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医学生手卫生认知状况调查与分析

上海医学 2018年第1期41卷 43-46页

作者：张军峰陶泠烨沈瑞红霍砚淼孙勇伟花荣上海交通大学医学院附属仁济医院胆胰外科上海200127 上海交通大学医学院附属仁济医院感染管理科上海200127

目的通过问卷调查了解医学生对手卫生科学的认知状况和重视程度,旨在为进一步的教学建议和系统性研究提供依据。方法选取上海交通大学医学院仁济临床医学院本科阶段的医学生进行调查,随机抽取实习前(见习组,56人)和实习后(实习组,35人)... 详细信息

目的通过问卷调查了解医学生对手卫生科学的认知状况和重视程度,旨在为进一步的教学建议和系统性研究提供依据。方法选取上海交通大学医学院仁济临床医学院本科阶段的医学生进行调查,随机抽取实习前(见习组,56人)和实习后(实习组,35人)各1个班级的医学生,采用自行设计的问卷调查表进行手卫生科学的问卷调查。共发放问卷91份,回收91份。对24道客观题予以计分,每题2分,总分共48分;主观题不计分。计算客观题答题正确率,比较两组医学生客观题平均分。统计主观题答题情况。结果客观题答题总正确率为63.9%(15.33/24),其中外科手消毒的答题正确率最高[78.0%(6.24/8)],其次为手卫生指征的答题正确率[58.8%(4.70/8)],手卫生知识的答题正确率最低[56.1%(4.49/8)];实习组的客观题答题总平均分和手卫生指征平均分均显著高于见习组(P值均0.05)。主观题答题情况:医学生获取手卫生知识的途径为专业课程、实习或见习过程、同学介绍、上网主动了解、培训或讲座。见习组在今后的实习工作中手卫生依从性自我评估情况为一定会严格实行手卫生者占76.8%(43/56),视大家的情况决定是否实行手卫生者占21.4%(12/56),肯定坚持实行手卫生者占1.8%(1/56);实习组在实习工作中手卫生依从性自我评估情况为很重视严格执行手卫生者占40.0%(14/35),比较重视但有时会疏忽执行手卫生者占48.6%(17/35),不重视执行手卫生者占11.4%(4/35)。实习组医学生认为实习工作中影响手卫生的因素为工作太忙易疏忽占71.4%(25/35),个人对手卫生不够重视占45.7%(16/35),对手卫生的作用持怀疑态度占31.4%(11/35),清洁剂或消毒剂影响皮肤占25.7%(9/35),洗手水池太少占20.0%(7/35),没有配备干手的工具占17.1%(6/35),医师或护师未形成手卫生的习惯占17.1%(6/35),医院或科室未给予足够的宣传教育和重视占14.3%(5/35)。结论医学生手卫生知识缺乏,主要是缺乏系统性的学习。应加强医学生手卫生科学的教育、宣传,并有效训练、监督医学生手卫生的执行,促其形成良好的职业习惯。

关键词：学生医科医学教育手卫生

Mechanism on progressive failure of a faulted rock slope due to slip-weakening

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Science China(Technological Sciences) 2005年第z1期48卷 18-26页

作者： ZHANG junfeng XU Yongjun QI tao LI Zhengguo Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China Institute of Mechanics Chinese Academy of Sciences Beijing 100080 China

Slip-weakening is one of the characteristics of geological materials under certain loadings. Non-uniform rock structure may exist in the vicinity of the slip surface for a rock slope. Some portion of the slip surface may be penetrated but the other not. For the latter case, the crack or the fault surface will undergo shear deformation before it becomes a successive surface under a certain loading. As the slipped portion advances, slip-weakening occurs over a distance behind the crack tip. In the weakening zone, the shear strength will decrease from its peak value to residual friction level. The stress will redistribute along the surface of crack and in the weakening zone. Thus the changed local stress concentration leads the crack to extend and the ratio of penetration of the slip surface to increase. From the view of large-scale for the whole slip surface, the shear strength will decrease due to the damage of interior rock structure, and the faulted rock behaves as a softening material. Such a kind of mechanism performs in a large number of practical landslides in the zones experienced strong earthquakes. It should be noted that the mechanism mentioned above is different from that of the breakage of structural clay, in which the geological material is regarded as a medium containing structural lumps and structural bands. In this paper, the softening behavior of a faulted rock should be regarded as a comprehensive result of the whole complicated process including slip-weakening, redistribution of stress, extension of crack tip, and the penetration of the slip surface. This process is accompanied by progressive failure and abrupt structural damage. The size of slip-weakening zone is related to the undergoing strain. Once the relative slide is initiated (local or integrated), the effect of slip-weakening will behave in a certain length behind the crack tip until the formation of the whole slip surface.

