Timely detection of dynamical complexity changes in natural and man-made systems has deep scientific and practical meanings. We introduce a complexity measure for time series： the base-scale entropy. The definition d...Timely detection of dynamical complexity changes in natural and man-made systems has deep scientific and practical meanings. We introduce a complexity measure for time series： the base-scale entropy. The definition directly applies to arbitrary real-word data. We illustrate our method on a practical speech signal and in a theoretical chaotic system. The results show that the simple and easily calculated measure of base-scale entropy can be effectively used to detect qualitative and quantitative dynamical changes.展开更多
Objective:To explore the effect of nursing intervention based on Caprini risk assessment scale for venous thromboembolism(VTE)in perioperative patients with liver cancer.Methods:A total of 128 hepatocellular cancer(HC...Objective:To explore the effect of nursing intervention based on Caprini risk assessment scale for venous thromboembolism(VTE)in perioperative patients with liver cancer.Methods:A total of 128 hepatocellular cancer(HCC)patients who were hospitalized in our department from January 2021 to March 2022 and met the research criteria were selected.According to odd and even numbers in the order of inclusion,64 cases were divided into two groups:a control group and an observation group.The control group received routine nursing intervention during perioperative period,while the observation group received nursing intervention based on Caprini risk assessment scale for VTE.The incidence of VTE and complications were compared between the two groups.Results:The incidence of VTE and postoperative complications in the observation group were lower than those in the control group(P<0.05).Conclusion:Nursing intervention based on Caprini risk assessment scale for VTE can reduce the incidence of perioperative deep vein thrombosis and complications in patients with liver cancer;thus,it is worthy of clinical application.展开更多
The closure of a turbulence field is a longstanding fundamental problem, while most closure models are introduced in spectral space. Inspired by Chou＇s quasi-normal closure method in spectral space, we propose an ana...The closure of a turbulence field is a longstanding fundamental problem, while most closure models are introduced in spectral space. Inspired by Chou＇s quasi-normal closure method in spectral space, we propose an analytical closure model for isotropic turbulence based on the extended scale similarity theory of the velocity structure function in physical space. The assumptions and certain approximations are justified with direct numerical simulation. The asymptotic scaling properties are reproduced by this new closure method, in comparison to the classical Batchelor model.展开更多
Many real-world networks are found to be scale-free. However, graph partition technology, as a technology capable of parallel computing, performs poorly when scale-free graphs are provided. The reason for this is that...Many real-world networks are found to be scale-free. However, graph partition technology, as a technology capable of parallel computing, performs poorly when scale-free graphs are provided. The reason for this is that traditional partitioning algorithms are designed for random networks and regular networks, rather than for scale-free networks. Multilevel graph-partitioning algorithms are currently considered to be the state of the art and are used extensively. In this paper, we analyse the reasons why traditional multilevel graph-partitioning algorithms perform poorly and present a new multilevel graph-partitioning paradigm, top down partitioning, which derives its name from the comparison with the traditional bottom-up partitioning. A new multilevel partitioning algorithm, named betweenness-based partitioning algorithm, is also presented as an implementation of top-down partitioning paradigm. An experimental evaluation of seven different real-world scale-free networks shows that the betweenness-based partitioning algorithm significantly outperforms the existing state-of-the-art approaches.展开更多
