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对船用千斤索稳索电气线路设计的探讨
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作者 林山鸣 徐慎康 《船电通讯》 1991年第1期36-37,共2页
关键词 船舶 千斤稳索 电气线路 设计
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船舶稳索绞车用电动机的工况及设计特点
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作者 张良基 《船电通讯》 1991年第4期29-31,共3页
关键词 船舶 稳索绞车 电动机 设计
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稳索系固位置对双吊杆受力的影响
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作者 于洋 顾玉升 李伟 《大连海事大学学报》 CAS CSCD 1996年第3期20-23,共4页
给出了双吊杆受力的数学表达式,通过数值模拟分析了稳索系固位置对吊杆、稳索和千斤索受力的影响,有助于合理选择稳索的系结位置.
关键词 双吊杆 稳索 千斤 船舶 起货设备 受力
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索他洛尔联合稳心颗粒对心动过速患者心率及血浆AngⅡ与VIP含量影响的研究 被引量:6
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作者 王鹏 姚光涛 +3 位作者 王莉 董宏伟 张强 李莹 《中华中医药学刊》 CAS 北大核心 2016年第3期763-766,共4页
目的:探讨索他洛尔联合稳心颗粒对心动过速患者心率及血浆血管紧张素Ⅱ(AngⅡ)与血管活性肠肽(VIP)含量的影响。方法:收集医院收治的阵发性室上性心动过速患者56例,随机分为对照组和实验组,每组各28例,对照组给予盐酸索他洛尔片口服治疗... 目的:探讨索他洛尔联合稳心颗粒对心动过速患者心率及血浆血管紧张素Ⅱ(AngⅡ)与血管活性肠肽(VIP)含量的影响。方法:收集医院收治的阵发性室上性心动过速患者56例,随机分为对照组和实验组,每组各28例,对照组给予盐酸索他洛尔片口服治疗,实验组在对照组基础上给予稳心颗粒口服治疗,治疗周期为2周,治疗结束后,对所有患者的血浆AngⅡ、肾素(PRA)、醛固酮(ALD)、VIP含量、心率、心率变异性情况及临床疗效进行检测。结果:治疗后,与对照组比较,(1)实验组患者心率明显较低,差异具有统计学意义(P<0.05);(2)实验组患者的SDNN、r MSSD、PNN50水平较高,SDANN水平较低(P<0.05);(3)实验组患者血浆AngⅡ、PRA、ALD含量较低(P<0.05);(4)实验组患者血浆VIP水平较高(P<0.05);(5)实验组患者总有效率较高(P<0.05)。结论:索他洛尔联合稳心颗粒能够显著升高心动过速患者血浆VIP水平,降低血浆AngⅡ、PRA、ALD水平,降低心率以及心率变异性,临床疗效显著,对临床有指导意义。 展开更多
关键词 他洛尔联合心颗粒 心动过速 AngⅡ VIP
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Aerodynamic stability of cable-supported bridges using CFRP cables 被引量:5
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作者 ZHANG Xin-jun YING Lei-dong 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第5期693-698,共6页
To gain understanding of the applicability of carbon fiber reinforced polymer (CFRP) cable in cable-supported bridges, based on the Runyang Bridge and Jinsha Bridge, a suspension bridge using CFRP cables and a cable-s... To gain understanding of the applicability of carbon fiber reinforced polymer (CFRP) cable in cable-supported bridges, based on the Runyang Bridge and Jinsha Bridge, a suspension bridge using CFRP cables and a cable-stayed bridge using CFRP stay cables are designed, in which the cable’s cross-sectional area is determined by the principle of equivalent axial stiffness. Numerical investigations on the aerodynamic stability of the two bridges are conducted by 3D nonlinear aerodynamic stability analysis. The results showed that as CFRP cables are used in cable-supported bridges, for suspension bridge, its aerodynamic stability is superior to that of the case using steel cables due to the great increase of the torsional frequency; for cable-stayed bridge, its aerodynamic stability is basically the same as that of the case using steel stay cables. Therefore as far as the wind stability is considered, the use of CFRP cables in cable-supported bridges is feasible, and the cable’s cross-sectional area should be deter-mined by the principle of equivalent axial stiffness. 展开更多
关键词 Cable-supported bridges Carbon fiber reinforced polymer (CFRP) cable Aerodynamic stability
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Aerodynamic stability of cable-stayed bridges under erection
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作者 张新军 孙炳楠 项海帆 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2005年第3期175-180,共6页
In this work, nonlinear multimode aerodynamic analysis of the Jingsha Bridge under erection over the Yangtze River is conducted, and the evolutions of structural dynamic characteristics and the aerodynamic stability w... In this work, nonlinear multimode aerodynamic analysis of the Jingsha Bridge under erection over the Yangtze River is conducted, and the evolutions of structural dynamic characteristics and the aerodynamic stability with erection are numerically generated. Instead of the simplified method, nonlinear multimode aerodynamic analysis is suggested to predict the aerodynamic stability of cable-stayed bridges under erection. The analysis showed that the aerodynamic stability maximizes at the relatively early stages, and decreases as the erection proceeds. The removal of the temporary piers in side spans and linking of the main girder to the anchor piers have important influence on the dynamic characteristics and aerodynamic stability of cable-stayed bridges under erection. 展开更多
关键词 Cable-stayed bridge Erection stage Aerodynamic stability Nonlinear multimode aerodynamic analysis
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Search for circular and noncircular critical slip surfaces in slope stability analysis by hybrid genetic algorithm 被引量:8
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作者 朱剑锋 陈昌富 《Journal of Central South University》 SCIE EI CAS 2014年第1期387-397,共11页
