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Accelerated design of high-performance Mg-Mn-based magnesium alloys based on novel bayesian optimization
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作者 Xiaoxi Mi Lili Dai +4 位作者 Xuerui Jing Jia She Bjørn Holmedal Aitao Tang Fusheng Pan 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第2期750-766,共17页
Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing ... Magnesium(Mg),being the lightest structural metal,holds immense potential for widespread applications in various fields.The development of high-performance and cost-effective Mg alloys is crucial to further advancing their commercial utilization.With the rapid advancement of machine learning(ML)technology in recent years,the“data-driven''approach for alloy design has provided new perspectives and opportunities for enhancing the performance of Mg alloys.This paper introduces a novel regression-based Bayesian optimization active learning model(RBOALM)for the development of high-performance Mg-Mn-based wrought alloys.RBOALM employs active learning to automatically explore optimal alloy compositions and process parameters within predefined ranges,facilitating the discovery of superior alloy combinations.This model further integrates pre-established regression models as surrogate functions in Bayesian optimization,significantly enhancing the precision of the design process.Leveraging RBOALM,several new high-performance alloys have been successfully designed and prepared.Notably,after mechanical property testing of the designed alloys,the Mg-2.1Zn-2.0Mn-0.5Sn-0.1Ca alloy demonstrates exceptional mechanical properties,including an ultimate tensile strength of 406 MPa,a yield strength of 287 MPa,and a 23%fracture elongation.Furthermore,the Mg-2.7Mn-0.5Al-0.1Ca alloy exhibits an ultimate tensile strength of 211 MPa,coupled with a remarkable 41%fracture elongation. 展开更多
关键词 Mg-Mn-based alloys high-performance Alloy design Machine learning Bayesian optimization
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Expansion Performance and Microstructure of High-performance Concrete using Differently Scaled MgO Agents and Mineral Powder
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作者 TIAN Changjin WANG Youzhi +1 位作者 QIU Kai YANG Qilin 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第6期1335-1347,共13页
To investigate the assumptions proposed in this paper,the evolution law governing the strength and expansion performance of MgO and nano-MgO micro-expansive concrete in the environment of mineral powder was firstly ob... To investigate the assumptions proposed in this paper,the evolution law governing the strength and expansion performance of MgO and nano-MgO micro-expansive concrete in the environment of mineral powder was firstly observed in this study.Secondly,SEM,XRD,and TG-DSC microscopic tests were conducted to reveal the effects of the active mineral-powder admixture on the hydration degree and expansion performance of MgO and nano-MgO in HPC.Our experimental results successfully verified our hypothesis,which indicated that the expansion performance of macro-MgO and nano-MgO was indeed depressed by the addition of active mineral power admixtures,even though the mechanical property of concrete composites was effectively improved.Furthermore,the hydration test also demonstrated the negative interference on the mineral powders,which was induced by the expansion agents.It is found the amounts of hydrates tend to decrease because the mineral powder ratio reaches and exceeds 40%.Moreover,it is also concluded the effect of expansion agents is governed by the alkalinity cement paste,especially for the nano-MgO.In other words,the expansion performance of nano-MgO will vary more obviously with the hydration process,than MgO.The results of this study provide that effective experimental and theoretical data support the hydration-inhibition mechanism of magnesium expansive agents. 展开更多
关键词 MGO Nano-MgO mineral powders high-performance concrete expansive agents MICROSTRUCTURES
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基于TeamSTEPPS风险防控模式的护理在气管切开患者感染防控中的应用
