检索结果-南通市图书馆

Chinese Journal of Polymer Science 2015年第11期33卷 1598-1605页

作者： Yin Yuan 孙培健 Xu-dong Shi Zhi-hua gan 王佛松 CAS Key Laboratory of Engineering Plastics Institute of Chemistry Chinese Academy of Sciences the Key Laboratory of Tobacco Chemistry Zhengzhou Tobacco Research Institute China National Tobacco Corporation State Key Laboratory of Organic-inorganic Composites Beijing Laboratory of Biomedical MaterialsCollege of Life Sciences and Technology

Microspheres with thermo-responsible surface were fabricated by PCL-b-PEO-b-PNIPAM triblock copolymers. Thermo-responsible morphological changes of PCL-b-PEO-b-PNIPAM microspheres immersed in aqueous solution at temperatures above the LCST（e.g. 37 ℃） were observed from porous surface structure to compact surface layer. Enzymatic degradation and in vitro drug release results showed that the thermo-responsible surface layer greatly influenced the degradation of microspheres as well as the drug release behavior from microspheres. With the copolymerization of PNIPAM block into PCL-b-PEO copolymers, the drug release could be well regulated by changing temperatures and microspheres composition, which revealed the great potentials of microspheres with thermo-responsible surface for controlled drug release.

关键词： Microspheres Poly(N-isopropylacrylamide) Thermo-sensitive Biodegradation

Measurement of boiling heat transfer coefficient in liquid nitrogen bath by inverse heat conduction method

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第5期10卷 691-696页

作者： Tao JIN Jian-ping HONG Hao ZHENG Ke TANG Zhi-hua gan Institute of Refrigeration and Cryogenics Zhejiang University Hangzhou 310027 China

Inverse heat conduction method (IHCM) is one of the most effective approaches to obtaining the boiling heat transfer coefficient from measured results. This paper focuses on its application in cryogenic boiling heat transfer. Experiments were conducted on the heat transfer of a stainless steel block in a liquid nitrogen bath, with the assumption of a 1D conduction condition to realize fast acquisition of the temperature of the test points inside the block. With the inverse-heat conduction theory and the explicit finite difference model, a solving program was developed to calculate the heat flux and the boiling heat transfer coefficient of a stainless steel block in liquid nitrogen bath based on the temperature acquisition data. Considering the oscillating data and some unsmooth transition points in the inverse-heat-conduction calculation result of the heat-transfer coefficient, a two-step data-fitting procedure was proposed to obtain the expression for the boiling heat transfer coefficients. The coefficient was then verified for accuracy by a comparison between the simulation results using this expression and the verifying experimental results of a stainless steel block. The maximum error with a revised segment fitting is around 6%, which verifies the feasibility of using IHCM to measure the boiling heat transfer coefficient in liquid nitrogen bath.

关键词： Inverse heat conduction method (IHCM) Liquid nitrogen bath Boiling heat transfer coefficient

Effect of molecular weight on reaction-induced phase separation of epoxy resin modified with fluorocarbon chain terminated polyetherimide

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2005年第6期48卷 560-566页

作者： gan Wenjun LI hua HU Zhiqiang LI Liang LI Shanjun Key Laboratory of Molecular Engineering of Polymer Ministry of Education Department of Macromolecular ScienceFudan UniversityShanghai 200433China

A series of fluorocarbon chain terminated polyetherimide is added to epoxy resin,and the effect of molecular weight on the process of phase separation is studied by time-resolved light scattering(TRLS),differential scanning calorimeter(DSC),scanning microscopy(SEM).The results indicate that the phase separation rate decreases due to the preventing effect in-duced by low surface energy of fluorocarbon chain terminated *** addition,evolu-tion time of morphology is shortened and the domain size decreases with the introduction of fluorocarbon chain terminated ***,when the molecular weight of fluorocarbon chain terminated polyetherimide increases,the morphology can change from dis-persed phase to co-continuous ***,changing the molecular weight of fluorocarbon chain terminated polyetherimide can control the morphology of the epoxy/polyetherimide blend,which is of great significance in many industries.

关键词： fluorocarbon chain terminated polyetherimide epoxy molecular weight reaction-induced phase separa-tion time-resolved light scattering.