A local improvement procedure based on tabu search(TS) was incorporated into a basic genetic algorithm(GA) and a global optimal algorithm,i.e.,hybrid genetic algorithm(HGA) approach was used to search the circular and... A local improvement procedure based on tabu search(TS) was incorporated into a basic genetic algorithm(GA) and a global optimal algorithm,i.e.,hybrid genetic algorithm(HGA) approach was used to search the circular and noncircular slip surfaces associated with their minimum safety factors.The slope safety factors of circular and noncircular critical slip surfaces were calculated by the simplified Bishop method and an improved Morgenstern-Price method which can be conveniently programmed,respectively.Comparisons with other methods were made which indicate the high efficiency and accuracy of the HGA approach.The HGA approach was used to calculate one case example and the results demonstrated its applicability to practical engineering. 展开更多
关键词 SLOPE STABILITY genetic algorithm tabu search algorithm safety factor
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Left atrial area index predicts adverse cardiovascular events in patients with unstable angina pectoris 被引量:6
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作者 Yi-Fan LI Wei-Hong LI +4 位作者 Zhao-Ping LI Xin-Heng FENG Wei-Xian XU Shao-Min CHEN Wei GAO 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2016年第8期652-657,共6页
Background The left atrial size has been considered as a useful marker of adverse cardiovascular outcomes. However, it is not well known whether left atrial area index (LAAI) has predictive value for prognosis in pa... Background The left atrial size has been considered as a useful marker of adverse cardiovascular outcomes. However, it is not well known whether left atrial area index (LAAI) has predictive value for prognosis in patients with unstable angina pectoris (UAP). This study was aimed to assess the association between LAAI and outcomes in UAP patients. Methods We enrolled a total of 391 in-hospital patients diag- nosed as UAP. Clinical and echocardiographic data at baseline were collected. The patients were followed for the development of ad- verse cardiovascular (CV) events, including hospital readmission for angina pectoris, acute myocardial infarction (AMI), congestive heart failure (CHF), stroke and all-cause mortality. Results During a mean follow-up time of 26.3±8.6 months, 98 adverse CV events occurred (84 hospital readmission for angina pectoris, four AMI, four CHF, one stroke and five all-cause mortality). In a multivariate Cox model, LAAI [OR: 1.140, 95% CI: 1.01±1.279, P = 0.026], diastolic blood pressure (OR: 0.976, 95% CI: 0.956-0.996, P = 0.020) and pulse pressure (OR 1.020, 95% CI: 1.007-1.034, P = 0.004) were independent predictors for adverse CV events in UAP patients. Conclusions LAAI is a predictor of adverse CV events independent of clinical and other echocardiographic parameters in UAP patients. 展开更多
关键词 Adverse cardiovascular events Left atrial area index Prognostic factor Unstable angina pectoris
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Damping Identification of Bridges Under Nonstationary Ambient Vibration 被引量:5
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作者 Sunjoong Kim Ho-Kyung Kim 《Engineering》 SCIE EI 2017年第6期839-844,共6页
This research focuses on identifying the damping ratio of bridges using nonstationary ambient vibration data. The damping ratios of bridges in service have generally been identified using operational modal analysis (... This research focuses on identifying the damping ratio of bridges using nonstationary ambient vibration data. The damping ratios of bridges in service have generally been identified using operational modal analysis (OMA) based on a stationary white noise assumption for input signals. However, most bridges are generally subjected to nonstationary excitations while in service, and this violation of the basic assumption can lead to uncertainties in damping identification. To deal with nonstationarity, an amplitude-modulating function was calculated from measured responses to eliminate global trends caused by nonstationary input. A natural excitation technique (NExT)-eigensystem realization algorithm (ERA) was applied to estimate the damping ratio for a stationarized process. To improve the accuracy of OMA-based damping estimates, a comparative analysis was performed between an extracted stationary process and nonstationary data to assess the effect of eliminating nonstationarity. The mean value and standard deviation of the damping ratio for the first vertical mode decreased after signal stationarization. 展开更多
关键词 DAMPING Operational modal analysis Traffic-induced vibration NONSTATIONARY Signal stationarization Amplitude-modulating Bridge CABLE-STAYED SUSPENSION
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Research on Stability Calculation Methods for Grillage Supporting Structure with Pre-stressed Anchor
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作者 Xiangling Zhou 《International Journal of Technology Management》 2014年第7期89-91,共3页
Aiming at prestressed anchor cable frame in the presence of reinforcement landslide problem, through the selection of test points, the paper study and tested soil pressure, frame internal force and prestress losses un... Aiming at prestressed anchor cable frame in the presence of reinforcement landslide problem, through the selection of test points, the paper study and tested soil pressure, frame internal force and prestress losses under prestressed anchor cable frame beam, reveal the law of internal force distribution, and provides a theory basis for the rational design of prestressed anchor cable in landslide. 展开更多
