Approaches toward the sustainable development need integrated considerations of technical, economical, environmental/ecological and social issues. Current approaches from different disciplines can be grouped into at l...Approaches toward the sustainable development need integrated considerations of technical, economical, environmental/ecological and social issues. Current approaches from different disciplines can be grouped into at least three levels: micro-scale, meso-scale and macro-scale. At the micro-scale, green chemistry carries out chemical activities such as chemical design and synthesis so that environmentally benign chemicals can be synthesized without using and generating hazardous substances. Green engineering, at the meso-scale, develops green industrial processes or clean technologies via pollution prevention and cleaner production, which will cause minimal damages or dangers to the environment and ecosystems when the product is manufactured and used. Industrial ecology at the industrial complex or community level seeks to optimize energy and materials use and minimize waste generation in industrial systems or communities by promoting planned materials and energy exchanges. Incorporation of ecological principles with the life cycle thinking in the chemical pathway synthesis, product design, process development, and industrial system and community planning appears to be the most promising engineering approach in achieving sustainable industrial development.展开更多
In order to analyze the effects of backfill materials, geometries and slab setting on the settlement of bridge approach embankment, scale model was built based on the structural characteristics of bridge approach emba...In order to analyze the effects of backfill materials, geometries and slab setting on the settlement of bridge approach embankment, scale model was built based on the structural characteristics of bridge approach embankment, and scale model tests were carried out under different conditions. The results show that when graded gravels were selected as the backfill materials, the effect of setting approach slab to reduce the differential settlement is more prominent. When lime soils were selected as the backfill material, approach slab can moderate the longitudinal settlement slope. When using different backfill materials, the ultimate settlement of the positive trapezoidal backfill geometries is less than that of the inverted trapezoid, and the backfill geometries have little effect on the settlement slope.展开更多
The Nesterov accelerated dynamical approach serves as an essential tool for addressing convex optimization problems with accelerated convergence rates.Most previous studies in this field have primarily concentrated on...The Nesterov accelerated dynamical approach serves as an essential tool for addressing convex optimization problems with accelerated convergence rates.Most previous studies in this field have primarily concentrated on unconstrained smooth con-vex optimization problems.In this paper,on the basis of primal-dual dynamical approach,Nesterov accelerated dynamical approach,projection operator and directional gradient,we present two accelerated primal-dual projection neurodynamic approaches with time scaling to address convex optimization problems with smooth and nonsmooth objective functions subject to linear and set constraints,which consist of a second-order ODE(ordinary differential equation)or differential conclusion system for the primal variables and a first-order ODE for the dual vari-ables.By satisfying specific conditions for time scaling,we demonstrate that the proposed approaches have a faster conver-gence rate.This only requires assuming convexity of the objective function.We validate the effectiveness of our proposed two accel-erated primal-dual projection neurodynamic approaches through numerical experiments.展开更多
Laser-induced breakdown spectroscopy (LIBS) was used to decipher the unique multi-elemental characteristics of Juncus effusus L. The spectral fingerprints of Juncus effusus L. were established based on elemental mic...Laser-induced breakdown spectroscopy (LIBS) was used to decipher the unique multi-elemental characteristics of Juncus effusus L. The spectral fingerprints of Juncus effusus L. were established based on elemental microanalysis via LIBS. Microanalysis and multimode sampling methodologies were designed in this study. The relative standard deviation (RSD) approach was performed to optimize the multi-shot measurements. Taking advantage of the capability with no or minimal sample pre-treatment of LIBS, a thermodynamic chart of four elements (Mg, Ca, Ba, and Na) was created from twelve collection regions. The diagram of elemental distribution on a micro-scale was generated to explore the nature of Juncus effusus L. by LIBS. The results demon- strated that LIBS is a promising technique for rapid elemental microanalysis of heterogeneous samples.展开更多