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作者 裴中霞 李伟 +5 位作者 刘莉莉 李志萍 江云兰 朱育琼 刘丹 李小月 《中国中西医结合耳鼻咽喉科杂志》 2024年第1期73-76,共4页
目的 探讨基于强化临床表现和医疗安全的团队策略与工具(Team STEPPS)?风险防控模式的护理在气管切开患者感染防控中的应用。方法 选取2021年1月~2022年12月在安庆市第一人民医院入住的82例气管切开患者。其中2021年41例为对照组,实施... 目的 探讨基于强化临床表现和医疗安全的团队策略与工具(Team STEPPS)?风险防控模式的护理在气管切开患者感染防控中的应用。方法 选取2021年1月~2022年12月在安庆市第一人民医院入住的82例气管切开患者。其中2021年41例为对照组,实施常规的气管切开术后护理;2022年41例为观察组,在常规的气管切开术后护理基础上,基于Team STEPPS风险防控模式的护理措施。比较两组患者感染高风险事件发生率、医护合作情况、患者满意度。结果 观察组患者感染高风险事件发生率低于对照组,医护合作得分、患者满意度明显高于对照组(P<0.05)。结论 基于Team STEPPS风险防控模式的护理在气管切开患者感染防控中应用,降低了感染风险发生的事件、医护合作程度明显增强,患者的满意度提高显著,值得在临床推广应用。 展开更多
关键词 团队策略与工具 气管切开 感染防控 风险评估
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Development of an Information-Based Leadership Evaluation Index System for School Management Teams:A Comprehensive Approach
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作者 Wei Li Fang Liu 《Journal of Contemporary Educational Research》 2024年第4期35-40,共6页
In the context of educational informatization reform,there are many uncertain factors in the process of education development.To optimize the educational environment so that it can be effectively combined with informa... In the context of educational informatization reform,there are many uncertain factors in the process of education development.To optimize the educational environment so that it can be effectively combined with information technology,teachers need to change their teaching ideas,strengthen the school’s own adaptability to informatization,and promote the development of informatization construction in schools.As a branch of information leadership,the management team should establish an evaluation index system for information leadership in order to ensure the construction of school informatization,so as to provide a boost for the integration of school resources and information technology.Based on the overview and connotation of information-based leadership of the management team,this paper explores the construction of an evaluation index system of information-based leadership of the school management team,aiming to provide references for the research of relevant personnel in the future. 展开更多
关键词 School management team Information-based leadership Evaluation index system
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Evaluation of Attending Medical Teams and Their Impact on the DRG Components of Cholecystectomy
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作者 Qi Zhang Chuanyu Chen +3 位作者 Yan Wang Huachen Fan Wenping Sun Jing Deng 《Journal of Clinical and Nursing Research》 2024年第1期113-118,共6页
Objective:This study assessed the role of the attending medical team in the cost control of the cholecystectomy DRG components.Methods:The association between team structure,workflow,and treatment outcomes was analyze... Objective:This study assessed the role of the attending medical team in the cost control of the cholecystectomy DRG components.Methods:The association between team structure,workflow,and treatment outcomes was analyzed using a mixed-methods approach combining quantitative data and qualitative interviews from 628 patients.Results:Inter-professional teamwork significantly affected length of stay,treatment costs,and recurrence rates,with experienced teams performing better in terms of emergency response and collaborative efficiency.Patient satisfaction was generally high,indicating that good teamwork enhances treatment outcomes.Significance:The study highlights the importance of optimizing team configuration to improve the quality,efficiency,and cost control of healthcare. 展开更多
关键词 Attending medical team intervention Diagnosis-related group(DRG)system Healthcare quality and efficiency Interprofessional collaboration
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敦煌文化在数字领域中的设计研究——以Team Lab为例
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作者 严春露 闫朝群 +1 位作者 闵元元 郭译蔓 《鞋类工艺与设计》 2024年第6期45-47,共3页
敦煌壁画在中国古代艺术中占据着至关重要的地位,其独特的艺术风格和丰富的文化内涵使其成为中国古代文化的瑰宝之一。而提及对敦煌壁画的保护和传承,“数字敦煌”居功至伟。在此基础上,敦煌壁画的数字艺术设计得以蓬勃发展。本文旨在... 敦煌壁画在中国古代艺术中占据着至关重要的地位,其独特的艺术风格和丰富的文化内涵使其成为中国古代文化的瑰宝之一。而提及对敦煌壁画的保护和传承,“数字敦煌”居功至伟。在此基础上,敦煌壁画的数字艺术设计得以蓬勃发展。本文旨在探究敦煌壁画在数字领域下的设计研究,通过对日本Team Lab及其作品的分析,探索敦煌文化在数字领域中的设计创新实践及其所面临的挑战,并展望其未来的发展。 展开更多
