeling for layout planning and rapidly reconfiguring of production line.展开更多
Three-dimensional(3D)printing is a highly automated platform that facilitates material deposition in a layer-by-layer approach to fabricate pre-defined 3D complex structures on demand.It is a highly promising techniqu...Three-dimensional(3D)printing is a highly automated platform that facilitates material deposition in a layer-by-layer approach to fabricate pre-defined 3D complex structures on demand.It is a highly promising technique for the fabrication of personalized medical devices or even patient-specific tissue constructs.Each type of 3D printing technique has its unique advantages and limitations,and the selection of a suitable 3D printing technique is highly dependent on its intended application.In this review paper,we present and highlight some of the critical processes(printing parameters,build orientation,build location,and support structures),material(batch-to-batch consistency,recycling,protein adsorption,biocompatibility,and degradation properties),and regulatory considerations(sterility and mechanical properties)for 3D printing of personalized medical devices.The goal of this review paper is to provide the readers with a good understanding of the various key considerations(process,material,and regulatory)in 3D printing,which are critical for the fabrication of improved patient-specific 3D printed medical devices and tissue constructs.展开更多
Constructed wetlands(CwW)are well known nature-based systems for water treatment.This study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in Jar...Constructed wetlands(CwW)are well known nature-based systems for water treatment.This study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in Jarabacoa,the Dominican Republic.The results showed that the CWs were efficient in reducing the degree of contamination of wastewater to levels below the Dominican wastewater discharge standards for parameters such as the 5-day biochemical oxygen demand(BOD5)and chemical oxygen demand,but not for the removal of phosphorus and fecal coliforms.In addition,a horizontal flow subsurface wetland in the peri-urban area El Dorado was evaluated in terms of the performance of wastewater treatment in tropical climatic conditions.The concentrations of heavy metals,such as zinc,copper,chromium,and iron,were found to decrease in the effluent of the wetland,and the concentrations for nickel and manganese tended to increase.The levels of heavy metals in the effluent were lower than the limit values of the Dominican wastewater discharge standards.The construction cost of these facilities was around 200 USD per population equivalent,similar to the cost in other countries in the same region.This study suggested some solutions to the improved performance of CWs:selection of a microbial flora that guarantees the reduction of nitrates and nitrites to molecular nitrogen,use of endemic plants that bioaccumulate heavy metals,combination of constructed wetlands with filtration on activated carbon,and inclusion of water purification processes that allow to evaluate the reuse of treated water.展开更多
Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capa...Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capacity.Based on panel data from 31 sample provinces,autonomous regions,and municipalities in China from 2005–2017,this study explored the impact of HSFC on grain yield using the difference-in-differences(DID)method.The results showed that HSFC significantly increased total grain production,which is robust to various checks.HSFC increased grain yield through three potential mechanisms.First,it could increase the grain replanting index.Second,it could effectively reduce yield loss due to droughts and floods.Last,HSFC could strengthen the cultivated land by renovating the low-and medium-yielding fields.Heterogeneity analysis found that the HSFC farmland showed a significant increase in grain yield only in the main grain-producing areas and balanced areas.In addition,HSFC significantly increased the yields of rice,wheat,and maize while leading to a reduction in soybean yields.The findings suggest the government should continue to promote HSFC,improve construction standards,and strictly control the“non-agriculturalization”and“non-coordination”of farmland to increase grain production further.At the same time,market mechanisms should be used to incentivize soybean farming,improve returns and stabilize soybean yields.展开更多
This paper introduces the model of China's direct grain subsidy policy, adopts computable general equilibrium (CGE) theory, and advances the scheme of constructing the model of China's direct grain subsidy pol...This paper introduces the model of China's direct grain subsidy policy, adopts computable general equilibrium (CGE) theory, and advances the scheme of constructing the model of China's direct grain subsidy policy. On the basis of some assumptions, such as conforming to the complete competition of market, inexistence of move of capital and labor forces among countries, unchanged exchange rate and incomplete substitution, and the main body of behavior comprising representative households, producers, local government and central government, the model established in this paper includes production module and demand module. Moreover, the model takes into account equilibrium structure, the definition of profiting and macro condition for closure, the related coefficients this CGE model needs include Armingtion substitution elasticity of intermediate composite product, investment composite product and consumption composite product between import and domestic production; substitution elasticity among production factors; conversion elasticity of total sales between domestic absorption and export; elasticity of residents' expenditure; elasticity of price; elasticity of export demand; the relative share of all sectors in capital stock. This paper also points out the advantages and limitations of CGE model in analyzing direct grain subsidy policy.展开更多
