检索结果-南通市图书馆

我国增材制造个性化医疗器械上市前监管现状和挑战

在线全文

学校读者我要写书评

暂无评论

中国药物评价 2024年第2期41卷 88-92页

作者：闵玥史新立国家药品监督管理局医疗器械技术审评中心北京100081

增材制造个性化医疗器械是当前研究热门和监管科学研究重点。本文全面梳理了当前我国增材制造个性化医疗器械的上市前监管现状,包括产品定义、监管模式和分类管理等法规要求,指导原则和标准体系建设等内容。同时,结合国际前沿的监管研... 详细信息

增材制造个性化医疗器械是当前研究热门和监管科学研究重点。本文全面梳理了当前我国增材制造个性化医疗器械的上市前监管现状,包括产品定义、监管模式和分类管理等法规要求,指导原则和标准体系建设等内容。同时,结合国际前沿的监管研究和技术进展,提出当前监管科学研究面临的新问题和挑战,为相关人员提供参考。

关键词：增材制造个性化医疗器械上市前监管

Topological Structure of Knotted Vortex lines in liquid Crystals

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2007年第6期47卷 1129-1134页

作者： DUAN Yi-shi ZHAO li ZHANG xin-Hui Institute of Theoretical Physics Lanzhou University Lanzhou 730000 China

In this paper, a novel decomposition expression for the U（1） gauge field in liquid crystals （LCs） is derived. Using this decomposition expression and the b-mapping topological current theory, we investigate the topological structure of the vortex lines in LCs in detail. A topological invariant, i.e., the Chern-Simons （CS） action for the knotted vortex lines is presented, and the CS action is shown to be the total sum of all the self-linking and linking numbers of the knot family. Moreover, it is pointed out that the CS action is preserved in the branch processes of the knotted vortex lines.

关键词： knotted vortex lines liquid crystals Chern-Simons action branch processes

Electrochemical corrosion behavior of arc sprayed Zn-Al coatings

在线全文

学校读者我要写书评

暂无评论

中国有色金属学会会刊：英文版 2004年第z1期14卷 443-445页

作者： liU Yan ZHU Zi-xin CHEN Yong-xiong XU Bin-shi MA shi-ning li Zhuo-xin National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China College of Materials Science and Engineering Beijng University of Technology Beijing 100022 China National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China National Key Laboratory for Remanufacturing Academy of Armored Forces Engineering Beijing 100072 China School of Materials Science and Engineering Surface Engineering Research Institute CMES Beijing 100072 China College of Materials Science and Engineering Beijng University of Technology Beijing 100022 China

Cored wires and high velocity arc spraying (HVAS) technique were applied to produce high Al content Zn-Al alloy coatings on low carbon steel substrates. The electrochemical corrosion behaviors of Zn, Al and Zn-Al coatings were studied with potentiodynamic measurement in 5 % NaCl solution. Compared with pure Zn, pure Al and Zn-15Al coatings, Zn-26Al coatings show a higher corrosion resistance in salt solution. The potentiodynamic polarization tests show that the corrosion resistance of Zn-Al coatings increases as Al content is raised. Pure Al coating exhibits different electrochemical behaviors with other coatings. The corrosion initiated at the micro-pores of the coating and the underlying corrosion mechanism is very similar to that of the pitting corrosion.

关键词： coating electrochemical corrosion high velocity arc spraying potentiodynamic polarization

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

寄主植物丹参对檀香幼苗生长的影响

中药材 2024年第2期47卷 290-294页

作者：李世新郑玲玲陈思羽蓝子欣陈彦钧夏靖祺周修腾中国中医科学院中药资源中心道地药材品质保障与资源持续利用全国重点实验室北京100700 广东药科大学广东广州510006 江西中医药健康产业研究院/中国中医科学院中医药健康产业研究所江西南昌330029

目的:研究丹参作为寄主植物对檀香幼苗生长的影响。方法:设置檀香空白对照组(TXCK)、檀香+假蒿寄生组(TXJH)、檀香+丹参寄生组(TXDS)3个不同处理组,测定檀香幼苗的生物量、叶绿素含量、生化组分和土壤营养成分等指标。结果:TXDS组的株... 详细信息