关键词 Frame anchor RELIABILITY lateral pressure coefficient landslide reinforcement
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Novel Adaptive Simulated Annealing Algorithm for Constrained Multi-Objective Optimization 被引量:4
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作者 Chuai Gang Zhao Dan Sun Li 《China Communications》 SCIE CSCD 2012年第9期68-78,共11页
In recent years, sinmlated annealing algo-rithms have been extensively developed and uti-lized to solve nmlti-objective optimization problems. In order to obtain better optimization perfonmnce, this paper proposes a N... In recent years, sinmlated annealing algo-rithms have been extensively developed and uti-lized to solve nmlti-objective optimization problems. In order to obtain better optimization perfonmnce, this paper proposes a Novel Adaptive Simulated Annealing (NASA) algorithm for constrained multi-objective optimization based on Archived Multi-objective Simulated Annealing (AMOSA). For han-dling multi-objective, NASA makes improverrents in three aspects: sub-iteration search, sub-archive and adaptive search, which effectively strengthen the stability and efficiency of the algorithnm For handling constraints, NASA introduces corresponding solution acceptance criterion. Furtherrrore, NASA has also been applied to optimize TD-LTE network perform-ance by adjusting antenna paranleters; it can achieve better extension and convergence than AMOSA, NS-GAII and MOPSO. Analytical studies and simulations indicate that the proposed NASA algorithm can play an important role in improving multi-objective optimi-zation performance. 展开更多
关键词 simulated annealing constrained rmlti-objective optimizaztion adaptive sub-iteration search-ing sub-archive PARETO-OPTIMAL
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A multi-objective gravitational search algorithm based approach of power system stability enhancement with UPFC 被引量:6
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作者 Ajami Ali Armaghan Mehdi 《Journal of Central South University》 SCIE EI CAS 2013年第6期1536-1544,共9页
On the basis of the theoretical analysis of a single-machine infinite-bus (SMIB), using the modified linearized Phil- lips-Heffron model installed with unified power flow controller (UPFC), the potential of the UP... On the basis of the theoretical analysis of a single-machine infinite-bus (SMIB), using the modified linearized Phil- lips-Heffron model installed with unified power flow controller (UPFC), the potential of the UPFC supplementary controller to enhance the dynamic stability of a power system is evaluated by measuring the electromechanical controllability through singular value decomposition (SVD) analysis. This controller is tuned to simultaneously shift the undamped electromeehanical modes to a prescribed zone in the s-plane. The problem of robust UPFC based damping controller is formulated as an optimization problem according to the eigenvalue-based multi-objective function comprising the damping factor, and the damping ratio of the undamped electromechanical modes to be solved using gravitational search algorithm (GSA) that has a strong ability to find the most optimistic results. The different loading conditions are simulated on a SMIB system and the rotor speed deviation, internal voltage deviation, DC voltage deviation and electrical power deviation responses are studied with the effect of this flexible AC transmission systems (FACTS) controller. The results reveal that the tuned GSA based UPFC controller using the proposed multi-objective function has an excellent capability in damping power system with low frequency oscillations and greatly enhances the dynamic stability of the power systems. 展开更多
关键词 unified power flow controller gravitational search algorithm power system stability
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The Application of the Combined Method for Selection of Optimal Excitation Parameters
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作者 Roman Petrichenko Inga Zicmane +1 位作者 Michal Kolcun Matus Novak 《Journal of Energy and Power Engineering》 2014年第4期724-728,共5页
The quality as well as reliability of electrical energy transmitted to consumers is one of the main parameters of successful operation of the power system. The searching of optimal coefficient's combination of PSS (... The quality as well as reliability of electrical energy transmitted to consumers is one of the main parameters of successful operation of the power system. The searching of optimal coefficient's combination of PSS (power system stabilizer) is the main goal of this article. The possibility of application of the new combined approach for the optimal excitation's settings search is presented. MC (Monte Carlo) method, in order to search and select the optimal combination of excitation system, was applied. The proposed method has been researched with a mathematical model of the power system. This model has been built using Matlab/Simulink software. Paper shows advantages and disadvantages of the proposed methods. 展开更多
关键词 Power systems stabilizer excitation parameters Monte Carlo method.