The Moon,as the closest celestial body to the Earth,plays a pivotal role in the progression of deep space exploration,and the establishment of research outposts on its surface represents a crucial step in this mission...The Moon,as the closest celestial body to the Earth,plays a pivotal role in the progression of deep space exploration,and the establishment of research outposts on its surface represents a crucial step in this mission.Lunar lava tubes are special underground caves formed by volcanic eruptions and are considered as ideal natural shelters and scientific laboratories for lunar base construction.This paper begins with an in-depth overview of the geological origins,exploration history,and distribution locations of lunar lava tubes.Subsequently,it delves into the presentation of four distinctive advantages and typical concepts for constructing bases within lava tubes,summarizing the ground-based attempts made thus far in lunar lava tube base construction.Field studies conducted on a lava tube in Hainan revealed rock compositions similar to those found during the Apollo missions and clear lava tube structures,making it a promising analog site.Lastly,the challenges and opportunities encountered in the field of geotechnical engineering regarding the establishment of lunar lava tube bases are discussed,encompassing cave exploration technologies,in-situ testing methods,geomechanical properties under lunar extreme environments,base design and structural stability assessment,excavation and reinforcement techniques,and simulated Earth-based lava tube base.展开更多
文摘The construction of advanced laboratories for precision instruments, such as electron microscopes, involves unique challenges that are influenced by the specific environmental conditions required for optimal functionality. These include mitigating interference from magnetic fields and vibrations, which are critical for maintaining the precision and accuracy of the instruments used. This study aims to offer enhanced project management strategies and detailed construction solutions that address the environmental and technical needs specific to electron microscopy labs, thereby facilitating effective lab operations and extending the lifecycle of high-end precision instruments. Case studies of existing laboratory constructions, onsite investigations, and comprehensive reviews of the technical and environmental requirements provide the basis for a best practice for constructing sophisticated electron microscopy labs. The approach integrates both pre-construction planning and post-construction adjustments to create optimal operational environments. The findings suggest that successful lab constructions are those that incorporate thorough onsite assessments, strategic location choices, and the use of advanced construction materials and techniques specifically designed to counteract environmental challenges like magnetic and vibration interferences. Actionable guidelines for both planning and executing the construction of electron microscope labs highlighted in this tutorial are intended as an important resource to troubleshoot or upgrade existing lab facilities and to consult in preparation of future lab construction projects.
基金Guizhou Provincial University Humanities and Social Sciences Research Project in 2024"Enhancing the Development of New Productive Forces through University Technological Innovation and Intellectual Property Management"(2024RW256)Guizhou University of Commerce Research Project in 2022"Study on the Ideas and Pathways to Drive Agricultural Powerhouse through Digital Economy"(2022XJZX315)。
文摘With the rapid development of globalization and information technology,intellectual property has been one of the key drivers of economic growth,and the construction of intellectual property system has become an important criterion for measuring the quality of business environment.This article is intended to explore the current status of intellectual property system construction in China,the challenges,and its relationship with the business environment,to propose the corresponding countermeasures and suggestions.The study finds that the legal system of intellectual property in China is gradually improving,and judicial and administrative protection are continuously strengthened.However,the challenges still remain such as frequent infringements,rights hard to protect and insufficient international cooperation.These issues not only affect the legitimate rights and interests of innovation entities,but also for the market fairness and the level of the business environment.Therefore,this article proposes that strengthening the perfection of the intellectual property legal system,enhancing intellectual property services and support capabilities,strengthening international cooperation and exchanges,and accelerating the cultivation of composite talents.It aims to provide theoretical references for the construction of intellectual property system and the optimization of the business environment,promote the high-quality development of economy and enhance the global competitiveness of the country.
