In the last decade, technical advancements and faster Internet speeds have also led to an increasing number ofmobile devices and users. Thus, all contributors to society, whether young or old members, can use these mo...In the last decade, technical advancements and faster Internet speeds have also led to an increasing number ofmobile devices and users. Thus, all contributors to society, whether young or old members, can use these mobileapps. The use of these apps eases our daily lives, and all customers who need any type of service can accessit easily, comfortably, and efficiently through mobile apps. Particularly, Saudi Arabia greatly depends on digitalservices to assist people and visitors. Such mobile devices are used in organizing daily work schedules and services,particularly during two large occasions, Umrah and Hajj. However, pilgrims encounter mobile app issues such asslowness, conflict, unreliability, or user-unfriendliness. Pilgrims comment on these issues on mobile app platformsthrough reviews of their experiences with these digital services. Scholars have made several attempts to solve suchmobile issues by reporting bugs or non-functional requirements by utilizing user comments.However, solving suchissues is a great challenge, and the issues still exist. Therefore, this study aims to propose a hybrid deep learningmodel to classify and predict mobile app software issues encountered by millions of pilgrims during the Hajj andUmrah periods from the user perspective. Firstly, a dataset was constructed using user-generated comments fromrelevant mobile apps using natural language processing methods, including information extraction, the annotationprocess, and pre-processing steps, considering a multi-class classification problem. Then, several experimentswere conducted using common machine learning classifiers, Artificial Neural Networks (ANN), Long Short-TermMemory (LSTM), and Convolutional Neural Network Long Short-Term Memory (CNN-LSTM) architectures, toexamine the performance of the proposed model. Results show 96% in F1-score and accuracy, and the proposedmodel outperformed the mentioned models.展开更多
A Recommender System(RS)is a crucial part of several firms,particularly those involved in e-commerce.In conventional RS,a user may only offer a single rating for an item-that is insufficient to perceive consumer prefe...A Recommender System(RS)is a crucial part of several firms,particularly those involved in e-commerce.In conventional RS,a user may only offer a single rating for an item-that is insufficient to perceive consumer preferences.Nowadays,businesses in industries like e-learning and tourism enable customers to rate a product using a variety of factors to comprehend customers’preferences.On the other hand,the collaborative filtering(CF)algorithm utilizing AutoEncoder(AE)is seen to be effective in identifying user-interested items.However,the cost of these computations increases nonlinearly as the number of items and users increases.To triumph over the issues,a novel expanded stacked autoencoder(ESAE)with Kernel Fuzzy C-Means Clustering(KFCM)technique is proposed with two phases.In the first phase of offline,the sparse multicriteria rating matrix is smoothened to a complete matrix by predicting the users’intact rating by the ESAE approach and users are clustered using the KFCM approach.In the next phase of online,the top-N recommendation prediction is made by the ESAE approach involving only the most similar user from multiple clusters.Hence the ESAE_KFCM model upgrades the prediction accuracy of 98.2%in Top-N recommendation with a minimized recommendation generation time.An experimental check on the Yahoo!Movies(YM)movie dataset and TripAdvisor(TA)travel dataset confirmed that the ESAE_KFCM model constantly outperforms conventional RS algorithms on a variety of assessment measures.展开更多
The behavior issues of preschoolers are closely related to their parents'parenting styles.This editorial discusses the value and strategies for solving behavior issues in preschoolers from the perspectives of mind...The behavior issues of preschoolers are closely related to their parents'parenting styles.This editorial discusses the value and strategies for solving behavior issues in preschoolers from the perspectives of mindfulness and mindful parenting.We expect that upcoming studies will place greater emphasis on the behavioral concerns of preschoolers and the parenting practices that shape them,particularly focusing on proactive interventions for preschoolers'behavioral issues.展开更多
In response to the United Nations Sustainable Development Goals and China’s“Dual Carbon”Goals(DCGs means the goals of“Carbon Peak and carbon neutrality”),this paper from the perspective of the construction of Ch...In response to the United Nations Sustainable Development Goals and China’s“Dual Carbon”Goals(DCGs means the goals of“Carbon Peak and carbon neutrality”),this paper from the perspective of the construction of China’s Innovation Demonstration Zones for Sustainable Development Agenda(IDZSDAs),combines carbon emission-related metrics to construct a comprehensive assessment system for Urban Sustainable Development Capacity(USDC).After obtaining USDC assessment results through the assessment system,an approach combining Least Absolute Shrinkage and Selection Operator(LASSO)regression and Random Forest(RF)based on machine learning is proposed for identifying influencing factors and characterizing key issues.Combining Coupling Coordination Degree(CCD)analysis,the study further summarizes the systemic patterns and future directions of urban sustainable development.A case study on the IDZSDAs from 2015 to 2022 reveals that:(1)the combined identification method based on machine learning and CCD models effectively quantifies influencing factors and key issues in the urban sustainable development process;(2)the correspondence between influencing factors and key subsystems identified by the LASSO-RF combination model is generally consistent with the development situations in various cities;and(3)the machine learning-based combined recognition method is scalable and dynamic.It enables decision-makers to accurately identify influencing factors and characterize key issues based on actual urban development needs.展开更多
