The thermal characteristics during the South China Sea (SCS) summer monsoon onset period near the Indo-China Peninsula are analyzed by using the South China Sea Monsoon Experiment (SCSMEX) reanalysis data from 1 May t...The thermal characteristics during the South China Sea (SCS) summer monsoon onset period near the Indo-China Peninsula are analyzed by using the South China Sea Monsoon Experiment (SCSMEX) reanalysis data from 1 May to 31 August 1998 and the NCEP/ NCAR pentad-mean reanalysis data from January 1980 to December 1995. The possible relationships between the anomaly of thermal features near the Indo-China Peninsula and the SCS monsoon onset are investigated, and the mechanism causing the SCS summer monsoon onset is also discussed. Results from the 1998 SCSMEX reanalysis data show that there exists a strong persistent surface sensible heating near the Indo-China Peninsula prior to the SCS monsoon onset, which has apparent low frequency oscillation features. This sensible healing leads lo a warmer center in the lower atmosphere near the Indo-China Peninsula and strong local horizontal temperature and geopotential height gradients which are favorable to strengthening the southwest wind over the Indo-China Peninsula. It is also found that stronger convergent winds at lower levels and stronger divergent winds at high levels appear, which provide a favorable configuration for the development of vertical motion, enhancement of precipitation, and onset of the SCS monsoon. These results can be verified by analysis of the multi-year mean data. Additionally, it is found that the temperature at 850 hPa increases more rapidly over the Indo-China Peninsula than the South China Sea prior to the SCS monsoon onset, which leads to a strengthening of the temperature difference between the Indo-China Peninsula and the South China Sea. Moreover, results from the analysis of the longitudinal temperature and geopotential height differences show that the eastern retreat of the subtropical high over the Indo-China Peninsula during the period of SCS monsoon onset is associated with the temperature increase over the Indo-China Peninsula and the eastern extension of low trough over the Bay of Bengal.展开更多
Some kinds of particular functions possessed by natural organisms are often formed by coupling up the multiple typical features on their body surfaces. Inspired by the coupling phenomenon in biological system, the med...Some kinds of particular functions possessed by natural organisms are often formed by coupling up the multiple typical features on their body surfaces. Inspired by the coupling phenomenon in biological system, the medium carbon steel specimens with the coupling effect of non-smooth mechanical property and microstructural features were fabricated by laser processing. Thermal fatigue behavior of specimens with biomimetic coupling surface was investigated and compared. The results confirmed that such a biomimetic method has the beneficial effect on improving the thermal fatigue property of medium carbon steel specimens. The related mechanisms behind the biomimetic coupling effect for explaining the enhanced thermal fatigue resistance were discussed preliminarily.展开更多
A two-dimensional axisymmetric finite element model is developed to analyze the transient thermal and mechanical behaviors of the Resistance Spot Welding （RSW） process using commercial software ANSYS. Firstly a dire...A two-dimensional axisymmetric finite element model is developed to analyze the transient thermal and mechanical behaviors of the Resistance Spot Welding （RSW） process using commercial software ANSYS. Firstly a direct-coupled electrical-thermal Finite Element Analysis （FEA） is performed to analyze the transient thermal characteristics of the RSW process. Then based on the thermal results a sequential coupled thermo-elastic-plastic analysis is conducted to determine the mechanical features of the RSW process. The thermal history of the whole process and the temperature distribution of the weldment are obtained through the analysis. The mechanical features, including the distributions of the contact pressure at both the faying surface and the electrode-workpiece interface, the stress and strain distributions in the weldment and their changes during the RSW process, the deformation of the weldment and the electrode displacement are also calculated.展开更多
