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Microstructure and martensitic transformation behavior of Ni_(56-x)Mn_(25)Fe_xGa_(19) shape memory alloys

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Rare Metals 2014年第1期33卷 41-46页

作者： yan xin Liang Chai School of Energy Power and Mechanical Engineering North China Electric Power University Beijing Key Laboratory for Advanced Functional Materials and Thin Film Technology

Microstructure, martensitic transformation behavior, mechanical and shape memory properties of ***25FexGa19 （x = 0, 2, 4, 6, 8） shape memory alloys were investigated using optical microscopy （OM）, X-ray diffraction analysis （XRD）, differential scanning calorimeter （DSC）, and compressive test. It is found that these alloys are composed of single non-modulated martensite phase with tetragonal structure at room temperature, which means substituting Fe for Ni in Ni56Mn25Ga19 alloy has no effect on phase structure. These alloys all exhibit a ther- moelastic martensitic transformation between the cubic parent phase and the tetragonal martensite phase. With the increase of Fe content, the martensitic transformation peak temperature （Mp） decreases from 356℃ for x = 0 to 20℃ for x = 8, which is contributed to the depressed electron concentration and tetragonality of martensite. Fe addition remarkably reduces the transformation hysteresis of Ni-Mn-Ga alloys. Substituting Fe for Ni in Ni56Mn25Ga19 alloy can decrease the strength of the alloys and almost has no influence on the ductility and shape memory property.

关键词： Shape memory alloys Microstructure Martensitic transformation Ni-Mn-Fe-Ga

Study on yan-xin Wang’s medication experience and regularity in treating Insomnia from the liver based on data mining

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TMR Integrative Medicine 2023年第17期7卷 1-9页

作者： yan-yan Chen yan-xin Wang Man Wen Zheng Yu Jing-Jing Wu First Clinical Medical College Anhui University of Chinese MedicineHefei 230031China Department of Neurology The First Affiliated Hospital of Anhui University of Chinese MedicineHefei 230031China

Background:Professor yan-xin Wang has been committed to the use of traditional Chinese medicine formulas to treat insomnia from the liver for many years,and has achieved excellent clinical *** order to better inherit yan-xin Wang’s academic *** purpose of this study is to use clinical data to explore the clinical experience of ***-xin Wang in the application of Chinese medicine to treat insomnia patients from the liver,explore the compatibility and medication rules of traditional Chinese medicine,and give more clinical treatment ideas for ***:The general data and prescription information of insomnia patients treated with Chinese herbal medicine by ***-xin Wang from January 1,2021,to December 31,2021,were summarized according to the inclusion and exclusion criteria,and the data were subjected to frequency statistics and drug association rules,complex network diagram analysis and cluster ***:A total of 159 patients and prescriptions were included in the study,of which 81.1%were women and 18.9%were men,containing 128 herbs;the highest frequency of use was 91.8%for Bupleuri *** Chinese herbs were used more than 70%of the time,namely Bupleuri Radix,Scutellariae Radix,oyster shell,Glycyrrhizae Radix,Os Draconis,and Ziziphi Spinosae *** top 20 herbs in terms of frequency of use were analyzed in terms of the four Qi,five flavours,and their *** four Qi were mainly calm and warm,the five flavours were mainly bitter and acrid,followed by sweet,and the attributions were mainly to the liver,spleen,and heart *** Chinese medicine association rules set the confidence level>80%and the support level>10%,resulting in 10 two-herb and three-herb associations with the highest confidence level,such as Os Draconis is associated with oyster shell,Platycodonis Radix is associated with Achyranthis Bidentatae Radix,Scutellariae Radix is associated with Bupleuri Radix,Os Draconis,Bupleuri Radix is associated

关键词： data mining insomnia liver-based treatment medication patterns

Aerodynamic interaction between forewing and hindwing of a hovering dragonfly

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Acta Mechanica Sinica 2014年第6期30卷 787-799页

作者： Zheng Hu xin-yan Deng School of Mechanical Engineering Purdue University 585 Purdue MallWest Lafayette IN 47906 USA

The phase change between the forewing and hindwing is a distinct feature that sets dragonfly apart from other *** this paper,we investigated the aerodynamic effects of varying forewing-hindwing phase di ff erence with a60 inclined stroke plane during hovering *** measurements on a pair of mechanical wing models showed that in-phase flight enhanced the forewing lift by 17%and the hindwing lift was reduced at most phase *** total lift of both wings was also reduced at most phase di ff erences and only increased at a phase range around *** results may explain the commonly observed behavior of the dragonfly where 0 is employed in *** further investigated the wing-wing interaction mechanism using the digital particle image velocimetry（PIV）system,and found that the forewing generated a downwash flow which is responsible for the lift reduction on the *** the other hand,an upwash flow resulted from the leading edge vortex of the hindwing helps to enhance lift on the *** results suggest that the dragonflies alter the phase di ff erences to control timing of the occurrence of flow interactions to achieve certain aerodynamic effects.