The development of this technology has favored the advances noted in recent years in the field of precise positioning. It has also paved the way for a wide range of research into the evaluation of their performance an...The development of this technology has favored the advances noted in recent years in the field of precise positioning. It has also paved the way for a wide range of research into the evaluation of their performance and reliability, their potential use in different fields, the improvement of performance and combined systems, etc. Single-frequency GNSS receivers, which for a long time remained the only category of low-cost GNSS receivers, often limited by their level of accuracy (metric) mainly due to their single-frequency nature, have been joined in the last decade by dual-frequency GNSS receivers developed by certain manufacturers of positioning equipment. These receivers now offer possible alternatives to the relatively expensive conventional (topographic quality) or geodetic receivers and. In this study, the performance of these low-cost dual-frequency receivers was evaluated in static and real-time kinematic GNSS positioning modes. Static positioning was carried out on three points with sessions of 2 h and 4 h over three days with antenna swapping (CHC i50, Leica GS14 and Emlid Reach RS2+). Real-time observations were carried out on eleven (11) points in open, poorly open and not at all open environments, in order to assess not only performance but also receiver sensitivity in environments with a high risk of multipath. The results obtained showed an average agreement of 2 cm in planimetry between the low-cost Emlid RS2+ receiver and the Leica GS14 and CHC i50 receivers. The differences in altimetry are nevertheless greater (sometimes up to decimetres for certain points). Real-time positioning results provided an average convergence of around 1 cm on the E, N and H components with the results from the low-cost Emlid Reach RS2+ and Ublox ZED-F9P receivers and the CHC i50 receiver. Analysis of the results obtained has enabled us to highlight the various issues and challenges associated with this new generation of GNSS receivers, with a view to enhancing their appropriation and optimal integration in the professional and research worlds.展开更多
Objective To study the content of China’s guiding principles on multiplicity issues in clinical trials,and to provide reference for the revision of China’s relevant guiding principles.Methods Based on ICH E9,the sim...Objective To study the content of China’s guiding principles on multiplicity issues in clinical trials,and to provide reference for the revision of China’s relevant guiding principles.Methods Based on ICH E9,the similarities and differences of the guiding principles of US Food and Drug Administration(FDA),European Medicines Agency(EMA),and National Medical Products Administration(NMPA)on the multiplicity issues in clinical trials were compared one by one.Results and Conclusion In general,NMPA guidelines are based on ICH E9,but in detail,the guidelines of FDA and EMA focus differently on the multiplicity issues.Therefore,NMPA guidelines need to be detailed and comprehensive.NMPA guidelines can be refined by referring to foreign guidelines to improve the practical guiding significance for clinical research and promote the level of domestic clinical trials in line with international standards.展开更多
All-solid-state Li metal batteries(ASSLBs)using inorganic solid electrolyte(SE)are considered promising alternatives to conventional Li-ion batteries,offering improved safety and boosted energy density.While significa...All-solid-state Li metal batteries(ASSLBs)using inorganic solid electrolyte(SE)are considered promising alternatives to conventional Li-ion batteries,offering improved safety and boosted energy density.While significant progress has been made on improving the ionic conductivity of SEs,the degradation and instability of Li metal/inorganic SE interfaces have become the critical challenges that limit the coulombic efficiency,power performance,and cycling stability of ASSLBs.Understanding the mechanisms of complex/dynamic interfacial phenomena is of great importance in addressing these issues.Herein,recent studies on identifying,understanding,and solving interfacial issues on anode side in ASSLBs are comprehensively reviewed.Typical issues at Li metal/SE interface include Li dendrite growth/propagation,SE cracking,physical contact loss,and electrochemical reactions,which lead to high interfacial resistance and cell failure.The causes of these issues relating to the chemical,physical,and mechanical properties of Li metal and SEs are systematically discussed.Furthermore,effective mitigating strategies are summarized and their effects on suppressing interfacial reactions,improving interfacial Li-ion transport,maintaining interfacial contact,and stabilizing Li plating/stripping are highlighted.The in-depth mechanistic understanding of interfacial issues and complete investigations on current solutions provide foundations and guidance for future research and development to realize practical application of high-performance ASSLB.展开更多
Introduction: In Nigeria, a major reason for marriage is procreation and married couples look forward to having children within a year or two of marriage. The inability to achieve conception and subsequently have a ch...Introduction: In Nigeria, a major reason for marriage is procreation and married couples look forward to having children within a year or two of marriage. The inability to achieve conception and subsequently have a child among couples may lead to psychological complications. Objective: This study assessed the psychological impact of infertility and its management on women receiving treatment at a Fertility Specialist Hospital in a poor resource setting. Methods: This was a cross-sectional study of 376 consenting married women who sought and received fertility treatment at a private Fertility Specialist Hospital, located at Abakaliki, South-East Nigeria between May 1, 2017 and May 31, 2022. Socio-demographic and Structured questionnaires were administered to the participants over a 5-year period. Results: The mean age of the women at presentation was 36.9 (±7.2 SD) years. The majority of the women (227) presented with secondary infertility accounting for 60.4%, while the rest had primary infertility (χ<sup>2</sup> = 16.18, P = 0.001). Male-only factor infertility accounted for 