The commercial cultivation of genetically modified(GM)crops has eased the global food crisis and brought considerable economic and social benefits to countries.Because of the potential safety problems,it is necessary ...The commercial cultivation of genetically modified(GM)crops has eased the global food crisis and brought considerable economic and social benefits to countries.Because of the potential safety problems,it is necessary to make clear the molecular genetic characteristics,edible safety,planting,processing,and other aspects of the safety evaluation of GM crops.The safety problems existing in the cultivation of GM crops,safety evaluation and detection of GM crops were introduced in this paper,which provided the basis for safety evaluation and effective supervision of GM crops and their products.Commercial cultivation and reasonable supervision based on safety evaluation have far-reaching significance for ensuring consumer safety,enhancing the credibility of the national political system and enhancing citizens'confidence in the safety of GM crop products for consumption.展开更多
Safety is one of the basic needs of tourists,and their sense of security is a necessary condition for the successful operation of homestays.Based on the theory of tourist perception,Nanjing Tangjiajia Hot Spring Villa...Safety is one of the basic needs of tourists,and their sense of security is a necessary condition for the successful operation of homestays.Based on the theory of tourist perception,Nanjing Tangjiajia Hot Spring Village is taken as the research object.This paper analyzes the tourists’perception of homestay safety facilities and services through questionnaire survey,field investigation,interview,and other methods.It proposes strategies for improving homestay safety,aiming to provide safety management references for China’s homestay industry and promote its sustainable development.展开更多
The objective of the present study was to evaluate potential adverse effects of diacylglycerol microemulsion (DAGM) in rats/mice. Acute safety evaluation was carried out by giving intragastrically with 20 mL 25% DAG...The objective of the present study was to evaluate potential adverse effects of diacylglycerol microemulsion (DAGM) in rats/mice. Acute safety evaluation was carried out by giving intragastrically with 20 mL 25% DAG kg-1 body weight of DAGM or water with two groups of mice. Chronic safety evaluation with 40 male and 40 female Sprague-Dawley rats was carried out by setting a control group and 3 different dose groups (n=10 male+10 female) administered with DAGM with 6.7, 10 and 20 mL kg-1 body weight per day. Relevant parameters of liver and kidney function and biochemistry were determined by standard methods at end point. Acute toxicity study revealed the maximum tolerated dose (MTD) of DAGM was 20 mL kg-1 body weight in mice. No death was observed at the dose of 20 mL kg-1 body weight per day. Chronic safety evaluation did not show significant changes on hematological, histopathologic, clinical, and biochemical tests when administered at levels of 6.7, 10 and 20 mL kg-1 body weight per day to rats for 30 d. No significant body weight changes were observed in different dosages in both male and female rats. Our results suggested that acute and chronic adverse effects were not observed in histology and clinical parameters in both mice and rats. The results suggested that DAGM is safe at the experimental levels.展开更多
The main objective of the work presented in this paper was to develop a customized safety training program that can be incorporated into the demolition projects undertaken as part of blight reduction efforts in urban ...The main objective of the work presented in this paper was to develop a customized safety training program that can be incorporated into the demolition projects undertaken as part of blight reduction efforts in urban centers. A subsidiary objective was to devise and implement a safety program evaluation methodology, and gain insights on the relationships between knowledge acquisition through training and trainee demographics. Salient aspects of blight elimination efforts, as well as the main facets of building demolition practices and requirements, were reviewed. Information on various related safety and health hazards was studied in depth with a focus on demolition operations dealing with blighted properties. A unique safety hazard awareness training program was created for demolition workers, contractors and inspectors based on this research. In addition to devising a curriculum of relevant training topics along with traditional and online delivery systems to be employed, effectiveness evaluation instruments were formulated. Based on the limited data collected from the trainees it was concluded that the program was well-received by them and provided effective learning. It was also found that no statistically significant associations existed between the knowledge gain of the trainees, and either their experience level or union status, after taking this training.展开更多
The wheel-rail force measurement is of great importance to the condition monitoring and safety evaluation of railway vehicles. In this paper, an improved indirect method for wheel-rail force measurement is proposed to...The wheel-rail force measurement is of great importance to the condition monitoring and safety evaluation of railway vehicles. In this paper, an improved indirect method for wheel-rail force measurement is proposed to evaluate the running safety of railway vehicles. In this method, the equilibrium equations of a suspended wheelset are derived and the wheel-rail forces are then be obtained from measured suspension and inertia forces. This indirect method avoids structural modifications to the wheelset and is applicable to the long-term operation of railway vehicles. As the wheel-rail lateral forces at two sides of the wheelset are difficult to separate, a new derailment criterion by combined use of wheelset derailment coefficient and wheel unloading ratio is proposed. To illustrate its effectiveness, the indirect method is applied to safety evaluation of rail- way vehicles in different scenarios, such as the cross wind safety of a high-speed train and the safety of a metro vehicle with hunting motions. Then, the feasibility of using this method to identify wheel-rail forces for low-floor light rail vehicles with resilient wheels is discussed. The values identified by this method is compared with that by Simpack simulation for the same low-floor vehicle, which shows a good coincidence between them in the time domain of the wheelset lateral force and the wheel-rail vertical force. In addition, use of the method to determine the high-frequency wheel-rail interaction forces reveals that it is possible to identify the high-frequency wheel-rail forces through the accelerations on the axle box.展开更多