Global change research and sustainable development need to be addressed at larger scales in the light of small scale process studies. Much remains to be done before the small scale, process level understanding of ecos...Global change research and sustainable development need to be addressed at larger scales in the light of small scale process studies. Much remains to be done before the small scale, process level understanding of ecosystem responses to global change can be reliably translated to larger scales. The paper reviews the status of scaling issues and tries to find how to extrapolate our observations and our findings at site scale up to regional scale and provide ecological information and interpretations at the regional scale. An integrated approach to scaling-up from site to region is proposed combining hierarchical theory, landscape ecology, remote sensing, geographical information system (GIS) with process/mechanistic modeling. Remote sensing and GIS will play key roles in spatial analysis, integration as well as cross scale modeling.展开更多
Assume that the Tonglu Canal would be widened and deepened in which a water lock is constructed atthe river side, and made open to the sea side. The canal's planned control dimensions are determined, and the erosi...Assume that the Tonglu Canal would be widened and deepened in which a water lock is constructed atthe river side, and made open to the sea side. The canal's planned control dimensions are determined, and the erosionand siltation characteristics along the river (totally 81. 8 km) are analyzed by the numerical calculation of one-dimen-sional unsteady flow and the relative standards. According to the data of the evolution, hydrology and sediment inthe Xiaomiaohong Waterway, it is found reasonable to select the channel near the Xingang Gate as the second sea-entering approach. This paper is helpful in planning and designing the approach.展开更多
This paper studies the optimal control with zero steady-state error problem for nonlinear large-scale systems affected by external persistent disturbances.The nonlinear large-scale system is transformed into N nonline...This paper studies the optimal control with zero steady-state error problem for nonlinear large-scale systems affected by external persistent disturbances.The nonlinear large-scale system is transformed into N nonlinear subsystems with interconnect terms.Based on the internal model principle,a disturbance compensator is constructed such that the ith subsystem with external persistent disturbances is transformed into an augmented subsystem without disturbances.According to the sensitivity approach,the optimal tracking control law for the ith nonlinear subsystem can be obtained.The optimal tracking control law for the nonlinear large-scale systems can be obtained.A numerical simulation shows that the method is effective.展开更多
An optimal tracking control (OTC) problem for linear time-delay large-scale systems affected by external persistent disturbances is investigated. Based on the internal model principle, a disturbance compensator is c...An optimal tracking control (OTC) problem for linear time-delay large-scale systems affected by external persistent disturbances is investigated. Based on the internal model principle, a disturbance compensator is constructed. The system with persistent disturbances is transformed into an augmented system without persistent disturbances. The original OTC problem of linear time-delay system is transformed into a sequence of linear two- point boundary value (TPBV) problems by introducing a sensitivity parameter and expanding Maclaurin series around it. By solving an OTC law of the augmented system, the OTC law of the original system is obtained. A numerical simulation is provided to illustrate the effectiveness of the proposed method.展开更多