22.9% of all the infertility cases, female-only factor 21.3% while both (male and female factors co-existing) accounted for 52.7% of all the cases. The commonest cause of infertility in the study was poor sperm parameters (176) accounting for 46.8% of cases, tubal factor 19.1% and anovulatory factor 22.3% (χ<sup>2</sup> = 214.21, P = 0.001). Three hundred and thirty four (88.8%) felt depressed, 266 (70.7%) felt guilty about the past, and 222 (59.0%) had suicidal tendencies because of the infertility ordeal. Two hundred and fifty one (66.8%) felt inferior, 237 (63.0%) cried often and 174 (46.3%) were socially withdrawn. However, 10.4% of the women felt satisfied and well. These negative psychological feelings were statistically significant. Concerning the effect on marriage, the closeness of couples was reduced significantly in 57.7%, 62.8% had reduced coital intimacy, 79.3% had frequent quarrel and misunderstanding, 27.9% had threats of divorce while 4.5% had actually divorced and 11.% separated. However, there was no negative effect of infertility in 8.8% of couples. Conclusion: Psychological issues associated with infertility and its management in women include feelings of depression, guilt feelings, suicidal ideation, weeping episodes, social withdrawal, feelings of inferiority, reduced libido, and poverty of intimacy with frequent quarrels and misunderstanding. Women appear to bear more of the psychological issues associated with infertility. Early marriage on the part of the women, preservation of their reproductive youthful ages, and a better understanding of the concept of infertility by the couple will not only reduce the prevalence of infertility but will also reduce the dangerous psychological issues associated with infertility.展开更多
This study aims to be the first to use meta-analysis to explore the relationship between meaning in life(MIL)and mental health issues among older adults.A meta-analysis was conducted using six databases,resulting in 1...This study aims to be the first to use meta-analysis to explore the relationship between meaning in life(MIL)and mental health issues among older adults.A meta-analysis was conducted using six databases,resulting in 16 studies with 5,074 participants in total.The“metacor”and“forestplot”packages in R-Studio were used for data analysis.The total effect was calculated using a random-effects model,with I2=86%in the heterogeneity test.The results showed a moderate negative correlation between MIL and mental health issues among older adults,with an average effect of−0.37.Five potential moderating variables were examined:the conceptualization of MIL(value vs.purpose),region(Asian vs.Western countries),residence status(community vs.nursing home vs.hospital),types of mental health issues,and evaluation methods(clinical vs.non-clinical).The first four had no significant moderating effect.The mean correlation coefficients between mental health issues and value/purpose were−0.49/−0.33;the mean correlation coefficients in Asian countries and Western countries were−0.48 and−0.34;the mean correlation coefficients among participants living in community/nursing home/mixed status were−0.33/−0.40/−0.40;the mean correlation coefficients between MIL and depression/others were−0.37/−0.35;however,the negative relationship between MIL and mental health issues was stronger when non-clinical evaluations(self-report only)were used.Specifically,the mean correlation coefficient for non-clinical evaluations was−0.42 and for clinical evaluations was−0.29.This study is the first meta-analysis to identify the negative correlation between older adults’MIL and mental health issues.Significant moderating effects of evaluation methods were found.展开更多
Editors Yang Wang,Xi'an Jiaotong University Dongbo Shi,Shanghai Jiaotong University Ye Sun,University College London Zhesi Shen,National Science Library,CAS Topic of the Special Issue What are the top questions to...Editors Yang Wang,Xi'an Jiaotong University Dongbo Shi,Shanghai Jiaotong University Ye Sun,University College London Zhesi Shen,National Science Library,CAS Topic of the Special Issue What are the top questions towards better science and innovation and the required data to answer these questions?展开更多
Based on the latest demographic and labor data, this paper reveals the changes in China's labor supply and demonstrates that China's key employment issues are no longer quantitative contradictions but increasingly h...Based on the latest demographic and labor data, this paper reveals the changes in China's labor supply and demonstrates that China's key employment issues are no longer quantitative contradictions but increasingly have become structural issues related to labor market mismatch. Due to real and potential economic growth rates being consistent, cyclical unemployment is, at least for now, not striking. If traditional policy measures continue to be followed in disregard of frictional and structural attributes of the labor market to increase total employment, not only will China's employment issues persist but new labor market problems may arise as well China should focus on addressing structural unemployment contradictions.展开更多
Concrete has traditionally been regarded as a durable material requiring little or no maintenance. However, over the past several decades, a number of durability related problems have emerged and stimulated research i...Concrete has traditionally been regarded as a durable material requiring little or no maintenance. However, over the past several decades, a number of durability related problems have emerged and stimulated research into the factors relating to concrete durability globally. The challenge now facing practicing engineers is how to design and build structures that not only satisfy the specified structural requirements, but also achieve the performance levels required from a durability standpoint. Research works on concrete structural durability have been widely reported in the literature over the last several decades. In this paper, reviews of four stages of research work on durability, i e, environments, materials, components, and structures, were presented. Afterwards, the key scientific issues in this field were also pointed out.展开更多