关键词 敦煌壁画 数字化设计 数字媒体艺术 teamlab
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TeamSTEPPS模式在消化内镜室综合管理中的应用效果
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作者 李雪蕊 杨海霞 +2 位作者 刘冬冬 崔艳艳 郑晓永 《河南医学研究》 CAS 2024年第9期1696-1699,共4页
目的探讨提高医疗质量与患者安全的团队策略和工具包(TeamSTEPPS)模式在消化内镜室综合管理中的应用效果。方法选取2021年6月至2022年2月河南省直第三人民医院消化内镜室收治的118例肠息肉患者作为对照组,接受常规管理;选取2022年3—9... 目的探讨提高医疗质量与患者安全的团队策略和工具包(TeamSTEPPS)模式在消化内镜室综合管理中的应用效果。方法选取2021年6月至2022年2月河南省直第三人民医院消化内镜室收治的118例肠息肉患者作为对照组,接受常规管理;选取2022年3—9月河南省直第三人民医院消化内镜室收治的126例肠息肉患者作为研究组,接受TeamSTEPPS模式综合管理。对比两组护理风险、不良事件发生率、护理质量、患者满意度。结果两组管理后护理风险评分均高于管理前(P<0.05),研究组管理后急救药品、消毒隔离、护理安全、仪器使用以及岗位安全等护理风险评分高于对照组(P<0.05);研究组不良事件发生率低于对照组(P<0.05);两组管理后护理质量评分高于管理前(P<0.05),管理后,相较于对照组,研究组技能操作、专科护理、病房护理、基础护理、消毒护理及分级护理评分均较高(P<0.05);研究组患者对服务态度、手术护理、专业素质等护理满意度高于对照组(P<0.05)。结论TeamSTEPPS模式下综合管理有助于减少消化内镜室护理不良事件发生,提高护理质量与患者对护理满意度。 展开更多
关键词 提高医疗质量与患者安全的团队策略和工具包 综合管理 消化内镜室 护理不良事件 护理质量
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Recent developments and applications on high-performance cast magnesium rare-earth alloys 被引量:42
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作者 Guohua Wu Cunlong Wang +1 位作者 Ming Sun Wenjiang Ding 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2021年第1期1-20,共20页
During the past decades,with the increasing demands in lightweight structural materials,Mg alloys with low density and high performance have been extensively investigated and partly applied in some industries.Especial... During the past decades,with the increasing demands in lightweight structural materials,Mg alloys with low density and high performance have been extensively investigated and partly applied in some industries.Especially when rare earth(RE)elements are added as major alloying elements to Mg alloys,the alloy strength and creep resistance are greatly improved,which have promoted several series of Mg-RE alloys.This paper reviews the progress and developments of high-performance Mg-RE alloys in recent years with emphasis on cast alloys.The main contents include the alloy design,melt purification,grain refinement,castability,novel liquid casting and semisolid forming approaches,and the industrial applications or trials made of Mg-RE alloys.The review will provide insights for future developments of new alloys,techniques and applications of Mg alloys. 展开更多
关键词 Magnesium alloys Rare-earth elements high-performance DEVELOPMENTS Applications CAST
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Plasma free amino acid profiling of esophageal cancer using high-performance liquid chromatography spectroscopy 被引量:11
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作者 Hong Ma Ayshamgul Hasim +3 位作者 Batur Mamtimin Bin Kong Hai-Ping Zhang Ilyar Sheyhidin 《World Journal of Gastroenterology》 SCIE CAS 2014年第26期8653-8659,共7页
AIM:To perform plasma free amino acid(PFAA)profiling of esophageal squamous cell carcinoma(ESCC)patients at different pathological stages and healthy subjects.METHODS:Plasma samples from ESCC patients(n=51)and healthy... AIM:To perform plasma free amino acid(PFAA)profiling of esophageal squamous cell carcinoma(ESCC)patients at different pathological stages and healthy subjects.METHODS:Plasma samples from ESCC patients(n=51)and healthy control adults(n=60)were analyzed by high-performance liquid chromatography(HPLC).The ESCC patients included moderate/poorly-differentiation(n=24),lymph node metastasis(n=17)and clinical stage>Ib2(n=36).Partial least squares discriminant analysis was performed to demonstrate that the PFAA metabolic patterns enabled discrimination between ESCC patients and controls,and the Student t test was applied to assess significant differences in PFAA concentrations between the two groups.RESULTS:There were significant differences in the PFAA profiles between controls and ESCC patients.Compared with healthy controls,the levels of Asp,Glu,Gly,His,Thr,Tau,Ala,Met,Ile,Leu,and Phe were decreased in ESCC patients,but Cys was increased.There exists a strong correlation between PFAA profiles and clinicopathological characteristics in ESCC patients.The levels of many PFAAs(i.e.,Glu,Asp,Ser,Gly,Tau,Ala,Tyr,Val,Ile,and Leu)were related to pathological grading,lymph node metastasis,and ESCC clinical stage.Very good discrimination between ESCC patients and control subjects was achieved by multivariate modeling of plasma profiles.CONCLUSION:HPLC-based plasma profiling analysis was shown to be an effective approach to differentiate between ESCC patients and controls.PFAA profiles may have potential value for screening or diagnosing ESCC. 展开更多
