The mechanism of radiotherapy or chemotherapy-induced oral mucositis is not yet clear.And model establishment is needed in further study.In order to summarize the methods of model establishment and make a comparison,l...The mechanism of radiotherapy or chemotherapy-induced oral mucositis is not yet clear.And model establishment is needed in further study.In order to summarize the methods of model establishment and make a comparison,literature databases including Web of Science、Pubmed and CNKI were searched for related researches from January 2015 to January 2021.Hamsters,mice,rats,guinea pigs and miniature pigs were chosen to be modeling animals and modeling methods could be classified into:chemotherapy,chemotherapy combined with superficial mucosal irritation,radiotherapy,radiotherapy combined with superficial mucosal irritation and chemoradiotherapy.Advantages and disadvantages had been analyzed in this study to provide reference for following studies.展开更多
Natural gas hydrate(hereinafter referred to as hydrate)is a kind of future energy with great potential.At present,the apparent factor hindering commercial hydrate development is the unqualified gas production rate,so ...Natural gas hydrate(hereinafter referred to as hydrate)is a kind of future energy with great potential.At present,the apparent factor hindering commercial hydrate development is the unqualified gas production rate,so it is necessary to research stimulation means from the perspective of hydrate exploitation method,and reservoir stimulation technology is particularly important.After systematically reviewing hydrate reservoir stimulation theories and technologies,this paper divides the field of reservoir stimulation into three directions,i.e.,hydraulic fracturing,near-well stimulation and chemical stimulation,summarizes the main research results,problems and challenges in these three directions,and carries out discussion and prospect.And the following research results are obtained.First,rapid progress has been made in the research of hydraulic fracturing and it results have verified the fracability of hydrate deposits.It is revealed that the fracturing mechanism of hydrate deposits is similar to the tensile failure of rocks.It is indicated that fractures can still make contribution to permeability improvement after they closed under confining pressure,which is beneficial to secondary opening.In addition,the effects of in-situ stress and fracturing fluid on fracturing behaviors of hydrate deposits are analyzed,the numerical model of fracturing process is established,the mechanisms of hydraulic fractures to improve the depressurization and heat injection effects of hydrate reservoirs are analyzed,and the improvement effects of hydraulic fractures,as high-permeability channels on gas production rate and other key production indexes are clarified.Second,the research of near-well stimulation reveals the washout mechanisms and laws of high-pressure water jet on hydrate deposits.It is verified by numerical simulation that water jet slotting,circumferential grouting column and stratified split grouting can effectively improve the production performance,but the research is in the stage of establishing gas production model to evaluate the stimulation effect and the feasibility and effectiveness needs verifying.Third,as for chemical stimulation,the potential of CO_(2) caprock reconstruction and methanol huff and puff to improve the production performance of hydrate reservoirs is explored,and the feasibility of CO_(2) caprock reconstruction and storage is analyzed.In conclusion,to deal with current problems and challenges,it is necessary to strengthen the construction of the reservoir stimulation theory and technology system with hydraulic fracturing as the leading role,near-well reservoir stimulation as the auxiliary and chemical stimulation as the supplement,so as to accelerate the industrialization process of hydrate resources.展开更多
