This study explored the relationship between perceived social support and employment anxiety among Chinese college students,as well as the mediating and moderating effects of psychological resilience and career adapta...This study explored the relationship between perceived social support and employment anxiety among Chinese college students,as well as the mediating and moderating effects of psychological resilience and career adaptability on this relationship.A total of 1928 college students(females=1371,mean age=20.42,SD=1.05)completed the Perceived Social Support Scale,Employment Anxiety Questionnaire,Connor-Davidson Resilience Scale and Career Adapt-Abilities Scale.Mediation analysis results showed that psychological resilience mediated the relationship between perceived social support and employment anxiety for lower employment anxiety.Career adaptability moderated the mediating effect of psychological resilience for lower employment anxiety than with either of the variables alone.Thefindings are consistent with cognitive diathesis-stress theory and career construction theory which propose that individuals’cognitive structures and psychological predispositions interact with environmental stressors to shape their career development and psychological well-being.Essentially,students who have a robust social support system,high career adaptability,and are psychologically resilient are less likely to experience employment anxiety.展开更多
BACKGROUND Depression significantly threatens human health.Purinergic receptors are reported to be associated with depression.However,there is no bibliometric research in this field have been published.AIM To provide ...BACKGROUND Depression significantly threatens human health.Purinergic receptors are reported to be associated with depression.However,there is no bibliometric research in this field have been published.AIM To provide some reference for the further research in the field of purinergic receptors and depression utilizing bibliometric analysis.METHODS Relevant researches were retrieved from the Web of Science Core Collection database.The period of the search was from January 1,2003 to December 31,2023.The CiteSpace(6.2.R7)and VOSviewer(1.6.19)were applied to identify the main contributors of countries,authors,institutions,references and journals.Besides,we evaluate keywords to assess the hotspots and trends over the previous 2 decades.RESULTS Totally,247 articles were identified,showing an increasing trend over time.The most productive country,institution,and journal in this field are China,Harvard University,and Biological Psychiatry,respectively.Liang SD and Rodrigues,Ana Lucia S were the most prolific authors.Burnstock G ranked first among the cited authors.The cooperation among countries and disciplines is crucial.The P2X7 receptor provides promising prospects for treating depression and further studies are warranted to validate the scope and significance of depression therapeutic strategies.CONCLUSION This study provides an overview of the worldwide research status and future trends in purinergic receptors and depression.P2X7 receptor is considered an appropriate target for the treatment of depression,as well as neurological diseases.It is implied that based on purinergic system,the future prospects for interventions aimed at depression treatment are promising,showing the way for both augmentation strategies and new drug treatments in the context of the pharmacology of depression.展开更多
As everyone knows,China has come to being one of the countries deserved paying attention to it‘s geological disaster which become seriously.Not only protect people’s lives,property and foundation against destroyed b...As everyone knows,China has come to being one of the countries deserved paying attention to it‘s geological disaster which become seriously.Not only protect people’s lives,property and foundation against destroyed but also ensure the continuable development of country’s economy and society,some must be taken.Therefore efficiency and equitableness system should be set up.According to the peculiarity of prevention measure against geological disaster,the emphases of the system were intensively studied.Beside this,the paper focused more attention on the methods of enhanced financing and analyzed keystones of some financing different finance channel.Integrating the peculiar of the Chongqing city and referencing some other engineering items,some means were summarized such as reinforcing essential investigation and confirming danger point of geological disaster.Based on this,forecast should be intensified and the procedure of disposal must be developed.展开更多
Under the background of deepening the reform of China's market economy system, in view of the marketing practice, it is also necessary to effectively optimize and perfect, fully meet the needs of consumers and the...Under the background of deepening the reform of China's market economy system, in view of the marketing practice, it is also necessary to effectively optimize and perfect, fully meet the needs of consumers and the market, and fully master the demand structure, so as to effectively improve the marketing level and lay a foundation for its own good development. In the process of marketing practice, the project management model can be applied more effectively, so as to reflect the good marketing practice effect and further promote the relevant enterprises to achieve sustainable development. Combined with this situation, this paper focuses on the analysis of the application advantages and practical strategies of project management in marketing practice, hoping that this analysis can contribute to the improvement of marketing practice.展开更多
China has become the world's largest PPP market. Over the past few years, the development of the PPP industry has been on a roller coaster, first rushing up and then stopping abruptly. Today, the situation has imp...China has become the world's largest PPP market. Over the past few years, the development of the PPP industry has been on a roller coaster, first rushing up and then stopping abruptly. Today, the situation has improved and the "Standardized and Orderly Promotion of Cooperation between Government and Social Capital (PPP)" has been included in the "14th Five-Year Plan" and the long-term target for 2035. The advantage of PPP is to enable partners to achieve more favorable results than expected by acting alone: less government spending and less investment risk for enterprises. This paper analyzes the investment and financing management strategies of PPP projects from the perspective of investors for reference.展开更多