Background: Promotion of Evidence-Based Practice (EBP) in nursing appears to be developing slowly. Research indicates that nurses’ beliefs in EBP may play an even more significant role than knowledge and resources in...Background: Promotion of Evidence-Based Practice (EBP) in nursing appears to be developing slowly. Research indicates that nurses’ beliefs in EBP may play an even more significant role than knowledge and resources in making implementation feasible. To address this issue, measurement of nurses’ beliefs regarding EBP is paramount. Aims and objectives: This study explores the internal consistency reliability and the construct factor structure of the Norwegian version of the original Evidence-Based Practice Beliefs Scale (EBP-BS). Methods: The study has a Non-experimental exploratory survey design. A Norwegian translation of the EBP-BS was tested in a convenience sample of 118 healthcare professionals (95% nurses) attending a continuing education program at a University College in Norway. The response rate was 95% (n = 112). The internal consistency of the scale was measured by Cronbach’s alpha, and an explorative Principal Component Analysis (PCA) was used to explore the construct structure. Results: The overall internal consistency of the EBP-BS was acceptable. The PCA indicated a four-factor structure. The psychometric properties of two of the factors were too weak for expanding to a four-factor model. Based on our investigation of the EBP-BS, we suggest a two-factor structure model. The factors were named 1) General knowledge and confidence concerning EBP and 2) Task specific beliefs in EBP. This finding differs from previous results that indicated a unidimensional structure. Conclusion: As a starting point, reliable and valid measurement of nurses’ beliefs about EBP is required in order to identify possible obstacles and to optimize implementation in the individual clinical setting. Our results indicate that the EBP-BS has a two-factor structure. Further exploration of the factor structure is needed. Further empirical research may contribute to the resolving of controversies concerning basic understandings of the concept of EBP.展开更多
Successful modeling and/or design of engineering systems often requires one to address the impact of multiple ＂design variables＂ on the prescribed outcome.There are often multiple,competing objectives based on which...Successful modeling and/or design of engineering systems often requires one to address the impact of multiple ＂design variables＂ on the prescribed outcome.There are often multiple,competing objectives based on which we assess the outcome of optimization.Since accurate,high fidelity models are typically time consuming and computationally expensive,comprehensive evaluations can be conducted only if an efficient framework is available.Furthermore,informed decisions of the model/hardware＇s overall performance rely on an adequate understanding of the global,not local,sensitivity of the individual design variables on the objectives.The surrogate-based approach,which involves approximating the objectives as continuous functions of design variables from limited data,offers a rational framework to reduce the number of important input variables,i.e.,the dimension of a design or modeling space.In this paper,we review the fundamental issues that arise in surrogate-based analysis and optimization,highlighting concepts,methods,techniques,as well as modeling implications for mechanics problems.To aid the discussions of the issues involved,we summarize recent efforts in investigating cryogenic cavitating flows,active flow control based on dielectric barrier discharge concepts,and lithium（Li）-ion batteries.It is also stressed that many multi-scale mechanics problems can naturally benefit from the surrogate approach for ＂scale bridging.＂展开更多
Nickel-based superalloys have become the key materials of micro-parts depending on excellent mechanical properties at high temperatures.The plastic deformation behavior is difficult to predict due to the occurrence of...Nickel-based superalloys have become the key materials of micro-parts depending on excellent mechanical properties at high temperatures.The plastic deformation behavior is difficult to predict due to the occurrence of size effect on the mesoscopic scale.In this paper,the effect of specimen diameter to grain size ratio(D/d)on the flow stress and inhomogeneous plastic deformation behavior in compression of nickel-based superalloy cylindrical specimens was investigated on the mesoscopic scale.The results showed that when D/d is less than 9.7,the flow stress increases with the grain size.Aiming at this phenomenon,a flow stress size effect model considering compressive strain partitioning was established.The calculated flow stress values agree well with the experimental values,thus revealing the effect of D/d on the flow stress in compression of nickel-base superalloy on the mesoscopic scale.The inhomogeneous plastic deformation during compression deformation increases with the grain size.The end surface profiles evolve from a regular circular shape to an irregular shape with the grain size.The surface folding phenomenon occurs only in partially compressed specimen with a few grains across the diameter.Crystal plasticity finite-element(CPFE)simulation of compression deformation on the mesoscopic scale real-time displayed the evolution of microstructure.The study of this paper has important guiding significance for understanding the influence of D/d on the compression deformation behavior of nickel-based superalloy on the mesoscopic scale.展开更多
