Foreword ISO(the International Organization for Standardization)is a worldwide federation of national standards bodies(ISO member bodies).The work of preparing International Standards is normally carried out through I...Foreword ISO(the International Organization for Standardization)is a worldwide federation of national standards bodies(ISO member bodies).The work of preparing International Standards is normally carried out through ISO technical committees.Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee.展开更多
To promote the production and application of artificial aggregates,save natural sand resources and protect the ecological environment,we evaluated the feasibility of using spherical porous functional aggregates(SPFAs)...To promote the production and application of artificial aggregates,save natural sand resources and protect the ecological environment,we evaluated the feasibility of using spherical porous functional aggregates(SPFAs) formed by basalt saw mud under autoclave curing in ordinary structural concrete.In our work,two types of prewetted functional aggregates were taken as replacements for natural aggregates with different volume substitution rates(0%,5%,10%,15%,20%,25%,and 30%) in the preparation of ordinary structural concrete with water-to-binder ratios(W/B) of 0.48 and 0.33.The effects of the functional aggregate properties and content,W/B,and curing age on the fluidity,density,mechanical properties and autogenous shrinkage of ordinary concrete were analyzed.The experimental results showed that the density of concrete declined at a rate of not more than 5%,and the 28 d compressive strength could reach 31.0-68.2 MPa.Low W/B,long curing age and high-quality functional aggregates were conducive to enhancing the mechanical properties of SPFAs concrete.Through the rolling effects,SPFAs can optimize the particle gradation of aggregate systems and improve the fluidity of concrete,and the water stored inside SPFAs provides an internal curing effect,which prolongs the cement hydration process and considerably reduces the autogenous shrinkage of concrete.SPFAs exhibits high strength and high density,as well as being more cost-effective and ecological,and is expected to be widely employed in ordinary structural concrete.展开更多
Introduction: Work-related accidents are frequent and serious in the construction sector. The aim of the study was to determine the frequency and factors associated with occupational accidents on the construction site...Introduction: Work-related accidents are frequent and serious in the construction sector. The aim of the study was to determine the frequency and factors associated with occupational accidents on the construction site of a referral hospital in Benin. Methods: A cross-sectional study was carried out. The sample size was calculated using the Schwartz form adjusted for the number of workers on site and was 129 workers. Random sampling was used. The dependent variable was work-related accidents. The other variables were socio-demographic and occupational characteristics. Data were collected through a questionnaire survey. Medians and proportions were calculated. An association was sought using Chi-square and Fisher tests with a threshold of p Results: A total of 132 workers were included. Their median age was 30 years with an ITQ of [27 - 38];men were the most represented 126 (95.45%) with a level of education higher than or equal to high school in 101 (76.52%) and in the majority with a permanent status 85 (64.39%). Seniority of more than 5 years was observed in 92 (69.7%). Workers working more than 8 hours of overtime per week numbered 57 (43.18%). Exposure to vibrating objects was 49 (37.12%). In terms of psychosocial constraints, 82.58% had high psychological demands;79.53% low decision-making latitude;50.76% low social support. The frequency of work-related accidents was 6.82%, and the only associated factor was the type of worker (p = 0.016). On the other hand, there were 10.2% accidents among workers handling vibrating objects versus 4.98% among those not using them. With regard to psychosocial constraints, the following frequencies were recorded respectively: 6.42% among those with high psychological demand versus 8.7% among those with low psychological demand;7.62% among those with low decision-making latitude versus 3.7% among those with high decision-making latitude;8.96% among those with low social support versus 4.62% among those with high support. Conclusion: Work-related accidents on construction sites must be avoided by all possible means including the management of psychosocial constraints.展开更多
Historical changes have taken place in China under the reform-and-opening-up policy over the past three decades. Changes in China's social and economic structures, cultural scenes and social operations are revolution...Historical changes have taken place in China under the reform-and-opening-up policy over the past three decades. Changes in China's social and economic structures, cultural scenes and social operations are revolutionary. The Chinese people, who account for one fifth of the human race, are working hard to bring about a national reiuvanation.展开更多