In recent years, in the process of the modernization of the construction industry, the project cost has become the focus of attention. In any project implementation, the project cost management can not be ignored. At ...In recent years, in the process of the modernization of the construction industry, the project cost has become the focus of attention. In any project implementation, the project cost management can not be ignored. At present, although many project owners have realized the importance of the information construction of project cost management, and also carried out a wealth of exploration and practice, there are still many deficiencies in the information construction of project cost management. In the future development process, the cost management in the engineering field should change the traditional concept and mode, carry out the corresponding information innovation, and improve the overall level of project cost information according to the lack of cost management information construction.展开更多
PBMC(performance-based maintenance contracts)provides incentives and/or disincentives to the contractor to achieve desired outcomes or results.In other words,the concept of PBMC is to pay a contractor based on the act...PBMC(performance-based maintenance contracts)provides incentives and/or disincentives to the contractor to achieve desired outcomes or results.In other words,the concept of PBMC is to pay a contractor based on the actual results(performance or LOS(level of service)),not on the performed work.PBMC does not detail to the contractor how,when,or where to do the work.Instead,it specifies performance standards or targets for measurable outcomes and sometimes outputs.There are several benefits from implementing PBMC.Higher LOS,i.e.,better quality,potential reduction in agency costs and downsized maintenance workforce are among these benefits.Also,there are several challenges facing the implementation of PBMC.One of the most complex challenges that relates to both the agency and contractor,and in some cases to the public,is how to manage LOS in an objective manner and to demonstrate that policy goals and objectives regarding quality of life expectancy are achieved without any increase in the LCC(life cycle cost)of the assets.This challenge,along with many other challenges,can be addressed through the adoption of an AM(asset management)approach.AM approach facilitates the long-term planning based on the current and future conditions and desired LOS.In addition,AM provides the necessary tools to objectively monitor LOS,and hence the contractor performance,which will contribute to the success of the implementation of PBMC.展开更多
Conventional repairing methods for asphalt pavement have some inconveniences,such as insufficient strength,and are typically time-consuming.To address these issues,this study proposes a new technological method to des...Conventional repairing methods for asphalt pavement have some inconveniences,such as insufficient strength,and are typically time-consuming.To address these issues,this study proposes a new technological method to design and prepare a high-performance assembled asphalt concrete block for fast repair of the potholes.A series of composite modified asphalt binders with 10%crumb rubber(CR)and different dosages(0%,1%,3%,5%)of polyurethane(PU)are examined to determine the optimized binder.Subsequently,the corresponding asphalt mixtures are prepared for further comparison and assessment of engineering properties,such as moistureinduced damage,high-temperature deformation,and low-temperature cracking characteristics.The test results show that PU can significantly improve the high-temperature performance and hardness of(crumb rubber modified asphalt)CRMA binder;3%PU contributes allowing the resistance of CRMA mixture to moisture-induced damage at higher levels,particularly under water whole immersion;as 3%PU is added,the high-temperature rutting deformation resistance of the CRMA mixture increases significantly,and the low-temperature anti-cracking properties are also improved slightly.Therefore,the innovatively designed high-quality assembled fast-repairing asphalt concrete block is recommended as an appropriate option for highway maintenance.展开更多
Traditional asphalt rejuvenators,like aromatic oil(AO),are known to be effective in improving the low-temperature properties and fatigue performances of aged SBS(styrene-butadiene-styrene)modified asphalt(SBSMA)binder...Traditional asphalt rejuvenators,like aromatic oil(AO),are known to be effective in improving the low-temperature properties and fatigue performances of aged SBS(styrene-butadiene-styrene)modified asphalt(SBSMA)binders and mixtures.However,these rejuvenators inevitably compromise their high-temperature properties and deformation resistances because they dilute asphalt binder but do not fix the damaged structures of aged SBS.In this study,a highly-active chemical called polymerized 4,4-diphenylmethane diisocyanate(PMDI)was used to assist the traditional AO asphalt rejuvenator.The physical and rheological characteristics of rejuvenated SBSMA binders and the moisture-induced damage and rut deformation performances of corresponding mixtures were comparatively evaluated.The results showed that the increasing proportion of AO compromises the hightemperature property and hardness of aged SBSMA binder,and an appropriate amount of PMDI works to compensate such losses;3%rejuvenator at mass ratio of AO:PMDI=70:30 can have a rejuvenated SBSMA binder with a high-temperature performance similar to that of fresh binder,approximately at 71.4°C;the use of AO can help reduce the viscosity of PMDI rejuvenated SBSMA binder for improving its workability;PMDI can help improve the resistance of AO rejuvenated SBSMA binder to deformation,especially at elevated temperatures,through its chemical reactions with aged SBS;moisture induction can enhance the resistance to damage of rejuvenated mixtures containing AO/PMDI or only PMDI;and the rejuvenator with a mass ratio of AO:PMDI=70:30 can lead the rejuvenated mixture to meet the application requirement,with a rut depth of only 2.973 mm,although more PMDI can result in a higher resistance of rejuvenated mixtures to high-temperature deformation.展开更多