关键词 Metabolomics high-performance LIQUID chromatograph
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High-Performance and Multifunctional Cement-Based Composite Material 被引量:10
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作者 Victor C. Li 《Engineering》 SCIE EI 2019年第2期250-260,共11页
Concrete is a continuously evolving material, and even the definition of high-performance concrete has changed over time. In this paper, high-performance characteristics of concrete material are considered to be those... Concrete is a continuously evolving material, and even the definition of high-performance concrete has changed over time. In this paper, high-performance characteristics of concrete material are considered to be those that support the desirable durability, resilience, and sustainability of civil infrastructure that directly impact our quality of life. It is proposed that high-performance material characteristics include tensile ductility, autogenous crack-width control, and material “greenness.” Furthermore, smart functionalities should be aimed at enhancing infrastructure durability, resilience, and sustainability by responding to changes in the surrounding environment of the structure in order to perform desirable functions, thus causing the material to behave in a manner more akin to certain biological materials. Based on recent advances in engineered cementitious composites (ECCs), this paper suggests that concrete embodying such high-performance characteristics and smart multifunctionalities can be designed, and holds the potential to fulfill the expected civil infrastructure needs of the 21st century. Highlights of relevant properties of ECCs are provided, and directions for necessary future research are indicated. 展开更多
关键词 high-performance concrete MULTIFUNCTION Smart CEMENT-BASED composite Durability RESILIENCE Sustainability Infrastructure
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Advancements in the preparation of high-performance liquid chromatographic organic polymer monoliths for the separation of small-molecule drugs 被引量:5
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作者 Xiali Ding Jing Yang Yuming Dong 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2018年第2期75-85,共11页
The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographer... The various advantages of organic polymer monoliths, including relatively simple preparation processes,abundant monomer availability, and a wide application range of pH, have attracted the attention of chromatographers. Organic polymer monoliths prepared by traditional methods only have macropores and mesopores, and micropores of less than 50 nm are not commonly available. These typical monoliths are suitable for the separation of biological macromolecules such as proteins and nucleic acids, but their ability to separate small molecular compounds is poor. In recent years, researchers have successfully modified polymer monoliths to achieve uniform compact pore structures. In particular, microporous materials with pores of 50 nm or less that can provide a large enough surface area are the key to the separation of small molecules. In this review, preparation methods of polymer monoliths for high-performance liquid chromatography, including ultra-high cross-linking technology, post-surface modification, and the addition of nanomaterials, are discussed. Modified monolithic columns have been used successfully to separate small molecules with obvious improvements in column efficiency. 展开更多