Many kinds of electrical equipment are used in civil and building engineering.The motor is one of the main power components of this electrical equipment,which can provide stable power output.During the long-term use o...Many kinds of electrical equipment are used in civil and building engineering.The motor is one of the main power components of this electrical equipment,which can provide stable power output.During the long-term use of motors,various motor faults may occur,which affects the normal use of electrical equipment and even causes accidents.It is significant to apply fault diagnosis for the motors at the construction site.Aiming at the problem that signal data of faulty motor lack diversity,this research designs a multi-layer perceptron Wasserstein generative adversarial network,which is used to enhance training data through distribution fusion.A discrete wavelet decomposition algorithm is employed to extract the low-frequency wavelet coefficients from the original motor current signals.These are used to train themulti-layer perceptron Wasserstein generative adversarial model.Then,the trainedmodel is applied to generate fake current wavelet coefficients with the fused distribution.A motor fault classification model consisting of a feature extractor and pattern recognizer is built based on perceptron.The data augmentation experiment shows that the fake dataset has a larger distribution than the real dataset.The classification model trained on a real dataset,fake dataset and combined dataset achieves 21.5%,87.2%,and 90.1%prediction accuracy on the unseen real data,respectively.The results indicate that the proposed data augmentation method can effectively generate fake data with the fused distribution.The motor fault classification model trained on a fake dataset has better generalization performance than that trained on a real dataset.展开更多
Buildings have contributed to the energy shortage, pollution and global climate change. To promote green buildings is the way access to the sustainable development. Currently, China has issued some regulations and sys...Buildings have contributed to the energy shortage, pollution and global climate change. To promote green buildings is the way access to the sustainable development. Currently, China has issued some regulations and systems to boost the green building. However, problems lie in China and the systems are not effective. USA and EU have rich experiences and fairly sophisticated legislation and policies to develop green building. China may get some lessens from these countries. This paper will make an overview of legal framework and main system of green building in China, then, analyses some important legal systems and typical case related green building in the USA and EU. Further, problems were pointed out in the China based on the comparative analysis of these countries. Lastly, according to the condition in China and lessons from USA and EU, this paper will put some suggests to promote green building, such as, take some measures to enhance the awareness of the stakeholders, create multi- incentive tools and so on.展开更多
This paper explains and discusses the concepts of ecological conservation and construction in China in three parts. The first part provides a brief description of the historical background of ecological activities in ...This paper explains and discusses the concepts of ecological conservation and construction in China in three parts. The first part provides a brief description of the historical background of ecological activities in China and their major achievements in the past. The second part is a comprehensive review of various types of ecological control activity aimed at the improvement of natural and artificially established ecosystems at the landscape,regional(watershed) and higher levels. The scope of and differences between some ecological terms used in China such as ecological protection, conservation, remediation(rehabilitation), restoration as well as the reestablishment of new ecosystems are elaborated. The review suggests that the term "ecological conservation and construction"should be used to embrace all types of ecological control activity in China. Finally, five guidelines are proposed for promoting the implementation of ecological conservation and construction in China based on the two important governmental documents related to the development of ecological civilization in China.展开更多
文摘Foreword ISO(the International Organization for Standardization)is a worldwide federation of national standards bodies(ISO member bodies).The work of preparing International Standards is normally carried out through ISO technical committees.Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee.
基金Funded by the National Natural Science Foundation of China(No.52378213)the Technology Development Project(No.20201902977180010) of CABR Technology Co.,Ltd。
文摘To promote the production and application of artificial aggregates,save natural sand resources and protect the ecological environment,we evaluated the feasibility of using spherical porous functional aggregates(SPFAs) formed by basalt saw mud under autoclave curing in ordinary structural concrete.In our work,two types of prewetted functional aggregates were taken as replacements for natural aggregates with different volume substitution rates(0%,5%,10%,15%,20%,25%,and 30%) in the preparation of ordinary structural concrete with water-to-binder ratios(W/B) of 0.48 and 0.33.The effects of the functional aggregate properties and content,W/B,and curing age on the fluidity,density,mechanical properties and autogenous shrinkage of ordinary concrete were analyzed.The experimental results showed that the density of concrete declined at a rate of not more than 5%,and the 28 d compressive strength could reach 31.0-68.2 MPa.Low W/B,long curing age and high-quality functional aggregates were conducive to enhancing the mechanical properties of SPFAs concrete.Through the rolling effects,SPFAs can optimize the particle gradation of aggregate systems and improve the fluidity of concrete,and the water stored inside SPFAs provides an internal curing effect,which prolongs the cement hydration process and considerably reduces the autogenous shrinkage of concrete.SPFAs exhibits high strength and high density,as well as being more cost-effective and ecological,and is expected to be widely employed in ordinary structural concrete.