<strong>Purpose:</strong> This study aims to verify the validity of the contents of the Nurse Administered Depression Scale for Elderly Inpatients16 (NDE16) using the Delphi approach in order to further im...<strong>Purpose:</strong> This study aims to verify the validity of the contents of the Nurse Administered Depression Scale for Elderly Inpatients16 (NDE16) using the Delphi approach in order to further improve the accuracy of the NDE16, a scale for rating potential depressive states in elderly inpatients through the observations reported by nurses.<strong> Methods:</strong> Participants were nurses working in general wards for longer than 3 years and who expressed consent to the study participation. Data were collected using the Delphi method (3 times). Responses are scored from 1 to 5 (3 - 5 points as positive) using the Likert method. The standard criteria for inclusion in the further evaluation are “mean ≥ 3.0”, “standard deviation < 1.0”, “median ≥ 3.0”, and “IQR ≤ 1.0”. Items that meet all the criteria at the third survey are employed as question items in the final questionnaire. <strong>Results: </strong>The respondents were 139 females, 10 males, and 1 unknown, aged 25 to 65. The collection rates of the three surveys were 75% to 82%. Based on the results of the first survey, wordings of 9 questions were modified. Since Question 13 “Queries are not really responded to.” did not meet the criteria (IQR = 2) at the third survey, we excluded this question and named the revised scale NDE15. <strong>Discussion: </strong>The reason why Question 13 did not meet the criteria could be due to the difficulty in distinguishing “Expressing thought suppression” from the state of cognitive decline in dementia. Further studies are needed to determine cutoff points.展开更多
We present a unified derivation of the pressure equation of states, thermodynamics and scaling functions for the one-dimensional (1D) strongly attractive Fermi gases with SU(w) symmetry. These physical quantities ...We present a unified derivation of the pressure equation of states, thermodynamics and scaling functions for the one-dimensional (1D) strongly attractive Fermi gases with SU(w) symmetry. These physical quantities provide a rigorous understanding on a universality class of quantum criticality characterized by the critical exponents z = 2 and correlation length exponent v= 1/2. Such a universality class of quantum criticality can occur when the Fermi sea of one branch of charge bound states starts to fill or becomes gapped at zero temperature. The quantum critical cone can be determined by the double peaks in specific heat, which serve to mark two crossover temperatures fanning out from the critical point. Our method opens to further study on quantum phases and phase transitions in strongly interacting fermions with large SU ( w) and non-SU ( w ) symmetries in one dimension.展开更多
场地-城市相互作用(site-city interaction,SCI)效应会显著改变场地地震波场分布及建筑反应,基于SCI效应理论计算研究方法的发展现状,发挥谱元(spectral element,SE)法可快速高效求解三维地震波场传播和多自由度(multi-degree of freedo...场地-城市相互作用(site-city interaction,SCI)效应会显著改变场地地震波场分布及建筑反应,基于SCI效应理论计算研究方法的发展现状,发挥谱元(spectral element,SE)法可快速高效求解三维地震波场传播和多自由度(multi-degree of freedom,MDOF)模型计算量小且可同时模拟大量建筑的优势,同时,结合频率波数域(frequency wave number analysis,FK)方法,以等效地震荷载的方式施加地震波场,建立了FK-SE-MDOF耦合方法,实现了SE-MDOF耦合模型中多种波型(P波、SV波和SH波)的斜入射输入,解决了当前三维SCI效应研究方法中未能同时考虑建筑非线性、频谱特性、地震波波型及入射角度影响的问题。首先对方法原理进行了介绍;然后,通过与振动台试验的对比,验证了方法的正确性;进而,采用该方法建立理想场地-城市建筑群相互作用耦合模型,主要探讨了入射角度和地震波波型对SCI效应的影响,得到了一些有益结论。该方法较为真实地反映SCI效应影响的同时,可反映建筑基础轮廓对地震波场的影响,适用于需考虑建筑轮廓信息的社区尺度SCI效应研究,可为城市规划、抗震设计、风险评估以及震后救援等工作提供定量指导。展开更多
背景:关节置换是治疗老年移位性股骨颈骨折的主要手段,全髋关节置换与半髋关节置换的选择是目前具有较大争论的焦点。目的:基于倾向性评分匹配法对比直接前入路下全髋与半髋关节置换治疗老年移位性股骨颈骨折的中远期生存状态。方法:选...背景:关节置换是治疗老年移位性股骨颈骨折的主要手段,全髋关节置换与半髋关节置换的选择是目前具有较大争论的焦点。目的:基于倾向性评分匹配法对比直接前入路下全髋与半髋关节置换治疗老年移位性股骨颈骨折的中远期生存状态。方法:选择2016年1月至2021年1月收治的147例老年移位性股骨颈骨折患者(≥65岁),其中88例行全髋关节置换,59例行人工股骨头置换(半髋关节置换)。对于患者术前合并症采用年龄校正Charlson合并症评分表,计算患者虚弱度,并采用倾向性评分匹配法对两组患者进行1∶1匹配,比较匹配后两组患者的手术时间、出血量、术后住院时间、住院费用、营养指标、术后并发症、死亡率和术后生存时间,其中术后生存时间采用Kaplan-Meier生存分析。结果与结论:①倾向性评分匹配后,两组共有42对匹配成功,匹配后两组患者术前资料均衡可比(P>0.05);②与半髋关节置换组相比,全髋关节置换组手术时间(79.71 min vs.59.07 min,P<0.001)、出血量(839.64 mL vs.597.83 mL,P=0.001)、住院费用(56508.15元vs.41702.85元,P<0.001)明显增加,但全髋关节置换组死亡率低于半髋关节置换组(36%vs.57%,HR=0.44,95%CI:0.23-0.87,P=0.018),平均生存时间长于半髋关节置换组(59.4个月vs.43.7个月,P=0.024);③两组患者在术后住院时间、术前术后营养指标、术后整体并发症发生率上,差异均无显著性意义(P>0.05);但在术后疼痛方面,半髋关节置换组疼痛发生率明显高于全髋关节置换组(24%vs.7%,P=0.035);④整体来看,全髋关节置换具有更好的长期预后生存效果,但对于身体素质差的患者则更适合行半髋关节置换;同时,术后的疼痛可能很大程度上会对患者髋关节置换后的生活质量及存活时间产生影响。展开更多