关键词 high-performance LIQUID chromatography Polymer MONOLITH Preparation methods Small molecules
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INFLUENCE OF MINERAL ADMIXTURES ON MECHANICAL PROPERTIES OF HIGH-PERFORMANCE CONCRETE 被引量:4
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作者 Ma, Baoguo Li, Jinzong Peng, Jun 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1999年第2期1-7,共7页
The improvements of the mechanical properties, including bulk density of fresh mixtures, elastic modulus, and compressive strengths of four high-performance concrete mixtures, made with the addition of fly ash, refine... The improvements of the mechanical properties, including bulk density of fresh mixtures, elastic modulus, and compressive strengths of four high-performance concrete mixtures, made with the addition of fly ash, refined ground blast - furnace microslag (microslag) and silica fume are studied. The concrete mixtures were determined based on the dispersion testing results. The study indicates that the elastic modulus at 28 and 91 days, and compressive strengths of the concretes are improved a lot when fly ash and microslag by 25 percent by weight of cement are added into the mixtures individually. The improvement is especially evident when silica fume by 5 percent and fly ash by 25 percent by weight of cement are added together into the mixture, while the fresh concrete mixture keeps a good workability. Through the analysis of chemically combined water ratios of the four mixtures at various hydration ages, it is found that the addition of all these mineral mixtures are beneficial to the hydration process, especially, at later stages, which might be one of the reasons for the improvement of mechanical properties. (Author abstract) 4 Refs. 展开更多
关键词 high-performance concrete mineral admixture mechanical properties
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High-performance self-assembly MnCo2O4 nanosheets for asymmetric supercapacitors 被引量:4
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作者 Jianwei Li Dongbin Xiong +2 位作者 Linzhe Wang Maleki Kheimeh Sari Hirbod Xifei Li 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2019年第10期66-72,共7页
In this study,MnCo2O4 nanosheets were proposed to be utilized as an electrode material for supercapacitors.A two-step hydrothermal method with post-annealing treatment was employed in preparation of the nanostructures... In this study,MnCo2O4 nanosheets were proposed to be utilized as an electrode material for supercapacitors.A two-step hydrothermal method with post-annealing treatment was employed in preparation of the nanostructures.MnCo2O4 electrode delivered a high specific capacitance of 2000 F g^-1 at 0.5 A g^-1,remarkable high-rate capability of 1150 F g^-1 at 20 A g^-1,and an excellent cycling stability of 92.3%at 5 A g^-1 after 5000 cycles.It is found that a three-electrode supercapacitor based on MnCo2O4 exhibits a promising electrochemical performance,better than the other similar materials,benefited from the synergistic effects of MnCo2O4 nanosheets.In fact,the self-assembly of nanosheets structure with high specific surface area and mesoporous structure can potentially enhance the electrochemical performance of supercapacitors. 展开更多
关键词 high-performance SELF-ASSEMBLY MnCo2O4 NANOSHEETS ASYMMETRIC SUPERCAPACITORS
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Determination of gouty arthritis' biomarkers in human urine using reversed-phase high-performance liquid chromatography 被引量:4
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作者 Lei-Wen Xiang Jing Li +1 位作者 Jin-Ming Lin Hai-Fang Li 《Journal of Pharmaceutical Analysis》 SCIE CAS 2014年第2期153-158,共6页