Due to the complexity of leadership and its variability across situations,it is suggested that research on leadership should focus on attempts to understand leadership in specific situations or roles,and develop local...Due to the complexity of leadership and its variability across situations,it is suggested that research on leadership should focus on attempts to understand leadership in specific situations or roles,and develop local knowledge about leadership in each situation or role.This paper validates the possibility and importance of building indigenous leadership theories from historical perspective.We demonstrated how to carry out research on indigenous Chinese leadership from a historical perspective by comparative case studies using historical data.Based on the principles of typicalness,representativeness,and comparativeness,we selected six counterparts of political elites in ancient China as comparative cases,which includes Guan Zhong&Shang Yang(organizational reformer),Liu Bang&Xiang Yu(entrepreneur),Li Shimin&Qin Shihuang(intergenerational transition successor),Zhuge Liang&Zeng Guofan(professional manager),Lu Su&Zhang Juzheng(mess-to-order maker),and Zuo Zongtang&Wang Anshi(national dream driver).The paper aims to develop indigenous leadership theory specific to Chinese mental states and culture.展开更多
Latent variable models can effectively determine the condition of essential rotating machinery without needing labeled data.These models analyze vibration data via an unsupervised learning strategy.Temporal preservati...Latent variable models can effectively determine the condition of essential rotating machinery without needing labeled data.These models analyze vibration data via an unsupervised learning strategy.Temporal preservation is necessary to obtain an informative latent manifold for the fault diagnosis task.In a temporalpreserving context,two approaches exist to develop a condition-monitoring methodology:offline and online.For latent variable models,the available training modes are not different.While many traditional methods use offline training,online training can dynamically adjust the latent manifold,possibly leading to better fault signature extraction from the vibration data.This study explores online training using temporal-preserving latent variable models.Within online training,there are two main methods:one focuses on reconstructing data and the other on interpreting the data components.Both are considered to evaluate how they diagnose faults over time.Using two experimental datasets,the study confirms that models from both training modes can detect changes in machinery health and identify faults even under varying conditions.Importantly,the complementarity of offline and online models is emphasized,reassuring their versatility in fault diagnostics.Understanding the implications of the training approach and the available model formulations is crucial for further research in latent variable modelbased fault diagnostics.展开更多
Four CrAlN coatings with various Al content were prepared by arc ion plating technology under different target currents. The effect of the Al content on the microstructure, chemical compositions, element chemical bond...Four CrAlN coatings with various Al content were prepared by arc ion plating technology under different target currents. The effect of the Al content on the microstructure, chemical compositions, element chemical bonding states and mechanical properties of the CrAlN coatings was analyzed. X-ray diffraction results show that the primary phase of the CrAlN coating is fcc-（Al, Cr）N when the Al content is about 44.02 at.%. However, when the Al content increases to about 53.34 at.%, hcp-AlN phase emerges in the coating. And the hcp-AlN phase becomes the main phase in the CrAlN coating with Al content of about 69.55 at.%. Cross-sectional images show that all the four coatings possess dense structures and the deposition rate of Al atom is higher than that of Cr atom. The hardness of the CrAlN coating with Al content about 44.02 at.% is the largest （3149.72 HV） due to the solid solution hardening effect of the Al element. When the hcp-AlN phase is generated in the CrAlN coating, the hardness declines. The tribological experiment shows that the wear resistance of the CrAlN coating decreases gradually with increasing Al content when sliding against 100Cr6 steel ball.展开更多
Faults and fractures of multiple scales are frequently induced and generated in compressional structural system. Comprehensive identification of these potential faults and fractures that cannot be distinguished direct...Faults and fractures of multiple scales are frequently induced and generated in compressional structural system. Comprehensive identification of these potential faults and fractures that cannot be distinguished directly from seismic profile of the complex structures is still an unanswered problem. Based on the compressional structural geometry and kinematics theories as well as the structural interpretation from seismic data, a set of techniques is established for the identification of potential faults and fractures in compressional structures. Firstly, three-dimensional(3D) patterns and characteristics of the faults directly interpreted from seismic profile were illustrated by 3D structural model. Then, the unfolding index maps, the principal structural curvature maps, and tectonic stress field maps were obtained from structural restoration. Moreover, potential faults and fractures in compressional structures were quantitatively identified relying on comprehensive analysis of these three maps. Successful identification of the potential faults and fractures in Mishrif limestone formation and in Asmari dolomite formation of Buzurgan anticline in Iraq demonstrates the applicability and reliability of these techniques.展开更多