Farmland abandonment is a global problem and considered one of the most important areas in land use change research. Farmland abandonment research currently focuses on understanding the factors that affect farmland ab...Farmland abandonment is a global problem and considered one of the most important areas in land use change research. Farmland abandonment research currently focuses on understanding the factors that affect farmland abandonment and developing scientific models to simulate farmland abandonment. The study reviewed the natural and political factors driving farmland abandonment and summarized the main models for farmland abandonment simulation together with their advantages and disadvantages. We discuss the main ecological effects of farmland abandonment and propose farmland abandonment research directions. The study found that:(1) the influence of labor cost change and ageing labor force on farmland abandonment needs further investigation,(2) simulation models for farmland abandonment must include the decision-making mechanism of individual farmers and focus on macro large-scale abandonment prediction models, and(3) the influence of farmland abandonment on landscape culture must be investigated in detail.展开更多
Geological Society Special Publications No.253,London,2006,456 pp.,Price List:£85.00,US$170 ISBN 1-86239-191-2 Earth science began with the observation of the Earth materials and processes,then asking specific qu...Geological Society Special Publications No.253,London,2006,456 pp.,Price List:£85.00,US$170 ISBN 1-86239-191-2 Earth science began with the observation of the Earth materials and processes,then asking specific questions,proposing and testing hypotheses,formulating general concepts and theories,and finally experimenting and modelling.On a larger scale,this has been the pattern of Earth science history;and on a smaller scale this also is how a comprehensive Earth science research project proceeds.Experimentation,modelling and simulation are relatively recent developments in Earth science,and in this regard Earth scientists have a long way to go compared with their colleagues in physics and chemistry.But serious steps have been taken in recent decades.This new book is a testimony to these developments in the field of tectonic modelling.展开更多
This article introduces and compares risk assessment models for venous thromboembolism in gynecological patients at home and abroad.The models assessed included the Caprini risk assessment model,the G-Caprini risk ass...This article introduces and compares risk assessment models for venous thromboembolism in gynecological patients at home and abroad.The models assessed included the Caprini risk assessment model,the G-Caprini risk assessment model,the Rogers risk assessment model,the Autar risk assessment model,the gynecological patient surgical venous thrombosis risk assessment scale,the Wells score,the COMPASS-CAT thrombus risk assessment model,the Khorana risk assessment model,the Padua risk assessment model,and the Chaoyang model.The purpose of this study is to provide a foundation for developing a risk assessment tool for gynecological venous thromboembolism tailored to Chinese patients and to assist clinical health care workers in selecting appropriate risk assessment tools and guiding individualized prevention measures.展开更多
Psychiatric disorders constitute a complex health issue,primarily manifesting as significant disturbances in cognition,emotional regulation,and behavior.However,due to limited resources within health care systems,only...Psychiatric disorders constitute a complex health issue,primarily manifesting as significant disturbances in cognition,emotional regulation,and behavior.However,due to limited resources within health care systems,only a minority of patients can access effective treatment and care services,highlighting an urgent need for improvement.large language models(LLMs),with their natural language understanding and generation capabilities,are gradually penetrating the entire process of psychiatric diagnosis and treatment,including outpatient reception,diagnosis and therapy,clinical nursing,medication safety,and prognosis follow-up.They hold promise for improving the current severe shortage of health system resources and promoting equal access to mental health care.This article reviews the application scenarios and research progress of LLMs.It explores optimization methods for LLMs in psychiatry.Based on the research findings,we propose a clinical LLM for mental health using the Mixture of Experts framework to improve the accuracy of psychiatric diagnosis and therapeutic interventions.展开更多