Bridge structure safety monitoring and assessment has been a great concern for the government and the public,and bridge structure safety monitoring and assessment technology has also developed rapidly over the years.I...Bridge structure safety monitoring and assessment has been a great concern for the government and the public,and bridge structure safety monitoring and assessment technology has also developed rapidly over the years.Its goal is to equip relevant organizations and professionals with a deep understanding of the principles and practical applications of these technologies.By doing so,it seeks to facilitate the effective implementation of safety monitoring and assessment practices in bridge management.Ultimately,the aim is to foster the constructive development of road and bridge construction and operational management at a broader level.展开更多
[ Objective] The study aimed to supply important basis for developing environment-friendly pesticides with myricetin and crude extract of Myrica rubra leaves as effective components. [ Method] According to "Test guid...[ Objective] The study aimed to supply important basis for developing environment-friendly pesticides with myricetin and crude extract of Myrica rubra leaves as effective components. [ Method] According to "Test guidelines for environmental safety evaluation on chemical pesticides", the toxicity of myricetin and crude extract of M. rubra leaves on non-target organisms was determined and the safety evaluation was carried out. [Result] MyriceUn and crude extract of M. rubra leaves had low toxicity on non-target organisms, such as earthworm, silkworm and soil microbes. Myricetin showed low toxicity and the crude extract of M. rubra leaves showed middle toxicity on tadpole. The high-concentration crude extract of M. rubra leaves had some antifeedant effect on silkworm. [ Conclusion] Myricetin and crude extract of M. rubra leaves had low toxicity on non-tar- get organisms in environment and they were relatively safe.展开更多
Based on the integration analysis of goods and shortcomings of various methods used in safety assessment of coal mines, combining nonlinear feature of mine safety sub-system, this paper establishes the neural network ...Based on the integration analysis of goods and shortcomings of various methods used in safety assessment of coal mines, combining nonlinear feature of mine safety sub-system, this paper establishes the neural network assessment model of mine safety, analyzes the ability of artificial neural network to evaluate mine safety state, and lays the theoretical foundation of artificial neural network using in the systematic optimi- zation of mine safety assessment and getting reasonable accurate safety assessment result.展开更多
Mechanical characterization of steel frame structure after fire are ana- lyzed based on fire dynamics, heat transfer theory, structural mechanics, and finite element theory. We study the temperature characteristics an...Mechanical characterization of steel frame structure after fire are ana- lyzed based on fire dynamics, heat transfer theory, structural mechanics, and finite element theory. We study the temperature characteristics and mechanical prop- erties of steel flame structure under different fire locations and propose a safety evaluation method. We also analyze damage level of main flame components, maximum temperature of fire, thermal characteristics of flame components, fir- ing duration, etc. to provide useful information for fire resistance design of the steel frame structure and post-disaster safety evaluation.展开更多
In an abnormal high-temperature fire environment,a structure with mechanical-thermal weak-link can be used to predict the permanent failure before the failure of some strong-links,such as explosive initiator,thus to p...In an abnormal high-temperature fire environment,a structure with mechanical-thermal weak-link can be used to predict the permanent failure before the failure of some strong-links,such as explosive initiator,thus to protect the latter. An effective design can be defined as that the weak-link fails before the failure of the strong-link,and the system is safe; while an unsuccessful design means that the weak-link fails after the failure of the strong-link,and the system loses in safety. The probability of safety failure exists due to the uncertain failure temperatures of the weak-link and strong-link. In order to obtain the probability of safety failure,a statistical method was used to deal with the uncertainty of the failure temperatures. The integral method and stochastic simulation method were used in calculations. Finally,a sample was given to verify the consistence of the results given by two methods.展开更多
A method of cable safety analysis is proposed for safety evaluation of long-span cable-stayed bridges. The Daniels' effect and the probability of broken wires in the cable are introduced to develop the cable strength...A method of cable safety analysis is proposed for safety evaluation of long-span cable-stayed bridges. The Daniels' effect and the probability of broken wires in the cable are introduced to develop the cable strength model and the reliability assessment technique for long-span cable-stayed bridges based on the safety factors analysis of stay cables in service. As an application of the proposed model, the cable safety reliability of the cable No. 25 of Zhaobaoshan cable-stayed bridge in China is calculated. The effects of various parameters on the estimated cable safety reliability are investigated. The results indicate that the proposed method can be used to assess the safety level of stay cables in cable-stayed bridges effectively. The Daniels' effect should be taken into account for assessment, and the probability of broken wires can be used to simulate the deterioration of stay cables in service.展开更多