With the development of industry and agriculture,nitrogen,phosphorus and other nutrients in the Hanshui River greatly increase and eutrophication has become an important threat to the water quality of the Hanshui Rive...With the development of industry and agriculture,nitrogen,phosphorus and other nutrients in the Hanshui River greatly increase and eutrophication has become an important threat to the water quality of the Hanshui River,especially in the middle and lower reaches.The primary objective of this study was to establish the water quality model for the middle and lower reaches of the Hanshui River based on the model of MIKE 11.The main pollutants migration and transformation process could be simulated using the water quality model.The rainfall-runoff model,hy-drodynamic model and water quality model were established using MIKE 11.The pollutants,such as chemical oxygen demand(COD),biochemical oxygen demand(BOD),ammonia nitrogen,nitrate nitrogen,phosphorus,dissolved oxy-gen(DO),were simulated and predicted using the above three models.A set of methods computing non-point source pollution load of the Hanshui River Basin was proposed in this study.The simulated and observed values of COD,BOD5,ammonia,nitrate,DO,and total phosphorus were compared after the parameter calibration of the water quality model.The simulated and observed results match better,thus the model can be used to predict water quality in the fu-ture for the Hanshui River.The pollution trend could be predicted using the water quality model according pollution load generation.It is helpful for government to take effective measures to prevent the water bloom and protect water quality in the river.展开更多
A new type of AlTiN coating containing about 29.13 at.% Al,16.02 at.% Ti and 54.85 at.% N was prepared by arc ion plating technology. The coating is composed of singular fcc-（Al, Ti）N phase and has no hcp-AlN phase ...A new type of AlTiN coating containing about 29.13 at.% Al,16.02 at.% Ti and 54.85 at.% N was prepared by arc ion plating technology. The coating is composed of singular fcc-（Al, Ti）N phase and has no hcp-AlN phase to be formed. Due to the high content of beneficial element Al, the hardness and effective elastic modulus of the coating are up to 33.9 and 486.1 GPa, respectively. The adhesion strength between the coating and substrate is about 39.7 N. Electro- chemical test shows that the corrosion current density of the AlTiN coating is nearly one-sixth of the substrate, and the charge transfer resistance Rct of the AlTiN coating is much larger than that of the substrate, which means that the coating could act as a protective barrier between the substrate and corrosive electrolyte, enhancing the corrosion resistance.展开更多
We report Ni/LaHA@ZrO2catalysts prepared by a facile modified successive adsorption and reaction method for CO methanation.N2adsorption,X‐ray diffraction,transmission electron microscopy,scanning electron microscopy,...We report Ni/LaHA@ZrO2catalysts prepared by a facile modified successive adsorption and reaction method for CO methanation.N2adsorption,X‐ray diffraction,transmission electron microscopy,scanning electron microscopy,thermogravimetric analysis,H2temperature‐programmed reduction,H2temperature‐programmed desorption,X‐ray photoelectron spectroscopy,thermogravimetric analysis,and inductively coupled plasma atomic emission spectrometry were used to characterize the samples.The results indicated that the ZrO2nanoparticles were distributed over the surface of the Ni/LaHA@ZrO2catalyst and even partially covered some Ni particles,resulting in the coating exerting a confinement effect.The excess ZrO2had an adverse effect on the enhancement of CO conversion because of the coverage of the surface Ni particles;however,the Ni/LaHA@ZrO2catalyst displayed much higher CH4selectivity than Ni/LaHA because of the activation of the byproduct CO2molecules by ZrO2species.Therefore,even though20Ni/LaHA@ZrO2‐5exhibited similar CO conversion as20Ni/LaHA,the use of the former resulted in a higher CH4yield than the use of the latter.A107‐h‐lifetime test revealed that the Ni/LaHA@ZrO2catalyst was highly stable with superior anti‐sintering and anti‐coking properties because of its coating structure and the promoter effect of ZrO2.展开更多
The typical characteristics of shale gas and the enrichment differences show that some shale gases are insufficiently explained by the existing continuous enrichment mode. These shale gases include the Wufeng–Longmax...The typical characteristics of shale gas and the enrichment differences show that some shale gases are insufficiently explained by the existing continuous enrichment mode. These shale gases include the Wufeng–Longmaxi shale gas in the Jiaoshiba and Youyang Blocks, the Lewis shale gas in the San Juan Basin. Further analysis reveals three static subsystems（hydrocarbon source rock, gas reservoirs and seal formations） and four dynamic subsystems（tectonic evolution, sedimentary sequence, diagenetic evolution and hydrocarbon-generation history） in shale-gas enrichment systems. Tectonic evolution drives the dynamic operation of the whole shale-gas enrichment system. The shale-gas enrichment modes controlled by tectonic evolution are classifiable into three groups and six subgroups. Group I modes are characterized by tectonically controlled hydrocarbon source rock, and include continuous in-situ biogenic shale gas（Ⅰ_1） and continuous in-situ thermogenic shale gas（Ⅰ_2）. Group Ⅱ modes are characterized by tectonically controlled gas reservoirs, and include anticline-controlled reservoir enrichment（Ⅱ_1） and fracture-controlled reservoir enrichment（Ⅱ_2）. Group Ⅲ modes possess tectonically controlled seal formations, and include faulted leakage enrichment（Ⅲ_1） and eroded residual enrichment（Ⅲ_2）. In terms of quantity and exploitation potential, Ⅰ_1 and Ⅰ_2 are the best shale-gas enrichment modes, followed by Ⅱ_1 and Ⅱ_2. The least effective modes are Ⅲ_1 and Ⅲ_2. The categorization provides a different perspective for deep shale-gas exploration.展开更多
基金Research on the Factors Influencing“Slow Employment”of College Students from the Perspective of CIP Theory in the 2023 Academic Research Project(Provincial and Ministerial Project Cultivation Project)of Zhejiang Agricultural Business College(KY202336)2024 Annual Special Task Project of Humanities and Social Science Research of the Ministry of Education“Research on the Psychological Mechanism and Effective Coping Strategies of“Social Anxiety”among College Students”(Research on College Counselors)(24JDSZ3017)“Major Humanities and Social Sciences Research Projects in Zhejiang”Higher Education Institutions(2024GH082).