目的:研究丹参作为寄主植物对檀香幼苗生长的影响。方法:设置檀香空白对照组(TXCK)、檀香+假蒿寄生组(TXJH)、檀香+丹参寄生组(TXDS)3个不同处理组,测定檀香幼苗的生物量、叶绿素含量、生化组分和土壤营养成分等指标。结果:TXDS组的株高、根长、吸器直径均显著高于TXJH组(P<0.05),是TXJH组的1.32~1.82倍。TXDS组的叶绿素a、叶绿素b及叶绿素总量均显著高于TXJH组(P<0.05),为TXJH组的1.41~1.49倍。TXDS组地上部分SOD和可溶性糖含量最高,但与TXJH组无显著差异;TXDS组地下部分SOD、可溶性糖含量显著高于TXCK、TXJH组(P<0.05);TXCK组地下部分蛋白含量显著高于TXDS组(P<0.05)。TXCK组全氮、全磷、碱解氮、速效磷和速效钾含量均显著高于TXDS组(P<0.05),是TXDS组的1.44~1.73倍,但与TXJH组无显著差异,TXCK组全钾含量为1.94%,显著高于TXJH组(P<0.05),是TXJH组的1.60倍,但与TXDS组无显著差异。结论:寄主植物丹参能更好地促进檀香的生长,提高其光合作用,增加营养物质含量,促进对土壤营养成分的吸收,是檀香幼苗期的优良寄主植物,为栽培檀香寄主植物的选择提供了参考。

关键词：檀香丹参假蒿寄生关系

A Rendezvous Mission to the Second Earth Trojan Asteroid 2020 XL_5 with Low-Thrust Multi-Gravity Assist Techniques

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第1期24卷 245-264页

作者： shi-Hai Yang Bo Xu xin li School of Aeronautics and Astronautics Sun Yat-sen UniversityShenzhen 518107China

As the second of Earth's Trojan asteroids, 2020 XL_(5) is worthy of rendezvous and even sample return missions in many aspects. In this paper, a rendezvous mission to Earth's second Trojan asteroid 2020 XL_(5) is ***, due to its high inclination and large eccentricity, direct impulsive transfer requires large amounts of fuel consumption. To address this challenge, we explore the benefits of electric propulsion and multi-gravity assist techniques for interplanetary missions. These two techniques are integrated in this mission design. The design of a low-thrust gravity-assist(LTGA) trajectory in multi-body dynamics is thoroughly investigated,which is a complex process. A comprehensive framework including three steps is presented here for optimization of LTGA trajectories in multi-body dynamics. The rendezvous mission to 2020 XL_(5) is designed with this three-step approach. The most effective transfer sequence among the outcomes involves Earth–Venus–Earth–Venus-2020 XL_(5). Numerical results indicate that the combination of electric propulsion and multi-gravity assists can greatly reduce the fuel consumption, with fuel consumption of 9.03%, making it a highly favorable choice for this rendezvous mission.

关键词： minor planets asteroids:general celestial mechanics Planetary Systems

Health diagnosis of ultrahigh arch dam performance using heterogeneous spatial panel vector model

在线全文

学校读者我要写书评

暂无评论

Water Science and Engineering 2024年第2期17卷 177-186页

作者： Er-feng Zhao xin li Chong-shi Gu The National Key Laboratory of Water Disaster Prevention Hohai UniversityNanjing 210098China NationalEngineering Research Centerof Water Resources Eficient Utilization and Engineering Safety Hohai UniversityNanjing 20098China

Currently,more than ten ultrahigh arch dams have been constructed or are being constructed in *** control is essential to long-term operation of these *** study employed the flexibility coefficient and plastic complementary energy norm to assess the structural safety of arch dams.A comprehensive analysis was conducted,focusing on differences among conventional methods in characterizing the structural behavior of the Xiaowan arch dam in ***,the spatiotemporal characteristics of the measured performance of the Xiaowan dam were explored,including periodicity,convergence,and time-effect *** findings revealed the governing mechanism of main ***,a heterogeneous spatial panel vector model was developed,considering both common factors and specific factors affecting the safety and performance of arch *** model aims to comprehensively illustrate spatial heterogeneity between the entire structure and local regions,introducing a specific effect quantity to characterize local deformation ***,the proposed model was applied to the Xiaowan arch dam,accurately quantifying the spatiotemporal heterogeneity of dam ***,the spatiotemporal distri-bution characteristics of environmental load effects on different parts of the dam were reasonably *** of the model prediction enhances its credibility,leading to the formulation of health diagnosis criteria for future long-term operation of the Xiaowan *** findings not only enhance the predictive ability and timely control of ultrahigh arch dams'performance but also provide a crucial basis for assessing the effectiveness of engineering treatment measures.