目的系统评价中医证候疗效评价量表的方法学质量及测量学特性,为中医临床实践选用高质量评估工具提供参考。方法检索中国知网、万方数据库、维普网、中国生物医学文献数据库、PubMed、Cochrane Library、Embase和Web of Science自建库至...目的系统评价中医证候疗效评价量表的方法学质量及测量学特性,为中医临床实践选用高质量评估工具提供参考。方法检索中国知网、万方数据库、维普网、中国生物医学文献数据库、PubMed、Cochrane Library、Embase和Web of Science自建库至2025年4月2日收录的涉及中医证候疗效评价量表测量学特性评价的文献,提取资料,依据健康测量工具共识标准(COSMIN)评估纳入量表的方法学质量及测量学特性,并结合证据分级标准形成相应推荐意见。结果共纳入46项研究,涵盖22个普适性证候疗效评价量表和24个疾病特异性证候疗效评价量表,均未报告跨文化效度和测量误差。推荐等级显示,2个量表符合A级推荐,建议临床使用;38个量表为B级推荐,提示存在潜在应用价值但需进一步验证;6个量表为C级推荐,建议进一步完善。结论现有中医证候疗效评价量表存在方法学质量参差不齐、测量学特性报告不完整及修订重视度不足等问题,未来应加强中医证候量表研制的规范化设计,完善关键测量属性的验证流程,注重对量表进行动态修订,为证候疗效的精准评价提供高质量工具支持。展开更多
The oxidation behavior of a novel multi-element alloyed Ti2A1Nb-based alloy （Ti-22Al-25Nb-1Mo-1V-1Zr-0.2Si） was studied in the temperature range of 650-850℃. X-ray diffraction （XRD） and scanning electron microsco...The oxidation behavior of a novel multi-element alloyed Ti2A1Nb-based alloy （Ti-22Al-25Nb-1Mo-1V-1Zr-0.2Si） was studied in the temperature range of 650-850℃. X-ray diffraction （XRD） and scanning electron microscopy （SEM） equipped with an energy-dispersive spectroscopy （EDS） were used to identify the phase constituents and microstructure of the scales formed on the specimens after oxidation at different temperatures. Isothermal oxidation tests show that the oxidation rate of the alloyed TiEAlNb-based alloy is obviously reduced at all temperatures, and the mass gains are very low for this alloy in comparison with those of Ti-22Al-25Nb alloy. The alloying elements Mo, V, Zr and Si have an obvious affect on the oxidation products of the alloys. The improved oxidation resistance for the alloy is ascribed to the introduction of Mo, V, Zr and Si elements, which are beneficial to the selective oxidation of Al to form protective oxides while are disadvantage of the formation of poor oxidation resistance oxides such as AlNbO4.展开更多
The oxidation behaviors of two kinds of low segregation Ht-Cr-Al based superalloys have been studied between 1000-1100℃, and compared with that of general Mt-Cr-Al based superalloys. The results indicated that the si...The oxidation behaviors of two kinds of low segregation Ht-Cr-Al based superalloys have been studied between 1000-1100℃, and compared with that of general Mt-Cr-Al based superalloys. The results indicated that the simultaneous additions of 0.1 wt% S and 0. 1 wt% Zr to low segregation alloys increase the oxidation rate of Al2O3-forming alloy and improve the scale adherence. The addition of 0.1 wt% Zr can ,minimize the negative effects of S on the adherence of Al2O3 scale. Low amounts of S(≤50 ppm wt) have no obviously negative effects on the adherence of Cr2O3 scale formed on one of the low segregation superalloys.展开更多
文摘Timely detection of dynamical complexity changes in natural and man-made systems has deep scientific and practical meanings. We introduce a complexity measure for time series： the base-scale entropy. The definition directly applies to arbitrary real-word data. We illustrate our method on a practical speech signal and in a theoretical chaotic system. The results show that the simple and easily calculated measure of base-scale entropy can be effectively used to detect qualitative and quantitative dynamical changes.
文摘Objective:To explore the effect of nursing intervention based on Caprini risk assessment scale for venous thromboembolism(VTE)in perioperative patients with liver cancer.Methods:A total of 128 hepatocellular cancer(HCC)patients who were hospitalized in our department from January 2021 to March 2022 and met the research criteria were selected.According to odd and even numbers in the order of inclusion,64 cases were divided into two groups:a control group and an observation group.The control group received routine nursing intervention during perioperative period,while the observation group received nursing intervention based on Caprini risk assessment scale for VTE.The incidence of VTE and complications were compared between the two groups.Results:The incidence of VTE and postoperative complications in the observation group were lower than those in the control group(P<0.05).Conclusion:Nursing intervention based on Caprini risk assessment scale for VTE can reduce the incidence of perioperative deep vein thrombosis and complications in patients with liver cancer;thus,it is worthy of clinical application.