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车辐式张拉结构体型研究与设计 被引量:28
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作者 郭彦林 王昆 +1 位作者 田广宇 张博浩 《建筑结构学报》 EI CAS CSCD 北大核心 2013年第5期1-10,共10页
掌握车辐式张拉结构的找形方法和了解体型对结构受力性能的影响,是设计该类轻型屋面的关键,为此结合理论推导和数值模拟方法对这两方面展开研究。首先,引入力密度法用于结构初始平衡态的确定,提出"由形找力再找形"的思路,从... 掌握车辐式张拉结构的找形方法和了解体型对结构受力性能的影响,是设计该类轻型屋面的关键,为此结合理论推导和数值模拟方法对这两方面展开研究。首先,引入力密度法用于结构初始平衡态的确定,提出"由形找力再找形"的思路,从而避免了拓展力密度法收敛性差的缺点,成功实现了马鞍形车辐式张拉结构的找形分析。然后,分别从内外环平面投影、外环空间形态以及索桁架形式等多个角度对单、双层车辐式结构的体型进行比选,分析不同体型结构的适用性和结构刚度的主要影响因素。研究结果表明:内外环形状相似对车辐式结构最为有利;马鞍形外环的高差对结构刚度影响很小;凸索桁架能有效提高结构刚度,但应注意避免侧向失稳。 展开更多
关键词 车辐式张拉结构 找形分析 力密度法 体型研究 桁架侧向失
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A novel superhard tungsten nitride predicted by machine-learning accelerated crystal structure search 被引量:16
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作者 Kang Xia Hao Gao +4 位作者 Cong Liu Jianan Yuan Jian Sun Hui-Tian Wang Dingyu Xing 《Science Bulletin》 SCIE EI CSCD 2018年第13期817-824,共8页
Transition metal nitrides have been suggested to have both high hardness and good thermal stability with large potential application value, but so far stable superhard transition metal nitrides have not been synthesiz... Transition metal nitrides have been suggested to have both high hardness and good thermal stability with large potential application value, but so far stable superhard transition metal nitrides have not been synthesized. Here, with our newly developed machine-learning accelerated crystal structure searching method, we designed a superhard tungsten nitride, h-WN6, which can be synthesized at pressure around 65 GPa and quenchable to ambient pressure. This h-WN6 is constructed with single-bonded armchair-like N6 rings and presents ionic-like features, which can be formulated as W^2.4+N^2.4-. It has a band gap of 1.6 eV at 0GPa and exhibits an abnormal gap broadening behavior under pressure. Excitingly, this h-WN6 is found to be the hardest among transition metal nitrides known so far (Vickers hardness around 57 GPa) and also has a very high melting temperature (around 1,900 K). Additionally, the good gravimet- ric (3.1 kJ/g/and volumetric (28.0 kJ/cm3) energy densities make this nitrogen-rich compound a potential high-energy-density material, These predictions support the designing rules and may stimulate future experiments to synthesize superhard and high-energy-density material. 展开更多
关键词 Tungsten nitride Transition metal nitrides Machine-learning accelerated crystal structure searching method Superhard tungsten nitride
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Behavioral constraints and the evolution of faithful social learning 被引量:1
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作者 Alberto ACERBI Pierre O. JACQUET Claudio TENNIE 《Current Zoology》 SCIE CAS CSCD 2012年第2期307-318,共12页
Behavioral "traditions", i.e. behavioral patterns that are acquired with the aid of social learning and that are relatively stable in a group, have been observed in several species. Recently, however, it has been qu... Behavioral "traditions", i.e. behavioral patterns that are acquired with the aid of social learning and that are relatively stable in a group, have been observed in several species. Recently, however, it has been questioned whether non-human social learning is faithful enough to stabilize those patterns. The observed stability could be interpreted as a result of various constraints that limit the number of possible alternative behaviors, rather than of the fidelity of transmission mechanisms. Those constraints can be roughly described as "internal", such as mechanical (bodily) properties or cognitive limitations and predispositions, and "ex- ternal", such as ecological availability or pressures. Here we present an evolutionary individual-based model that explores the re- lationships between the evolution of faithful social learning and behavioral constraints, represented both by the size of the beha- vioral repertoire and by the "shape" of the search space of a given task. We show that the evolution of high-fidelity transmission mechanisms, when associated with costs (e.g. cognitive, biomechanical, energetic, etc.), is only likely if the potential behavioral repertoire of a species is large and if the search space does not provide information that can be exploited by individual learning. Moreover we show how stable behavioral patterns ("traditions") can be achieved at the population level as an outcome of both high-fidelity and low-fidelity transmission mechanisms, given that the latter are coupled with a small behavioral repertoire or with a search space that provide substantial feedback. Finally, by introducing the possibility of environmental change, we show that intermediate rates of change favor the evolution of faithful social learning 展开更多