Creatinine, uric acid, hypoxanthine and xanthine are important diagnostic biomarkers in human urine for gouty arthritis or renal disease diacrisis. A simple method for simultaneous determination of these biomarkers in... Creatinine, uric acid, hypoxanthine and xanthine are important diagnostic biomarkers in human urine for gouty arthritis or renal disease diacrisis. A simple method for simultaneous determination of these biomarkers in urine based on reversed-phase high-performance liquid chromatography (RP-HPLC) with ultraviolet (UV) detector was proposed. After pretreatment by dilution, centrifugation and filtration, the biomarkers in urine samples were separated by ODS-BP column by elution with methanol/50 mM NaH2PO4 buffer solution at pH 5.26 (5:95). Good linearity between peak areas and concentrations of standards was obtained for the biomarkers with correlation coefficients in the range of 0.9957-0.9993. The proposed analytical method has satisfactory repeatability (the recovery of data in a range of creatinine, uric acid, hypoxanthine and xanthine was 93.49-97.90%, 95.38-96.45%, 112.46-115.78%and 90.82-97.13%with standard deviation of o5%, respectively) and the limits of detection (LODs, S/N Z 3) for creatinine, uric acid, hypoxanthine, and xanthine were 0.010, 0.025, 0.050 and 0.025 mg/L, respectively. The established method was proved to be simple, accurate, sensitive and reliable for the quantitation of gouty arthritis' biomarkers in human urine samples. The ratio of creatinine to uric acid was found to be a possible factor for assessment of gouty arthritis. 展开更多
关键词 Gouty arthritis CREATININE Uric acid HYPOXANTHINE XANTHINE high-performance liquid chromatography
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SYNTHESIS AND PROPERTIES OF NOVEL POLY(IMINO KETONE)S AS HIGH-PERFORMANCE POLYMERS 被引量:11
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作者 Chang, Guan-jun Luo, Xuan +1 位作者 Zhang, Lin Lin, Run-xiong 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2008年第1期55-61,共7页
Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation... Di(4-bromophenyl)ketone and various aromatic diamines as the monomers,a series of novel poly(imino ketone)s (PIKs)have been synthesized via palladium-catalyzed aryl amination,which is Hartwig-Buchwald polycondensation reaction.The structures of PIKs are characterized by means of elemental analysis,FT-IR,~1H-NMR and UV-Vis spectroscopy. The results show a good agreement with the proposed structure.The general properties of PIKs are studied by DSC,TG and wide-angle X-ray diffraction,the solubility behavior is... 展开更多
关键词 Di(4-bromophenyl)ketone Aromatic diamines Palladium-catalyzed aryl amination high-performance Poly(imino ketone)
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Influence of shrinkage-reducing admixture on drying shrinkage and mechanical properties of high-performance concrete 被引量:5
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作者 Nguyen Quangphu Jiang Linhua +2 位作者 Liu Jiaping Tian Qian Do Tienquan 《Water Science and Engineering》 EI CAS 2008年第4期67-74,共8页
High-performance concrete (HPC) has specific performance advantages over conventional concrete in strength and durability. HPC mixtures are usually produced with water/binder mass ratios (mW/mB) in the range of 0.... High-performance concrete (HPC) has specific performance advantages over conventional concrete in strength and durability. HPC mixtures are usually produced with water/binder mass ratios (mW/mB) in the range of 0.2-0.4, so volume changes of concrete as a result of drying, chemical reactions, and temperature change cannot be avoided. For these reasons, shrinkage and cracking are frequent phenomena. It is necessary to add some types of admixture for reduction of shrinkage and cracking of HPC. This study used a shrinkage-reducing admixture (SRA) for that purpose. Concrete was prepared with two different mW/mB (0.22 and 0.40) and four different mass fractions of SRA to binder (w(SRA) = 0%, 1%, 2%, and 4%). The mineral admixtures used for concrete mixes were: 25% fly ash (FA) and 25% slag by mass of binder for the mixture with mW/mB = 0.40, and 15% silica fume (SF) and 25% FA for the mixture with mW/mB = 0.22. Tests were conducted on 24 prismatic specimens, and shrinkage strains were measured through 120 days of drying. Compressive strength, splitting strength, and static modulus of elasticity were also determined. The results show that the SRA effectively reduces some mechanical properties of HPC. The reductions in compressive strength, splitting tensile strength, and elastic modulus of the concrete were 7%-24%, 9%-19%, and 5%-12%, respectively, after 90 days, compared to concrete mixtures without SRA. SRA can also help reduce drying shrinkage of concrete. The shrinkage strains of HPC with SRA were only as high as 41% of the average free shrinkage of concrete without SRA after 120 days of drying. 展开更多