By standard method to determine thallium content in 34 batches of cosmetic products sold in Shenzhen,including cushions and sunscreens for children,all results of samples are within the range of not detected to 0.62 m...By standard method to determine thallium content in 34 batches of cosmetic products sold in Shenzhen,including cushions and sunscreens for children,all results of samples are within the range of not detected to 0.62 mg/kg.By calculating the Maximum Theoretical Safety Limit,according to guidance of Scientific Committee on Consumer Safety(SCCS)of European Union and Toxicological Review of Thallium and Compounds 2009 of United States Environmental Protection Agency(EPA)to assess the risk of cosmetic products.As a result,if the mean concentration of thallium in different kind of cosmetic products does not exceed 0.031 mg/kg,the products will not show significant toxicological risk for consumers.展开更多
[Objective] The biological safety of white insect tea in Xifeng County of Guizhou Province was evaluated in order to provide a scientific basis for the development of white insect tea. [Method] Acute toxicity test in ...[Objective] The biological safety of white insect tea in Xifeng County of Guizhou Province was evaluated in order to provide a scientific basis for the development of white insect tea. [Method] Acute toxicity test in mice, Ames microbiological test and mouse bone marrow polychromatic erythrocyte micronucleus test were done with wild white inset tea produced in Xifeng County. At the same time, the contents of six kinds of limit pollutants were determined, including Pb,Cr,Cd,Hg,As,and F-. [Result] The results showed that white insect tea had LD505.0 g/kg(BW)in acute toxicity test, negative response in Ames test and microkernel test. In addition, the contents of Pb,Cr,Cd,Hg,As,and F- in the white inset tea were 2.20,1.06,0.46,0.09,0.71,21.50 mg/kg, much less than the national standard of tea (GB2762-2005,NY 659-2003). [Conclusion] The white insect tea produced in Xifeng County of Guizhou Province is non-toxic, and good for human as beverage.展开更多
This paper describes a set of on-site earthquake safety evaluation systems for buildings, which were developed based on a network platform. The system embedded into the quantitative research results which were complet...This paper describes a set of on-site earthquake safety evaluation systems for buildings, which were developed based on a network platform. The system embedded into the quantitative research results which were completed in accordance with the provisions from Post-earthquake Field Works, Part 2: Safety Assessment of Buildings, GB18208.2 -2001, and was further developed into an easy-to-use software platform. The system is aimed at allowing engineering professionals, civil engineeing technicists or earthquake-affected victims on site to assess damaged buildings through a network after earthquakes. The authors studied the function structure, process design of the safety evaluation module, and hierarchical analysis algorithm module of the system in depth, and developed the general architecture design, development technology and database design of the system. Technologies such as hierarchical architecture design and Java EE were used in the system development, and MySQL5 was adopted in the database development. The result is a complete evaluation process of information collection, safety evaluation, and output of damage and safety degrees, as well as query and statistical analysis of identified buildings. The system can play a positive role in sharing expert post-earthquake experience and promoting safety evaluation of buildings on a seismic field.展开更多
Stem cell therapy is a promising strategy for the treatment of traumatic brain injury(TBI). However, animal experiments are needed to evaluate safety;in particular, to examine the immunogenicity and tumorigenicity of ...Stem cell therapy is a promising strategy for the treatment of traumatic brain injury(TBI). However, animal experiments are needed to evaluate safety;in particular, to examine the immunogenicity and tumorigenicity of human umbilical cord mesenchymal stem cells(hu MSCs) before clinical application. In this study, hu MSCs were harvested from human amniotic membrane and umbilical cord vascular tissue. A rat model of TBI was established using the controlled cortical impact method. Starting from the third day after injury, the rats were injected with 10 μL of 5 × 10^(6)/m L hu MSCs by cerebral stereotaxis or with 500 μL of 1 × 10^(6)/m L hu MSCs via the tail vein for 3 successive days. hu MSC transplantation decreased the serum levels of proinflammatory cytokines in rats with TBI and increased the serum levels of anti-inflammatory cytokines, thereby exhibiting good immunoregulatory function. The transplanted hu MSCs were distributed in the liver, lung and brain injury sites. No abnormal proliferation or tumorigenesis was found in these organs up to 12 months after transplantation. The transplanted hu MSCs negligibly proliferated in vivo, and apoptosis was gradually observed at later stages. These findings suggest that hu MSC transplantation for the treatment of traumatic brain injury displays good safety. In addition, hu MSCs exhibit good immunoregulatory function, which can help prevent and reduce secondary brain injury caused by the rapid release of inflammatory factors after TBI. This study was approved by the Ethics Committee of Wuhan General Hospital of PLA(approval No. 20160054) on November 1, 2016.展开更多
Key methods developed and used in the USSR and in the Russian Federation to determine the impact and friction sensitivity of energetic materials and explosives have been discussed.Experimental methodologies and instru...Key methods developed and used in the USSR and in the Russian Federation to determine the impact and friction sensitivity of energetic materials and explosives have been discussed.Experimental methodologies and instruments that underlie the assessment of their production and handling safety have been described.Studies of a large number of compounds have revealed relationships between their sensitivity parameters and structure of individual compounds and compositions.The range of change of physical and chemical characteristics for the compounds we examined covers the entire region of their existence.Theoretical methodology and equations have been formulated to estimate the impact and friction sensitivity parameters of energetic materials and to evaluate the technological safety in use.The developed methodology is characterized by high-accuracy calculations and prediction of sensitivity parameters.展开更多