文摘The closure of a turbulence field is a longstanding fundamental problem, while most closure models are introduced in spectral space. Inspired by Chou＇s quasi-normal closure method in spectral space, we propose an analytical closure model for isotropic turbulence based on the extended scale similarity theory of the velocity structure function in physical space. The assumptions and certain approximations are justified with direct numerical simulation. The asymptotic scaling properties are reproduced by this new closure method, in comparison to the classical Batchelor model.
基金supported by the National Science Foundation for Distinguished Young Scholars of China(Grant Nos.61003082 and 60903059)the National Natural Science Foundation of China(Grant No.60873014)the Foundation for Innovative Research Groups of the National Natural Science Foundation of China(Grant No.60921062)
文摘Many real-world networks are found to be scale-free. However, graph partition technology, as a technology capable of parallel computing, performs poorly when scale-free graphs are provided. The reason for this is that traditional partitioning algorithms are designed for random networks and regular networks, rather than for scale-free networks. Multilevel graph-partitioning algorithms are currently considered to be the state of the art and are used extensively. In this paper, we analyse the reasons why traditional multilevel graph-partitioning algorithms perform poorly and present a new multilevel graph-partitioning paradigm, top down partitioning, which derives its name from the comparison with the traditional bottom-up partitioning. A new multilevel partitioning algorithm, named betweenness-based partitioning algorithm, is also presented as an implementation of top-down partitioning paradigm. An experimental evaluation of seven different real-world scale-free networks shows that the betweenness-based partitioning algorithm significantly outperforms the existing state-of-the-art approaches.
文摘Background: Promotion of Evidence-Based Practice (EBP) in nursing appears to be developing slowly. Research indicates that nurses’ beliefs in EBP may play an even more significant role than knowledge and resources in making implementation feasible. To address this issue, measurement of nurses’ beliefs regarding EBP is paramount. Aims and objectives: This study explores the internal consistency reliability and the construct factor structure of the Norwegian version of the original Evidence-Based Practice Beliefs Scale (EBP-BS). Methods: The study has a Non-experimental exploratory survey design. A Norwegian translation of the EBP-BS was tested in a convenience sample of 118 healthcare professionals (95% nurses) attending a continuing education program at a University College in Norway. The response rate was 95% (n = 112). The internal consistency of the scale was measured by Cronbach’s alpha, and an explorative Principal Component Analysis (PCA) was used to explore the construct structure. Results: The overall internal consistency of the EBP-BS was acceptable. The PCA indicated a four-factor structure. The psychometric properties of two of the factors were too weak for expanding to a four-factor model. Based on our investigation of the EBP-BS, we suggest a two-factor structure model. The factors were named 1) General knowledge and confidence concerning EBP and 2) Task specific beliefs in EBP. This finding differs from previous results that indicated a unidimensional structure. Conclusion: As a starting point, reliable and valid measurement of nurses’ beliefs about EBP is required in order to identify possible obstacles and to optimize implementation in the individual clinical setting. Our results indicate that the EBP-BS has a two-factor structure. Further exploration of the factor structure is needed. Further empirical research may contribute to the resolving of controversies concerning basic understandings of the concept of EBP.
文摘Successful modeling and/or design of engineering systems often requires one to address the impact of multiple ＂design variables＂ on the prescribed outcome.There are often multiple,competing objectives based on which we assess the outcome of optimization.Since accurate,high fidelity models are typically time consuming and computationally expensive,comprehensive evaluations can be conducted only if an efficient framework is available.Furthermore,informed decisions of the model/hardware＇s overall performance rely on an adequate understanding of the global,not local,sensitivity of the individual design variables on the objectives.The surrogate-based approach,which involves approximating the objectives as continuous functions of design variables from limited data,offers a rational framework to reduce the number of important input variables,i.e.,the dimension of a design or modeling space.In this paper,we review the fundamental issues that arise in surrogate-based analysis and optimization,highlighting concepts,methods,techniques,as well as modeling implications for mechanics problems.To aid the discussions of the issues involved,we summarize recent efforts in investigating cryogenic cavitating flows,active flow control based on dielectric barrier discharge concepts,and lithium（Li）-ion batteries.It is also stressed that many multi-scale mechanics problems can naturally benefit from the surrogate approach for ＂scale bridging.＂
基金the financial support of the project from the National Natural Science Foundation of China(Grant No.51575129)Key Research and Development Program of Shandong Province(Grant No.2016GGX102026)the Training Program of the Major Research Plan of the National Natural Science Foundation of China(Grant No.91860129).