Plant virus disease is one of the major causes of biological disasters in agriculture worldwide. Given the complexity of transmission media and plant disease infection mechanisms, the prevention and control of plant v...Plant virus disease is one of the major causes of biological disasters in agriculture worldwide. Given the complexity of transmission media and plant disease infection mechanisms, the prevention and control of plant viral diseases is a great challenge, and an efficient green pesticide is urgently needed. For this reason, when developing candidate drug leads to regulate plant viruses, pesticide experts have focused on characteristics such as low pesticide resistance, eco-friendliness, and novel mechanism. Researchers have also theoretically investigated the molecular targets of viruses infecting agricultural crops. Antiviral screening models have been constructed based on these molecular targets, and the mechanisms of commercial drugs and high-activity compounds have been extensively investigated. After screening, some compounds have been applied in the field and found to have good commercial prospects; these drugs may be used to create new green antiviral pesticides to control plant viruses. This paper reviews the screening, mode of action, development and application of recently used plant-based antiviral agents.展开更多
胃肠动力障碍性疾病(Disorders of Gastrointestinal Motility Diseases,DGIMD)是临床常见疾病,具有病程迁延、症状反复等特点。DGIMD的发病机制复杂,尚未完全阐明,涉及肠脑神经网络系统等多种调节机制,治疗常面临疗效不佳等问题。故明...胃肠动力障碍性疾病(Disorders of Gastrointestinal Motility Diseases,DGIMD)是临床常见疾病,具有病程迁延、症状反复等特点。DGIMD的发病机制复杂,尚未完全阐明,涉及肠脑神经网络系统等多种调节机制,治疗常面临疗效不佳等问题。故明确机制找准治疗方法和药物成为重要研究方向;随着对胃肠动力障碍性疾病研究的不断深入,寻找合理的动物模型对开展相关研究发挥着至关重要的作用。目前研究模型有化学诱导模型、应激诱导模型、疾病继发诱导模型、基因诱导模型等;本文将讨论各类胃肠动力障碍模型的特点和进展,以期为DGIMD动物模型的构建及研究提供依据。展开更多
Ecopath model is an important evaluation model in the field of ecological research.At present,Ecopath model is mainly applied in the structure of food web,material circulation and energy flow,environmental capacity an...Ecopath model is an important evaluation model in the field of ecological research.At present,Ecopath model is mainly applied in the structure of food web,material circulation and energy flow,environmental capacity and so on.The Ecopath models in ocean,lake and reservoir ecosystems were reviewed,including the ecological nutrient conversion efficiency(EE),ecosystem characteristic index(CI),Niche Overlap and energy flow characteristics of trophic level.The practical significance of Ecopath model in marine ecosystem evaluation and application is expounded by comparing and analyzing the literature data,which provides the technical support for the scientific management of inland ecosystem in the future.展开更多
With recent advances in numerical modeling, design of underground structures increasingly relies on numerical modeling-based analysis approaches. While modeling tools like the discrete element method(DEM) and the comb...With recent advances in numerical modeling, design of underground structures increasingly relies on numerical modeling-based analysis approaches. While modeling tools like the discrete element method(DEM) and the combined finite-discrete element method(FDEM) are useful for investigating small-scale damage processes, continuum models remain the primary practical tool for most field-scale problems.The results obtained from such models are significantly dependent on the selection of an appropriate yield criterion and dilation angle. Towards improving its capabilities in handling mining-related problems, the authors have previously developed a new yield criterion(called progressive S-shaped criterion). The focus of the current study is to demonstrate its use in modeling rock pillars through a comparative analysis against four other yield criteria. In addition to the progressive S-shaped criterion,only one out of the four other criteria predicted a trend in strength consistent with an empirical pillar strength database compiled from the literature. Given the closely-knit relationship between yield criteria and dilation angle in controlling the overall damage process, a separate comparison was conducted using a mobilized dilation model, a zero degree dilation angle and a constant non-zero dilation angle. This study also investigates the impact of meso-scale heterogeneity in mechanical properties on the overall model response by assigning probability distributions to the input parameters. The comparisons revealed that an isotropic model using a combination of progressive S-shaped criterion and mobilized dilation angle model is sufficient in capturing the behaviors of rock pillars. Subsequently, the pillar model was used to assess the effect of L/W(length/width) ratio on the peak strength.展开更多