A comprehensive safety evaluation system taking the most influential factors into account has been developed to evaluate the reliability of hydraulic metal structures. Applying the techniques of AI and DB, the idea of...A comprehensive safety evaluation system taking the most influential factors into account has been developed to evaluate the reliability of hydraulic metal structures. Applying the techniques of AI and DB, the idea of a one-machine and three-base system is proposed. The framework of the three-base system has been designed and the structural framework constructed in turn. A practical example is given to illustrate the process of using this system and it can be used for comparison and analysis purposes. The key technology of the system is its ability to reorganize and improve the expert system's knowledge base by establishing the expert system. This system utilizes the computer technology inference process, making safety evaluation conclusions more reasonable and applicable to the actual situation. The system is not only advanced, but also feasible, reliable, artificially intelligent, and has the capacity to constantly grow.展开更多
Reinforcement quality evaluation at the abutment is an important research direction. Prototype monitoring and theoretical derivation were integrated to study the replacement reinforcement quality in abutment contact z...Reinforcement quality evaluation at the abutment is an important research direction. Prototype monitoring and theoretical derivation were integrated to study the replacement reinforcement quality in abutment contact zones of the Xiaowan ultra-high arch dam. The principles of monitoring layout and design are introduced in detail. Prototype monitoring shows that the increment of the interfacial compressive stress is much larger in the impoundment stage than in the regulating stage. The water pressure and time-effect are two main factors affeeting the interfacial stress. The time-effect is the key factor in the initial impoundment stage, and the water pressure is the key factor after impoundment. The contact properties are significantly improved by grouting. This study shows that there are three typical stages in the joint opening hydrographs, namely the compression stage, opening stage, and stable stage. There is a nonlinear relationship between the joint opening and temperature, which can be well described by the S-function. In conclusion, the reinforcement effect is satisfying, and the abutment is safe.展开更多
The objective of this work is to obtain the seismic safety coefficient and fracture surface and proceed with the seismic safety evaluation for the rock mass or soil mass surrounding a tunnel,and the limitation of eval...The objective of this work is to obtain the seismic safety coefficient and fracture surface and proceed with the seismic safety evaluation for the rock mass or soil mass surrounding a tunnel,and the limitation of evaluating seismic stability is considered using the pseudo-static strength reduction.By using the finite element software ANSYS and the strength reduction method,new methods of seismic safety evaluation for the rock mass or soil mass surrounding a tunnel are put forward,such as the dynamic finite element static shear strength reduction method and dynamic finite element shear strength reduction method.In order to prove the feasibility of the proposed methods,the results of numerical examples are compared with that of the pseudo-static strength reduction method.The results show that 1) the two methods are both feasible,and the plastic zone first appears near the bottom corners; 2) the safety factor of new method Ⅱ is smaller than that of new method I but generally,and the difference is very small.Therefore,in order to ensure the safety of the structure,two new methods are proposed to evaluate the seismic stability of the rock mass or soil mass surrounding a tunnel.A theoretical basis is provided for the seismic stability of the rock mass or soil mass and the lining surrounding a tunnel and also provided for the engineering application.展开更多
Based on fuzzy integrated evaluation theory, the safety of coal industry was analyzed, the factors affecting the safety of coal industry was considered, and its fuzzy in- tegrated estimating theory and results were gi...Based on fuzzy integrated evaluation theory, the safety of coal industry was analyzed, the factors affecting the safety of coal industry was considered, and its fuzzy in- tegrated estimating theory and results were given. Finally this paper proposed a new method of industry safety estimation. According to this method, we can integrate the fac- tors affecting coal industry and deal with the parameters and targets of evaluating factors by quantitative analysis, thus give a scientific and reasonable safety degree analyzing evaluation.展开更多
基金Supported by the China Postdoctoral Science Foundation(2023M730312)the Science and Technology Plan Projects of the State Administration for Market Regulation(2022MK002)the National Key Research and Development Program(2022YFF0606105)。
文摘The commercial cultivation of genetically modified(GM)crops has eased the global food crisis and brought considerable economic and social benefits to countries.Because of the potential safety problems,it is necessary to make clear the molecular genetic characteristics,edible safety,planting,processing,and other aspects of the safety evaluation of GM crops.The safety problems existing in the cultivation of GM crops,safety evaluation and detection of GM crops were introduced in this paper,which provided the basis for safety evaluation and effective supervision of GM crops and their products.Commercial cultivation and reasonable supervision based on safety evaluation have far-reaching significance for ensuring consumer safety,enhancing the credibility of the national political system and enhancing citizens'confidence in the safety of GM crop products for consumption.