The current status of chemical fertilizers production and consumption in China as well as their important roles in Chinese modern agriculture are discussed with special concerns to the environmental issues related to ...The current status of chemical fertilizers production and consumption in China as well as their important roles in Chinese modern agriculture are discussed with special concerns to the environmental issues related to chemical fertilizer use. On the one hand, the total amount of chemical fertilizer produced is insufficient to meet the agricultural needs. On the other hand, the production and consumption of chemical fertilizers in China are obviously not balanced. In some areas over application of nitrogen fertilizers and loss of phosphate fertilizer due to soil erosion have resulted in some undesirable environmental problems such as increase of nitrate in water and eutrophication of water bodies. Maximum scientific uses of organic manures in combination with reasonable use of chemical fertilizers are part of good practices not only in increasing soil productivity and keeping sustainable agriculture development but also in mimimizing their detrimental effects on the environment.展开更多
Northeast India has a good deposit of sub-bituminous tertiary coal. The northeast Indian coals have unusual physico-chemical characteristics such as high sulfur, volatile matter and vitrinite content, and low ash cont...Northeast India has a good deposit of sub-bituminous tertiary coal. The northeast Indian coals have unusual physico-chemical characteristics such as high sulfur, volatile matter and vitrinite content, and low ash content. In addition, many environmental sensitive organic and mineral bound elements such as Fe, Mg, Bi, AI, V, Cu, Cd, Ni, Pb, and Mn etc. remain enriched in these coals. Such characteristics are associated with more severe environmental impacts due to mining and its utilization in coal based industries. Environmental challenges include large scale landscape damage, soil erosion, loss of forest ecosystem and wildlife habitat, air, water and soil pollution. Several physical and chemical methods are reported in literature for the removal of mineral matter, total sulfur and different forms of sulfur from high sulfur coal in northeast India. This paper may help different researchers and stakeholders to understand current state of research in the field. Initiatives may be taken towards sustainable use of coal resources by adopting innovative clean technologies and by implementing effective control measures and regulatory policies.展开更多
The global carbon market has developed rapidly with two significant trends of globalization and financialization.Deriving economic interest is a nation driven-force behind the international climate negotiation and car...The global carbon market has developed rapidly with two significant trends of globalization and financialization.Deriving economic interest is a nation driven-force behind the international climate negotiation and carbon market.According to deeply analyzed relationships between the carbon market and the key subjects of the climate negotiation,this article reveals that promoting the development of the global carbon market is one of the core interests of developed nations.Based on the background of international carbon market development and domestic carbon market pilots,four suggestions to the key issues of China's carbon market are provided.The first is that the goal of China's carbon market should be in line with and contribute to the national objectives and policies addressing climate change.The second is that the Chinese carbon market should mainly target the emission reduction of production-sectors,and contribute to their upgradation and transformation.The third is mat the development of the nation-wide carbon market in China should first take the principle of unbalanced regional development into consideration.The fourth is that linking China's carbon market to the international market should keep steps in line with international opening-up of China's financing system.展开更多
The urban and community forestry movement in the United States has matured over the last 20 years from managing street trees, to understanding the benefits of trees in urban ecosystems, and now to managing urban green...The urban and community forestry movement in the United States has matured over the last 20 years from managing street trees, to understanding the benefits of trees in urban ecosystems, and now to managing urban green infrastructure. This paper introduced the history, development, and major accomplishments of the urban and community forestry movement, highlighted the economic, ecological, environmental, and social values of forests and trees to communities, and discussed issues and trends of the urban and community forestry program in the United States.展开更多
Safety issues in hormonal therapy have been discussed in recent years especially in the field of hormone replacement therapy(HRT).The most important study Women's Health Initiative(WHI)has been stopped in 2002 due...Safety issues in hormonal therapy have been discussed in recent years especially in the field of hormone replacement therapy(HRT).The most important study Women's Health Initiative(WHI)has been stopped in 2002 due to increased risk of venous thromboembolism,myocardial infarction,stroke and breast cancer.This overview will concentrate on these main risks.There are options of different HRT regimens to minimize these risks.Especially plausible is the use of minimal dosages of transdermal administration avoiding first liver passage which should reduce hepatic and cardiovascular risks,which,however,is not based on placebo-controlled studies.For breast cancer development,first fear of most women,further research on the two main mechanisms are most importantproliferation effects and conditions for potential genotoxic estrogen metabolites.To individualize hormonal therapy also preexisting risks have to be considered,and with early start,within a"window of opportunity",most patients will benefit from HRT if indicated.展开更多