文摘Nickel-based superalloys have become the key materials of micro-parts depending on excellent mechanical properties at high temperatures.The plastic deformation behavior is difficult to predict due to the occurrence of size effect on the mesoscopic scale.In this paper,the effect of specimen diameter to grain size ratio(D/d)on the flow stress and inhomogeneous plastic deformation behavior in compression of nickel-based superalloy cylindrical specimens was investigated on the mesoscopic scale.The results showed that when D/d is less than 9.7,the flow stress increases with the grain size.Aiming at this phenomenon,a flow stress size effect model considering compressive strain partitioning was established.The calculated flow stress values agree well with the experimental values,thus revealing the effect of D/d on the flow stress in compression of nickel-base superalloy on the mesoscopic scale.The inhomogeneous plastic deformation during compression deformation increases with the grain size.The end surface profiles evolve from a regular circular shape to an irregular shape with the grain size.The surface folding phenomenon occurs only in partially compressed specimen with a few grains across the diameter.Crystal plasticity finite-element(CPFE)simulation of compression deformation on the mesoscopic scale real-time displayed the evolution of microstructure.The study of this paper has important guiding significance for understanding the influence of D/d on the compression deformation behavior of nickel-based superalloy on the mesoscopic scale.
文摘目的系统评价中医证候疗效评价量表的方法学质量及测量学特性,为中医临床实践选用高质量评估工具提供参考。方法检索中国知网、万方数据库、维普网、中国生物医学文献数据库、PubMed、Cochrane Library、Embase和Web of Science自建库至2025年4月2日收录的涉及中医证候疗效评价量表测量学特性评价的文献,提取资料,依据健康测量工具共识标准(COSMIN)评估纳入量表的方法学质量及测量学特性,并结合证据分级标准形成相应推荐意见。结果共纳入46项研究,涵盖22个普适性证候疗效评价量表和24个疾病特异性证候疗效评价量表,均未报告跨文化效度和测量误差。推荐等级显示,2个量表符合A级推荐,建议临床使用;38个量表为B级推荐,提示存在潜在应用价值但需进一步验证;6个量表为C级推荐,建议进一步完善。结论现有中医证候疗效评价量表存在方法学质量参差不齐、测量学特性报告不完整及修订重视度不足等问题,未来应加强中医证候量表研制的规范化设计,完善关键测量属性的验证流程,注重对量表进行动态修订,为证候疗效的精准评价提供高质量工具支持。
基金financially supported by the National Natural Science Foundation of China (No. 51601146)the China Postdoctoral Science Foundation (No. 2017M613234)
文摘The oxidation behavior of a novel multi-element alloyed Ti2A1Nb-based alloy （Ti-22Al-25Nb-1Mo-1V-1Zr-0.2Si） was studied in the temperature range of 650-850℃. X-ray diffraction （XRD） and scanning electron microscopy （SEM） equipped with an energy-dispersive spectroscopy （EDS） were used to identify the phase constituents and microstructure of the scales formed on the specimens after oxidation at different temperatures. Isothermal oxidation tests show that the oxidation rate of the alloyed TiEAlNb-based alloy is obviously reduced at all temperatures, and the mass gains are very low for this alloy in comparison with those of Ti-22Al-25Nb alloy. The alloying elements Mo, V, Zr and Si have an obvious affect on the oxidation products of the alloys. The improved oxidation resistance for the alloy is ascribed to the introduction of Mo, V, Zr and Si elements, which are beneficial to the selective oxidation of Al to form protective oxides while are disadvantage of the formation of poor oxidation resistance oxides such as AlNbO4.
文摘The oxidation behaviors of two kinds of low segregation Ht-Cr-Al based superalloys have been studied between 1000-1100℃, and compared with that of general Mt-Cr-Al based superalloys. The results indicated that the simultaneous additions of 0.1 wt% S and 0. 1 wt% Zr to low segregation alloys increase the oxidation rate of Al2O3-forming alloy and improve the scale adherence. The addition of 0.1 wt% Zr can ,minimize the negative effects of S on the adherence of Al2O3 scale. Low amounts of S(≤50 ppm wt) have no obviously negative effects on the adherence of Cr2O3 scale formed on one of the low segregation superalloys.