We prepared concretes（RC0, RC30, and RC100） with three different mixes. The poresize distribution parameters of RAC were examined by high-precision mercury intrusion method（MIM） and nuclear magnetic resonance（NMR...We prepared concretes（RC0, RC30, and RC100） with three different mixes. The poresize distribution parameters of RAC were examined by high-precision mercury intrusion method（MIM） and nuclear magnetic resonance（NMR） imaging. A capillary-bundle physical model with random-distribution pores（improved model, IM） was established according to the parameters, and dry-shrinkage strain values were calculated and verified. Results show that in all pore types, capillary pores, and gel pores have the greatest impacts on concrete shrinkage, especially for pores 2.5-50 and 50-100 nm in size. The median radii are 34.2, 31, and 34 nm for RC0, RC30, and RC100, respectively. Moreover, the internal micropore size distribution of RC0 differs from that of RC30 and RC100, and the pore descriptions of MIM and NMR are consistent both in theory and in practice. Compared with the traditional capillary-bundle model, the calculated results of IM have higher accuracy as demonstrated by experimental verifi cation.展开更多
Based on the mathematical model of one dimension transient flow of the polymer foam in porous media, the numerical calculation method of the flow mentioned above by using the finite difference method is given. Through...Based on the mathematical model of one dimension transient flow of the polymer foam in porous media, the numerical calculation method of the flow mentioned above by using the finite difference method is given. Through the experiments of one dimension transient flow of HPAM (Hydrolytic Polyacrylamide) foam in the artificial sandstone core, the HPAM foam generation and coalescence coefficient of the mathematical model mentioned above are determined. The profiles of the liquid phase saturation, the pressure drop and the number density of one dimension transient flow of HPAM foam with the dimensionless time in artificial sandstone core are numerically calculated and analyzed by using the numerical calculation method.展开更多
Femoral head necrosis has become one of the common and difficult diseases of orthopedics,and its incidence is now on a clear upward trend.If the effective treatment is not carried out in the early stage,it will lead t...Femoral head necrosis has become one of the common and difficult diseases of orthopedics,and its incidence is now on a clear upward trend.If the effective treatment is not carried out in the early stage,it will lead to the collapse of local necrotic bone,which will seriously endanger human health and even cause it to lose its ability to work and self-care,and eventually cause disability.Its treatment program has not made great breakthroughs at home and abroad.However,an animal model that fully reflects human osteonecrosis has not yet been fully replicated.Therefore,it is necessary to establish an animal model that can conform to the pathological evolution process of avascular necrosis of human femoral head.It is necessary to study the preparation of liquid nitrogen-type ONFH model by reviewing relevant literatures at home and abroad in recent years.展开更多
基金National Natural Science Foundation of China(No.81973693)。
文摘The mechanism of radiotherapy or chemotherapy-induced oral mucositis is not yet clear.And model establishment is needed in further study.In order to summarize the methods of model establishment and make a comparison,literature databases including Web of Science、Pubmed and CNKI were searched for related researches from January 2015 to January 2021.Hamsters,mice,rats,guinea pigs and miniature pigs were chosen to be modeling animals and modeling methods could be classified into:chemotherapy,chemotherapy combined with superficial mucosal irritation,radiotherapy,radiotherapy combined with superficial mucosal irritation and chemoradiotherapy.Advantages and disadvantages had been analyzed in this study to provide reference for following studies.
基金supported by the Program of National Natural Science Foundation of China“Research on evolution mechanism of hydrate reservoirs stimulated by water jet cutting”(No.42002309)the Intergovernmental Cooperation Project under National Key R&D Program of China“Dynamic response behaviors and control of reservoirs around borehole during exploitation of natural gas hydrate”(No.2018YFE0126400)+1 种基金the Fundamental Research Funds for the Central Universities“Supercritical fluid enhanced dry hot rock development”(No.CUG190635)the Natural Science Foundation of Hubei Province“Research on dynamic properties of abrasive supercritical CO_(2) jet”(No.2020CFB730).