关键词： faulted rock slope, slip-weakening, progressive failure.

Compressive Mechanical and Heat Conduction Properties of AlSi10Mg Gradient Metamaterials Fabricated via Laser Powder Bed Fusion

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Chinese Journal of Mechanical Engineering 2024年第5期37卷 76-93页

作者： Qidong Sun Geng Zhi Sheng Zhou Ran tao junfeng Qi Institute of Advanced Structure Technology Beijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Lightweight Multi‑functional Composite Materials and Structures Beijing Institute of TechnologyBeijing 100081China Second Institute of China Aerospace Science and Technology Corporation Beijing Institute of Radio MeasurementBeijing 100854China Beijing Spacecrafts Manufacturing Factory Beijing 100094China

Metamaterials are defined as artificially designed micro-architectures with unusual physical properties,including optical,electromagnetic,mechanical,and thermal *** study investigates the compressive mechanical and heat transfer properties of AlSi10Mg gradient metamaterials fabricated by Laser Powder Bed Fusion(LPBF).The morphology of the AlSi10Mg metamaterials was examined using an ultrahigh-resolution ***-static uniaxial compression tests were conducted at room temperature,with deformation behavior captured through camera *** findings indicate that the proposed gradient metamaterial exhibits superior compressive strength properties and energy absorption *** Gradient-SplitP structure demonstrated better compressive performance compared to other strut-based structures,including Gradient-Gyroid and Gradient-Lidinoid *** an apparent density of 0.796,the Gradient-SplitP structure exhibited an outstanding energy absorption capacity,reaching an impressive 23.57 MJ/m^(3).In addition,heat conductivity tests were performed to assess the thermal resistance of these structures with different cell *** gradient metamaterials exhibited higher thermal resistance and lower thermal ***,the designed gradient metamaterials can be considered valuable in various applications,such as thermal management,load-bearing,and energy absorption components.

关键词： Compressive mechanical properties Thermal conductivity Finite element analysis Gradient metamaterials Laser powder bed fusion

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食管闭锁术后吻合口狭窄的治疗体会

江西医药 2019年第1期54卷 15-17,39页

作者：刘智文陶俊峰陈快樊纬黄金狮陶强江西省儿童医院新生儿外科南昌330006

目的探讨先天性食管闭锁患儿胸腔镜食管重建术后吻合口狭窄的治疗经验。方法收集2013年1月-2017年12月收治的26例行胃镜下沙氏探条扩张的食管闭锁术后吻合口狭窄的患儿临床资料,以扩张后的临床表现和钡餐造影为标准(其中扩张后超过6个... 详细信息

目的探讨先天性食管闭锁患儿胸腔镜食管重建术后吻合口狭窄的治疗经验。方法收集2013年1月-2017年12月收治的26例行胃镜下沙氏探条扩张的食管闭锁术后吻合口狭窄的患儿临床资料,以扩张后的临床表现和钡餐造影为标准(其中扩张后超过6个月无呕吐、痰多、吞咽困难等临床症状,造影显示吻合口基本无狭窄诊断为治愈;扩张后仍偶有临床症状,复查造影显示吻合口轻微狭窄,但未达到需扩张治疗标准为有效;患儿年龄>1岁,扩张次数>12次,临床症状反复出现,且缓解期<1个月,诊断为失败)评价吻合口狭窄的发生发展及探条扩张治疗食管闭锁胸腔镜手术后吻合口狭窄的临床疗效。结果 26例患儿共扩张143次,平均5.5次/例;扩张间隔频率3.5d-3个月,平均27d/次。扩张时无食管破裂及大出血等并发症。共随访2～48个月,其中18例治愈,6例有效,2例失败后再次行瘢痕段切除+食管重建。24例有效、治愈患儿中,2例中度营养不良,7例身高体重稍低于同龄儿童,余患儿生长发育状况良好。结论吻合口狭窄的诊治是食管闭锁术后续贯治疗的关键,探条扩张技术能改善吻合口狭窄程度,效果满意,安全、有效。

