检索结果-南通市图书馆

Temperature-dependent Raman spectroscopic study of ferroelastic K_2Sr(MoO_4)

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第11期27卷 591-595页

作者： Ji zhang De-Ming zhang ran-ran zhang An Hui Xin Hua University Hefei 230088 China Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei 230031 China High Magnetic Field Laboratory of the Chinese Academy of Sciences Hefei 230031 China

Raman scattering measurements of K_2 Sr（MoO_4）2 were performed in the temperature range of 25–750？C. The Raman spectrum of the low-temperature phase α-K_2 Sr（MoO_4）2 that was obtained by first-principle calculations indicated that the Raman bands in the wavenumber region of 250–500 cm-1 are related to Mo–O bending vibrations in MoO4 tetrahedra,while the Raman bands in the wavenumber region of 650–950 cm-1 are attributed to stretching vibrations of Mo–O *** temperature-dependent Raman spectra reveal that K_2 Sr（MoO_4）2 exhibits two sets of modifications in the Raman spectra at ～ 150？C and ～ 475？C, attributed to structural phase transitions. The large change of the Raman spectra in the temperature range of 150？C to 475？C suggests structural instability of the medium-temperature phase β-K_2 Sr（MoO_4）2.

关键词： ferroelastics K2Sr(MoO4)2 crystal Raman spectroscopy phase transition

Laser ablation assisted spark induced breakdown spectroscopy and its application

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2020年第5期15卷 111-117页

作者： Wei-Dong Zhou Yu-Hui Guo ran-ran zhang Key Laboratory of Optical Information Detection and Display Technology of Zhejiang Zhejiang Normal UniversityJinhua 321004China

Recently,laser ablation assisted spark induced breakdown spectroscopy(LA-SIBS)has been growing rapidly and continue to be extended to a broad range of materials *** by employ-ing a speifically designed high voltage and pulse discharge cireuit to generate a spark and used to enhance plasma emission produced by laser ablation,allows direct analysis of materials without prior sample *** paper reviews recent development and application of laser ablation assisted spark induced breakdown spectrosoopy for material *** a summary of fundamentals and instrumentation of the LA-SIBS analytical techmique,the development and applications of laser ablation assisted spark induced breakdown spectroscopy for the analysis of conducting materials and insulating materials is described.

关键词： laser induced breakdown spectroscopy laser ablation assisted spark induced breakdown spectroscopy discharge cireuit charactor

Dy_(2-x)Y_xTi_2O_7: phonon vibration and magnetization with dilution

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

Rare Metals 2015年第2期34卷 81-88页

作者： Hui Liu You-Ming Zou Shi-Le zhang ran-ran zhang Chang-Jin zhang Yu-Heng zhang High Magnetic Field Laboratory Chinese Academy of Sciences and University of Science and Technology of China

In this paper, the dilution effects of non-magnetic Y ions on spin-ice compound Dy_2Ti_2O_7 by infrared and Raman spectra and magnetization measurements were investigated. An anomalous phonon softening with temperature decreasing is found in both the parent and diluted compounds, and Y doping can relax the softening of phonons except that of the IR mode near 233 cm^-1, indicating a strong phonon–phonon coupling in the spin-ice *** magnetization measurements reveal that the nonmagnetic impurities do not severely influence the spin-ice rules in the ground state when the level of dilution is not very high. However, a large amount of dilution enhance the disorder and break the spin-ice state because the collective spin-flip clusters are no longer available.

关键词： Dilution effect Spin ice Pyrochlore Frustration

Lepithiohydimerins A-D:Four Pairs of Neuroprotective Thiohydantoin Dimers Bearing a Disulfide Bond from Maca(Lepidium meyenii Walp.)

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2021年第10期39卷 2738-2744页

作者： Xing-Rong Peng ran-ran zhang Jun-Hong Liu Zhong-Rong Li Lin Zhou Ming-Hua Qiu State Key Laboratory of Phytochemistry and Plant Resources in West China Kunming Institute of BotanyChinese Academy of SciencesKunmingYunnan650201 China University of the Chinese Academy of Sciences Beijing 100049China

Main observation and conclusion An HPLC-UV-guided separation was performed and four pairs of unprecedented macathiohydantoin dimers,lepithiohydimerins A—D(1—4)bearing a rare disulfide bond were isolated from the tubers of *** structures were unambiguously confirmed by NMR spectroscopic,X-ray crystallographic and electronic circular dichroism(ECD)*** the concentration of 20μmol/L,compounds 2-1,2-2,and 4-1 increased the viability of PC12 cells with the cell viability at(72.06±1.14)%,(72.64±1.49)%,and(70.93±1.22)%,***,the serial concentration experiment showed that they can protect PC12 cells in a dose-dependent manner.