文摘Natural gas hydrate(hereinafter referred to as hydrate)is a kind of future energy with great potential.At present,the apparent factor hindering commercial hydrate development is the unqualified gas production rate,so it is necessary to research stimulation means from the perspective of hydrate exploitation method,and reservoir stimulation technology is particularly important.After systematically reviewing hydrate reservoir stimulation theories and technologies,this paper divides the field of reservoir stimulation into three directions,i.e.,hydraulic fracturing,near-well stimulation and chemical stimulation,summarizes the main research results,problems and challenges in these three directions,and carries out discussion and prospect.And the following research results are obtained.First,rapid progress has been made in the research of hydraulic fracturing and it results have verified the fracability of hydrate deposits.It is revealed that the fracturing mechanism of hydrate deposits is similar to the tensile failure of rocks.It is indicated that fractures can still make contribution to permeability improvement after they closed under confining pressure,which is beneficial to secondary opening.In addition,the effects of in-situ stress and fracturing fluid on fracturing behaviors of hydrate deposits are analyzed,the numerical model of fracturing process is established,the mechanisms of hydraulic fractures to improve the depressurization and heat injection effects of hydrate reservoirs are analyzed,and the improvement effects of hydraulic fractures,as high-permeability channels on gas production rate and other key production indexes are clarified.Second,the research of near-well stimulation reveals the washout mechanisms and laws of high-pressure water jet on hydrate deposits.It is verified by numerical simulation that water jet slotting,circumferential grouting column and stratified split grouting can effectively improve the production performance,but the research is in the stage of establishing gas production model to evaluate the stimulation effect and the feasibility and effectiveness needs verifying.Third,as for chemical stimulation,the potential of CO_(2) caprock reconstruction and methanol huff and puff to improve the production performance of hydrate reservoirs is explored,and the feasibility of CO_(2) caprock reconstruction and storage is analyzed.In conclusion,to deal with current problems and challenges,it is necessary to strengthen the construction of the reservoir stimulation theory and technology system with hydraulic fracturing as the leading role,near-well reservoir stimulation as the auxiliary and chemical stimulation as the supplement,so as to accelerate the industrialization process of hydrate resources.
基金National Natural Science Foundation of China(41501192)The Strategic Priority Research Program of Chinese Academy of Sciences(XDA20040201)Key Laboratory of Earth Observation and Geospatial Information Science of NASG(201807)
文摘Farmland abandonment is a global problem and considered one of the most important areas in land use change research. Farmland abandonment research currently focuses on understanding the factors that affect farmland abandonment and developing scientific models to simulate farmland abandonment. The study reviewed the natural and political factors driving farmland abandonment and summarized the main models for farmland abandonment simulation together with their advantages and disadvantages. We discuss the main ecological effects of farmland abandonment and propose farmland abandonment research directions. The study found that:(1) the influence of labor cost change and ageing labor force on farmland abandonment needs further investigation,(2) simulation models for farmland abandonment must include the decision-making mechanism of individual farmers and focus on macro large-scale abandonment prediction models, and(3) the influence of farmland abandonment on landscape culture must be investigated in detail.
文摘Geological Society Special Publications No.253,London,2006,456 pp.,Price List:£85.00,US$170 ISBN 1-86239-191-2 Earth science began with the observation of the Earth materials and processes,then asking specific questions,proposing and testing hypotheses,formulating general concepts and theories,and finally experimenting and modelling.On a larger scale,this has been the pattern of Earth science history;and on a smaller scale this also is how a comprehensive Earth science research project proceeds.Experimentation,modelling and simulation are relatively recent developments in Earth science,and in this regard Earth scientists have a long way to go compared with their colleagues in physics and chemistry.But serious steps have been taken in recent decades.This new book is a testimony to these developments in the field of tectonic modelling.
基金funded by the National College Students Innovation and Entrepreneurship Training Program(S202310760049).
文摘This article introduces and compares risk assessment models for venous thromboembolism in gynecological patients at home and abroad.The models assessed included the Caprini risk assessment model,the G-Caprini risk assessment model,the Rogers risk assessment model,the Autar risk assessment model,the gynecological patient surgical venous thrombosis risk assessment scale,the Wells score,the COMPASS-CAT thrombus risk assessment model,the Khorana risk assessment model,the Padua risk assessment model,and the Chaoyang model.The purpose of this study is to provide a foundation for developing a risk assessment tool for gynecological venous thromboembolism tailored to Chinese patients and to assist clinical health care workers in selecting appropriate risk assessment tools and guiding individualized prevention measures.