为探究植物群落空间特征与小气候因子和人体舒适度间的关系,文章以聊城市东昌湖湿地公园为研究对象,选择覆盖空间(CS)、封闭空间(ES)、半开敞空间(SOS)和开敞空间(OS)进行样地调查和小气候实测,借助RayMan Pro 3.1计算秋季生理等效温度(...为探究植物群落空间特征与小气候因子和人体舒适度间的关系,文章以聊城市东昌湖湿地公园为研究对象,选择覆盖空间(CS)、封闭空间(ES)、半开敞空间(SOS)和开敞空间(OS)进行样地调查和小气候实测,借助RayMan Pro 3.1计算秋季生理等效温度(PET)对植物群落空间进行热舒适评价。结果表明:1)不同类型的植物空间温湿度和风速均存在显著差异(P<0.05)。2)CS不存在热不适时段,OS的热不适时段最长。3)空气温度与PET呈线性正相关,相对湿度与PET呈线性负相关,风速与PET不相关。4)天空可视因子(SVF)对植物空间舒适度影响最大;绿化用地比例(GR)不影响舒适度;围合度通过影响风速间接影响舒适度。研究结果揭示了不同类型植物空间的舒适度状况,建议在公园绿地建设中增加CS的种植、适当降低植物空间种植密度等,旨在为营造更加多元且舒适的植物空间提供科学依据。展开更多
The pyrolysis parameter S1,which indicates the amount of free hydrocarbons present in shale,is often underestimated due to hydrocarbon loss during sample handling and measurement processes.To remedy this issue,we stro...The pyrolysis parameter S1,which indicates the amount of free hydrocarbons present in shale,is often underestimated due to hydrocarbon loss during sample handling and measurement processes.To remedy this issue,we strongly recommend an immediate three-step hydrocarbon thermal desorption(HTD)approach to be conducted on oil shale at the drilling site.This approach measures S_(g),S_(O),and S_(1)^(*),which refer to gaseous,light,and free hydrocarbons,respectively.The new shale oil content value,calculated from the total of these three parameters,is far more precise and reliable than traditional pyrolysis S1.Moreover,we thoroughly investigated the components and microscopic occurrence features of hydrocarbons thermally desorbed at three temperature stages using gas chromatography(GC)and X-ray microcomputed tomography(CT).For example,we selected Chang 7_(3)mud shale.Our experimental results irrefutably indicate that the ultimate shale oil content of poor resource rocks is significantly impacted by evaporative loss,with this effect being greater when the total organic carbon(TOC)is lower.Additionally,C_(1-5)and C_(1-7)hydrocarbons constitute almost all of S_(g)and S_(O),respectively.S_(g)and S_(O)are predominantly composed of C_(1-3)gaseous hydrocarbons,with a maximum proportion of 42.93%.In contrast,S_(1)^(*)contains a substantial amount of C_(16-31)hydrocarbons.A three-dimensional reconstruction model of an X-ray micro-CT scan shows that while the amount of shale organic matter greatly decreases from the frozen state to 300℃,the pore volume significantly increases,particularly between 90 and 300℃.The increased pore volume is mainly due to macropores and fractures.It is imperative to note that the shale oil triple-division boundaries must be adjusted based on more accurate oil content,although this would not affect the resource zones to which the samples already belong(ineffective,low-efficient,and enriched resources).In conclusion,we strongly advise conducting an immediate well-site analysis or utilizing preservati展开更多
With recent advancements in information and communication technology,a huge volume of corporate and sensitive user data was shared consistently across the network,making it vulnerable to an attack that may be brought ...With recent advancements in information and communication technology,a huge volume of corporate and sensitive user data was shared consistently across the network,making it vulnerable to an attack that may be brought some factors under risk:data availability,confidentiality,and integrity.Intrusion Detection Systems(IDS)were mostly exploited in various networks to help promptly recognize intrusions.Nowadays,blockchain(BC)technology has received much more interest as a means to share data without needing a trusted third person.Therefore,this study designs a new Blockchain Assisted Optimal Machine Learning based Cyberattack Detection and Classification(BAOML-CADC)technique.In the BAOML-CADC technique,the major focus lies in identifying cyberattacks.To do so,the presented BAOML-CADC technique applies a thermal equilibrium algorithm-based feature selection(TEA-FS)method for the optimal choice of features.The BAOML-CADC technique uses an extreme learning machine(ELM)model for cyberattack recognition.In addition,a BC-based integrity verification technique is developed to defend against the misrouting attack,showing the innovation of the work.The experimental validation of BAOML-CADC algorithm is tested on a benchmark cyberattack dataset.The obtained values implied the improved performance of the BAOML-CADC algorithm over other techniques.展开更多
基金This study is supported by the Nationul Natural Science Foundation of China under Grant No. 40175021is purtly funded by the Ministry of Education through the start-up project for scientists who have returned from abroud.
