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Effect of Time-Dependent Atomic Scattering Length on Solitons in Bose-Einstein Condensates with a Complex Potential

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Communications in Theoretical Physics 2009年第2期51卷 255-258页

作者： WANG tian-yuan School of Physics and Electronics Yunnan Nationalities University Kunming 650031 China

We consider the one-dimensional nonlinear Schrǒdinger equations that describe the dynamics of a Bose-Einstein Condensates with time-dependent scattering length in a complex potential. Our results show that as long as the integrable relation is satisfied, exact solutions of the one-dimensional nonlinear Schrǒdinger equation can be found in a general closed form, and interactions between two solitons are modulated in a complex potential We find that the changes of the scattering length and trapping potential can be effectively used to control the interaction between two bright soliton.

关键词： Bos-Einstein condensate scattering length soliton

An algorithm based on evidence theory and fuzzy entropy to defend against SSDF

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Journal of Systems Engineering and Electronics 2020年第2期31卷 243-251页

作者： YE Fang BAI Ping tian yuan College of Information and Communication Engineering Harbin Engineering UniversityHarbin 150001China

In cognitive radio networks, spectrum sensing is one of the most important functions to identify available spectrum for improving the spectrum utilization. Due to the open characteristic of the wireless electromagnetic environment, the wireless network is vulnerable to be attacked by malicious users(MUs), and spectrum sensing data falsification(SSDF) attack is one of the most harmful attacks on spectrum sensing performance. In this article,an algorithm based on the evidence theory and fuzzy entropy is proposed to resist SSDF attacks. In this algorithm, secondary users(SUs) obtain the corresponding degree of membership function and basic probability assignment function based on the local energy detection result. The new conflicting coefficient is calculated based on the evidence distance and classical conflicting coefficient, and the conflicting weight of the evidence is *** fuzzy weight is calculated by the fuzzy entropy. The credibility weight is obtained by updating the credibility. On this basis, the probability assignment function of the evidence is corrected, and the final result is obtained by using the fusion formula. Simulation results show that the proposed algorithm has a higher detection probability and lower false alarm probability than other *** can effectively defend against SSDF attacks and improve the performance of spectrum sensing.

关键词： cooperative spectrum sensing evidence theory fuzzy entropy spectrum sensing data falsification(SSDF)

Cornerstone of molecular spintronics: Strategies for reliable organic spin valves

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Nano Research 2021年第11期14卷 3653-3668页

作者： Shuaishuai Ding yuan tian Wenping Hu tianjin Key Laboratory of Molecular Optoelectronic Sciences Department of ChemistrySchool of SciencesTianjin UniversityTianjin300072China School of Physics&Electronics Hunan UniversityHunan410082China Collaborative Innovation Center of Chemical Science and Engineering Tianjin300072China Joint School of National University of Singapore and tianjin University International Campus of Tianjin UniversityBinhai New CityFuzhou350207China

Organic spin valve (OSV), one of the most promising and representative devices involving spin injection, transport and detection, has drawn tremendous attention owing to their ultra-long spin relaxation time in the field of molecular spintronics. Since the first demonstration of truly worked vertical OSV device in 2004, efforts in enhancement of high performance and pursuit of spin-related nature have been devoted in related field. It offers a new opportunity to develop the integrated flexible multi-functional arrays based on spintronics in the future. However, the unreliable working state in OSVs due to the lack of exploration on interface control will cause severe impact on the performance evaluation and further restrict their practical application. Herein, we focus on the recent progress in strategies for reliable fabrication and evaluation of typical OSVs in vertical configuration. Firstly, the challenges in protection of two spin interface properties and identification of spin-valve-like signals were proposed. Then, three points for attention including selection of bottom electrodes, optimization of organic spacer, and prevention of metal penetration to improve the device performance and reliability were mentioned. Particularly, various modified strategies to solve the “dead layer” issue were highlighted. Furthermore, we discussed the general protocols in the reliable evaluation of OSVs’ performance and transport mechanism identification. Notably, several key fundamentals resulting in spurious magnetoresistance (MR) response were illustrated. Finally, we also highlighted the future perspectives on spintronic devices of organic materials.

