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Deep-ultraviolet nonlinear optical crystals: concept development and materials discovery

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Light(Science & Applications) 2022年第8期11卷 1718-1729页

作者： lei kang Zheshuai Lin Functional Crystals Lab Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing100190China

Deep-ultraviolet (DUV, wavelength λ < 200 nm) nonlinear optical (NLO) crystal is the core component of frequency conversion to generate DUV laser, which plays an important role in cutting-edge laser technology and fundamental science. Significant progress has been made in both experimental exploration and theoretical design in the field of DUV NLO crystals over the past three decades. In-depth insight into “structure-property correlations”, in particular, allows for rigorous and precise identification of DUV NLO crystals. In this article, we reviewed the current experimental and theoretical research progress while elucidating the core concepts and stringent criteria of qualified DUV phase-matched second-harmonic generation crystals. We also discussed the development of the DUV NLO “structure-property correlations” from first principles and how it has sparked interest in related materials, as well as future directions for obtaining potential DUV NLO crystals.

关键词： optical ultraviolet Deep

Characteristics of industrial structure evolution and isomorphism in Central Asia

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Journal of Geographical Sciences 2020年第11期30卷 1781-1801页

作者： kang lei LIU Yi Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

This study undertakes a systematic examination of characteristics of the spatio-temporal evolution of industrial economies in Central Asia from the perspectives of industrial scale,structural rationality,industrial competitiveness,and industrial *** results show that industrial structures in Central Asian countries are becoming increasingly advanced,with certain differences among them in the characteristics of this *** has long had a tertiary-secondary-primary industrial pattern,and productive services have played an increasingly prominent role in the development of its tertiary *** transformation of the industrial structure in Uzbekistan,from a secondary-tertiary-primary pattern at its independence from the Soviet Union to a tertiary-secondary-primary pattern,is ***'s industrial structure has also changed significantly in recent *** secondary industries shrunk while tertiary industries developed *** Kyrgyzstan,the ratios of secondary and tertiary industries to total industrial output have fluctuated significantly while considerable progress has been made in the service *** industrial structure of Turkmenistan is significantly lower than the other countries,and Turkmenistan is the only country in the Central Asian region which still shows a tertiary-secondary-primary industrial *** feasibility and competitiveness of the industrial structures of these five Central Asian countries have different *** has structural advantages but lags in competitiveness,Uzbekistan is driven by both structural and competitive advantages,Tajikistan enjoys structural advantages while Kyrgyzstan lags behind in competitiveness,and Turkmenistan has a competitiveness-driven ***,values of the similar coefficient index of the three industrial structures in these countries were mostly above 0.95,the coefficients of the secondary industrial subdivisions in some countries were b

关键词： industrial structure evolution industrial isomorphism shift-share analysis similar coefficient index Central Asian countries

A promising van der Waals two-dimensional nonlinear optical crystal NbOCl_(2) for ultrathin quantum light source

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Chinese Journal of Structural Chemistry 2023年第3期42卷 1-3页

作者： Hao Huo lei kang Functional Crystals Lab Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing100190China University of Chinese Academy of Sciences Beijing 100049China

Nonlinear optical(NLO)crystals are the key fundamental materials in modern optoelectronic information technology,which play an irre-placeable role in modern quantum optics and photonics in addition to traditional laser frequency conversion applications[1,2].Especially at a time when the international competition of quantum information tech-nology is becoming increasingly intense,high-performing NLO crystals as the strategic materials for optical quantum technology have received continuous attention from physical chemists and materials scientists.

关键词： optical quantum nonlinear

Large sliding regulation in van der waals layered nonlinear optical ternary chalcogenides

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npj Computational Materials 2023年第1期9卷 574-583页

作者： Qingchen Wu lei kang Jian Wu Zheshuai Lin Functional Crystals Lab Key Laboratory of Functional Crystals and Laser TechnologyTechnical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190People’s Republic of China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049People’s Republic of China State Key Laboratory of Low-Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084People’s Republic of China

Interlayer sliding modulation in van der Waals(vdW)layered materials opens opportunities to seek tunable applications for photonics and optoelectronics at the *** this work,focusing on ternary chalcogenides,dozens of typical vdW layered materials with the formula of A_(2)MZ_(4)(A,M=metal cation;Z=S/Se)were systematically classified and studied to illustrate the interlayer sliding modulation performance on nonlinear optical(NLO)effect and underlying *** on first-principles analysis,the screened Cd_(2)GeSe_(4) exhibits large second harmonic generation(SHG)deviation(>36 times between high-and low-SHG states)under sliding among all studied *** phenomenon arises from the polarization modulation induced by the vdW interlayer charge redistribution of two tetrahedral primitives in the ternary edge-sharing tetrahedral *** findings present a strategy to substantially modulate NLO properties by altering the interlayer charge coupling which is commonly thought to be very weak in vdW layered materials.