Sustainable development and environmental protection are the themes of the day. One popular policy tool that government uses to promote sustainable development and to protect the environment is green public procuremen...Sustainable development and environmental protection are the themes of the day. One popular policy tool that government uses to promote sustainable development and to protect the environment is green public procurement. Chinese government established its public procurement system in the late 1990s. It has moved to implement green procurement since 2004. In this paper, the authors will first trace the development of Chinese green public procurement program. The authors will then examine the issues involved in its implementation and make suggestions as to how to make green public procurement program more effective. This is one of the first papers examining China’s green public procurement program.展开更多
文摘In the last decade, technical advancements and faster Internet speeds have also led to an increasing number ofmobile devices and users. Thus, all contributors to society, whether young or old members, can use these mobileapps. The use of these apps eases our daily lives, and all customers who need any type of service can accessit easily, comfortably, and efficiently through mobile apps. Particularly, Saudi Arabia greatly depends on digitalservices to assist people and visitors. Such mobile devices are used in organizing daily work schedules and services,particularly during two large occasions, Umrah and Hajj. However, pilgrims encounter mobile app issues such asslowness, conflict, unreliability, or user-unfriendliness. Pilgrims comment on these issues on mobile app platformsthrough reviews of their experiences with these digital services. Scholars have made several attempts to solve suchmobile issues by reporting bugs or non-functional requirements by utilizing user comments.However, solving suchissues is a great challenge, and the issues still exist. Therefore, this study aims to propose a hybrid deep learningmodel to classify and predict mobile app software issues encountered by millions of pilgrims during the Hajj andUmrah periods from the user perspective. Firstly, a dataset was constructed using user-generated comments fromrelevant mobile apps using natural language processing methods, including information extraction, the annotationprocess, and pre-processing steps, considering a multi-class classification problem. Then, several experimentswere conducted using common machine learning classifiers, Artificial Neural Networks (ANN), Long Short-TermMemory (LSTM), and Convolutional Neural Network Long Short-Term Memory (CNN-LSTM) architectures, toexamine the performance of the proposed model. Results show 96% in F1-score and accuracy, and the proposedmodel outperformed the mentioned models.
文摘A Recommender System(RS)is a crucial part of several firms,particularly those involved in e-commerce.In conventional RS,a user may only offer a single rating for an item-that is insufficient to perceive consumer preferences.Nowadays,businesses in industries like e-learning and tourism enable customers to rate a product using a variety of factors to comprehend customers’preferences.On the other hand,the collaborative filtering(CF)algorithm utilizing AutoEncoder(AE)is seen to be effective in identifying user-interested items.However,the cost of these computations increases nonlinearly as the number of items and users increases.To triumph over the issues,a novel expanded stacked autoencoder(ESAE)with Kernel Fuzzy C-Means Clustering(KFCM)technique is proposed with two phases.In the first phase of offline,the sparse multicriteria rating matrix is smoothened to a complete matrix by predicting the users’intact rating by the ESAE approach and users are clustered using the KFCM approach.In the next phase of online,the top-N recommendation prediction is made by the ESAE approach involving only the most similar user from multiple clusters.Hence the ESAE_KFCM model upgrades the prediction accuracy of 98.2%in Top-N recommendation with a minimized recommendation generation time.An experimental check on the Yahoo!Movies(YM)movie dataset and TripAdvisor(TA)travel dataset confirmed that the ESAE_KFCM model constantly outperforms conventional RS algorithms on a variety of assessment measures.
基金Supported by The Education and Teaching Reform Project of the First Clinical College of Chongqing Medical University,No.CMER202305The Natural Science Foundation of Tibet Autonomous Region,No.XZ2024ZR-ZY100(Z).
文摘The behavior issues of preschoolers are closely related to their parents'parenting styles.This editorial discusses the value and strategies for solving behavior issues in preschoolers from the perspectives of mindfulness and mindful parenting.We expect that upcoming studies will place greater emphasis on the behavioral concerns of preschoolers and the parenting practices that shape them,particularly focusing on proactive interventions for preschoolers'behavioral issues.
基金supported by the National Key Research and Development Program of China under the sub-theme“Research on the Path of Enhancing the Sustainable Development Capacity of Cities and Towns under the Carbon Neutral Goal”[Grant No.2022YFC3802902-04].
文摘In response to the United Nations Sustainable Development Goals and China’s“Dual Carbon”Goals(DCGs means the goals of“Carbon Peak and carbon neutrality”),this paper from the perspective of the construction of China’s Innovation Demonstration Zones for Sustainable Development Agenda(IDZSDAs),combines carbon emission-related metrics to construct a comprehensive assessment system for Urban Sustainable Development Capacity(USDC).After obtaining USDC assessment results through the assessment system,an approach combining Least Absolute Shrinkage and Selection Operator(LASSO)regression and Random Forest(RF)based on machine learning is proposed for identifying influencing factors and characterizing key issues.Combining Coupling Coordination Degree(CCD)analysis,the study further summarizes the systemic patterns and future directions of urban sustainable development.A case study on the IDZSDAs from 2015 to 2022 reveals that:(1)the combined identification method based on machine learning and CCD models effectively quantifies influencing factors and key issues in the urban sustainable development process;(2)the correspondence between influencing factors and key subsystems identified by the LASSO-RF combination model is generally consistent with the development situations in various cities;and(3)the machine learning-based combined recognition method is scalable and dynamic.It enables decision-makers to accurately identify influencing factors and characterize key issues based on actual urban development needs.