关键词 high-performance concrete shrinkage-reducing admixture compressive strength elastic modulus splitting tensile strength drying shrinkage
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The effects of 12 weeks of functional strength training on muscle strength,volume and activity upon exposure to elevated Gz forces in high-performance aircraft personnel 被引量:5
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作者 Monika Rausch Frank Weber +3 位作者 Sven Kühn Carla Ledderhos Christoph Zinner Billy Sperlich 《Military Medical Research》 SCIE CSCD 2021年第4期481-489,共9页
Background:Technological advancements in modern military and acrobatic jet planes have resulted in extraordinary psychophysiological loads being exerted upon flying personnel,including inducing neck and back pain.The ... Background:Technological advancements in modern military and acrobatic jet planes have resulted in extraordinary psychophysiological loads being exerted upon flying personnel,including inducing neck and back pain.The purpose of this study was to examine the effects of 12 weeks of functional strength training on 1)the volume and strength of the neck and shoulder muscles and 2)muscular activity upon exposure to helmets of different masses and elevated Gz forces in a long-arm centrifuge in high-performance aircraft personnel.Methods:Eighteen participants underwent 12 weeks of functional strength training(n=12)or the control protocol(n=6)without additional strength training.Pre-and post-intervention tests included evaluations of isometric strength of the head extensor muscles,flexion,and lateral flexion and rotation,as well as magnetic resonance imaging(MRI)to measure the volume of the m.sternocleidomastoideus,m.trapezius,and deep neck muscles.Furthermore,during a long-arm centrifuge(+1.4 and+3Gz)protocol,the muscular activity levels of the m.sternocleidomastoideus,m.trapezius and m.erector spinae muscles were assessed without a flight helmet,with a helmet,and with a helmet and night vision goggles.Each participant’s perception of muscular strain was noted immediately after the long-arm centrifuge protocol.Results:The maximal isometric strength in all exercises and muscle volumes increased in the training group but not the control group(P<0.05).Relative muscle activity(%MVC)with a helmet decreased after the intervention in the training but not the control group(P=0.01).Relative muscle activity while wearing a helmet and night vision goggles was higher after intervention in the control group than in the training group(P<0.01).The perceived muscular strain of the neck muscles induced by the long-arm centrifuge did not differ between the groups.Conclusions:Twelve weeks of functional strength training improves the maximal isometric strength and volume of neck and shoulder muscles and leads to lower relative muscle activation upon exposure to elevated Gz forces in a long-arm centrifuge. 展开更多
关键词 Fighter pilots Long-arm centrifuge Muscular strain Strength training Neck muscle high-performance aircraft Gz forces
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Dispersive Liquid-liquid Microextraction Combined with High-performance Liquid Chromatography for the Determination of Clozapine and Chlorpromazine in Urine 被引量:3
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作者 陈静 熊朝梅 +1 位作者 阮金兰 苏邹 《Journal of Huazhong University of Science and Technology(Medical Sciences)》 SCIE CAS 2011年第2期277-284,共8页