文摘Approaches toward the sustainable development need integrated considerations of technical, economical, environmental/ecological and social issues. Current approaches from different disciplines can be grouped into at least three levels: micro-scale, meso-scale and macro-scale. At the micro-scale, green chemistry carries out chemical activities such as chemical design and synthesis so that environmentally benign chemicals can be synthesized without using and generating hazardous substances. Green engineering, at the meso-scale, develops green industrial processes or clean technologies via pollution prevention and cleaner production, which will cause minimal damages or dangers to the environment and ecosystems when the product is manufactured and used. Industrial ecology at the industrial complex or community level seeks to optimize energy and materials use and minimize waste generation in industrial systems or communities by promoting planned materials and energy exchanges. Incorporation of ecological principles with the life cycle thinking in the chemical pathway synthesis, product design, process development, and industrial system and community planning appears to be the most promising engineering approach in achieving sustainable industrial development.
基金Project(51978068) supported by the National Natural Science Foundation of ChinaProject(2018YFE0103800) supported by the National Key R&D Program of China+1 种基金Project(2017M620434) supported by the China Postdoctoral Science FoundationProject(310821173501) support by the Special Fund for Basic Scientific Research of Central College of Chang’an University, China。
文摘In order to analyze the effects of backfill materials, geometries and slab setting on the settlement of bridge approach embankment, scale model was built based on the structural characteristics of bridge approach embankment, and scale model tests were carried out under different conditions. The results show that when graded gravels were selected as the backfill materials, the effect of setting approach slab to reduce the differential settlement is more prominent. When lime soils were selected as the backfill material, approach slab can moderate the longitudinal settlement slope. When using different backfill materials, the ultimate settlement of the positive trapezoidal backfill geometries is less than that of the inverted trapezoid, and the backfill geometries have little effect on the settlement slope.
基金supported by the National Natural Science Foundation of China(62176218,62176027)the Fundamental Research Funds for the Central Universities(XDJK2020TY003)the Funds for Chongqing Talent Plan(cstc2024ycjh-bgzxm0082)。
文摘The Nesterov accelerated dynamical approach serves as an essential tool for addressing convex optimization problems with accelerated convergence rates.Most previous studies in this field have primarily concentrated on unconstrained smooth con-vex optimization problems.In this paper,on the basis of primal-dual dynamical approach,Nesterov accelerated dynamical approach,projection operator and directional gradient,we present two accelerated primal-dual projection neurodynamic approaches with time scaling to address convex optimization problems with smooth and nonsmooth objective functions subject to linear and set constraints,which consist of a second-order ODE(ordinary differential equation)or differential conclusion system for the primal variables and a first-order ODE for the dual vari-ables.By satisfying specific conditions for time scaling,we demonstrate that the proposed approaches have a faster conver-gence rate.This only requires assuming convexity of the objective function.We validate the effectiveness of our proposed two accel-erated primal-dual projection neurodynamic approaches through numerical experiments.
基金supported by National Natural Science Foundation of China(No.81303218)Beijing Municipal Government for the University Affiliated with the Party Central CommitteeDoctoral Fund of Ministry of Education of China(No.20130013120006)
文摘Laser-induced breakdown spectroscopy (LIBS) was used to decipher the unique multi-elemental characteristics of Juncus effusus L. The spectral fingerprints of Juncus effusus L. were established based on elemental microanalysis via LIBS. Microanalysis and multimode sampling methodologies were designed in this study. The relative standard deviation (RSD) approach was performed to optimize the multi-shot measurements. Taking advantage of the capability with no or minimal sample pre-treatment of LIBS, a thermodynamic chart of four elements (Mg, Ca, Ba, and Na) was created from twelve collection regions. The diagram of elemental distribution on a micro-scale was generated to explore the nature of Juncus effusus L. by LIBS. The results demon- strated that LIBS is a promising technique for rapid elemental microanalysis of heterogeneous samples.