文摘The development of this technology has favored the advances noted in recent years in the field of precise positioning. It has also paved the way for a wide range of research into the evaluation of their performance and reliability, their potential use in different fields, the improvement of performance and combined systems, etc. Single-frequency GNSS receivers, which for a long time remained the only category of low-cost GNSS receivers, often limited by their level of accuracy (metric) mainly due to their single-frequency nature, have been joined in the last decade by dual-frequency GNSS receivers developed by certain manufacturers of positioning equipment. These receivers now offer possible alternatives to the relatively expensive conventional (topographic quality) or geodetic receivers and. In this study, the performance of these low-cost dual-frequency receivers was evaluated in static and real-time kinematic GNSS positioning modes. Static positioning was carried out on three points with sessions of 2 h and 4 h over three days with antenna swapping (CHC i50, Leica GS14 and Emlid Reach RS2+). Real-time observations were carried out on eleven (11) points in open, poorly open and not at all open environments, in order to assess not only performance but also receiver sensitivity in environments with a high risk of multipath. The results obtained showed an average agreement of 2 cm in planimetry between the low-cost Emlid RS2+ receiver and the Leica GS14 and CHC i50 receivers. The differences in altimetry are nevertheless greater (sometimes up to decimetres for certain points). Real-time positioning results provided an average convergence of around 1 cm on the E, N and H components with the results from the low-cost Emlid Reach RS2+ and Ublox ZED-F9P receivers and the CHC i50 receiver. Analysis of the results obtained has enabled us to highlight the various issues and challenges associated with this new generation of GNSS receivers, with a view to enhancing their appropriation and optimal integration in the professional and research worlds.
基金supported by the Special Foundation of Research Institute of Drug Regulatory Science,Shenyang Pharmaceutical University(2021jgkx004).
文摘Objective To study the content of China’s guiding principles on multiplicity issues in clinical trials,and to provide reference for the revision of China’s relevant guiding principles.Methods Based on ICH E9,the similarities and differences of the guiding principles of US Food and Drug Administration(FDA),European Medicines Agency(EMA),and National Medical Products Administration(NMPA)on the multiplicity issues in clinical trials were compared one by one.Results and Conclusion In general,NMPA guidelines are based on ICH E9,but in detail,the guidelines of FDA and EMA focus differently on the multiplicity issues.Therefore,NMPA guidelines need to be detailed and comprehensive.NMPA guidelines can be refined by referring to foreign guidelines to improve the practical guiding significance for clinical research and promote the level of domestic clinical trials in line with international standards.
基金supported by the Outstanding Youth Fund Project by the Department of Science and Technology of Jiangsu Province(Grant No.BK20220045)the Key R&D Project funded by the Department of Science and Technology of Jiangsu Province(Grant No.BE2020003)+6 种基金Key Program-Automobile Joint Fund of National Natural Science Foundation of China(Grant No.U1964205)General Program of National Natural Science Foundation of China(Grant No.51972334)General Program of National Natural Science Foundation of Beijing(Grant No.2202058)Cultivation project of leading innovative experts in Changzhou City(CQ20210003)National Overseas High-level Expert recruitment Program(Grant No.E1JF021E11)Talent Program of Chinese Academy of Sciences,“Scientist Studio Program Funding”from Yangtze River Delta Physics Research Center,and Tianmu Lake Institute of Advanced Energy Storage Technologies(Grant No.TIESSS0001)Science and Technology Research Institute of China Three Gorges Corporation(Grant No.202103402)
文摘All-solid-state Li metal batteries(ASSLBs)using inorganic solid electrolyte(SE)are considered promising alternatives to conventional Li-ion batteries,offering improved safety and boosted energy density.While significant progress has been made on improving the ionic conductivity of SEs,the degradation and instability of Li metal/inorganic SE interfaces have become the critical challenges that limit the coulombic efficiency,power performance,and cycling stability of ASSLBs.Understanding the mechanisms of complex/dynamic interfacial phenomena is of great importance in addressing these issues.Herein,recent studies on identifying,understanding,and solving interfacial issues on anode side in ASSLBs are comprehensively reviewed.Typical issues at Li metal/SE interface include Li dendrite growth/propagation,SE cracking,physical contact loss,and electrochemical reactions,which lead to high interfacial resistance and cell failure.The causes of these issues relating to the chemical,physical,and mechanical properties of Li metal and SEs are systematically discussed.Furthermore,effective mitigating strategies are summarized and their effects on suppressing interfacial reactions,improving interfacial Li-ion transport,maintaining interfacial contact,and stabilizing Li plating/stripping are highlighted.The in-depth mechanistic understanding of interfacial issues and complete investigations on current solutions provide foundations and guidance for future research and development to realize practical application of high-performance ASSLB.