文摘Introduction: Work-related accidents are frequent and serious in the construction sector. The aim of the study was to determine the frequency and factors associated with occupational accidents on the construction site of a referral hospital in Benin. Methods: A cross-sectional study was carried out. The sample size was calculated using the Schwartz form adjusted for the number of workers on site and was 129 workers. Random sampling was used. The dependent variable was work-related accidents. The other variables were socio-demographic and occupational characteristics. Data were collected through a questionnaire survey. Medians and proportions were calculated. An association was sought using Chi-square and Fisher tests with a threshold of p Results: A total of 132 workers were included. Their median age was 30 years with an ITQ of [27 - 38];men were the most represented 126 (95.45%) with a level of education higher than or equal to high school in 101 (76.52%) and in the majority with a permanent status 85 (64.39%). Seniority of more than 5 years was observed in 92 (69.7%). Workers working more than 8 hours of overtime per week numbered 57 (43.18%). Exposure to vibrating objects was 49 (37.12%). In terms of psychosocial constraints, 82.58% had high psychological demands;79.53% low decision-making latitude;50.76% low social support. The frequency of work-related accidents was 6.82%, and the only associated factor was the type of worker (p = 0.016). On the other hand, there were 10.2% accidents among workers handling vibrating objects versus 4.98% among those not using them. With regard to psychosocial constraints, the following frequencies were recorded respectively: 6.42% among those with high psychological demand versus 8.7% among those with low psychological demand;7.62% among those with low decision-making latitude versus 3.7% among those with high decision-making latitude;8.96% among those with low social support versus 4.62% among those with high support. Conclusion: Work-related accidents on construction sites must be avoided by all possible means including the management of psychosocial constraints.
文摘Historical changes have taken place in China under the reform-and-opening-up policy over the past three decades. Changes in China's social and economic structures, cultural scenes and social operations are revolutionary. The Chinese people, who account for one fifth of the human race, are working hard to bring about a national reiuvanation.
基金supported by the National Key Research and Development Program of China (No.2020YFB1713503)the Fundamental Research Funds for the Central Universities (No.20720190009)2019 Industry-University-Research Cooperation Project of Aero Engine Corporation of China (No.HFZL2019CXY02).
文摘Many kinds of electrical equipment are used in civil and building engineering.The motor is one of the main power components of this electrical equipment,which can provide stable power output.During the long-term use of motors,various motor faults may occur,which affects the normal use of electrical equipment and even causes accidents.It is significant to apply fault diagnosis for the motors at the construction site.Aiming at the problem that signal data of faulty motor lack diversity,this research designs a multi-layer perceptron Wasserstein generative adversarial network,which is used to enhance training data through distribution fusion.A discrete wavelet decomposition algorithm is employed to extract the low-frequency wavelet coefficients from the original motor current signals.These are used to train themulti-layer perceptron Wasserstein generative adversarial model.Then,the trainedmodel is applied to generate fake current wavelet coefficients with the fused distribution.A motor fault classification model consisting of a feature extractor and pattern recognizer is built based on perceptron.The data augmentation experiment shows that the fake dataset has a larger distribution than the real dataset.The classification model trained on a real dataset,fake dataset and combined dataset achieves 21.5%,87.2%,and 90.1%prediction accuracy on the unseen real data,respectively.The results indicate that the proposed data augmentation method can effectively generate fake data with the fused distribution.The motor fault classification model trained on a fake dataset has better generalization performance than that trained on a real dataset.
基金the key research project on the selection and application of the regulated tools [CLS(2011)B13],awarded by the China Law Societythe foundation from the United States Agency of the International Development,awarded by the Vermont Law School
文摘Buildings have contributed to the energy shortage, pollution and global climate change. To promote green buildings is the way access to the sustainable development. Currently, China has issued some regulations and systems to boost the green building. However, problems lie in China and the systems are not effective. USA and EU have rich experiences and fairly sophisticated legislation and policies to develop green building. China may get some lessens from these countries. This paper will make an overview of legal framework and main system of green building in China, then, analyses some important legal systems and typical case related green building in the USA and EU. Further, problems were pointed out in the China based on the comparative analysis of these countries. Lastly, according to the condition in China and lessons from USA and EU, this paper will put some suggests to promote green building, such as, take some measures to enhance the awareness of the stakeholders, create multi- incentive tools and so on.
文摘This paper explains and discusses the concepts of ecological conservation and construction in China in three parts. The first part provides a brief description of the historical background of ecological activities in China and their major achievements in the past. The second part is a comprehensive review of various types of ecological control activity aimed at the improvement of natural and artificially established ecosystems at the landscape,regional(watershed) and higher levels. The scope of and differences between some ecological terms used in China such as ecological protection, conservation, remediation(rehabilitation), restoration as well as the reestablishment of new ecosystems are elaborated. The review suggests that the term "ecological conservation and construction"should be used to embrace all types of ecological control activity in China. Finally, five guidelines are proposed for promoting the implementation of ecological conservation and construction in China based on the two important governmental documents related to the development of ecological civilization in China.