关键词： Dragonfly aerodynamics Forewing-hindwing interaction Phase di ff erence Interactive flow

Aging-induced two-stage reverse martensitic transformation behavior in Co_(46)Ni_(27)Ga_(27) high-temperature shape memory alloy

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Rare Metals 2011年第5期30卷 527-532页

作者： SU Dashuai LI yan xin yan YUAN Bifei School of Materials Science and Engineering Beihang University Beijing 100191 China Beijing Key Laboratory for Advanced Functional Materials and Thin Film Technology Beihang University Beijing 100191 China Key Laboratory of Aerospace Materials and Performance （Ministry of Education of China） Beihang University Beijing 100191 China School of Energy Power and Mechanical Engineering North China Electric Power University Beijing 102206 China

The effect of austenite aging at 823 K on the microstructures and martensitic transformation behavior of Co 46 Ni 27 Ga 27 alloy has been investigated using optical microscopy （OM）, transmission electron microscopy （TEM）, X-ray diffraction analysis （XRD）, and differential scanning calorimeter （DSC）. The microstructure observation results show that the unaged Co 46 Ni 27 Ga 27 alloy is composed of the tetragonal nonmodulated martensite phase and face-centered cubic γ phase. It is found that a new nanosized fcc phase precipitates in the process of austenite aging, leading to the formation of metastable age-affected martensite around the precipitates with composition inhomogeneity. Two-stage reverse martensitic transformation occurs in the samples aged for 2 and 24 h due to the composition difference between the age-affected martensite and the original martensite. For the Co 46 Ni 27 Ga 27 alloy aged for 120 h, no reverse transformation can be detected due to the disappearance of the metastable age-affected martensite and the small latent heat of the original martensite. The martensitic transformation temperatures of the Co 46 Ni 27 Ga 27 alloy decrease with an increase in aging time.

关键词： shape memory alloys aging phase transformations microstructure

Distributed QoS multicast routing in networks with imprecise state information

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Journal of Systems Engineering and Electronics 2005年第4期16卷 866-874页

作者： yan xin Li Layuan Dept. of Computer Science Wuhan Univ. of Technology Wuhan 430063 P.R. China

The goal of quality-of-service （QoS） multicast routing is to establish a multicast tree which satisfies certain constraints on bandwidth, delay and other metrics. The network state information maintained at every node is often im- precise in a dynamic environment because of non-negligible propagation delay of state messages, periodic updates due to overhead concern, and hierarchical state aggregation. The existing QoS multicast routing algorithms do not provide satisfactory performance with imprecise state information. We propose a distributed QoS multicast routing scheme based on traffic lights, called QMRI algorithm, which can probe multiple feasible tree branches, and select the optimal or near-optimal branch through the UR or TL mode for constructing a multicast tree with QoS guarantees if it exists. The scheme is designed to work with imprecise state information. The proposed algorithm considers not only the QoS requirements but also the cost optimality of the multicast tree. The correctness proof and the complexity analysis about the QMRI algorithm are also given. In addition, we develop NS2 so that it is able to simulate the imprecise network state information. Extensive simulations show that our algorithm achieves high call-admission ratio and low-cost multicast trees with modest message overhead.

关键词： quality-of-service muting multicast imprecise state traffic lights simulation.

Down-regulated expressions of PPAR_γ and its coactivator PGC-1 are related to gastric carcinogenesis and Lauren's classification in gastric carcinoma

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Chinese Journal of Cancer Research 2013年第6期25卷 704-714页

作者： Han Yu yan xin Department of Gastrointestinal Tumor Pathology of Cancer Institute and General Surgery Institute the First Hospital of China Medical University

Objective： To explore the relationship between peroxisome proliferator activated receptor-gamma （PPARγ） and peroxisome proliferator-activated receptor-gamma coactivator-1 （PGC-1） expression in gastric carcinoma （GC）, and analyze their correlations with clinicopathological features and clinical outcomes of patients. Methods：The two-step immunohistochemical method was used to detect the expression of PPARγ and PGC-1 in 179 cases of GC, and 108 cases of matched normal gastric mucosa. Besides, 16 cases of fresh GC specimens and corresponding normal gastric mucosa were detected for PGC-1 expression with Western blotting. Results： The positive rates of PPART and PGC-1 expression were significantly lower in GC （54.75%, 49.16%） than in normal gastric mucosa （70.37%, 71.30%）, respectively （P〈0.05）. The decreased expression of PGC-1 in GC was confirmed ha our Western blot analysis （P=0.004）. PPAR7 and PGC-1 expressions were related to Lauren＇s types ofGC （P〈0.05）. Positive correlation was found between PPART and PGC-1 expression in GC （rk=0.422, P〈0.001）. The survival time of PPART negative and positive patients was 36.6±3.0 vs. 38.5_＋2.7 months, and no statistical difference was found between the 5-year survival rates of two groups （34.4% vs. 44.1%, P=0.522, log-rank test）; the survival time of PGC-1 negative and positive patients was 36.2±2.8 vs. 39.9±2.9 months, while no statistical difference was found between the 5-year survival rates of the two groups （32.0% vs. 48.2%, P=0.462, log-rank test） Conclusions＇. Decreased expression of PPARγand PGC-1 in GC was related to the Lauren＇s classification. Their expressions in GC were positively correlated, indicating that their fimctions in gastric carcinogenesis may be closely related.