关键词： Lepidium meyenii Walp. Thiohydantoin dimers Natural products Structure elucidation Biological activity

4-Hydroxy phenyl Retinamide Preferentially Targets FLT3 Mutated Acute Myeloid Leukemia via ROS Induction and NF-κB Inhibition

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

Current Medical Science 2020年第5期40卷 810-816页

作者： Xin-ying ZHAO ran-ran zhang Qian YE Fei QIU Hao-yu XU Feng-gui WEI Hui zhang Department of Hematology/Oncology Guangzhou Women and Children's Medical CenterGuangzhou 510623China Institute of Pediatrics Guangzhou Women and Children’s Medical CenterGuangzhou 510623China Department of Pediatrics The First Affiliated Hospital of Guangzhou Medical UniversityGuangzhou 510120China Bioinspired Engineering and Biomechanics Center Xi'an Jiaotong UniversityXi'an 710049China

FMS-like tyrosine kinase 3(FLT3)mutation is strongly associated with poor prognosis in acute myeloid leukemia(AML).Though many FLT3 inhibitors have been developed for clinical application with 34%-56%complete remission rate,patients would develop resistance sooner or later after initial response to tyrosine kinase inhibitors(TKIs),such as *** increasing studies have shown that several resistance related mutations of FLT3 emerged during the AML ***,further investigation is warranted for these FLT3mu,AML patients to achieve a better treatment outcome.4-Hydroxyphenyl retinamide(4-HPR)has been investigated extensively in animal models and clinical trials as an anticancer/chemopreventive agent and is currently used for protection against cancer development/recurrence,with minimal side *** this study,we performed gene-set enrichment analysis and found that down-regulated genes induced by 4-HPR were associated with FLT3-ITD gene ***34+ AML stem/progenitor cells separated from 32 AML samples were treated with *** analysis showed that AML cells with FLT3-ITD genetic alteration were more sensitive to 4-HPR treatment than those without ***,we treated 22 primary AML cells with 4-HPR and found that 4-HPR was more toxic to AML cells with *** results indicated that 4-HPR was preferentially cytotoxic to all FLT3-ITD AML cells irrespective of stem/progenitor cells or blast cells.4-HPR-induced reactive oxygen species(ROS)production and NF-kB inhibition might be the reason of 4-HPR selectivity on FLT3 mutated AML cells.

关键词： 4-Hydroxyphenyl retinamide acute myeloid leukemia FLT3 mutations ROS induction NF-κB inhibition

Transforming a Two-Dimensional Layered Insulator into a Semiconductor or a Highly Conductive Metal through Transition Metal Ion Intercalation

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 Physics Letters 2021年第5期38卷 89-93页

作者： Xiu Yan Wei-Li Zhen Shi-Rui Weng ran-ran zhang Wen-Ka Zhu Li Pi Chang-Jin zhang High Magnetic Field Laboratory Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230031China University of Science and Technology of China Hefei 230026China Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601China

Atomically thin two-dimensional(2D) materials are the building bricks for next-generation electronics and optoelectronics, which demand plentiful functional properties in mechanics, transport, magnetism and *** electronic devices, not only metals and high-performance semiconductors but also insulators and dielectric materials are highly desirable. Layered structures composed of 2D materials of different properties can be delicately designed as various useful heterojunction or homojunction devices, in which the designs on the same material(namely homojunction) are of special interest because preparation techniques can be greatly simplified and atomically seamless interfaces can be achieved. We demonstrate that the insulating pristine ZnPS_3, a ternary transition-metal phosphorus trichalcogenide, can be transformed into a highly conductive metal and an n-type semiconductor by intercalating Co and Cu atoms, respectively. The field-effect-transistor(FET) devices are prepared via an ultraviolet exposure lithography technique. The Co-ZnPS_3 device exhibits an electrical conductivity of 8 × 10^(4) S/m, which is comparable to the conductivity of graphene. The Cu-ZnPS_3 FET reveals a current ON/OFF ratio of 1-05 and a mobility of 3 × 10^(-2 )cm^(2)·V^(-1)·s^(-1). The realization of an insulator, a typical semiconductor and a metallic state in the same 2D material provides an opportunity to fabricate n-metal homojunctions and other in-plane electronic functional devices.