基金Supported by National Natural Science Foundation of China(41261018)~~
文摘Yunnan is one of the most typical mountalnous provinces in western Chi-na. For the geographical features of mountalnous areas accounting for most parts and fIatIand areas accounting for smal parts, the contradiction between farmIand protection and construction guarantee is very prominent. In the first half of 2011, Yunnan Province estabIished creativeIy the strategy of "protecting farmIand in fIat-Iand areas and constructing mountalnous cities" (hereinafter referred to as the strat-egy of "constructing mountalnous cities"), which was almed at protecting effectiveIy the Iimited and high quality arabIe Iand resources in fIatIand area and providing new construction area for new type of urbanization and industrialization, so as to achieve win-win situation between arabIe Iand protection and urbanization deveIopment. Im-pIementing this strategy in Yunnan Province is feasibIe, malnIy in the Iarge deveIop-ment potentials in the gentIe gradient between 8° to 25°. The gentIe sIope area be-tween 8° to 25° occupies 51% of the total Iand area in Yunnan Province, which is almost 140 times of the area of urban construction Iand in Yunnan in 2009. The surrounding areas of fIatIand or maln town in most counties (cities, regions) dis-tribute with different sizes of Iow hiI s and gentIe sIopes, thus mountalnous construc-tion Iand reserves are abundant, which benefits for impeI ing the strategy of "con-structing mountalnous cities" in the Iight of Iocal conditions.
文摘In this study, we reported the repaid construction of a molecular marker linkage map of rice (Oryza sativa L.). An F-2 population from the cross between Annong S-1 and Nanjing 11 was used to construct a genetic linkage map of rice. Total of 142 newly screened AFLP markers and 30 anchor markers (25 SSR markers and 5 RFLP markers) were mapped on the 12 chromosomes covering 1537.4 cM of rice genome. The average interval between these markers was 9.0 cM. The total work which usually was finished in more than one year was finished within only 3 months by one person. This is the first plant AFLP map developed in China. A new thermosensitive genic male sterile gene in rice, tms5, was Egged and mapped onto chromosome 2 during the development of the linkage map.
基金Supported by National Natural Science Foundation of China(41261018)Lianghe Government Authorized Project~~
文摘According to the particularity of towns' construction in the southwestern mountainous areas of Yunnan Province, this study has built constructive land suit- ability evaluation index system which is different to flat area. Then this study deter- mined single evaluation factors index and comprehensive suitability index using "ex- treme conditions method" and "suitability index method", and analyzed and assessed the constructive land suitability on each evaluation unit polygons and its suitability level by using GIS software. Taking Lianghe County of Dehong Dai-Jingpo Au- tonomous Prefecture as an example to evaluate land suitability in Lianghe County's main towns around the gentle slope, the results show, in the evaluation area, the area of land suitable for construction and unsuitable for construction respectively ac- count 73.58% and 26.42%. And first-class, second and third-class of land suitable for construction should be composited at the ratio of about 11:49:40. The suitability evaluation index system and method developed in this paper is applicable for evalu- ating the construction land suitability in mountainous areas of southwest Yunnan Province, and will provide theoretical and technical support for land policy measures which strengthen the protection of farmland and promote the scientific development of urbanization in Yunnan Province and even similar mountainous areas of the whole China.
基金Supported by National Natural Science Foundation of China(41261018)Scientific Research Foundation of Yunnan Education Committee(2015YUFEYC011)~~
文摘In 2011, Yunnan provincial committee and government proposed the strat- egy of constructing mountainous cities in order to protect farmlands and guarantee crop safety, which makes full use of hills and gentle-slopes and transforms land use pattern. However, social and economic development performs unevenly in Yun- nan, supplemented by varied geographical conditions, so that constructing mountain- ous cities should proceed as per local conditions. The research proposed the con- trol of constructing mountainous cities provided crop safety under the principle of farmland protection and measured the quantities of demanded construction lands ac- cording to science of population prediction and ekistics, based on which the control scales of constructing mountainous cities were determined by multiplying basic farm- land coefficient and the area of newly increased construction lands. The research is of significance for guiding the construction of mountainous cities and avoiding the occupation of construction lands on farmlands.