A new species of the genus Amolops(Anura:Ranidae)from Yunnan,China

在线全文

学校读者我要写书评

暂无评论

Zoological Research 2020年第2期41卷 188-193页

作者： Yu-Lu gan Guo-hua Yu Zheng-Jun Wu Key Laboratory of Ecology of Rare and Endangered Species and Environmental Protection(Guangxi Normal University) Ministry of EducationGuilinGuangxi 541004China Guangxi Key Laboratory of Rare and Endangered Animal Ecology College of Life ScienceGuangxi Normal UniversityGuilinGuangxi 541004China

DEAR EDITOR,A new species of the genus Amolops,Amolops tuanjieensis ***.,is described from Yunnan,*** new species can be distinguished by the following characters:dorsolateral folds present;dorsal and ventral surfaces smooth;top of head and dorsum brown-red with irregular gray and dark spots;flank green;side of head black,from tip of snout,diffusing posteriorly to axilla,continuing as black streak below edge of dorsolateral fold;SVL 39.5-40.4 mm in males,56.8-60.7 mm in females;tympanum distinct;supratympanic fold indistinct;vomerine teeth in two oblique rows between choanae,closer to each other than choanae;vocal sacs present;nuptial pads present;outer metatarsal tubercle absent,supernumerary tubercles absent;all fingertips expanded into discs;limbs dorsally brown with dark brown bars and irregular dark brown blotches.

关键词： black closer brown

An in-depth mechanistic insight into the redox reaction and degradation of aqueous Zn-MnO_(2) batteries

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2023年第4期34卷 531-536页

作者： Zongyuan You Wei hua Na Li huanyan Liu Jian-gan Wang State Key Laboratory of Solidication Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical UniversityShaanxi Joint Lab of Graphene(NPU)Xi’an 710072China

Rechargeable aqueous Zn/MnO_(2)batteries raise massive research activities in recent years. However, both the working principle and the degradation mechanism of this battery chemistry are still under debate. Herein, we provide an in-depth electrochemical and structural investigation on this controversial issue based on α-MnO_(2)crystalline nanowires. Mechanistic analysis substantiates a two-electron reaction pathway of Mn2+/Mn4+redox couple from part of MnO_(2)accompanying with a reversible precipitation/dissolution of flaky zinc sulfate hydroxide(ZSH) during the discharge/charge processes. The formation of the ZSH layer is double-edged, which passivates the deep dissolution of MnO_(2)upon discharging,but promotes the electrochemical deposition kinetics of active MnO_(2)upon charging. The cell degradation originates primarily from the corrosion failure of metallic zinc anode and the accumulation of irreversible ZnMn2O_(4)phases on the cathode. The addition of MnSO_(4)to the electrolyte could afford supplementary capacity contribution via electro-oxidation of Mn2+. However, a high MnSO_(4)concentration will expedite the cell failure by corroding the metallic zinc anodes. The present study will shed a fundamental insight on developing new strategies toward practically viable Zn/MnO_(2)batteries.

关键词： Zinc-ion battery MnO_(2)cathode Working mechanism Degradation mechanism Zinc anode

Scheme for the excitation of thorium-229 nuclei based on electronic bridge excitation

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2023年第2期34卷 88-97页

作者： Lin Li Zi Li Chen Wang Wen‑Ting gan Xia hua Xin Tong State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Innovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China Wuhan Institute of Quantum Technology Wuhan 430206China

Thorium-229 possesses the lowest first nuclear excited state,with an energy of approximately 8 *** extremely narrow linewidth of the first nuclear excited state,with an uncertainty of 53 THz,prevents direct laser excitation and realization of the nuclear *** present a proposal using the Coulomb crystal of a linear chain formed by229Th^(3+)ions,where the nuclei of229Th3+ions in the ion trap are excited by the electronic bridge(EB)*** 7 P1∕2state of the thorium-229 nuclear ground state is chosen for EB *** the two-level optical Bloch equation under experimental conditions,we calculate that 2 out of 36 prepared thorium ions in the Coulomb crystal can be excited to the first nuclear excited state,and it takes approximately 2 h to scan over an uncertainty of 0.22 *** advantage of the transition enhancement of EB and the long stability of the Coulomb crystal,the energy uncertainty of the first excited state can be limited to the order of 1 GHz.