文摘The thermal characteristics during the South China Sea (SCS) summer monsoon onset period near the Indo-China Peninsula are analyzed by using the South China Sea Monsoon Experiment (SCSMEX) reanalysis data from 1 May to 31 August 1998 and the NCEP/ NCAR pentad-mean reanalysis data from January 1980 to December 1995. The possible relationships between the anomaly of thermal features near the Indo-China Peninsula and the SCS monsoon onset are investigated, and the mechanism causing the SCS summer monsoon onset is also discussed. Results from the 1998 SCSMEX reanalysis data show that there exists a strong persistent surface sensible heating near the Indo-China Peninsula prior to the SCS monsoon onset, which has apparent low frequency oscillation features. This sensible healing leads lo a warmer center in the lower atmosphere near the Indo-China Peninsula and strong local horizontal temperature and geopotential height gradients which are favorable to strengthening the southwest wind over the Indo-China Peninsula. It is also found that stronger convergent winds at lower levels and stronger divergent winds at high levels appear, which provide a favorable configuration for the development of vertical motion, enhancement of precipitation, and onset of the SCS monsoon. These results can be verified by analysis of the multi-year mean data. Additionally, it is found that the temperature at 850 hPa increases more rapidly over the Indo-China Peninsula than the South China Sea prior to the SCS monsoon onset, which leads to a strengthening of the temperature difference between the Indo-China Peninsula and the South China Sea. Moreover, results from the analysis of the longitudinal temperature and geopotential height differences show that the eastern retreat of the subtropical high over the Indo-China Peninsula during the period of SCS monsoon onset is associated with the temperature increase over the Indo-China Peninsula and the eastern extension of low trough over the Bay of Bengal.
基金Supported by the Key Program of National Natural Science Foundation of China (Grant No. 50635030)Project 985-Automotive Engineering of Jilin University, International Cooperation key Project (Grant No. 2005DFA00850)Transfer Foundation of Scientific and Technical Fruits in Agriculture (Grant No. 2007GB23600467) of Ministry of Science and Technology of China
文摘Some kinds of particular functions possessed by natural organisms are often formed by coupling up the multiple typical features on their body surfaces. Inspired by the coupling phenomenon in biological system, the medium carbon steel specimens with the coupling effect of non-smooth mechanical property and microstructural features were fabricated by laser processing. Thermal fatigue behavior of specimens with biomimetic coupling surface was investigated and compared. The results confirmed that such a biomimetic method has the beneficial effect on improving the thermal fatigue property of medium carbon steel specimens. The related mechanisms behind the biomimetic coupling effect for explaining the enhanced thermal fatigue resistance were discussed preliminarily.
文摘A two-dimensional axisymmetric finite element model is developed to analyze the transient thermal and mechanical behaviors of the Resistance Spot Welding （RSW） process using commercial software ANSYS. Firstly a direct-coupled electrical-thermal Finite Element Analysis （FEA） is performed to analyze the transient thermal characteristics of the RSW process. Then based on the thermal results a sequential coupled thermo-elastic-plastic analysis is conducted to determine the mechanical features of the RSW process. The thermal history of the whole process and the temperature distribution of the weldment are obtained through the analysis. The mechanical features, including the distributions of the contact pressure at both the faying surface and the electrode-workpiece interface, the stress and strain distributions in the weldment and their changes during the RSW process, the deformation of the weldment and the electrode displacement are also calculated.