文摘This paper expounds the practical necessity of constructing diversified rural food safety supervision system as follows: it is the necessary requirements of guaranteeing people's health and life safety; it is an important component of governmental function of social management and the logical extension of administrative responsibilities; it is the basis of maintaining order of rural society and constructing harmonious society. The main problems existing in the supervision of rural food safety are analyzed as follows: first, the legislative work of rural food safety lags behind to some extent; second, the supervision of governmental departments on rural food safety is insufficient; third, the industrial supervision mechanism of rural food security is not perfect; fourth, the role of rural social organizations in supervising food safety is limited; fifth, the farmers' awareness of food safety supervision is not strong. Based on these problems, the targeted strategies of constructing diversified rural food safety supervision system are put forward as follows: accelerate the legislation of rural food safety, and ensure that there are laws to go by; give play to the dominant role of government, and strengthen administrative supervision on rural food safety; perfect industrial convention of rural food safety, and improve industrial supervision mechanism; actively support the fostering of social organizations, and give play to the role of supervision of organizations; cultivate correct concept of rights and obligations of farmers, and form awareness of food safety supervision.
基金Supported by Harbin Experts and Advisors Council Project (2008)
文摘The construction of rural residents' living style is the fundamental significance of building the new socialist countryside. With the deep development of the urban and rural, rural residents' living style has changed profoundly on the labour, consumption, entertainment, marriage and family, etc., and the differences of living style between the urban and rural are becoming smaller and smaller. Therefore, this paper suggested to promote the rural residents to build the scientific, cultural and healthy modern life style, and put forward the rational development thoughts.
基金supported by the National High Technology Research and Development Program of China under Grant No. 2011AA010803
文摘The theory of quantum error correcting codes is a primary tool for fighting decoherence and other quantum noise in quantum communication and quantum computation. Recently, the theory of quantum error correcting codes has developed rapidly and been extended to protect quantum information over asymmetric quantum channels, in which phase-shift and qubit-flip errors occur with different probabilities. In this paper, we generalize the construction of symmetric quantum codes via graphs (or matrices) to the asymmetric case, converting the construction of asymmetric quantum codes to finding matrices with some special properties. We also propose some asymmetric quantum Maximal Distance Separable (MDS) codes as examples constructed in this way.
基金partially sponsored by National Key Project of China (No.2012ZX03001013-003)
文摘In typical Wi-Fi based indoor positioning systems employing fingerprint model,plentiful fingerprints need to be trained by trained experts or technician,which extends labor costs and restricts their promotion.In this paper,a novel approach based on crowd paths to solve this problem is presented,which collects and constructs automatically fingerprints database for anonymous buildings through common crowd customers.However,the accuracy degradation problem may be introduced as crowd customers are not professional trained and equipped.Therefore,we define two concepts:fixed landmark and hint landmark,to rectify the fingerprint database in the practical system,in which common corridor crossing points serve as fixed landmark and cross point among different crowd paths serve as hint landmark.Machinelearning techniques are utilized for short range approximation around fixed landmarks and fuzzy logic decision technology is applied for searching hint landmarks in crowd traces space.Besides,the particle filter algorithm is also introduced to smooth the sample points in crowd paths.We implemented the approach on off-the-shelf smartphones and evaluate the performance.Experimental results indicate that the approach can availably construct WiFi fingerprint database without reduce the localization accuracy.
文摘With the mine exploitation depth getting deeper and deeper, the mine heat-harm turns into another natural disaster after the five disasters, which are the roof, the gas, the fire, the dust and the flood disaster. Compared with other researches on prevention and cure against the heat-harm, the research on prevention and cure against the heat-harm in constructing mine are less. Referring to the experience of prevention and cure against the heat-harm home and 'abroad, analyzing the characteristic of cooling in the constructing mine, and based on the ground former freezing equipments and the modified mine temporary cooling equipments, the paper proposed four technical projects. By comparing with the four technical projects, the second project is preponderant both in technology and economy and can solve the heat-harm of the constructing mine, which is proved by the forecast and calculation. The project can be widely applied in de-temperature tasks of high temperature and heat-harm mines during the mine constructing period and in the exploiting preparing phase.
文摘A teaching model based on constructivism is proposed in this paper. The model contains five teaching steps, e.g. interpretation teaching, questioning- dialogue, knowledge and skills teaching, discussion- collaboration and field training. Practice proves that it can effectively improve the training efficiency of the training of English guides of stone inscription relics and enhance their interpretation quality and English skills.