文摘This study explored the relationship between perceived social support and employment anxiety among Chinese college students,as well as the mediating and moderating effects of psychological resilience and career adaptability on this relationship.A total of 1928 college students(females=1371,mean age=20.42,SD=1.05)completed the Perceived Social Support Scale,Employment Anxiety Questionnaire,Connor-Davidson Resilience Scale and Career Adapt-Abilities Scale.Mediation analysis results showed that psychological resilience mediated the relationship between perceived social support and employment anxiety for lower employment anxiety.Career adaptability moderated the mediating effect of psychological resilience for lower employment anxiety than with either of the variables alone.Thefindings are consistent with cognitive diathesis-stress theory and career construction theory which propose that individuals’cognitive structures and psychological predispositions interact with environmental stressors to shape their career development and psychological well-being.Essentially,students who have a robust social support system,high career adaptability,and are psychologically resilient are less likely to experience employment anxiety.
基金Supported by the National Key Research and Development Program of China,No.2019YFC1709703Jiangxi Provincial Science and Technology Department,No.20212BAG70037+1 种基金Jiangxi Provincial Education Department Science Program,No.GJJ201259Jiangxi Provincial Administration of Traditional Chinese Medicine,No.2021B324.
文摘BACKGROUND Depression significantly threatens human health.Purinergic receptors are reported to be associated with depression.However,there is no bibliometric research in this field have been published.AIM To provide some reference for the further research in the field of purinergic receptors and depression utilizing bibliometric analysis.METHODS Relevant researches were retrieved from the Web of Science Core Collection database.The period of the search was from January 1,2003 to December 31,2023.The CiteSpace(6.2.R7)and VOSviewer(1.6.19)were applied to identify the main contributors of countries,authors,institutions,references and journals.Besides,we evaluate keywords to assess the hotspots and trends over the previous 2 decades.RESULTS Totally,247 articles were identified,showing an increasing trend over time.The most productive country,institution,and journal in this field are China,Harvard University,and Biological Psychiatry,respectively.Liang SD and Rodrigues,Ana Lucia S were the most prolific authors.Burnstock G ranked first among the cited authors.The cooperation among countries and disciplines is crucial.The P2X7 receptor provides promising prospects for treating depression and further studies are warranted to validate the scope and significance of depression therapeutic strategies.CONCLUSION This study provides an overview of the worldwide research status and future trends in purinergic receptors and depression.P2X7 receptor is considered an appropriate target for the treatment of depression,as well as neurological diseases.It is implied that based on purinergic system,the future prospects for interventions aimed at depression treatment are promising,showing the way for both augmentation strategies and new drug treatments in the context of the pharmacology of depression.
文摘As everyone knows,China has come to being one of the countries deserved paying attention to it‘s geological disaster which become seriously.Not only protect people’s lives,property and foundation against destroyed but also ensure the continuable development of country’s economy and society,some must be taken.Therefore efficiency and equitableness system should be set up.According to the peculiarity of prevention measure against geological disaster,the emphases of the system were intensively studied.Beside this,the paper focused more attention on the methods of enhanced financing and analyzed keystones of some financing different finance channel.Integrating the peculiar of the Chongqing city and referencing some other engineering items,some means were summarized such as reinforcing essential investigation and confirming danger point of geological disaster.Based on this,forecast should be intensified and the procedure of disposal must be developed.
文摘Under the background of deepening the reform of China's market economy system, in view of the marketing practice, it is also necessary to effectively optimize and perfect, fully meet the needs of consumers and the market, and fully master the demand structure, so as to effectively improve the marketing level and lay a foundation for its own good development. In the process of marketing practice, the project management model can be applied more effectively, so as to reflect the good marketing practice effect and further promote the relevant enterprises to achieve sustainable development. Combined with this situation, this paper focuses on the analysis of the application advantages and practical strategies of project management in marketing practice, hoping that this analysis can contribute to the improvement of marketing practice.
文摘China has become the world's largest PPP market. Over the past few years, the development of the PPP industry has been on a roller coaster, first rushing up and then stopping abruptly. Today, the situation has improved and the "Standardized and Orderly Promotion of Cooperation between Government and Social Capital (PPP)" has been included in the "14th Five-Year Plan" and the long-term target for 2035. The advantage of PPP is to enable partners to achieve more favorable results than expected by acting alone: less government spending and less investment risk for enterprises. This paper analyzes the investment and financing management strategies of PPP projects from the perspective of investors for reference.