关键词： materials mechanism layered

Quantitative Evaluation of Ecological Cumulative Effects and Zoning Regulations for Prefectural Mining Units in China

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Chinese Geographical Science 2022年第1期32卷 49-63页

作者： MA Li kang lei TIAN Huazheng XU Die Institute of Geographic Sciences and Nature Resources Research Chinese Academy of SciencesBeijing 100101China Key Laboratory of Regional Sustainable Development Modeling Chinese Academy of SciencesBeijing 100101.China College of Resources ancl Environment University of Chinese Academy of SciencesBeijing 100049China

Although the development of energy and mineral resources strongly supports China’s rapid industrialization and urbanization,it has led to a series of ecological and environmental *** the spatial regulation considering the ecological and environmental protection on energy and mineral resource development areas is an important aspect of realizing China’s sustainable *** this study,we mapped,categorized,and analyzed the ecological cumulative effects of the Chinese 134 prefectural mining units based on the pressure-state-response model,which is demonstrated as impact of mining activities on ecological environment,ecological environmental fragility,and ecological *** investigation developed a stress zoning typology of the mining units based on scores of three dimensions of the ecological cumulative effects and classified 134 prefectural mining units into eight types of stress zones.A series of regulation and policy suggestions have been proposed to different types of zones from three aspects:space control,intensity control,and development mode *** application of this evaluation and spatial zoning system will contribute to the refined spatial management of China’s mining areas.

关键词： ecological cumulative effects quantitative evaluation pressure-state-response model zoning

Experimental study of an anti-icing method over an airfoil based on pulsed dielectric barrier discharge plasma

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Chinese Journal of Aeronautics 2018年第7期31卷 1449-1460页

作者： Yongqiang TIAN Zhengke ZHANG Jinsheng CAI leilei YANG lei kang National Key Laboratory of Science and Technology on Aerodynamical Design and Research Northwestern Polytechnical University

Aircraft icing has long been a plague to aviation for its serious threat to flight safety. Even though lots of methods for anti-icing have been in use or studied for quite a long time, new methods are still in great demand for both civil and military aircraft. The current study in this paper uses widely used Dielectric Barrier Discharge（DBD） plasma actuation to anti-ice on a NACA0012 airfoil model with a chord length of 53.5 cm in a closed-circuit icing wind tunnel. An actuator was installed at the leading edge of the airfoil model, and actuated by a pulsed low-temperature plasma power source. The actuator has two types of layout, a striped electrode layout and a meshy electrode *** ice accretion process or anti-icing process was recorded by a CCD camera and an infrared camera. Instantaneous pictures and infrared contours show that both types of DBD plasma actuators have the ability for anti-ice under a freestream velocity of 90 m/s, a static temperature of -7℃,an Median Volume droplet Diameter（MVD） of 20 lm, and an Liquid Water Content（LWC） of 0.5 g/m^3. The detected variations of temperatures with time at specific locations reveal that the temperatures oscillate for some time after spraying at first, and then tend to be nearly constant *** shows that the key point of the anti-icing mechanism with DBD plasma actuation is to achieve a thermal equilibrium on the model surface. Besides, the power consumption in the anti-icing process was estimated in this paper by Lissajous figures measured by an oscilloscope, and it is lower than those of existing anti-icing methods. The experimental results presented in this paper indicate that the DBD plasma anti-icing method is a promising technique in the future.

关键词： Anti,icing Icing wind tunnel Lissajous figures PlaSma actuator Pulsed dielectric barrier discharge

Metamorphism and geochronology of garnet amphibolite from the Beishan Orogen,southern Central Asian Orogenic Belt:Constraints from P-T path and zircon U-Pb dating

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Geoscience Frontiers 2020年第4期11卷 1189-1201页

作者： Wenbin kang Wei Li lei kang Yunpeng Dong Dazhi Jiang Jiwei Liang Haoqiang Dong State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi’an 710069China Key Laboratory for the Study of Focused Magmatism and Giant Ore Deposits of Ministry of Natural Resources Xi'an Center of China Geological SurveyCGSXi'an 710054ShaanxiChina Department of Earth Sciences Western UniversityLondonOntarioN6A 5B7Canada School of Earth Science&Resources Chang’an UniversityXi’an 710054China