文摘Introduction: In Nigeria, a major reason for marriage is procreation and married couples look forward to having children within a year or two of marriage. The inability to achieve conception and subsequently have a child among couples may lead to psychological complications. Objective: This study assessed the psychological impact of infertility and its management on women receiving treatment at a Fertility Specialist Hospital in a poor resource setting. Methods: This was a cross-sectional study of 376 consenting married women who sought and received fertility treatment at a private Fertility Specialist Hospital, located at Abakaliki, South-East Nigeria between May 1, 2017 and May 31, 2022. Socio-demographic and Structured questionnaires were administered to the participants over a 5-year period. Results: The mean age of the women at presentation was 36.9 (±7.2 SD) years. The majority of the women (227) presented with secondary infertility accounting for 60.4%, while the rest had primary infertility (χ<sup>2</sup> = 16.18, P = 0.001). Male-only factor infertility accounted for 22.9% of all the infertility cases, female-only factor 21.3% while both (male and female factors co-existing) accounted for 52.7% of all the cases. The commonest cause of infertility in the study was poor sperm parameters (176) accounting for 46.8% of cases, tubal factor 19.1% and anovulatory factor 22.3% (χ<sup>2</sup> = 214.21, P = 0.001). Three hundred and thirty four (88.8%) felt depressed, 266 (70.7%) felt guilty about the past, and 222 (59.0%) had suicidal tendencies because of the infertility ordeal. Two hundred and fifty one (66.8%) felt inferior, 237 (63.0%) cried often and 174 (46.3%) were socially withdrawn. However, 10.4% of the women felt satisfied and well. These negative psychological feelings were statistically significant. Concerning the effect on marriage, the closeness of couples was reduced significantly in 57.7%, 62.8% had reduced coital intimacy, 79.3% had frequent quarrel and misunderstanding, 27.9% had threats of divorce while 4.5% had actually divorced and 11.% separated. However, there was no negative effect of infertility in 8.8% of couples. Conclusion: Psychological issues associated with infertility and its management in women include feelings of depression, guilt feelings, suicidal ideation, weeping episodes, social withdrawal, feelings of inferiority, reduced libido, and poverty of intimacy with frequent quarrels and misunderstanding. Women appear to bear more of the psychological issues associated with infertility. Early marriage on the part of the women, preservation of their reproductive youthful ages, and a better understanding of the concept of infertility by the couple will not only reduce the prevalence of infertility but will also reduce the dangerous psychological issues associated with infertility.
基金This research was funded by a research Grant 32171076 from National Social Sciences Foundation of China20BSH139 from National Social Sciences Foundation of China.
文摘This study aims to be the first to use meta-analysis to explore the relationship between meaning in life(MIL)and mental health issues among older adults.A meta-analysis was conducted using six databases,resulting in 16 studies with 5,074 participants in total.The“metacor”and“forestplot”packages in R-Studio were used for data analysis.The total effect was calculated using a random-effects model,with I2=86%in the heterogeneity test.The results showed a moderate negative correlation between MIL and mental health issues among older adults,with an average effect of−0.37.Five potential moderating variables were examined:the conceptualization of MIL(value vs.purpose),region(Asian vs.Western countries),residence status(community vs.nursing home vs.hospital),types of mental health issues,and evaluation methods(clinical vs.non-clinical).The first four had no significant moderating effect.The mean correlation coefficients between mental health issues and value/purpose were−0.49/−0.33;the mean correlation coefficients in Asian countries and Western countries were−0.48 and−0.34;the mean correlation coefficients among participants living in community/nursing home/mixed status were−0.33/−0.40/−0.40;the mean correlation coefficients between MIL and depression/others were−0.37/−0.35;however,the negative relationship between MIL and mental health issues was stronger when non-clinical evaluations(self-report only)were used.Specifically,the mean correlation coefficient for non-clinical evaluations was−0.42 and for clinical evaluations was−0.29.This study is the first meta-analysis to identify the negative correlation between older adults’MIL and mental health issues.Significant moderating effects of evaluation methods were found.
文摘Editors Yang Wang,Xi'an Jiaotong University Dongbo Shi,Shanghai Jiaotong University Ye Sun,University College London Zhesi Shen,National Science Library,CAS Topic of the Special Issue What are the top questions towards better science and innovation and the required data to answer these questions?
文摘Based on the latest demographic and labor data, this paper reveals the changes in China's labor supply and demonstrates that China's key employment issues are no longer quantitative contradictions but increasingly have become structural issues related to labor market mismatch. Due to real and potential economic growth rates being consistent, cyclical unemployment is, at least for now, not striking. If traditional policy measures continue to be followed in disregard of frictional and structural attributes of the labor market to increase total employment, not only will China's employment issues persist but new labor market problems may arise as well China should focus on addressing structural unemployment contradictions.