关键词：先天性食管闭锁吻合口狭窄探条扩张

The thermal stability of dispersion-strengthened tungsten as plasma-facing materials:a short review

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Tungsten 2019年第3期1卷 187-197页

作者： tao Zhang Zhuoming Xie junfeng Yang Ting Hao Changsong Liu School of Physics and Electronic Engineering GuangZhou UniversityGuangzhou 510006China Institute of Solid State Physics Chinese Academy of SciencesHefei 230031China

One key challenge for the development of fusion energy is plasma-facing ***-based materials are promising candidates for plasma-facing components(PFCs)in the magnetic confinement nuclear fusion reactors because of their high melt temperature,high-thermal conductivity,high-thermal load resistance,low tritium retention,and low sputtering *** fusion reactors,PFCs are exposed to high-thermal flux,because there are some transient events such as plasma disruptions,edge-localized modes,and vertical displacement events(VDEs).Especially,in VDEs,a heat flux of 10-100 MW m−2 with duration of milliseconds-to-several seconds can induce recrystallization and then change the microstructure of tungsten-based plasma-facing materials,leading to instability of ***,a significant degradation of material properties is caused such as a reduction of mechanical strength and fracture toughness,a rise in the ductile-to-brittle-transition tempera-ture well,and decrease of irradiation/high-thermal load ***,many efforts were devoted to improve the thermal stability of tungsten-based materials as high as possible,such as oxide dispersion strengthening,carbide dispersion strengthening,and K bubbles dispersion ***,the thermal stabilities of various dispersion-strengthened tungsten materials are reviewed by evaluating their recrystallization temperature and the corresponding hardness *** addition,the possible development trends are proposed.

关键词： Tungsten Plasma-facing materials Thermal stability Dispersion strengthening

Pull-out Behaviour of Axially Loaded Screwed-in Threaded Rods Embedded in CLT Elements: Experimental Study

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Journal of Renewable Materials 2022年第1期10卷 105-117页

作者： Huifeng Yang junfeng Ji Haotian tao Benkai Shi Junbin Hu Bo Wen Nanjing Tech University Nanjing211816China Southeast University Nanjing211189China Sanjiang University Nanjing210012China

Experimental investigation on the pull-out behaviour,including the withdrawal capacity,slip stiffness and inter-facial shear stress,of axially loaded screwed-in threaded rod embedded in cross laminated timber(CLT)was *** with varying embedment length and different number of threaded rods were tested in this *** prevent premature splitting failure of timber,some specimens were reinforced in the direction perpen-dicular to the timber grain with self-tapping *** results showed that the screwed-in threaded rod con-nections exhibited good pull-out behaviour with high withdrawal capacity and slip *** a certain range,the withdrawal capacity increases considerably with the increase of embedment length,while the average interfacial shear stress shows the opposite *** self-tapping screws played an important role on reducing the splitting of the timber and improving the withdrawal capacity and slip stiffness of the screwed-in threaded ***,for the specimens with self-tapping screw reinforcements,the improvement of withdrawal capacity and stiffness when increasing the number of threaded rods are much more obvious than that of the speci-mens without the self-tapping screws,due to the change of failure modes.

关键词： Threaded rods screwed-in pull-out behaviour timber structure experimental study

Microstructures and Properties of Biomedical Mg-Zn-Sn-Zr Rolled Alloys

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Journal of Wuhan University of Technology(Materials Science) 2024年第3期39卷 766-773页

作者：周生刚 ZHANG Daxin XU Yang DUAN Jihao LI tao LIU junfeng WANG Peng 曹勇 Faculty of Material Science and Engineering Kunming University of Science and TechnologyKunming 650093China

The as-cast Mg-2.0Zn-1.5Sn-xZr(x=0,0.4,0.6,0.8,1.0 wt%)alloy was rolled with the pressure less than 5%each *** microstructure,mechanical properties,corrosion properties and biocompatibility of the alloy were *** microstructure of the alloy was observed and analyzed by scanning electron microscope,and the tensile test was carried out by universal tensile *** corrosion resistance of the alloy in Hank's solution was studied by hydrogen evolution experiment and electrochemical test,and the biocompatibility of the alloy was tested by L929 *** results show that Mg-2Zn-1.5Sn-xZr alloy has excellent mechanical *** elongation of Mg-2Zn-1.5Sn-xZr alloy decreases with the increase of Zr content,but the tensile strength first increases and then decreases with the increase of Zr *** the Zr content is 0.8 wt%,the maximum tensile strength of the alloy is 235 *** results of hydrogen evolution experiment and electrochemical analysis show that the corrosion resistance of the alloy is the best when the Zr content is 0.8 wt%,and all the five alloys have high *** conclusion,the rolled alloy has good properties and has broad application prospects in the field of biomaterials.