关键词： molecular spintronics organic spin valves magnetoresistance device reliability fair performance evaluation

Deformation‑Induced Strengthening Mechanism in a Newly Designed L‑40 Tool Steel Manufactured by Laser Powder Bed Fusion

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Acta Metallurgica Sinica(English Letters) 2023年第1期36卷 21-34页

作者： yuan tian Kanwal Chadha Clodualdo Aranas Jr Voestalpine Additive Manufacturing Centre Ltd MississaugaON L5N 7Y3Canada Department of Mechanical Engineering University of New BrunswickFrederictonNB E3B 5A3Canada Planetary and Space Science Centre University of New BrunswickFrederictonNB E3B 5A3Canada

The microstructural and mechanical properties of a newly designed tool steel(L-40),specifcally designed to be employed in the laser powder bed fusion(LPBF)technique,were *** pool boundaries with submicron dendritic structures and about 14%retained austenite phase were evident after *** grain orientation after high cooling rate solidifcation is mostlyα∥building direction(BD).Then,the heat treatment converted the microstructure into a conventional martensitic phase,reduced the retained austenite to about 1.5%,and increasedα∥BD *** heat-treated sample exhibits higher tensile strength(1720±14 MPa)compared to the as-printed sample(1540±26 MPa)along the building direction,mainly due to hardening caused by a lower volume fraction of retained austenite phase and precipitation of *** a consequence of the strength-to-ductility trade-of,the heat-treated sample showed lower elongation(10%±2%)than that of the as-printed sample(18%±2%).It was observed that transformation-induced plasticity(TRIP)occurs in both the as-printed and heat-treated samples during tensile testing,which dynamically transforms the retained austenite into martensite,leading to improved *** minimum driving force to initiate the displacive phase transformation is about 6000 J/mol,which was achieved during tensile *** strength and ductility of LPBF-produced L-40 were compared with the other LPBF-produced tool steels in literature;the data indicate that heat-treated L-40 has an excellent combination of strength and ductility complemented with high printability.

关键词： Additive manufacturing Laser powder bed fusion L-40 tool steel Phase transformation

木犀草素改善脊髓损伤大鼠血清诱导的心肌细胞死亡

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中国组织工程研究 2025年第1期29卷 38-43页

作者：张稳稳徐梦如田园张立飞师姝王宁原媛王丽郝海虎山西中医药大学第一临床学院山西省晋中市030600 山西医科大学第三医院山西白求恩医院山西医学科学院骨科山西省太原市030000 山西医科大学基础医学研究中心山西省晋中市030600 山西医科大学基础医学院病理教研室山西省晋中市030600

背景:脊髓损伤导致的心功能不全是脊髓损伤患者死亡的重要原因,但具体机制并不清楚。因此,揭示脊髓损伤患者出现心功能不全的机制对于提高患者的生存质量和生存率有重要意义。目的:探讨木犀草素改善脊髓损伤大鼠血清诱导心肌细胞死亡的... 详细信息

背景:脊髓损伤导致的心功能不全是脊髓损伤患者死亡的重要原因,但具体机制并不清楚。因此,揭示脊髓损伤患者出现心功能不全的机制对于提高患者的生存质量和生存率有重要意义。目的:探讨木犀草素改善脊髓损伤大鼠血清诱导心肌细胞死亡的作用机制。方法:使用Allen’s冲击仪损伤雄性SD大鼠脊椎T9-T11,进行脊髓损伤造模,设置假手术组作为对照,取各组大鼠血清。将H9c2细胞分为空白对照组、假手术大鼠血清组、脊髓损伤大鼠血清组以及木犀草素预处理组,空白对照组为普通培养基培养,假手术大鼠血清组使用含体积分数10%假手术大鼠血清的培养基培养,脊髓损伤大鼠血清组使用含体积分数10%脊髓损伤大鼠血清的培养基培养,木犀草素预处理组预先使用含有终浓度为20μmol/L木犀草素的培养基培养心肌细胞4 h,之后更换含体积分数10%脊髓损伤大鼠血清的培养基培养,培养24 h后使用CCK-8法检测各组H9c2心肌细胞的存活率,采用Western blot检测各组H9c2心肌细胞自噬相关蛋白LC3及p62的蛋白表达。结果与结论:与空白对照组相比,假手术大鼠血清组细胞存活率无明显改变(P>0.05);与假手术大鼠血清组相比,脊髓损伤大鼠血清组细胞存活率显著降低(P<0.01),LC3蛋白表达显著降低(P<0.05),p62蛋白表达显著升高(P<0.05);与脊髓损伤大鼠血清组相比,木犀草素预处理组细胞存活率明显回升(P<0.0001),LC3蛋白表达显著升高(P<0.05),p62蛋白表达显著降低(P<0.05)。结果表明:木犀草素可能通过促进自噬进而改善脊髓损伤大鼠血清诱导的心肌细胞死亡。

关键词：脊髓损伤血清 H9c2细胞自噬木犀草素心功能不全

The influence of soil compaction in explaining spatial heterogeneity of different larch forest types: a preliminary study