基金Sponsored by Jiangsu Province Social Science Application Research Project(24SZC-117).
文摘Safety is one of the basic needs of tourists,and their sense of security is a necessary condition for the successful operation of homestays.Based on the theory of tourist perception,Nanjing Tangjiajia Hot Spring Village is taken as the research object.This paper analyzes the tourists’perception of homestay safety facilities and services through questionnaire survey,field investigation,interview,and other methods.It proposes strategies for improving homestay safety,aiming to provide safety management references for China’s homestay industry and promote its sustainable development.
基金supported by a grant from the National High-Tech R&D Program of China (863 Program, N20080753)
文摘The objective of the present study was to evaluate potential adverse effects of diacylglycerol microemulsion (DAGM) in rats/mice. Acute safety evaluation was carried out by giving intragastrically with 20 mL 25% DAG kg-1 body weight of DAGM or water with two groups of mice. Chronic safety evaluation with 40 male and 40 female Sprague-Dawley rats was carried out by setting a control group and 3 different dose groups (n=10 male+10 female) administered with DAGM with 6.7, 10 and 20 mL kg-1 body weight per day. Relevant parameters of liver and kidney function and biochemistry were determined by standard methods at end point. Acute toxicity study revealed the maximum tolerated dose (MTD) of DAGM was 20 mL kg-1 body weight in mice. No death was observed at the dose of 20 mL kg-1 body weight per day. Chronic safety evaluation did not show significant changes on hematological, histopathologic, clinical, and biochemical tests when administered at levels of 6.7, 10 and 20 mL kg-1 body weight per day to rats for 30 d. No significant body weight changes were observed in different dosages in both male and female rats. Our results suggested that acute and chronic adverse effects were not observed in histology and clinical parameters in both mice and rats. The results suggested that DAGM is safe at the experimental levels.
文摘The main objective of the work presented in this paper was to develop a customized safety training program that can be incorporated into the demolition projects undertaken as part of blight reduction efforts in urban centers. A subsidiary objective was to devise and implement a safety program evaluation methodology, and gain insights on the relationships between knowledge acquisition through training and trainee demographics. Salient aspects of blight elimination efforts, as well as the main facets of building demolition practices and requirements, were reviewed. Information on various related safety and health hazards was studied in depth with a focus on demolition operations dealing with blighted properties. A unique safety hazard awareness training program was created for demolition workers, contractors and inspectors based on this research. In addition to devising a curriculum of relevant training topics along with traditional and online delivery systems to be employed, effectiveness evaluation instruments were formulated. Based on the limited data collected from the trainees it was concluded that the program was well-received by them and provided effective learning. It was also found that no statistically significant associations existed between the knowledge gain of the trainees, and either their experience level or union status, after taking this training.