文摘In recent years, in the process of the modernization of the construction industry, the project cost has become the focus of attention. In any project implementation, the project cost management can not be ignored. At present, although many project owners have realized the importance of the information construction of project cost management, and also carried out a wealth of exploration and practice, there are still many deficiencies in the information construction of project cost management. In the future development process, the cost management in the engineering field should change the traditional concept and mode, carry out the corresponding information innovation, and improve the overall level of project cost information according to the lack of cost management information construction.
文摘PBMC(performance-based maintenance contracts)provides incentives and/or disincentives to the contractor to achieve desired outcomes or results.In other words,the concept of PBMC is to pay a contractor based on the actual results(performance or LOS(level of service)),not on the performed work.PBMC does not detail to the contractor how,when,or where to do the work.Instead,it specifies performance standards or targets for measurable outcomes and sometimes outputs.There are several benefits from implementing PBMC.Higher LOS,i.e.,better quality,potential reduction in agency costs and downsized maintenance workforce are among these benefits.Also,there are several challenges facing the implementation of PBMC.One of the most complex challenges that relates to both the agency and contractor,and in some cases to the public,is how to manage LOS in an objective manner and to demonstrate that policy goals and objectives regarding quality of life expectancy are achieved without any increase in the LCC(life cycle cost)of the assets.This challenge,along with many other challenges,can be addressed through the adoption of an AM(asset management)approach.AM approach facilitates the long-term planning based on the current and future conditions and desired LOS.In addition,AM provides the necessary tools to objectively monitor LOS,and hence the contractor performance,which will contribute to the success of the implementation of PBMC.
基金the Scientific Technology R&D Project of CCCC Asset Management Co.,Ltd.(RP2022015294&RP2022015296).
文摘Conventional repairing methods for asphalt pavement have some inconveniences,such as insufficient strength,and are typically time-consuming.To address these issues,this study proposes a new technological method to design and prepare a high-performance assembled asphalt concrete block for fast repair of the potholes.A series of composite modified asphalt binders with 10%crumb rubber(CR)and different dosages(0%,1%,3%,5%)of polyurethane(PU)are examined to determine the optimized binder.Subsequently,the corresponding asphalt mixtures are prepared for further comparison and assessment of engineering properties,such as moistureinduced damage,high-temperature deformation,and low-temperature cracking characteristics.The test results show that PU can significantly improve the high-temperature performance and hardness of(crumb rubber modified asphalt)CRMA binder;3%PU contributes allowing the resistance of CRMA mixture to moisture-induced damage at higher levels,particularly under water whole immersion;as 3%PU is added,the high-temperature rutting deformation resistance of the CRMA mixture increases significantly,and the low-temperature anti-cracking properties are also improved slightly.Therefore,the innovatively designed high-quality assembled fast-repairing asphalt concrete block is recommended as an appropriate option for highway maintenance.
基金supported by the Scientific Technology R&D Project of CCCC Asset Management Co.,Ltd.(RP2022015294).
文摘Traditional asphalt rejuvenators,like aromatic oil(AO),are known to be effective in improving the low-temperature properties and fatigue performances of aged SBS(styrene-butadiene-styrene)modified asphalt(SBSMA)binders and mixtures.However,these rejuvenators inevitably compromise their high-temperature properties and deformation resistances because they dilute asphalt binder but do not fix the damaged structures of aged SBS.In this study,a highly-active chemical called polymerized 4,4-diphenylmethane diisocyanate(PMDI)was used to assist the traditional AO asphalt rejuvenator.The physical and rheological characteristics of rejuvenated SBSMA binders and the moisture-induced damage and rut deformation performances of corresponding mixtures were comparatively evaluated.The results showed that the increasing proportion of AO compromises the hightemperature property and hardness of aged SBSMA binder,and an appropriate amount of PMDI works to compensate such losses;3%rejuvenator at mass ratio of AO:PMDI=70:30 can have a rejuvenated SBSMA binder with a high-temperature performance similar to that of fresh binder,approximately at 71.4°C;the use of AO can help reduce the viscosity of PMDI rejuvenated SBSMA binder for improving its workability;PMDI can help improve the resistance of AO rejuvenated SBSMA binder to deformation,especially at elevated temperatures,through its chemical reactions with aged SBS;moisture induction can enhance the resistance to damage of rejuvenated mixtures containing AO/PMDI or only PMDI;and the rejuvenator with a mass ratio of AO:PMDI=70:30 can lead the rejuvenated mixture to meet the application requirement,with a rut depth of only 2.973 mm,although more PMDI can result in a higher resistance of rejuvenated mixtures to high-temperature deformation.
文摘Due to the complexity of leadership and its variability across situations,it is suggested that research on leadership should focus on attempts to understand leadership in specific situations or roles,and develop local knowledge about leadership in each situation or role.This paper validates the possibility and importance of building indigenous leadership theories from historical perspective.We demonstrated how to carry out research on indigenous Chinese leadership from a historical perspective by comparative case studies using historical data.Based on the principles of typicalness,representativeness,and comparativeness,we selected six counterparts of political elites in ancient China as comparative cases,which includes Guan Zhong&Shang Yang(organizational reformer),Liu Bang&Xiang Yu(entrepreneur),Li Shimin&Qin Shihuang(intergenerational transition successor),Zhuge Liang&Zeng Guofan(professional manager),Lu Su&Zhang Juzheng(mess-to-order maker),and Zuo Zongtang&Wang Anshi(national dream driver).The paper aims to develop indigenous leadership theory specific to Chinese mental states and culture.