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Journal of Forestry Research 2020年第6期31卷 2395-2401页

作者： yuan tian Qiuliang Zhang Xuan Liu Department of Forest Management College of ForestryInner Mongolia Agricultural UniversityHohhot 010019Inner Mongolia Autonomous RegionPeople’s Republic of China

Compacted soil has an adverse effect on plant roots and affects water and nutrient ***,different degrees of soil compaction may be suitable for growth and development of different understory *** study determined whether soil compaction could explain characteristics of 10 different Dahurian larch(Larix gmelinii Rupr.)forest types in the Daxing’anling *** relationship of soil compaction to soil depth was also ***-five tests were conducted on soil compaction of the 10 forest types with multiple comparisons,of which five showed no significant *** different soil depths,there were significant differences in soil compaction among forest *** correlation between the degree of soil compaction and depth was positive and *** Larix gmelinii—shrub forest type,***—herb forest type,and ***—swamp forest type were significantly different in soil compaction according to soil *** research indicates that,as a physical property,soil compaction may.

关键词： Vegetation distribution Biogeocenosis Species response Forest management Soil compaction

A novel six-legged walking machine tool for in-situ operations

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Frontiers of Mechanical Engineering 2020年第3期15卷 351-364页

作者： Jimu LIU yuan tian Feng GAO State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

The manufacture and maintenance of large parts in ships,trains,aircrafts,and so on create an increasing demand for mobile machine tools to perform in-situ ***,few mobile robots can accommodate the complex environment of industrial plants while performing machining *** study proposes a novel six-legged walking machine tool consisting of a legged mobile robot and a portable parallel kinematic machine *** kinematic model of the entire system is presented,and the workspace of different components,including a leg,the body,and the head,is analyzed.A hierarchical motion planning scheme is proposed to take advantage of the large workspace of the legged mobile platform and the high precision of the parallel machine *** repeatability of the head motion,body motion,and walking distance is evaluated through experiments,which is 0.11,1.0,and 3.4 mm,***,an application scenario is shown in which the walking machine tool steps successfully over a 250 mmhigh obstacle and drills a hole in an aluminum *** experiments prove the rationality of the hierarchical motion planning scheme and demonstrate the extensive potential of the walking machine tool for in-situ operations on large parts.

关键词： legged robot parallel mechanism mobile machine tool in-situ machining

Novel method of gait switching in six-legged robot walking on continuous-nondifferentiable terrain by utilizing stability and interference criteria

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Science China(Technological Sciences) 2020年第12期63卷 2527-2540页

作者： MAO LiHeng tian yuan GAO Feng ZHAO Yue State Key Laboratory of Mechanical System and Vibration Department of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Continuous-nondifferentiable terrains are extremely challenging for the environment adaption of six-legged robots. Previous researches have focused on gait planning methods to improve inherent ability of legged robots to walk over moderate ***,most six-legged robots utilize relatively monotonic gait so that they still cannot well adapt tough terrains. As a result,the current legged robots easily get stuck and fall when encountering continuous-nondifferentiable terrains,such as ***,a method of gait switching is proposed so that six-legged robots can flexibly generate multiple gaits to adapt complex terrains. This study investigated the relationship between six-legged robot gait topologies and physical constraints,such as robot stability and robot-terrain interference. The proposed gait switcher can generate 0-6,1-5,2-4 and 3-3 gaits,which is instructed by the stability and interference criteria. Simulations and experiments were performed on a novel six-legged robot Hexa-XIII that succeeded climbing stairs over 45°. The effectiveness of the gait switching method is validated by the experiment results.

关键词： six-legged robot continuous-nondifferentiable terrain gait switching method stability criteria interference criteria

Dynamic access clustering selecting mechanism based on Markov decision process for MANET

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The Journal of China Universities of Posts and Telecommunications 2007年第4期14卷 88-92页

作者： WANG Dao-yuan tian Hui Wireless Technology Investigate Laboratory Beijing University of Posts and Telecommunications Beijing 100876 China

Clustering is an important method in the mobile Ad-hoc network（MANET）. As a result of their mobility, the cluster selection is inevitable for the mobile nodes during their roaming between the different clusters. In this study, based on the analysis of the cluster-selecting problem in the environment containing multiple clusters, which are overlaying and intercrossing, a novel dynamic selecting mechanism is proposed to resolve the dynamic selection optimization of roaming between the different clusters in MANET. This selecting mechanism is also based on the consideration of the stability of communication system, the communicating bandwidth, and the effect of cluster selecting on the communication and also in accordance with the Markov decision-making model.

关键词： MANET roam cluster selection effect