关键词： Transforming a Two-Dimensional Layered Insulator into a Semiconductor or a Highly Conductive Metal through Transition Metal Ion Intercalation

Concurrent Structural and Electronic Phase Transitions in V_(2)O_(3)Thin Films with Sharp Resistivity Change

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2021年第7期38卷 79-84页

作者： Chuang Xie Ling Hu ran-ran zhang Shun-Jin Zhu Min Zhu Ren-Huai Wei Xian-Wu Tang Wen-Hai Song Xue-Bin Zhu Yu-Ping Sun Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601China Key Laboratory of Materials Physics Institute of Solid State PhysicsHFIPSChinese Academy of SciencesHefei 230031China High Magnetic Field Laboratory HFIPSChinese Academy of SciencesHefei 230031China Collaborative Innovation Center of Advanced Microstructures Nanjing 210093China

The relationship between structural and electronic phase transitions in V_(2)O_(3)thin films is of critical importance for understanding of the mechanism behind metal–insulator transition(MIT)and related technological *** being extensively studied,there are currently no clear consensus and picture of the relation between structural and electronic phase transitions so *** V_(2)O_(3)thin films grown on r-plane Al2O3 substrates,which exhibit abrupt MIT and structural phase transition,we show that the electronic phase transition occurs concurrently with the structural phase transition as revealed by the electrical transport and Raman spectra *** result provides experimental evidence for clarifying this issue,which could form the basis of theoretical studies as well as technological applications in V_(2)O_(3).

关键词： structural transition Transition

Pressure-induced enhancement of optoelectronic properties in PtS2

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第6期27卷 345-349页

作者： Yi-Fang Yuan Zhi-Tao zhang Wei-Ke Wang Yong-Hui Zhou Xu-Liang Chen Chao An ran-ran zhang Ying Zhou Chuan-Chuan Gu Liang Li Xin-Jian Li Zhao-Rong Yang Department of Physics and Laboratory of Material Physics Zhengzhou UniversityZhengzhou 450052China Anhui Provincial Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field LaboratoryChinese Academy of SciencesHefei 230031China Synergetic Innovation Center for Quantum Effects and Application Key Laboratory of Low-dimensional Quantum Structures and Quantum Control of Ministry of EducationCollege of Physics and Information ScienceHunan Normal UniversityChangsha 410081China State Key Laboratory of Material Processing and Die and Mould Technology School of Materials Science and EngineeringHuazhong University of Science and Technology(HUST)Wuhan 430074China Institute of Physical Science and Information Technology Anhui UniversityHefei 230601China

PtS2, which is one of the group-10 transition metal dichalcogenides, attracts increasing attention due to its extraordinary properties under external modulations as predicted by theory, such as tunable bandgap and indirect-to-direct gap transition under strain; however, these properties have not been verified experimentally. Here we report the first experimental exploration of its optoelectronic properties under external pressure. We find that the photocurrent is weakly pressuredependent below 3 GPa but increases significantly in the pressure range of 3 GPa–4 GPa, with a maximum ～ 6 times higher than that at ambient pressure. X-ray diffraction data shows that no structural phase transition can be observed up to26.8 GPa, which indicates a stable lattice structure of PtS2 under high pressure. This is further supported by our Raman measurements with an observation of linear blue-shifts of the two Raman-active modes to 6.4 GPa. The pressure-enhanced photocurrent is related to the indirect-to-direct/quasi-direct bandgap transition under pressure, resembling the gap behavior under compression strain as predicted theoretically.

关键词： high pressure optoelectronic properties transition metal disulfide

Pressure-Induced Metallization Accompanied by Elongated S–S Dimer in Charge Transfer Insulator NiS2

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2019年第10期36卷 53-57页

作者： Hao Wu Yong-Hui Zhou Yi-Fang Yuan Chun-Hua Chen Ying Zhou Bo-Wen zhang Xu-Liang Chen Chuan-Chuan Gu Chao An Shu-Yang Wang Meng-Yao Qi ran-ran zhang Li-Li zhang Xin-Jian Li Zhao-Rong Yang Department of Physics and Laboratory of Material Physics Zhengzhou UniversityZhengzhou 450052 Anhui Province Key Laboratory of Condensed Matter Physics at Extreme Conditions High Magnetic Field LaboratoryChinese Academy of SciencesHefei 230031 University of Science and Technology of China Hefei 230026 Institutes of Physical Science and Information Technology Anhui UniversityHefei 230601 Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204

The insulator-metal transition triggered by pressure in charge transfer insulator NiS2 is investigated by combining high-pressure electrical transport,synchrotron x-ray diffraction and Raman spectroscopy measurements up to40-50 *** compression,we show that the metallization firstly appears in the low temperature region at^3.2 GPa and then extends to room temperature at^8.0 *** the insulator-metal transition,the bond length of S-S dimer extracted from the synchrotron x-ray diffraction increases with pressure,which is supported by the observation of abnormal red-shift of the Raman modes between 3.2 and 7.1 *** the decreasing bonding-antibonding splitting due to the expansion of S-S dimer,the charge gap between the S-ppπ* band and the upper Hubbard band of Ni-3 d eg state is remarkabl.y *** results consistently indicate that the elongated S-S dimer plays a predominant role in the insulator-metal transition under high pressure,even though the p-d hybridization is enhanced simultaneously,in accordance with a scenario of charge-gap-controlled type.

关键词： NiS2 bonding charge