文摘The European Union(EU)seeks to build a Europe fit for the digital age.For this purpose,the EU has accelerated the process of catching up with digital technology and issued a number of legal and regulatory documents to establish a digital governance rule regime with EU characteristics.This paper analyzes the EU’s path towards the construction of digital governance rules.This path is composed of three aspects,i.e.,strict digital supervision,differentiation of the free market,and multi-stakeholder governance.This three-step path has intrinsic logical implications.That is,strict digital supervision is applied to defend the EU’s unified market and values;differentiation of the free market takes the principle of adequate protection as the core to make the EU an exporter of rules;multi-stakeholder governance brings multiple stakeholders together in the governance to deal with the ethical anomie that arises during the use of big data.By setting up a series of digital governance rules,the EU seeks to achieve rule dominance to gain regulatory power for global digital governance.However,due to multiple constraints,there is a long way to go,and there are obstacles in the way.
基金supported by the National Key Research and Development Program of China(2023YFB3711300 and 2021YFF0500300)the Strategic Research and Consulting Project of the Chinese Academy of Engineering(2023-XZ-90 and 2023-JB-09-10)the National Key Research and Development Program of China(2021YFF0500300).
文摘The construction of extraterrestrial bases has become a new goal in the active exploration of deep space.Among the construction techniques,in situ resource-based construction is one of the most promising because of its good sustainability and acceptable economic cost,triggering the development of various types of extraterrestrial construction materials.A comprehensive survey and comparison of materials from the perspective of performance was conducted to provide suggestions for material selection and optimization.Thirteen types of typical construction materials are discussed in terms of their reliability and applicability in extreme extraterrestrial environment.Mechanical,thermal and optical,and radiation-shielding properties are considered.The influencing factors and optimization methods for these properties are analyzed.From the perspective of material properties,the existing challenges lie in the comprehensive,long-term,and real characterization of regolith-based construction materials.Correspondingly,the suggested future directions include the application of high-throughput characterization methods,accelerated durability tests,and conducting extraterrestrial experiments.
文摘In order to study the constructing technology of virtual production line, the structure model of virtual production line was presented, and the object oriented technique was used to establish its basic classes and relevant models, including solid model, behavior model and object oriented Petri net based control model, and based on this, the constructing of virtual production line was realized. The application proved that the virtual production line had many good characteristics, such as visualization, interaction, multi layer and reusability, and it's an efficient tool of analyzing and modeling for layout planning and rapidly reconfiguring of production line.
文摘Three-dimensional(3D)printing is a highly automated platform that facilitates material deposition in a layer-by-layer approach to fabricate pre-defined 3D complex structures on demand.It is a highly promising technique for the fabrication of personalized medical devices or even patient-specific tissue constructs.Each type of 3D printing technique has its unique advantages and limitations,and the selection of a suitable 3D printing technique is highly dependent on its intended application.In this review paper,we present and highlight some of the critical processes(printing parameters,build orientation,build location,and support structures),material(batch-to-batch consistency,recycling,protein adsorption,biocompatibility,and degradation properties),and regulatory considerations(sterility and mechanical properties)for 3D printing of personalized medical devices.The goal of this review paper is to provide the readers with a good understanding of the various key considerations(process,material,and regulatory)in 3D printing,which are critical for the fabrication of improved patient-specific 3D printed medical devices and tissue constructs.
基金support of the Yaque del Norte Water Fund(FAYN),INTEC(Grant No.CBA-330810-2020-P-1)Fondo Dominicano de Ciencia y Tecnologia(FONDOCYT)(Grant No.2022-2B2-161)。
文摘Constructed wetlands(CwW)are well known nature-based systems for water treatment.This study evaluated the efficiency and effectiveness of seven domestic wastewater treatment systems based on horizontal flow CWs in Jarabacoa,the Dominican Republic.The results showed that the CWs were efficient in reducing the degree of contamination of wastewater to levels below the Dominican wastewater discharge standards for parameters such as the 5-day biochemical oxygen demand(BOD5)and chemical oxygen demand,but not for the removal of phosphorus and fecal coliforms.In addition,a horizontal flow subsurface wetland in the peri-urban area El Dorado was evaluated in terms of the performance of wastewater treatment in tropical climatic conditions.The concentrations of heavy metals,such as zinc,copper,chromium,and iron,were found to decrease in the effluent of the wetland,and the concentrations for nickel and manganese tended to increase.The levels of heavy metals in the effluent were lower than the limit values of the Dominican wastewater discharge standards.The construction cost of these facilities was around 200 USD per population equivalent,similar to the cost in other countries in the same region.This study suggested some solutions to the improved performance of CWs:selection of a microbial flora that guarantees the reduction of nitrates and nitrites to molecular nitrogen,use of endemic plants that bioaccumulate heavy metals,combination of constructed wetlands with filtration on activated carbon,and inclusion of water purification processes that allow to evaluate the reuse of treated water.