基金Supported by the STI2030-Major Projects,No.2021ZD0203400 and No.2021ZD0200800the National Natural Science Foundation of China,No.82171477。
文摘Psychiatric disorders constitute a complex health issue,primarily manifesting as significant disturbances in cognition,emotional regulation,and behavior.However,due to limited resources within health care systems,only a minority of patients can access effective treatment and care services,highlighting an urgent need for improvement.large language models(LLMs),with their natural language understanding and generation capabilities,are gradually penetrating the entire process of psychiatric diagnosis and treatment,including outpatient reception,diagnosis and therapy,clinical nursing,medication safety,and prognosis follow-up.They hold promise for improving the current severe shortage of health system resources and promoting equal access to mental health care.This article reviews the application scenarios and research progress of LLMs.It explores optimization methods for LLMs in psychiatry.Based on the research findings,we propose a clinical LLM for mental health using the Mixture of Experts framework to improve the accuracy of psychiatric diagnosis and therapeutic interventions.
基金supported by the National Natural Science Foundation of China (21132003, 31460460, 21502032 and 21732002)the Subsidy Project for Outstanding Key Laboratory of Guizhou Province in China (20154004)+1 种基金the Provincial University Cooperation Plan of Guizhou Province in China (20147001)the Collaborative Innovation Center for Natural Products and Biological Drugs of Yunnan, China
文摘Plant virus disease is one of the major causes of biological disasters in agriculture worldwide. Given the complexity of transmission media and plant disease infection mechanisms, the prevention and control of plant viral diseases is a great challenge, and an efficient green pesticide is urgently needed. For this reason, when developing candidate drug leads to regulate plant viruses, pesticide experts have focused on characteristics such as low pesticide resistance, eco-friendliness, and novel mechanism. Researchers have also theoretically investigated the molecular targets of viruses infecting agricultural crops. Antiviral screening models have been constructed based on these molecular targets, and the mechanisms of commercial drugs and high-activity compounds have been extensively investigated. After screening, some compounds have been applied in the field and found to have good commercial prospects; these drugs may be used to create new green antiviral pesticides to control plant viruses. This paper reviews the screening, mode of action, development and application of recently used plant-based antiviral agents.
文摘胃肠动力障碍性疾病(Disorders of Gastrointestinal Motility Diseases,DGIMD)是临床常见疾病,具有病程迁延、症状反复等特点。DGIMD的发病机制复杂,尚未完全阐明,涉及肠脑神经网络系统等多种调节机制,治疗常面临疗效不佳等问题。故明确机制找准治疗方法和药物成为重要研究方向;随着对胃肠动力障碍性疾病研究的不断深入,寻找合理的动物模型对开展相关研究发挥着至关重要的作用。目前研究模型有化学诱导模型、应激诱导模型、疾病继发诱导模型、基因诱导模型等;本文将讨论各类胃肠动力障碍模型的特点和进展,以期为DGIMD动物模型的构建及研究提供依据。
基金supported by the National large-scale freshwater fish industry technology system(CARS-45)Tianjin Freshwater Aquaculture Industry Technology System Innovation Team+2 种基金Tianjin Science and Technology Program(16zzync00100)Tianjin Science and Technology Program(18ZXZYNC00150)the Opening Foundation of Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria(2019-04).
文摘Ecopath model is an important evaluation model in the field of ecological research.At present,Ecopath model is mainly applied in the structure of food web,material circulation and energy flow,environmental capacity and so on.The Ecopath models in ocean,lake and reservoir ecosystems were reviewed,including the ecological nutrient conversion efficiency(EE),ecosystem characteristic index(CI),Niche Overlap and energy flow characteristics of trophic level.The practical significance of Ecopath model in marine ecosystem evaluation and application is expounded by comparing and analyzing the literature data,which provides the technical support for the scientific management of inland ecosystem in the future.