Numerous lenses of garnet amphibolite occur in the garnet-bearing biotite-plagioclase gneiss belt in the Baishan area of the Beishan Orogen,which connects the Tianshan Orogen to the west and the Mongolia-Xing’anling Orogen to the *** study of metamorphism in Beishan area is of great significance to explain the tectonic evolution of Beishan *** to the microstructures,mineral relationships,and geothermobarometry,we identified four stages of mineral assemblages from the garnet amphibolite sample:(1) a pre-peak stage,which is recorded by the cores of garnet together with core-inclusions of plagioclase(Pl1);(2) a peak stage,which is recorded by the mantles of garnet together with mantle-inclusions of plagioclase(Pl2)+amphibole(Amp1)+Ilmenite(Ilm1)+biotite(Bt1),developed at temperature-pressure(P-T) conditions of 818.9-836.5℃ and7.3-9.2 kbar;(3) a retrograde stage,which is recorded by garnet rims + plagioclase(Pl3)+amphibole(Amp2)+orthopyroxene(Opx1)+biotite(Bt2)+Ilmenite(Ilm2),developed at P-T conditions of 796.1-836.9℃ and5.6-7.5 kbar;(4) a symplectitic stage,which is recorded by plagioclase(Pl4)+orthopyroxene(Opx2)+amphibole(Amp3)+biotite(Bt3) symplectites,developed at P-T conditions of 732 ±59.6℃ and 6.1 ±0.6 ***,the U-Pb dating of the Beishan garnet amphibolite indicates an age of 301.9 ±4.7 Ma for the protolith and 281.4±8.5 Ma for the peak metamorphic ***,the mineral assemblage,P-T conditions,and zircon U-Pb ages of the Beishan garnet amphibolite define a near-isothermal decompression of a clockwise P-T-t(Pressure-Temperature-time) path,indicating the presence of over thickened continental crust in the Huaniushan arc until the Early Permian,then the southern Beishan area underwent a process of thinning of the continental crust.

关键词： Beishan orogen Garnet amphibolite P-T-t path Zircon U-Pb dating

Synthesis of a Novelα-Methylene-β-carboxy-γ-thiobutyrolactones

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Chinese Chemical Letters 2005年第11期16卷 1431-1433页

作者： Xiao Kui WANG Jian lei kang Song LI Beijing Institute of Pharmacology ＆ Toxicology Beijing 100850

A new series compounds, α-methylene-β-carboxy-γ-thiobutyrolactones, have been prepared and their biological evaluation in vitro and in vivo have been described. The structures of these compounds were confirmed by ^... 详细信息

关键词： Fatty acid synthase α-methylene-β-carboxy-γ-thiobutyrolactones synthesis.

Prediction of properties distribution of 7B50 alloy thick plates after quenching and aging by quench factor analysis method

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Rare Metals 2019年第11期38卷 1043-1050页

作者： lei kang Yi-Ran Zhou Gang Zhao Kun Liu Ni Tian Key Laboratory for Anisotropy and Texture of Materials Ministry of EducationSchool of Materials Science and EngineeringNortheastern UniversityShenyang 110819China Department of Applied Science University of Quebec at ChicoutimiSaguenayQC G7H 2B1Canada

In the present work,continuous cooling curves were accurately measured by the modified Jominy specimen of 7B50 alloy during water-spray quenching ***,the time-temperature-properties(TTP) curves of this alloy were obtained during isothermal *** on the accurate cooling curves and TTP curves,the hardness distribution along the thickness direction of 7B50 alloy thick plates was predicted by quench factor analysis *** is found that the quench sensitive temperature range of 7B50 alloy is 240-410℃,the nose temperature is 335℃,and the incubation period at the nose temperature is about 0.87 *** 7B50 alloy was isothermal treated at 180-400℃ after solid solution treatment(470℃ for 1 h followed by 483℃ for 2 h),the exponent(n) in the Johnson-Mehl-Avrami equation is close to 1 until transformed fraction of new precipitates is up to 60%,indicating that new precipitates first grow into rodlike shape and then coarsen or *** the distance is less than 65 mm from the spray quenching surface of the modified Jominy specimen,the deviation between the predicted and measured hardness is less than 2.7%,confirming the quench factor analysis method as the feasible way to predict the hardness distribution along the thickness direction of 7B50 alloy thick *** the distance from the spray quenching surface is 25 mm,the average cooling rate in quench sensitive temperature range is 9.93 ℃·s^-1,while the quench factor(τ) is 9.89 and the corresponding predicted hardness is HV 185.1 equivalent to 97.3% of the maximum measured hardness of 7B50 alloy in T6 temper.

关键词： 7B50 aluminum alloy Quench factor analysis method Time-temperature-properties curve Continuous cooling curve Properties prediction