关键词： Ultrahigh arch dam Structural performance Deformation behavior Diagnosis criterion Panel data model

Management of Acute Lower Extremity Thrombosis Associated with Bilateral Popliteal Aneurysms Using Combined Thrombolytic Therapy and Stent Graft Repair

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Medical Journal 2015年第4期128卷 564-566页

作者： Bao-Lei Guo Wei-Guo Fu Zhen-Yu shi li-xin Wang Da-Qiao Guo Department of Vascular Surgery Zhongshan Hospital Fudan University Institute of Vascular Surgery Shanghai 200032 China

To the Editor：This is a brief clinical report on different endovascular procedures in the treatment of popliteal artery aneurysms （PAAs）.A 75-year-old man presented at the vascular clinic with progressive left lower limb pain at rest associated with coolness,pain,and *** medical history was significant for hypertension and *** femoral and popliteal pulsations were only felt in the left ***,pallor,paresthesia,delayed capillary refilling,and color changes were noted in the left limb together with rest *** ultrasound was performed and an embolization （Rutherford Grade 2b） and bilateral PAAs were found,which on computed tomography angiogram （CTA） measured 62 mm and 82 mm with the maximum diameters in the right and left popliteal artery,*** was found in both aneurysm sacs [Figure 1 a and b].Thromboembolism from the left PAA could be seen in the distal *** potentially associated aneurysms were excluded by magnetic resonance *** erythrocyte sedimentation rate and C-reactive protein were moderately elevated,and thrombophilia profile was negative,and history for any orogenital ulcers was negative.

关键词： Popliteal Artery Aneurysms Endovascular Therapy Stent Grafts

Experimental study on the size effect on the equation of state of concretes under shock loading

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第3期33卷 160-167页

作者： Mei li Jian Cui Yanchao shi Baijian Tang xin Chen Key Laboratory of Coast Civil Structural Safety of the Ministry of Education Tianjin UniversityTianjin 300072China School of Civil Engineering Suzhou University of Science and Technology1701 Binhe RoadSuzhou 215011JiangsuChina School of Civil Engineering Tianjin UniversityTianjin 300072China

Adopting the classical theory of hydrocodes,the constitutive relations of concretes are separated into an equation of state(EoS)which describes the volumetric behavior of concrete material and a strength model which depicts the shear properties of *** experiments on the EoS of concrete is always challenging due to the technical difficulties and equipment limitations,especially for the specimen size effect on the *** some researchers investigate the shock properties of concretes by fly-plate impact tests,the specimens used in their tests are usually in one *** this paper,the fly-plate impact tests on concrete specimens with different sizes are performed to investigate the size effect on the shock properties of concrete *** mechanical background of the size effect on the shock properties are revealed,which is related to the lateral rarefaction effect and the deviatoric stress produced in the *** to the tests results,the modified EoS considering the size effect on the shock properties of concrete are proposed,which the bulk modulus of concrete is unpredicted by up to 20% if size effects are not accounted for.

关键词： Concrete Equation of state Size effect Shock wave Fly-plate impact test

Enhancing force sensing in a squeezed optomechanical system with quantum nondemolition measurement

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第1期76卷 49-60页

作者： shi-Lei Chao Zi-Hao li xin-You Lü School of Physics Huazhong University of Science and Technology430074 WuhanChina

A theoretical scheme is proposed to enhance the sensitivity of force sensors with quantum nondemolition measurement(QND)in an optomechanical setup assisted by four-tone optical driving and an optical parametric amplifier(OPA).With the help of special drive,the system can be simplified as the typical type of QND for force sensing,so that the backaction noise can be evaded to surpass the standard quantum ***,the added noise can be suppressed owing to the modified optical susceptibility resulting from the *** introducing two oscillators coupling with two charged bodies respectively,the signal can be enhanced with the nonlinearity caused by Coulomb interaction,while the noise presents an exponential ***,considering the homodyne detection effect,the range of system parameters and frequency bands will be *** present investigation may provide a route toward simultaneously evading backaction noise,reducing the mechanical thermal noise,and enhancing the external signal,which can be an alternative design for sensitive devices.

关键词： force sensing optical parametric amplifier quantum non-demolition measurement optomechanical system