基金the Important Directional Project of Knowledge Innovation of the Chinese Academy of Sciences (No: KZCX2-308-4).
文摘Global change research and sustainable development need to be addressed at larger scales in the light of small scale process studies. Much remains to be done before the small scale, process level understanding of ecosystem responses to global change can be reliably translated to larger scales. The paper reviews the status of scaling issues and tries to find how to extrapolate our observations and our findings at site scale up to regional scale and provide ecological information and interpretations at the regional scale. An integrated approach to scaling-up from site to region is proposed combining hierarchical theory, landscape ecology, remote sensing, geographical information system (GIS) with process/mechanistic modeling. Remote sensing and GIS will play key roles in spatial analysis, integration as well as cross scale modeling.
文摘Assume that the Tonglu Canal would be widened and deepened in which a water lock is constructed atthe river side, and made open to the sea side. The canal's planned control dimensions are determined, and the erosionand siltation characteristics along the river (totally 81. 8 km) are analyzed by the numerical calculation of one-dimen-sional unsteady flow and the relative standards. According to the data of the evolution, hydrology and sediment inthe Xiaomiaohong Waterway, it is found reasonable to select the channel near the Xingang Gate as the second sea-entering approach. This paper is helpful in planning and designing the approach.
基金supported by the National Natural Science Foundation of China(No.60574023)the Natural Science Foundation of Shandong Province(No.Z2005G01)
文摘This paper studies the optimal control with zero steady-state error problem for nonlinear large-scale systems affected by external persistent disturbances.The nonlinear large-scale system is transformed into N nonlinear subsystems with interconnect terms.Based on the internal model principle,a disturbance compensator is constructed such that the ith subsystem with external persistent disturbances is transformed into an augmented subsystem without disturbances.According to the sensitivity approach,the optimal tracking control law for the ith nonlinear subsystem can be obtained.The optimal tracking control law for the nonlinear large-scale systems can be obtained.A numerical simulation shows that the method is effective.
基金supported by the National Natural Science Foundation of China(60574023)the Natural Science Foundation of Shandong Province(Z2005G01).
文摘An optimal tracking control (OTC) problem for linear time-delay large-scale systems affected by external persistent disturbances is investigated. Based on the internal model principle, a disturbance compensator is constructed. The system with persistent disturbances is transformed into an augmented system without persistent disturbances. The original OTC problem of linear time-delay system is transformed into a sequence of linear two- point boundary value (TPBV) problems by introducing a sensitivity parameter and expanding Maclaurin series around it. By solving an OTC law of the augmented system, the OTC law of the original system is obtained. A numerical simulation is provided to illustrate the effectiveness of the proposed method.
文摘<strong>Purpose:</strong> This study aims to verify the validity of the contents of the Nurse Administered Depression Scale for Elderly Inpatients16 (NDE16) using the Delphi approach in order to further improve the accuracy of the NDE16, a scale for rating potential depressive states in elderly inpatients through the observations reported by nurses.<strong> Methods:</strong> Participants were nurses working in general wards for longer than 3 years and who expressed consent to the study participation. Data were collected using the Delphi method (3 times). Responses are scored from 1 to 5 (3 - 5 points as positive) using the Likert method. The standard criteria for inclusion in the further evaluation are “mean ≥ 3.0”, “standard deviation < 1.0”, “median ≥ 3.0”, and “IQR ≤ 1.0”. Items that meet all the criteria at the third survey are employed as question items in the final questionnaire. <strong>Results: </strong>The respondents were 139 females, 10 males, and 1 unknown, aged 25 to 65. The collection rates of the three surveys were 75% to 82%. Based on the results of the first survey, wordings of 9 questions were modified. Since Question 13 “Queries are not really responded to.” did not meet the criteria (IQR = 2) at the third survey, we excluded this question and named the revised scale NDE15. <strong>Discussion: </strong>The reason why Question 13 did not meet the criteria could be due to the difficulty in distinguishing “Expressing thought suppression” from the state of cognitive decline in dementia. Further studies are needed to determine cutoff points.