关键词： Peroxisome proliferator activated receptor-gamma (PPARγ) peroxisome proliferator-activatedreceptor-gamma coactivator-1 (PGC-I) gastric carcinoma (GC) clinicopathological feature

Topological and Spectral Perturbations in Complex Networks

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Chinese Physics Letters 2012年第12期29卷 249-253页

作者： yan xin WU yang Department of Computer Science Wuhan University of TechnologyWuhan 430063

Recently many network perturbation techniques,mainly involving topological and spectral perturbations,have been employed to analyze and improve the robustness of complex ***,to the best of our knowledge,the relationship between topological perturbation and spectral perturbation has not been studied intensively so *** introduce a new robustness measure,subgraph centrality defined by eigenvalue spectrum,to investigate the impact of topological perturbation on eigenvalue spectrum.A specific definition of spectral perturbation is given,such that we can examine the impact of spectral perturbation on topological property by a measure of topological performance:global *** main finding is that the spectral perturbations we define are equivalent to the conventional topological perturbations,especially for scale-free networks.

关键词： spectrum. topological perturbation

Effect of matrix structure on mechanical properties and dry rolling-sliding wear performance of alloyed ductile iron

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Journal of Iron and Steel Research International 2019年第8期26卷 888-897页

作者： Hua Zhang yan-xin Wu Qiu-ju Li xin Hong State Key Laboratory of Advanced Special Steel and Shanghai Key Laboratory of Advanced Ferrometallurgy and School of Materials Science and Engineering Shanghai University Shanghai 200072 China Jiangsu Yonggang Group Co. Ltd. Zhangjiagang 215628 Jiangsu China Institute of Engineering Technology University of Science and Technology Beijing Beijing 100083 China

The influence of matrix structure on mechanical properties and dry rolling-sliding wear performance of alloyed ductile iron was examined. Four kinds of alloyed ductile irons with different matrix structures were produced through an adequate balance of alloying elements. Tensile tests and dry rolling-sliding wear tests were carried out at room temperature. The results show that yield strength and ultimate tensile strength increase, while elongation decreases until the matrix fully becomes pearlite. The lower matrix hardness results in more graphite emerging on the contact surface, which yields the decrease in friction coefficient. Besides, the wear rate decreases with the increase in matrix hardness among alloyed ductile irons except that with full pearlite matrix, the wear performance of which seems to be deteriorated due to poor fracture toughness. The main wear mechanism is delamination under an air-cooling condition. Based on the results of mechanical and wear tests, ductile iron with about 80% pearlite exhibits better wear performance as well as relatively reasonable mechanical properties.

关键词： Ductile iron Microstructure Mechanical property Wear Delamination

Biochemical characterization of chitin synthase activity and inhibition in the African malaria mosquito, Anopheles gambiae

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Insect Science 2013年第2期20卷 158-166页

作者： xin Zhang Kun yan Zhu Department of Entomology Kansas State University Manhattan KS 66506 USA

Chitin synthase （CHS） is an important enzyme catalyzing the formation of chitin polymers in all chitin containing organisms and a potential target site for insect pest control. However, our understanding of biochemical properties of insect CHSs has been very limited. We here report enzymatic and inhibitory properties of CHS prepared from the African malaria mosquito, Anopheles gambiae. Our study, which represents the first time to use a nonradioactive method to assay CHS activity in an insect species, determined the optimal conditions for measuring the enzyme activity, including pH, temperature, and concentrations of the substrate uridine diphosphate N-acetyl-D-glucosamine （UDP- GlcNAc） and Mg＋＋. The optimal pH was about 6.5-7.0, and the highest activity was detected at temperatures between 37℃ and 44℃. Dithithreitol is required to prevent melanization of the enzyme extract. CHS activity was enhanced at low concentration of GIcNAc, but inhibited at high concentrations. Proteolytic activation of the activity is significant both in the 500×g supernatant and the 40 000×g pellet. Our study revealed only slight in vitro inhibition ofA. gambiae CHS activity by diflubenzuron and nikkomycin Z at the highest concentration （2.5μmol/L） examined. There was no in vitro inhibition by polyoxin D at any concentration examined. Furthermore, we did not observe any in vivo inhibition of CHS activity by any of these chemicals at any concentration examined. Our results suggest that the inhibition of chitin synthesis by these chemicals is not due to direct inhibition of CHS in A. gambiae.

关键词： Anophele gambiae chitin synthase diflubenzuron enzyme inhibition