基金supported by the National Natural Science Foundation of China (Grant No. U1334206 and No. 51475388)Science & Technology Development Project of China Railway Corporation (Grant No. J012-C)
文摘The wheel-rail force measurement is of great importance to the condition monitoring and safety evaluation of railway vehicles. In this paper, an improved indirect method for wheel-rail force measurement is proposed to evaluate the running safety of railway vehicles. In this method, the equilibrium equations of a suspended wheelset are derived and the wheel-rail forces are then be obtained from measured suspension and inertia forces. This indirect method avoids structural modifications to the wheelset and is applicable to the long-term operation of railway vehicles. As the wheel-rail lateral forces at two sides of the wheelset are difficult to separate, a new derailment criterion by combined use of wheelset derailment coefficient and wheel unloading ratio is proposed. To illustrate its effectiveness, the indirect method is applied to safety evaluation of rail- way vehicles in different scenarios, such as the cross wind safety of a high-speed train and the safety of a metro vehicle with hunting motions. Then, the feasibility of using this method to identify wheel-rail forces for low-floor light rail vehicles with resilient wheels is discussed. The values identified by this method is compared with that by Simpack simulation for the same low-floor vehicle, which shows a good coincidence between them in the time domain of the wheelset lateral force and the wheel-rail vertical force. In addition, use of the method to determine the high-frequency wheel-rail interaction forces reveals that it is possible to identify the high-frequency wheel-rail forces through the accelerations on the axle box.
文摘Bridge structure safety monitoring and assessment has been a great concern for the government and the public,and bridge structure safety monitoring and assessment technology has also developed rapidly over the years.Its goal is to equip relevant organizations and professionals with a deep understanding of the principles and practical applications of these technologies.By doing so,it seeks to facilitate the effective implementation of safety monitoring and assessment practices in bridge management.Ultimately,the aim is to foster the constructive development of road and bridge construction and operational management at a broader level.
基金Supported by Major Program in Zhejiang Science and Technology Department(2008C22G2100038)Emerging Artists Project in Zhejiang Province(21000037)~~
文摘[ Objective] The study aimed to supply important basis for developing environment-friendly pesticides with myricetin and crude extract of Myrica rubra leaves as effective components. [ Method] According to "Test guidelines for environmental safety evaluation on chemical pesticides", the toxicity of myricetin and crude extract of M. rubra leaves on non-target organisms was determined and the safety evaluation was carried out. [Result] MyriceUn and crude extract of M. rubra leaves had low toxicity on non-target organisms, such as earthworm, silkworm and soil microbes. Myricetin showed low toxicity and the crude extract of M. rubra leaves showed middle toxicity on tadpole. The high-concentration crude extract of M. rubra leaves had some antifeedant effect on silkworm. [ Conclusion] Myricetin and crude extract of M. rubra leaves had low toxicity on non-tar- get organisms in environment and they were relatively safe.
基金Supported by the National Natural Science Foundation of China(50274060) and State Administration of Work Safety(03-103)
文摘Based on the integration analysis of goods and shortcomings of various methods used in safety assessment of coal mines, combining nonlinear feature of mine safety sub-system, this paper establishes the neural network assessment model of mine safety, analyzes the ability of artificial neural network to evaluate mine safety state, and lays the theoretical foundation of artificial neural network using in the systematic optimi- zation of mine safety assessment and getting reasonable accurate safety assessment result.
基金supported by the National Basic Research Program of China(2012CB719703)University of Anhui Provincial Natural Science Fund Project(J2013A068)
文摘Mechanical characterization of steel frame structure after fire are ana- lyzed based on fire dynamics, heat transfer theory, structural mechanics, and finite element theory. We study the temperature characteristics and mechanical prop- erties of steel flame structure under different fire locations and propose a safety evaluation method. We also analyze damage level of main flame components, maximum temperature of fire, thermal characteristics of flame components, fir- ing duration, etc. to provide useful information for fire resistance design of the steel frame structure and post-disaster safety evaluation.
基金Sponsored by Science and technology development fund of China academy of engineering physics( 2011A0203010)
文摘In an abnormal high-temperature fire environment,a structure with mechanical-thermal weak-link can be used to predict the permanent failure before the failure of some strong-links,such as explosive initiator,thus to protect the latter. An effective design can be defined as that the weak-link fails before the failure of the strong-link,and the system is safe; while an unsuccessful design means that the weak-link fails after the failure of the strong-link,and the system loses in safety. The probability of safety failure exists due to the uncertain failure temperatures of the weak-link and strong-link. In order to obtain the probability of safety failure,a statistical method was used to deal with the uncertainty of the failure temperatures. The integral method and stochastic simulation method were used in calculations. Finally,a sample was given to verify the consistence of the results given by two methods.
基金The Opening Fund of the Key Laboratory of UrbanSecurity and Disaster Engineering of Ministry of Education (NoEESR200701)the Opening Fund of Beijing Laboratory of EarthquakeEngineering and Structural Retrofit
文摘A method of cable safety analysis is proposed for safety evaluation of long-span cable-stayed bridges. The Daniels' effect and the probability of broken wires in the cable are introduced to develop the cable strength model and the reliability assessment technique for long-span cable-stayed bridges based on the safety factors analysis of stay cables in service. As an application of the proposed model, the cable safety reliability of the cable No. 25 of Zhaobaoshan cable-stayed bridge in China is calculated. The effects of various parameters on the estimated cable safety reliability are investigated. The results indicate that the proposed method can be used to assess the safety level of stay cables in cable-stayed bridges effectively. The Daniels' effect should be taken into account for assessment, and the probability of broken wires can be used to simulate the deterioration of stay cables in service.