文摘Latent variable models can effectively determine the condition of essential rotating machinery without needing labeled data.These models analyze vibration data via an unsupervised learning strategy.Temporal preservation is necessary to obtain an informative latent manifold for the fault diagnosis task.In a temporalpreserving context,two approaches exist to develop a condition-monitoring methodology:offline and online.For latent variable models,the available training modes are not different.While many traditional methods use offline training,online training can dynamically adjust the latent manifold,possibly leading to better fault signature extraction from the vibration data.This study explores online training using temporal-preserving latent variable models.Within online training,there are two main methods:one focuses on reconstructing data and the other on interpreting the data components.Both are considered to evaluate how they diagnose faults over time.Using two experimental datasets,the study confirms that models from both training modes can detect changes in machinery health and identify faults even under varying conditions.Importantly,the complementarity of offline and online models is emphasized,reassuring their versatility in fault diagnostics.Understanding the implications of the training approach and the available model formulations is crucial for further research in latent variable modelbased fault diagnostics.
基金supported by the National Natural Science Foundation of China (Grant Nos.51501130 and 51301181)the Tianjin Key Research Program of Application Foundation and Advanced Technology (Grant No.15JCZDJC39700)+2 种基金the Innovation Team Training Plan of Tianjin Universities and colleges (Grant No.TD12-5043)the Tianjin Science and Technology Correspondent Project (16JCTPJC49500)the Research Development Foundation of Tianjin University of Technology and Education (Grant No.KYQD14046)
文摘Four CrAlN coatings with various Al content were prepared by arc ion plating technology under different target currents. The effect of the Al content on the microstructure, chemical compositions, element chemical bonding states and mechanical properties of the CrAlN coatings was analyzed. X-ray diffraction results show that the primary phase of the CrAlN coating is fcc-（Al, Cr）N when the Al content is about 44.02 at.%. However, when the Al content increases to about 53.34 at.%, hcp-AlN phase emerges in the coating. And the hcp-AlN phase becomes the main phase in the CrAlN coating with Al content of about 69.55 at.%. Cross-sectional images show that all the four coatings possess dense structures and the deposition rate of Al atom is higher than that of Cr atom. The hardness of the CrAlN coating with Al content about 44.02 at.% is the largest （3149.72 HV） due to the solid solution hardening effect of the Al element. When the hcp-AlN phase is generated in the CrAlN coating, the hardness declines. The tribological experiment shows that the wear resistance of the CrAlN coating decreases gradually with increasing Al content when sliding against 100Cr6 steel ball.
基金Project(2014CB239205)supported by the National Basic Research Program of ChinaProject(20011ZX05030-005-003)supported by the National Science and Technology Major Project of China
文摘Faults and fractures of multiple scales are frequently induced and generated in compressional structural system. Comprehensive identification of these potential faults and fractures that cannot be distinguished directly from seismic profile of the complex structures is still an unanswered problem. Based on the compressional structural geometry and kinematics theories as well as the structural interpretation from seismic data, a set of techniques is established for the identification of potential faults and fractures in compressional structures. Firstly, three-dimensional(3D) patterns and characteristics of the faults directly interpreted from seismic profile were illustrated by 3D structural model. Then, the unfolding index maps, the principal structural curvature maps, and tectonic stress field maps were obtained from structural restoration. Moreover, potential faults and fractures in compressional structures were quantitatively identified relying on comprehensive analysis of these three maps. Successful identification of the potential faults and fractures in Mishrif limestone formation and in Asmari dolomite formation of Buzurgan anticline in Iraq demonstrates the applicability and reliability of these techniques.
基金Under the auspices of National Science and Technology Research during the 11th Five-Year Plan Period (No.2008BAI62B05)National Natural Science Foundation of China (No. 50879005,51179006)
文摘With the development of industry and agriculture,nitrogen,phosphorus and other nutrients in the Hanshui River greatly increase and eutrophication has become an important threat to the water quality of the Hanshui River,especially in the middle and lower reaches.The primary objective of this study was to establish the water quality model for the middle and lower reaches of the Hanshui River based on the model of MIKE 11.The main pollutants migration and transformation process could be simulated using the water quality model.The rainfall-runoff model,hy-drodynamic model and water quality model were established using MIKE 11.The pollutants,such as chemical oxygen demand(COD),biochemical oxygen demand(BOD),ammonia nitrogen,nitrate nitrogen,phosphorus,dissolved oxy-gen(DO),were simulated and predicted using the above three models.A set of methods computing non-point source pollution load of the Hanshui River Basin was proposed in this study.The simulated and observed values of COD,BOD5,ammonia,nitrate,DO,and total phosphorus were compared after the parameter calibration of the water quality model.The simulated and observed results match better,thus the model can be used to predict water quality in the fu-ture for the Hanshui River.The pollution trend could be predicted using the water quality model according pollution load generation.It is helpful for government to take effective measures to prevent the water bloom and protect water quality in the river.