基金Funded by the National Natural Science Foundation of China (No.50538070)
文摘Concrete has traditionally been regarded as a durable material requiring little or no maintenance. However, over the past several decades, a number of durability related problems have emerged and stimulated research into the factors relating to concrete durability globally. The challenge now facing practicing engineers is how to design and build structures that not only satisfy the specified structural requirements, but also achieve the performance levels required from a durability standpoint. Research works on concrete structural durability have been widely reported in the literature over the last several decades. In this paper, reviews of four stages of research work on durability, i e, environments, materials, components, and structures, were presented. Afterwards, the key scientific issues in this field were also pointed out.
文摘The current status of chemical fertilizers production and consumption in China as well as their important roles in Chinese modern agriculture are discussed with special concerns to the environmental issues related to chemical fertilizer use. On the one hand, the total amount of chemical fertilizer produced is insufficient to meet the agricultural needs. On the other hand, the production and consumption of chemical fertilizers in China are obviously not balanced. In some areas over application of nitrogen fertilizers and loss of phosphate fertilizer due to soil erosion have resulted in some undesirable environmental problems such as increase of nitrate in water and eutrophication of water bodies. Maximum scientific uses of organic manures in combination with reasonable use of chemical fertilizers are part of good practices not only in increasing soil productivity and keeping sustainable agriculture development but also in mimimizing their detrimental effects on the environment.
文摘Northeast India has a good deposit of sub-bituminous tertiary coal. The northeast Indian coals have unusual physico-chemical characteristics such as high sulfur, volatile matter and vitrinite content, and low ash content. In addition, many environmental sensitive organic and mineral bound elements such as Fe, Mg, Bi, AI, V, Cu, Cd, Ni, Pb, and Mn etc. remain enriched in these coals. Such characteristics are associated with more severe environmental impacts due to mining and its utilization in coal based industries. Environmental challenges include large scale landscape damage, soil erosion, loss of forest ecosystem and wildlife habitat, air, water and soil pollution. Several physical and chemical methods are reported in literature for the removal of mineral matter, total sulfur and different forms of sulfur from high sulfur coal in northeast India. This paper may help different researchers and stakeholders to understand current state of research in the field. Initiatives may be taken towards sustainable use of coal resources by adopting innovative clean technologies and by implementing effective control measures and regulatory policies.
文摘The global carbon market has developed rapidly with two significant trends of globalization and financialization.Deriving economic interest is a nation driven-force behind the international climate negotiation and carbon market.According to deeply analyzed relationships between the carbon market and the key subjects of the climate negotiation,this article reveals that promoting the development of the global carbon market is one of the core interests of developed nations.Based on the background of international carbon market development and domestic carbon market pilots,four suggestions to the key issues of China's carbon market are provided.The first is that the goal of China's carbon market should be in line with and contribute to the national objectives and policies addressing climate change.The second is that the Chinese carbon market should mainly target the emission reduction of production-sectors,and contribute to their upgradation and transformation.The third is mat the development of the nation-wide carbon market in China should first take the principle of unbalanced regional development into consideration.The fourth is that linking China's carbon market to the international market should keep steps in line with international opening-up of China's financing system.
文摘The urban and community forestry movement in the United States has matured over the last 20 years from managing street trees, to understanding the benefits of trees in urban ecosystems, and now to managing urban green infrastructure. This paper introduced the history, development, and major accomplishments of the urban and community forestry movement, highlighted the economic, ecological, environmental, and social values of forests and trees to communities, and discussed issues and trends of the urban and community forestry program in the United States.
文摘Safety issues in hormonal therapy have been discussed in recent years especially in the field of hormone replacement therapy(HRT).The most important study Women's Health Initiative(WHI)has been stopped in 2002 due to increased risk of venous thromboembolism,myocardial infarction,stroke and breast cancer.This overview will concentrate on these main risks.There are options of different HRT regimens to minimize these risks.Especially plausible is the use of minimal dosages of transdermal administration avoiding first liver passage which should reduce hepatic and cardiovascular risks,which,however,is not based on placebo-controlled studies.For breast cancer development,first fear of most women,further research on the two main mechanisms are most importantproliferation effects and conditions for potential genotoxic estrogen metabolites.To individualize hormonal therapy also preexisting risks have to be considered,and with early start,within a"window of opportunity",most patients will benefit from HRT if indicated.
文摘Sustainable development and environmental protection are the themes of the day. One popular policy tool that government uses to promote sustainable development and to protect the environment is green public procurement. Chinese government established its public procurement system in the late 1990s. It has moved to implement green procurement since 2004. In this paper, the authors will first trace the development of Chinese green public procurement program. The authors will then examine the issues involved in its implementation and make suggestions as to how to make green public procurement program more effective. This is one of the first papers examining China’s green public procurement program.