A simple method has been proposed for the determination of clozapine (CLZ) and chlorpromazine (CPZ) in human urine by dispersive liquid-liquid microextraction (DLLME) in combination with high-performance liquid ... A simple method has been proposed for the determination of clozapine (CLZ) and chlorpromazine (CPZ) in human urine by dispersive liquid-liquid microextraction (DLLME) in combination with high-performance liquid chromatography-ultraviolet detector (HPLC-UV). All important variables influencing the extraction efficiency, such as pH, types of the extraction solvent and the disperser solvent and their volume, ionic strength and centrifugation time were investigated and optimized. Under the optimal conditions, the limit of detection (LODs) and quantification (LOQs) of the method were 13 and 39 ng/mL for CLZ, and 2 and 6 ng/mL for CPZ, respectively. The relative standard deviations (RSDs) of the targets were less than 5.1% (C=0.100 μg/mL, n=9). Good linear behaviors over the tested concentration ranges were obtained with the values of R20.999 for the targets. The absolute extraction efficiencies of CLZ and CPZ from the spiked blank urine samples were 98.3% and 97.8%, respectively. The applicability of the technique was validated by analyzing urine samples and the mean recoveries for spiked urine samples ranged from 93.3% to 105.0%. The method was successfully applied for the determination of CLZ and CPZ in real human urine. 展开更多
关键词 dispersive liquid-liquid microextraction CLOZAPINE CHLORPROMAZINE high-performance liquid chromatography human urine
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Assessment of early-age cracking of high-performance concrete in restrained ring specimens 被引量:2
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作者 Quang-phu NGUYEN Lin-hua JIANG Qiao ZHU 《Water Science and Engineering》 EI CAS 2010年第1期113-120,共8页
High-performance concrete (HPC) is stronger and more durable than conventional concrete. However, shrinkage and shrinkage cracking are common phenomena in HPC, especially early-age cracking. This study assessed earl... High-performance concrete (HPC) is stronger and more durable than conventional concrete. However, shrinkage and shrinkage cracking are common phenomena in HPC, especially early-age cracking. This study assessed early-age cracking of HPC for two mixtures using restrained ring tests. The two mixtures were produced with water/binder mass ratio (mw/mB) of 0.22 and 0.40, respectively. The results show that, with greater steel thickness, the higher degree of restraint resulted in a higher interface pressure and earlier cracking. With steel thickness of 6 mm, 19 mm, and 30 mm, the age of cracking were, respectively, 12 days, 8 days, and 5.4 days with the mw/mB = 0.22 mixture; and 22.5 days, 12.6 days, and 7.1 days with the mw/mB= 0.40 mixture. Cases of the same steel thickness show that the ring specimens with a thicker concrete wall crack later. With the mw/mB = 0.22 mixture, concrete walls with thicknesses of 37.5 mm, 75 mm, and 112.5 mm cracked at 3.4 days, 8.0 days, and 9.8 days, respectively; with the mw/mB = 0.40 mixture, the ages of cracking were 7.1 days, 12.6 days, and 16.0 days, respectively. 展开更多
关键词 high-performance concrete SHRINKAGE early-age cracking restrained ring test
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Studies on Chromatography Fingerprint of Hongqi by High-performance Liquid Chromatography 被引量:2
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作者 ShiLanFENG FangDiHU +2 位作者 JianXiongZHAO JingWenXU LiRenCHEN 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第11期1335-1338,共4页
Chromatography fingerprint (CFP) of 10 samples of hongqi were studied. 23 common peaks were analyzed, their average similarity was 97.29%. CFP were positioned with main index composition such as formononetin, calyco... Chromatography fingerprint (CFP) of 10 samples of hongqi were studied. 23 common peaks were analyzed, their average similarity was 97.29%. CFP were positioned with main index composition such as formononetin, calycosin and then the contents of index composition were determined. The character and exclusive of CFP of 10 samples of hongqi were clear. CFP and content determination of index composition of hongqi could be used to evaluate the quality of hongqi comprehensively. 展开更多
关键词 Hongqi chromatography fingerprint high-performance liquid chromatography.
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