基金funded by The National Institute for Occupational Safety and Health,USA(NIOSH)(Grant No.200-2016-90154)
文摘With recent advances in numerical modeling, design of underground structures increasingly relies on numerical modeling-based analysis approaches. While modeling tools like the discrete element method(DEM) and the combined finite-discrete element method(FDEM) are useful for investigating small-scale damage processes, continuum models remain the primary practical tool for most field-scale problems.The results obtained from such models are significantly dependent on the selection of an appropriate yield criterion and dilation angle. Towards improving its capabilities in handling mining-related problems, the authors have previously developed a new yield criterion(called progressive S-shaped criterion). The focus of the current study is to demonstrate its use in modeling rock pillars through a comparative analysis against four other yield criteria. In addition to the progressive S-shaped criterion,only one out of the four other criteria predicted a trend in strength consistent with an empirical pillar strength database compiled from the literature. Given the closely-knit relationship between yield criteria and dilation angle in controlling the overall damage process, a separate comparison was conducted using a mobilized dilation model, a zero degree dilation angle and a constant non-zero dilation angle. This study also investigates the impact of meso-scale heterogeneity in mechanical properties on the overall model response by assigning probability distributions to the input parameters. The comparisons revealed that an isotropic model using a combination of progressive S-shaped criterion and mobilized dilation angle model is sufficient in capturing the behaviors of rock pillars. Subsequently, the pillar model was used to assess the effect of L/W(length/width) ratio on the peak strength.
基金Funded by the National Natural Science Foundation of China(51202304)the China Postdoctoral Science Foundation(2014M552320)+1 种基金Scientific,the Technological Talents’Special Funds of Wanzhou District and Scientific and Technological Research Program of Chongqing Municipal Education Commission(KJ1401016)the Youth Project of Chongqing Three Gorges College(13QN-20)
文摘We prepared concretes（RC0, RC30, and RC100） with three different mixes. The poresize distribution parameters of RAC were examined by high-precision mercury intrusion method（MIM） and nuclear magnetic resonance（NMR） imaging. A capillary-bundle physical model with random-distribution pores（improved model, IM） was established according to the parameters, and dry-shrinkage strain values were calculated and verified. Results show that in all pore types, capillary pores, and gel pores have the greatest impacts on concrete shrinkage, especially for pores 2.5-50 and 50-100 nm in size. The median radii are 34.2, 31, and 34 nm for RC0, RC30, and RC100, respectively. Moreover, the internal micropore size distribution of RC0 differs from that of RC30 and RC100, and the pore descriptions of MIM and NMR are consistent both in theory and in practice. Compared with the traditional capillary-bundle model, the calculated results of IM have higher accuracy as demonstrated by experimental verifi cation.
文摘Based on the mathematical model of one dimension transient flow of the polymer foam in porous media, the numerical calculation method of the flow mentioned above by using the finite difference method is given. Through the experiments of one dimension transient flow of HPAM (Hydrolytic Polyacrylamide) foam in the artificial sandstone core, the HPAM foam generation and coalescence coefficient of the mathematical model mentioned above are determined. The profiles of the liquid phase saturation, the pressure drop and the number density of one dimension transient flow of HPAM foam with the dimensionless time in artificial sandstone core are numerically calculated and analyzed by using the numerical calculation method.
基金Shenyang Bureau of Science and Technology(18-014-4-05).
文摘Femoral head necrosis has become one of the common and difficult diseases of orthopedics,and its incidence is now on a clear upward trend.If the effective treatment is not carried out in the early stage,it will lead to the collapse of local necrotic bone,which will seriously endanger human health and even cause it to lose its ability to work and self-care,and eventually cause disability.Its treatment program has not made great breakthroughs at home and abroad.However,an animal model that fully reflects human osteonecrosis has not yet been fully replicated.Therefore,it is necessary to establish an animal model that can conform to the pathological evolution process of avascular necrosis of human femoral head.It is necessary to study the preparation of liquid nitrogen-type ONFH model by reviewing relevant literatures at home and abroad in recent years.