关键词 Animal social learning Cultural evolution Cultural transmission Copying fidelity Individual based modeling
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Holocene climate change in the Central Tibetan Plateau inferred by lacustrine sediment geochemical records 被引量:16
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作者 Andreas LüCKE Bernd WüNNEMANN 《Science China Earth Sciences》 SCIE EI CAS 2007年第10期1548-1555,共8页
Multi-proxies of lacustrine sediments, such as total carbon (TC), total organic carbon (TOC), total inorganic carbon (TIC), total nitrogen (TN), total sulfur (TS), hydrogen index (HI), oxygen index (OI) and stable car... Multi-proxies of lacustrine sediments, such as total carbon (TC), total organic carbon (TOC), total inorganic carbon (TIC), total nitrogen (TN), total sulfur (TS), hydrogen index (HI), oxygen index (OI) and stable carbon isotopic composition of organic matter (δ^(13)C_(org)), were analyzed using a 7.3 m core from Zige Tangco. The source of the organic matter in the sediment was mainly from autochthonous phyto-plankton, therefore the significances of proxies can be interpreted as that high TOC, TOC/TS, HI and δ^(13)C_(org) values, low TC, TIC values corresponded to warm and wet climatic condition, and vice versa. The process of climatic development in the Zige Tangco region was hence recovered. During the early and Mid-Holocene, the climate was warm and wet and intensive cold events occurred during the periods of 8600 to 8400 cal a BP and 7400 to 7000 cal a BP. In the second half of Holocene, the climate became cold and dry gradually. The palaeoclimatic process during Holocene in Zige Tangco region matched well with that in Co Ngoin region which is ca 40 km to the south-east. Therefore this palaeoclimatic process represents the Holocene climatic feature in the Central Tibetan Plateau which has the same pattern in the Northern Tibetan Plateau, but the time and duration of some climatic events might be different. We can conclude that in Holocene solar insolation controlled the climatic pattern on the central Tibetan Plateau. 展开更多
关键词 lacustrine sediment hydrogen index (HI) stable carbon isotopic composition (δ^(13)C_(org)) PALAEOCLIMATE Central Tibetan Plateau
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Rational design of new phases of tin monosulfide by first-principles structure searches 被引量:1
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作者 XueTing Wang YuWei Li +4 位作者 Yu-Xuan Pang YuanHui Sun Xin-Gang Zhao Jin-Rui Wang LiJun Zhang 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2018年第10期78-84,共7页
Tin monosulfide(Sn S), which is composed of earth-abundant elements, holds promise as useful high-performance solar absorber and thermoelectric material. In addition to the ground-state Pnma phase, a series of metasta... Tin monosulfide(Sn S), which is composed of earth-abundant elements, holds promise as useful high-performance solar absorber and thermoelectric material. In addition to the ground-state Pnma phase, a series of metastable phases in different crystalline structures have been reported experimentally or theoretically, yet the phase stability diagrams remain elusive. In this article, we provide a comprehensive materials design study of new phases of Sn S using first-principles global optimization structure search calculations. We find that the two-dimensional layered phases are generally more energetically favored than the three-dimensional connected phases. In addition, we discover several new phases with comparable energetics. Four lower-energy phases show clear phonon stabilities evidenced by an absence of imaginary modes. The electronic band structures, carrier transport properties, and absorption spectra of the newly discovered phases are investigated and discussed toward potential applications for solar cells and thermoelectric devices. 展开更多
关键词 tin monosulfide PHOTOVOLTAIC ANISOTROPIC effective masses
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