文摘为探究植物群落空间特征与小气候因子和人体舒适度间的关系,文章以聊城市东昌湖湿地公园为研究对象,选择覆盖空间(CS)、封闭空间(ES)、半开敞空间(SOS)和开敞空间(OS)进行样地调查和小气候实测,借助RayMan Pro 3.1计算秋季生理等效温度(PET)对植物群落空间进行热舒适评价。结果表明:1)不同类型的植物空间温湿度和风速均存在显著差异(P<0.05)。2)CS不存在热不适时段,OS的热不适时段最长。3)空气温度与PET呈线性正相关,相对湿度与PET呈线性负相关,风速与PET不相关。4)天空可视因子(SVF)对植物空间舒适度影响最大;绿化用地比例(GR)不影响舒适度;围合度通过影响风速间接影响舒适度。研究结果揭示了不同类型植物空间的舒适度状况,建议在公园绿地建设中增加CS的种植、适当降低植物空间种植密度等,旨在为营造更加多元且舒适的植物空间提供科学依据。
基金This study is financially supported by the National Natural Science Foundation of China(Grant Number 41972122,42172139 and 42072186)the China Scholarship Council(CSC),the Open Foundation of Cooperative Innovation Center of Uncon-ventional Oil and Gas,Yangtze University(Ministry of Education&Hubei Province)(Grant Number UOGBX 2022-03)Petro-China Innovation Found(No.2020D-5007-0101)。
文摘The pyrolysis parameter S1,which indicates the amount of free hydrocarbons present in shale,is often underestimated due to hydrocarbon loss during sample handling and measurement processes.To remedy this issue,we strongly recommend an immediate three-step hydrocarbon thermal desorption(HTD)approach to be conducted on oil shale at the drilling site.This approach measures S_(g),S_(O),and S_(1)^(*),which refer to gaseous,light,and free hydrocarbons,respectively.The new shale oil content value,calculated from the total of these three parameters,is far more precise and reliable than traditional pyrolysis S1.Moreover,we thoroughly investigated the components and microscopic occurrence features of hydrocarbons thermally desorbed at three temperature stages using gas chromatography(GC)and X-ray microcomputed tomography(CT).For example,we selected Chang 7_(3)mud shale.Our experimental results irrefutably indicate that the ultimate shale oil content of poor resource rocks is significantly impacted by evaporative loss,with this effect being greater when the total organic carbon(TOC)is lower.Additionally,C_(1-5)and C_(1-7)hydrocarbons constitute almost all of S_(g)and S_(O),respectively.S_(g)and S_(O)are predominantly composed of C_(1-3)gaseous hydrocarbons,with a maximum proportion of 42.93%.In contrast,S_(1)^(*)contains a substantial amount of C_(16-31)hydrocarbons.A three-dimensional reconstruction model of an X-ray micro-CT scan shows that while the amount of shale organic matter greatly decreases from the frozen state to 300℃,the pore volume significantly increases,particularly between 90 and 300℃.The increased pore volume is mainly due to macropores and fractures.It is imperative to note that the shale oil triple-division boundaries must be adjusted based on more accurate oil content,although this would not affect the resource zones to which the samples already belong(ineffective,low-efficient,and enriched resources).In conclusion,we strongly advise conducting an immediate well-site analysis or utilizing preservati
基金This work was funded by the Deanship of Scientific Research at Princess Nourah bint Abdulrahman University,through the Research Groups Program Grant No.(RGP-1443-0051)。
文摘With recent advancements in information and communication technology,a huge volume of corporate and sensitive user data was shared consistently across the network,making it vulnerable to an attack that may be brought some factors under risk:data availability,confidentiality,and integrity.Intrusion Detection Systems(IDS)were mostly exploited in various networks to help promptly recognize intrusions.Nowadays,blockchain(BC)technology has received much more interest as a means to share data without needing a trusted third person.Therefore,this study designs a new Blockchain Assisted Optimal Machine Learning based Cyberattack Detection and Classification(BAOML-CADC)technique.In the BAOML-CADC technique,the major focus lies in identifying cyberattacks.To do so,the presented BAOML-CADC technique applies a thermal equilibrium algorithm-based feature selection(TEA-FS)method for the optimal choice of features.The BAOML-CADC technique uses an extreme learning machine(ELM)model for cyberattack recognition.In addition,a BC-based integrity verification technique is developed to defend against the misrouting attack,showing the innovation of the work.The experimental validation of BAOML-CADC algorithm is tested on a benchmark cyberattack dataset.The obtained values implied the improved performance of the BAOML-CADC algorithm over other techniques.