文摘By standard method to determine thallium content in 34 batches of cosmetic products sold in Shenzhen,including cushions and sunscreens for children,all results of samples are within the range of not detected to 0.62 mg/kg.By calculating the Maximum Theoretical Safety Limit,according to guidance of Scientific Committee on Consumer Safety(SCCS)of European Union and Toxicological Review of Thallium and Compounds 2009 of United States Environmental Protection Agency(EPA)to assess the risk of cosmetic products.As a result,if the mean concentration of thallium in different kind of cosmetic products does not exceed 0.031 mg/kg,the products will not show significant toxicological risk for consumers.
基金Supported by Science and Technology Foundation of Guizhou Province(LKS[2009]No.24)Technological Innovation Team-building Projects of Guizhou Province([2009]4007)~~
文摘[Objective] The biological safety of white insect tea in Xifeng County of Guizhou Province was evaluated in order to provide a scientific basis for the development of white insect tea. [Method] Acute toxicity test in mice, Ames microbiological test and mouse bone marrow polychromatic erythrocyte micronucleus test were done with wild white inset tea produced in Xifeng County. At the same time, the contents of six kinds of limit pollutants were determined, including Pb,Cr,Cd,Hg,As,and F-. [Result] The results showed that white insect tea had LD505.0 g/kg(BW)in acute toxicity test, negative response in Ames test and microkernel test. In addition, the contents of Pb,Cr,Cd,Hg,As,and F- in the white inset tea were 2.20,1.06,0.46,0.09,0.71,21.50 mg/kg, much less than the national standard of tea (GB2762-2005,NY 659-2003). [Conclusion] The white insect tea produced in Xifeng County of Guizhou Province is non-toxic, and good for human as beverage.
基金Major Research Plan of the National Natural Science Foundation of China under Grant No.91315301-10Project of Earthquake Code Compilation and Revising:Postearthquake Field Works-Part 2:Safety Assessment of Buildings under Grant No.14410024701Basic Scientific Research Special Project of IEM,CEA under Grant No.2009A01
文摘This paper describes a set of on-site earthquake safety evaluation systems for buildings, which were developed based on a network platform. The system embedded into the quantitative research results which were completed in accordance with the provisions from Post-earthquake Field Works, Part 2: Safety Assessment of Buildings, GB18208.2 -2001, and was further developed into an easy-to-use software platform. The system is aimed at allowing engineering professionals, civil engineeing technicists or earthquake-affected victims on site to assess damaged buildings through a network after earthquakes. The authors studied the function structure, process design of the safety evaluation module, and hierarchical analysis algorithm module of the system in depth, and developed the general architecture design, development technology and database design of the system. Technologies such as hierarchical architecture design and Java EE were used in the system development, and MySQL5 was adopted in the database development. The result is a complete evaluation process of information collection, safety evaluation, and output of damage and safety degrees, as well as query and statistical analysis of identified buildings. The system can play a positive role in sharing expert post-earthquake experience and promoting safety evaluation of buildings on a seismic field.
基金supported by the General Project of Hubei Health Committee of China,No.WJ2019M263(to GW)。
文摘Stem cell therapy is a promising strategy for the treatment of traumatic brain injury(TBI). However, animal experiments are needed to evaluate safety;in particular, to examine the immunogenicity and tumorigenicity of human umbilical cord mesenchymal stem cells(hu MSCs) before clinical application. In this study, hu MSCs were harvested from human amniotic membrane and umbilical cord vascular tissue. A rat model of TBI was established using the controlled cortical impact method. Starting from the third day after injury, the rats were injected with 10 μL of 5 × 10^(6)/m L hu MSCs by cerebral stereotaxis or with 500 μL of 1 × 10^(6)/m L hu MSCs via the tail vein for 3 successive days. hu MSC transplantation decreased the serum levels of proinflammatory cytokines in rats with TBI and increased the serum levels of anti-inflammatory cytokines, thereby exhibiting good immunoregulatory function. The transplanted hu MSCs were distributed in the liver, lung and brain injury sites. No abnormal proliferation or tumorigenesis was found in these organs up to 12 months after transplantation. The transplanted hu MSCs negligibly proliferated in vivo, and apoptosis was gradually observed at later stages. These findings suggest that hu MSC transplantation for the treatment of traumatic brain injury displays good safety. In addition, hu MSCs exhibit good immunoregulatory function, which can help prevent and reduce secondary brain injury caused by the rapid release of inflammatory factors after TBI. This study was approved by the Ethics Committee of Wuhan General Hospital of PLA(approval No. 20160054) on November 1, 2016.