基金supported by the National Natural Science Foundation of China(41871184)the National Social Science Fund of China(21ZDA056)the Scientific and Technological Innovation Project of the Chinese Academy of Agricultural Sciences(10-IAED-ZT-01-2023and 10-IAED-RC-07-2023)。
文摘Food security is a strategic priority for a country’s economic development.In China,high-standard farmland construction(HSFC)is an important initiative to stabilize grain production and increase grain production capacity.Based on panel data from 31 sample provinces,autonomous regions,and municipalities in China from 2005–2017,this study explored the impact of HSFC on grain yield using the difference-in-differences(DID)method.The results showed that HSFC significantly increased total grain production,which is robust to various checks.HSFC increased grain yield through three potential mechanisms.First,it could increase the grain replanting index.Second,it could effectively reduce yield loss due to droughts and floods.Last,HSFC could strengthen the cultivated land by renovating the low-and medium-yielding fields.Heterogeneity analysis found that the HSFC farmland showed a significant increase in grain yield only in the main grain-producing areas and balanced areas.In addition,HSFC significantly increased the yields of rice,wheat,and maize while leading to a reduction in soybean yields.The findings suggest the government should continue to promote HSFC,improve construction standards,and strictly control the“non-agriculturalization”and“non-coordination”of farmland to increase grain production further.At the same time,market mechanisms should be used to incentivize soybean farming,improve returns and stabilize soybean yields.
文摘This paper introduces the model of China's direct grain subsidy policy, adopts computable general equilibrium (CGE) theory, and advances the scheme of constructing the model of China's direct grain subsidy policy. On the basis of some assumptions, such as conforming to the complete competition of market, inexistence of move of capital and labor forces among countries, unchanged exchange rate and incomplete substitution, and the main body of behavior comprising representative households, producers, local government and central government, the model established in this paper includes production module and demand module. Moreover, the model takes into account equilibrium structure, the definition of profiting and macro condition for closure, the related coefficients this CGE model needs include Armingtion substitution elasticity of intermediate composite product, investment composite product and consumption composite product between import and domestic production; substitution elasticity among production factors; conversion elasticity of total sales between domestic absorption and export; elasticity of residents' expenditure; elasticity of price; elasticity of export demand; the relative share of all sectors in capital stock. This paper also points out the advantages and limitations of CGE model in analyzing direct grain subsidy policy.
基金supported by the National Natural Science Foundation of China(Nos.52125903 and 52339001).
文摘The Moon,as the closest celestial body to the Earth,plays a pivotal role in the progression of deep space exploration,and the establishment of research outposts on its surface represents a crucial step in this mission.Lunar lava tubes are special underground caves formed by volcanic eruptions and are considered as ideal natural shelters and scientific laboratories for lunar base construction.This paper begins with an in-depth overview of the geological origins,exploration history,and distribution locations of lunar lava tubes.Subsequently,it delves into the presentation of four distinctive advantages and typical concepts for constructing bases within lava tubes,summarizing the ground-based attempts made thus far in lunar lava tube base construction.Field studies conducted on a lava tube in Hainan revealed rock compositions similar to those found during the Apollo missions and clear lava tube structures,making it a promising analog site.Lastly,the challenges and opportunities encountered in the field of geotechnical engineering regarding the establishment of lunar lava tube bases are discussed,encompassing cave exploration technologies,in-situ testing methods,geomechanical properties under lunar extreme environments,base design and structural stability assessment,excavation and reinforcement techniques,and simulated Earth-based lava tube base.