关键词： Coulomb crystal Thorium-229 Electronic bridge transition Isomeric state

Investigation of the magnetoresistance in EuS/Nb:SrTiO3 junction

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第11期29卷 492-496页

作者： Jia Lu Yu-Lin gan Yun-Lin lei lei Yan Hong Ding Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of Sciences(CAS)Beijing 100190China College of Physics and Materials Science Tianjin Normal UniversityTianjin 300387China Department of Physics University of Chinese Academy of SciencesBeijing 100049China CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of SciencesBeijing 100049China

EuS is one of typical ferromagnetic semiconductor using as spin filter in spintronic devices,and the doped one could be a good spin ***,we fabricate a spin-functional tunnel junction by epitaxially growing the ferromagnetic EuS film on Nb-doped *** improvement of Curie temperature up to 35 K is associated with indirect exchange through additional charge carriers at the interface of EuS/Nb:STO *** magnetic field controlled current-voltage curves indicate the large magnetoresistance(MR)effect in EuS barriers as a highly spin-polarized *** negative MR is up to 60%in 10-nm EuS/Nb:STO at 4 T and 30 *** MR is enhanced with increasing thickness of EuS *** large negative MR effect over a wide temperature range makes this junction into a potential candidate for spintronic devices.

关键词： EuS/Nb:SrTiO3 tunnel junction spin filter magnetoresistance

Effect of Co substitution on the glass forming ability and magnetocaloric effect of Fe88Zr8B4 amorphous alloys

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2017年第7期60卷 81-84页

作者： Lianghua gan LiYan Ma BenZhen Tang Ding Ding lei Xia Laboratory for Microstructure Institute of Materials Shanghai University Shanghai 200072 China

As greater attention is paid to energy consumption and global warming, magnetic refrigeration （MR） technologies based on the magneto-caloric effect （MCE） have been developed. Systems based on MR are expected to be more compact, energy efficient, and environmentally safe compared with traditional vapor-cycle refrigeration technologies .

关键词： Effect of Co substitution on the glass forming ability and magnetocaloric effect of Fe Co Figure Zr8B4 amorphous alloys

Modeling, Simulation and Analysis of Thermal Resistance in Multi-finger Algan/gan HEMTs on SiC Substrates

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2012年第8期29卷 279-283页

作者： WANG Jian-Hui WANG Xin-hua PANG lei CHEN Xiao-Juan LIU Xin-Yu Key Laboratory of Microelectronics Device&Integrated Technology Institute of MicroelectronicsChinese Academy of SciencesBeijing 100029

The effects of varying layout geometries and various thermal boundary resistances(TBRs)on the thermal resistance of multi-finger Algan/gan HEMTs are thoroughly investigated using a combination of a two-dimensional electro-thermal model coupled with the three-dimensional thermal *** measurement using micro-Raman thermography is performed to verify and enhance the accuracy of the thermal *** results indicate that thermal resistance weakly depends on the layout design because of the high thermal conductivity of ***,the analysis reveals that optimizing the TBR of the device could efficiently reduce the thermal resistance since TBR takes a significant proportion of the total thermal resistance.

关键词： Algan/gan HEMTs Simulation

Regulation of pseudographitic carbon domain to boost sodium energy storage

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

Nano Research 2024年第6期17卷 5188-5196页

作者： Zhidong Hou Mingwei Jiang Da lei Xiang Zhang Yuyang Gao Jian-gan Wang State Key Laboratory of Solidification Processing Center for Nano Energy MaterialsSchool of Materials Science and EngineeringNorthwestern Polytechnical University and Shaanxi Joint Lab of Graphene(NPU)Xi’an 710072China

Hard carbon anode has shown extraordinary potentials for sodium-ion batteries(SIBs)owing to the cost-effectiveness and advantaged ***,the widespread application of hard carbon is still hindered by the insufficient sodium storage capacity and depressed rate property,which are mainly induced by the undesirable pseudographitic ***,we develop a molten-salt-mediated strategy to regulate the pseudographitic structure of hard carbon with suitable interlayer spacing and enlarged pseudographitic domain,which is conducive to the intercalation capacity and diffusion kinetics of sodium ***,the optimized hard carbon anode delivers a high reversible capacity of 320 mAh·g^(−1),along with superior rate property(138 mAh·g−1 at 2 A·g^(−1))and stable cyclability over 1800 ***,the in situ Raman spectroscopic study and full-cell assembly further investigate the sodium storage mechanism and practical implement of obtained hard *** work pioneers a low-cost and effective route to regulate the pseudographitic structure of hard carbon materials for advanced SIBs.

关键词： pseudographitic structure molten salt hard carbon anode sodium-ion batteries