基金supported by the National Nature Science Foundation of China (Grant Nos. 51501130 and 51301181)the Tianjin Key Research Program of Application Foundation and Advanced Technology (Grant No. 15JCZDJC39700)+2 种基金the Innovation Team Training Plan of Tianjin Universities and colleges (Grant No. TD12-5043)the Tianjin Science and Technology correspondent project (16JCTPJC49500)Research Development Foundation of Tianjin University of Technology and Education (Grant No. KJ1422)
文摘A new type of AlTiN coating containing about 29.13 at.% Al,16.02 at.% Ti and 54.85 at.% N was prepared by arc ion plating technology. The coating is composed of singular fcc-（Al, Ti）N phase and has no hcp-AlN phase to be formed. Due to the high content of beneficial element Al, the hardness and effective elastic modulus of the coating are up to 33.9 and 486.1 GPa, respectively. The adhesion strength between the coating and substrate is about 39.7 N. Electro- chemical test shows that the corrosion current density of the AlTiN coating is nearly one-sixth of the substrate, and the charge transfer resistance Rct of the AlTiN coating is much larger than that of the substrate, which means that the coating could act as a protective barrier between the substrate and corrosive electrolyte, enhancing the corrosion resistance.
基金supported by the National Natural Science Foundation of China (21606146)Natural Science Foundation of Shandong Province (ZR2016BB17,2016ZRB01037)+3 种基金Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents (2016RCJJ005,2016RCJJ006)Government Sponsored Visiting Scholar Foundation of Shandong University of Science and Technology (2016)Qingdao Postdoctoral Applied Research Project (2015202)China National Coal Association Science and Technology Research Program (MTKJ2016-266)~~
文摘We report Ni/LaHA@ZrO2catalysts prepared by a facile modified successive adsorption and reaction method for CO methanation.N2adsorption,X‐ray diffraction,transmission electron microscopy,scanning electron microscopy,thermogravimetric analysis,H2temperature‐programmed reduction,H2temperature‐programmed desorption,X‐ray photoelectron spectroscopy,thermogravimetric analysis,and inductively coupled plasma atomic emission spectrometry were used to characterize the samples.The results indicated that the ZrO2nanoparticles were distributed over the surface of the Ni/LaHA@ZrO2catalyst and even partially covered some Ni particles,resulting in the coating exerting a confinement effect.The excess ZrO2had an adverse effect on the enhancement of CO conversion because of the coverage of the surface Ni particles;however,the Ni/LaHA@ZrO2catalyst displayed much higher CH4selectivity than Ni/LaHA because of the activation of the byproduct CO2molecules by ZrO2species.Therefore,even though20Ni/LaHA@ZrO2‐5exhibited similar CO conversion as20Ni/LaHA,the use of the former resulted in a higher CH4yield than the use of the latter.A107‐h‐lifetime test revealed that the Ni/LaHA@ZrO2catalyst was highly stable with superior anti‐sintering and anti‐coking properties because of its coating structure and the promoter effect of ZrO2.
基金supported by the National Basic Research Program of China(grant No.2014CB239205)the sub-project of the National Science and Technology Major Project(grant No.2017ZX05035003)
文摘The typical characteristics of shale gas and the enrichment differences show that some shale gases are insufficiently explained by the existing continuous enrichment mode. These shale gases include the Wufeng–Longmaxi shale gas in the Jiaoshiba and Youyang Blocks, the Lewis shale gas in the San Juan Basin. Further analysis reveals three static subsystems（hydrocarbon source rock, gas reservoirs and seal formations） and four dynamic subsystems（tectonic evolution, sedimentary sequence, diagenetic evolution and hydrocarbon-generation history） in shale-gas enrichment systems. Tectonic evolution drives the dynamic operation of the whole shale-gas enrichment system. The shale-gas enrichment modes controlled by tectonic evolution are classifiable into three groups and six subgroups. Group I modes are characterized by tectonically controlled hydrocarbon source rock, and include continuous in-situ biogenic shale gas（Ⅰ_1） and continuous in-situ thermogenic shale gas（Ⅰ_2）. Group Ⅱ modes are characterized by tectonically controlled gas reservoirs, and include anticline-controlled reservoir enrichment（Ⅱ_1） and fracture-controlled reservoir enrichment（Ⅱ_2）. Group Ⅲ modes possess tectonically controlled seal formations, and include faulted leakage enrichment（Ⅲ_1） and eroded residual enrichment（Ⅲ_2）. In terms of quantity and exploitation potential, Ⅰ_1 and Ⅰ_2 are the best shale-gas enrichment modes, followed by Ⅱ_1 and Ⅱ_2. The least effective modes are Ⅲ_1 and Ⅲ_2. The categorization provides a different perspective for deep shale-gas exploration.