关键词： magnesium alloy corrosion performance mechanical properties biocompatibility

Non-matrix-matched analysis of U-Th-Pb geochronology of bastn?site by laser ablation inductively coupled plasma mass spectrometry

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Science China Earth Sciences 2021年第4期64卷 667-676页

作者： tao LUO He ZHAO Wen ZHANG Jingliang GUO Keqing ZONG Yongsheng LIU junfeng ZHANG Zhaochu HU State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China

Bastn?site is widespread in alkali granite, carbonatite and REE ore deposits. The U-Th-Pb ages of bastn?site can constrain the mineralization age. Currently, the lack of suitable in situ analysis reference material is the major obstacle of bastn?site U-Th-Pb geochronology. In this study, the matrix effects of U-Pb and Th-Pb age determination in bastn?site using glass NIST 610 as the external calibration reference were evaluated with the 193-nm excimer LA-ICP-MS analysis in normal and additional gases laser ablation modes. The obtained U-Th-Pb ages of bastn?site were approximately 7–11% lower than their reference values in the normal analytical mode(without additional gas). Fortunately, the determined systematic age biases in UTh-Pb dating were significantly reduced(less than 1–2%) with the addition of water vapor within the ablation chamber. This reduction may be attributed to the observed significant suppression of206 Pb/238 U and208 Pb/232 Th downhole fractionation in both NIST 610 glass and bastn?site by introducing a small quantity of water vapor in the ablation chamber. In addition, the obtained206 Pb/238 U and208 Pb/232 Th ages of bastn?site K-9, LZ1384, and MAD809 showed great consistency with their corresponding recommended values. The obtained results show that accurate and precise U-Th-Pb ages of bastn?site can be simultaneously obtained by using glass NIST 610 as the primary calibration standard in 193-nm LA-ICP-MS with the water vapor-assisted method. This simple and effective water vapor-assisted non-matrix-matched laser ablation method helps to promote the geological application of bastn?site U-Th-Pb geochronology.

关键词： LA-ICP-MS U-Th-Pb ages Non-matrix-matched method Bastn?site

Ⅰ型食管闭锁治疗中食管内张力延长技术的应用

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临床小儿外科杂志 2017年第4期16卷 360-363页

作者：樊纬黄金狮陈快陶俊峰刘智文徐美汉万颢李辉兵陶强江西省儿童医院新生儿外科江西省南昌市330006

目的探讨食管内张力延长技术对Ⅰ型食管闭锁患儿的疗效和临床应用价值。方法回顾性分析2014年6月至2016年9月本院应用食管内张力延长技术辅助治疗的6例Ⅰ型食管闭锁患儿临床资料,男3例,女3例,出生后行胃造瘘手术并完善食管造影及支气管... 详细信息

目的探讨食管内张力延长技术对Ⅰ型食管闭锁患儿的疗效和临床应用价值。方法回顾性分析2014年6月至2016年9月本院应用食管内张力延长技术辅助治疗的6例Ⅰ型食管闭锁患儿临床资料,男3例,女3例,出生后行胃造瘘手术并完善食管造影及支气管镜检查诊断Ⅰ型食管闭锁,检查3月龄以上患儿上、下食管盲端相距仍大于4个椎体间隙,分别于上、下两盲端食管内行张力延长。结果 6例患儿分别给予36 d、42 d、69 d、28 d、55 d、64 d食管内张力延长后顺利完成胸腔镜下食管端端吻合,术后吻合口瘘1例,经保守治疗17 d愈合,全部患儿治愈出院。随访2个月至1年11个月,吻合口狭窄3例,行1~5次食管扩张。结论食管内张力延长技术在Ⅰ型食管闭锁的治疗中疗效确切,能避免食管吻合前胸腔内手术操作,达到依靠本身食管完成食管端端吻合的目的,值得进一步推广应用。

关键词：食管闭锁延长吻合口治疗应用