文摘Key methods developed and used in the USSR and in the Russian Federation to determine the impact and friction sensitivity of energetic materials and explosives have been discussed.Experimental methodologies and instruments that underlie the assessment of their production and handling safety have been described.Studies of a large number of compounds have revealed relationships between their sensitivity parameters and structure of individual compounds and compositions.The range of change of physical and chemical characteristics for the compounds we examined covers the entire region of their existence.Theoretical methodology and equations have been formulated to estimate the impact and friction sensitivity parameters of energetic materials and to evaluate the technological safety in use.The developed methodology is characterized by high-accuracy calculations and prediction of sensitivity parameters.
基金supported by the National Natural Science Foundation of China (Grant No. 50539010)
文摘A comprehensive safety evaluation system taking the most influential factors into account has been developed to evaluate the reliability of hydraulic metal structures. Applying the techniques of AI and DB, the idea of a one-machine and three-base system is proposed. The framework of the three-base system has been designed and the structural framework constructed in turn. A practical example is given to illustrate the process of using this system and it can be used for comparison and analysis purposes. The key technology of the system is its ability to reorganize and improve the expert system's knowledge base by establishing the expert system. This system utilizes the computer technology inference process, making safety evaluation conclusions more reasonable and applicable to the actual situation. The system is not only advanced, but also feasible, reliable, artificially intelligent, and has the capacity to constantly grow.
基金supported by the National Natural Science Foundation of China(Grant No51139001)the Natural Science Foundation of Jiangsu Province(Grant NoBK2009479)+2 种基金the Scientific Research Foundation of the State Human Resource Ministry for Returned Chinese Scholars(Grant No2009003)the Scientific Research Foundation for Doctors in Jiangsu Enterprises(Grant No2011-33)the Jiangsu Provincial Postdoctoral Sustentation Fund(Grant No1101049C)
文摘Reinforcement quality evaluation at the abutment is an important research direction. Prototype monitoring and theoretical derivation were integrated to study the replacement reinforcement quality in abutment contact zones of the Xiaowan ultra-high arch dam. The principles of monitoring layout and design are introduced in detail. Prototype monitoring shows that the increment of the interfacial compressive stress is much larger in the impoundment stage than in the regulating stage. The water pressure and time-effect are two main factors affeeting the interfacial stress. The time-effect is the key factor in the initial impoundment stage, and the water pressure is the key factor after impoundment. The contact properties are significantly improved by grouting. This study shows that there are three typical stages in the joint opening hydrographs, namely the compression stage, opening stage, and stable stage. There is a nonlinear relationship between the joint opening and temperature, which can be well described by the S-function. In conclusion, the reinforcement effect is satisfying, and the abutment is safe.
基金Project(2011CB013600) supported by State Key Program for Basic Research of ChinaProject(20136201110003) supported by the Education Ministry Doctoral Tutor Foundation of China+1 种基金Project(51368039) supported by the National Natural Science Foundation of ChinaProject(2013-4-94) supported by the Program of Science and Technology Research in Lanzhou City,China
文摘The objective of this work is to obtain the seismic safety coefficient and fracture surface and proceed with the seismic safety evaluation for the rock mass or soil mass surrounding a tunnel,and the limitation of evaluating seismic stability is considered using the pseudo-static strength reduction.By using the finite element software ANSYS and the strength reduction method,new methods of seismic safety evaluation for the rock mass or soil mass surrounding a tunnel are put forward,such as the dynamic finite element static shear strength reduction method and dynamic finite element shear strength reduction method.In order to prove the feasibility of the proposed methods,the results of numerical examples are compared with that of the pseudo-static strength reduction method.The results show that 1) the two methods are both feasible,and the plastic zone first appears near the bottom corners; 2) the safety factor of new method Ⅱ is smaller than that of new method I but generally,and the difference is very small.Therefore,in order to ensure the safety of the structure,two new methods are proposed to evaluate the seismic stability of the rock mass or soil mass surrounding a tunnel.A theoretical basis is provided for the seismic stability of the rock mass or soil mass and the lining surrounding a tunnel and also provided for the engineering application.
文摘Based on fuzzy integrated evaluation theory, the safety of coal industry was analyzed, the factors affecting the safety of coal industry was considered, and its fuzzy in- tegrated estimating theory and results were given. Finally this paper proposed a new method of industry safety estimation. According to this method, we can integrate the fac- tors affecting coal industry and deal with the parameters and targets of evaluating factors by quantitative analysis, thus give a scientific and reasonable safety degree analyzing evaluation.