基金Supported by the National Natural Science Foundation of China under Grant No 11374331the key NSFC under Grant No11534014partially supported by the Australian Research Council
文摘We present a unified derivation of the pressure equation of states, thermodynamics and scaling functions for the one-dimensional (1D) strongly attractive Fermi gases with SU(w) symmetry. These physical quantities provide a rigorous understanding on a universality class of quantum criticality characterized by the critical exponents z = 2 and correlation length exponent v= 1/2. Such a universality class of quantum criticality can occur when the Fermi sea of one branch of charge bound states starts to fill or becomes gapped at zero temperature. The quantum critical cone can be determined by the double peaks in specific heat, which serve to mark two crossover temperatures fanning out from the critical point. Our method opens to further study on quantum phases and phase transitions in strongly interacting fermions with large SU ( w) and non-SU ( w ) symmetries in one dimension.
文摘场地-城市相互作用(site-city interaction,SCI)效应会显著改变场地地震波场分布及建筑反应,基于SCI效应理论计算研究方法的发展现状,发挥谱元(spectral element,SE)法可快速高效求解三维地震波场传播和多自由度(multi-degree of freedom,MDOF)模型计算量小且可同时模拟大量建筑的优势,同时,结合频率波数域(frequency wave number analysis,FK)方法,以等效地震荷载的方式施加地震波场,建立了FK-SE-MDOF耦合方法,实现了SE-MDOF耦合模型中多种波型(P波、SV波和SH波)的斜入射输入,解决了当前三维SCI效应研究方法中未能同时考虑建筑非线性、频谱特性、地震波波型及入射角度影响的问题。首先对方法原理进行了介绍;然后,通过与振动台试验的对比,验证了方法的正确性;进而,采用该方法建立理想场地-城市建筑群相互作用耦合模型,主要探讨了入射角度和地震波波型对SCI效应的影响,得到了一些有益结论。该方法较为真实地反映SCI效应影响的同时,可反映建筑基础轮廓对地震波场的影响,适用于需考虑建筑轮廓信息的社区尺度SCI效应研究,可为城市规划、抗震设计、风险评估以及震后救援等工作提供定量指导。
文摘背景:关节置换是治疗老年移位性股骨颈骨折的主要手段,全髋关节置换与半髋关节置换的选择是目前具有较大争论的焦点。目的:基于倾向性评分匹配法对比直接前入路下全髋与半髋关节置换治疗老年移位性股骨颈骨折的中远期生存状态。方法:选择2016年1月至2021年1月收治的147例老年移位性股骨颈骨折患者(≥65岁),其中88例行全髋关节置换,59例行人工股骨头置换(半髋关节置换)。对于患者术前合并症采用年龄校正Charlson合并症评分表,计算患者虚弱度,并采用倾向性评分匹配法对两组患者进行1∶1匹配,比较匹配后两组患者的手术时间、出血量、术后住院时间、住院费用、营养指标、术后并发症、死亡率和术后生存时间,其中术后生存时间采用Kaplan-Meier生存分析。结果与结论:①倾向性评分匹配后,两组共有42对匹配成功,匹配后两组患者术前资料均衡可比(P>0.05);②与半髋关节置换组相比,全髋关节置换组手术时间(79.71 min vs.59.07 min,P<0.001)、出血量(839.64 mL vs.597.83 mL,P=0.001)、住院费用(56508.15元vs.41702.85元,P<0.001)明显增加,但全髋关节置换组死亡率低于半髋关节置换组(36%vs.57%,HR=0.44,95%CI:0.23-0.87,P=0.018),平均生存时间长于半髋关节置换组(59.4个月vs.43.7个月,P=0.024);③两组患者在术后住院时间、术前术后营养指标、术后整体并发症发生率上,差异均无显著性意义(P>0.05);但在术后疼痛方面,半髋关节置换组疼痛发生率明显高于全髋关节置换组(24%vs.7%,P=0.035);④整体来看,全髋关节置换具有更好的长期预后生存效果,但对于身体素质差的患者则更适合行半髋关节置换;同时,术后的疼痛可能很大程度上会对患者髋关节置换后的生活质量及存活时间产生影响。