Xin Wang
共找到 18 条论著文献

1、Systems and computer technology : proceedings of the 2014 International Symposium and Computer Technology (ISSCT 2014), Shanghai, China, 15-17 November 2014 2015

2、Incremental graph pattern matching

摘要:Graph pattern matching is commonly used in a variety of emerging applications such as social network analysis. These applications highlight the need for studying the following two issues. First, graph pattern matching is traditionally defined in terms of subgraph isomorphism or graph simulation. These notions, however, often impose too strong a topological constraint on graphs to identify meaningful matches. Second, in practice a graph is typically large, and is frequently updated with small changes. It is often prohibitively expensive to recompute matches starting from scratch via batch algorithms when the graph is updated. This article studies these two issues. (1) We propose to define graph pattern matching based on a notion of bounded simulation, which extends graph simulation by specifying the connectivity of nodes in a graph within a predefined number of hops. We show that bounded simulation is able to find sensible matches that the traditional matching notions fail to catch. We also show that matching via bounded simulation is in cubic time, by giving such an algorithm. (2) We provide an account of results on incremental graph pattern matching, for matching defined with graph simulation, bounded simulation, and subgraph isomorphism. We show that the incremental matching problem is unbounded, that is, its cost is not determined alone by the size of the changes in the input and output, for all these matching notions. Nonetheless, when matching is defined in terms of simulation or bounded simulation, incremental matching is semibounded, that is, its worst-time complexity is bounded by a polynomial in the size of the changes in the input, output, and auxiliary information that is necessarily maintained to reuse previous computation, and the size of graph patterns. We also develop incremental matching algorithms for graph simulation and bounded simulation, by minimizing unnecessary recomputation. In contrast, matching based on subgraph isomorphism is neither bounded nor semibounded. (3) We experimentally verify the effectiveness and efficiency of these algorithms, and show that: (a) the revised notion of graph pattern matching allows us to identify communities commonly found in real-life networks, and (b) the incremental algorithms substantially outperform their batch counterparts in response to small changes. These suggest a promising framework for real-life graph pattern matching.
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3、Pathway into the silicon nucleation on silicene substrate at nanoscale

摘要:The solidification process of silicon atoms on the heterogeneous surface of silicene in different shapes, ranging from plane, curved to tubular substrates, is studied by means of molecular dynamics (MD) simulations. The shape of nucleus determines the stacking sequence of silicon atoms. Silicene plate induces strong ordered liquid layers while the silicene nanotube (SNT) makes the silicon imprint its cylindrical structure. In the confined nanospace between SNTs, the growth competition has been observed, which causes structural changes at the shared interface. The internal potential field around SNT is responsible for the formation of spiral structures and the growth competition. The ordering degree decays with increasing distances from the SNT, which is the result of the decreasing acting force from nucleus. This study provides an opportunity for comprehensive and satisfactory understanding of the heterogeneous nucleation at nanoscale.Display Omitted• Adding silicene nanotube (SNT) into silicon melt forms spiral atomic chains. • These silicon helical nanostructures show structural relevance with SNT. • The SNT-induced mechanism influences the epitaxial growth of silicon. • The field around SNT is responsible for the formation of nanostructures. • This study allows us to see the growth pattern of silicon induced by silicene.
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4、Overexpression of ShDHN, a dehydrin gene from Solanum habrochaites enhances tolerance to multiple abiotic stresses in tomato 2015

摘要:1 online resource Highlights: ShDHN expression was induced by abiotic stresses and exogenous signaling molecules. Overexpression of ShDHN enhanced tolerance to multiple abiotic stresses in tomato. Transgenic plants exhibited higher ROS scavenging ability under stress conditions. Transgenic plants had better water-retention capacity under dehydration conditions. Transgenic plants showed altered expression of antioxidant and JA-responsive genes. Abstract: Dehydrins (DHNs) play important roles in plant adaptation to abiotic stress. In this study, a cold-induced SK3-type DHN gene ( ShDHN ) isolated from wild tomato species Solanum habrochaites was characterized for its function in abiotic stress tolerance. ShDHN was constitutively expressed in root, leaf, stem, flower and fruit. ShDHN was continuously up-regulated during cold stress and showed higher expression level in the cold-tolerant S. habrochaites than in the susceptible S. lycopersicum . Moreover, ShDHN expression was also regulated by drought, salt, osmotic stress, and exogenous signaling molecules. Overexpression of ShDHN in cultivated tomato increased tolerance to cold and drought stresses and improved seedling growth under salt and osmotic stresses. Compared with the wild-type, the transgenic plants accumulated more proline, maintained higher enzymatic activities of superoxide dismutase and catalase, and suffered less membrane damage under cold and drought stresses. Moreover, the transgenic plants accumulated lower levels of H2 O2 and O2 − under cold stress, and had higher relative water contents and lower water loss rates under dehydration conditions. Furthermore, overexpression of ShDHN in tomato led to the up- or down-regulated expression of several genes involved in ROS scavenging and JA signaling pathway, including SOD1, GST, POD, LOX, PR1 and PR2. Taken together, these results indicate that ShDHN has pleiotropic effects on improving plant adaptation to abiotic stresses and that it possesses potential usefulness in genetic improvement of stress tolerance in tomato.
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5、Differential diagnosis of eccrine spiradenoma: A case report

摘要:Eccrine spiradenoma (ES) is a rare, benign adnexal neoplasm that may easily be mistaken for glomus lesions or angioleiomyoma due to its painfulness and florid vascularization. A 44‑year‑old male with a blue-colored, nodular tumor on the left knee, present for 10 years, was submitted for diagnosis. Dermatological examination was undertaken, followed by surgical excision of the subcutaneous lesion and histopathological examination of the tissue. Subjective symptoms included tenderness upon palpation and routine investigations were within normal limits. Immunohistochemical analysis of the tumor cells demonstrated positive staining for CK5/CK6, CK8/CK18, S100, as well as small vacuole-like positive for EMA, and was therefore diagnosed as ES. The results of the present study suggest that immunohistochemical assays may be helpful to clarify the diagnosis and differentiate ES from other painful subcutaneous tumors exhibiting similar clinical and histological presentations.
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6、Query preserving graph compression 2012

摘要:p.157-168 It is common to find graphs with millions of nodes and billions of edges in, e.g. , social networks. Queries on such graphs are often prohibitively expensive. These motivate us to propose query preserving graph compression , to compress graphs relative to a class Λ of queries of users' choice. We compute a small G r from a graph G such that (a) for any query Q Ε Λ Q , Q ( G ) = Q'( G r ), where Q' Ε Λ can be efficiently computed from Q ; and (b) any algorithm for computing Q ( G ) can be directly applied to evaluating Q' on G r as is . That is, while we cannot lower the complexity of evaluating graph queries, we reduce data graphs while preserving the answers to all the queries in Λ. To verify the effectiveness of this approach, (1) we develop compression strategies for two classes of queries: reachability and graph pattern queries via (bounded) simulation. We show that graphs can be efficiently compressed via a reachability equivalence relation and graph bisimulation, respectively, while reserving query answers. (2) We provide techniques for aintaining compressed graph G r in response to changes Δ G to the original graph G . We show that the incremental maintenance problems are unbounded for the two lasses of queries, i.e. , their costs are not a function of the size of Δ G and changes in G r . Nevertheless, we develop incremental algorithms that depend only on Δ G and G r , independent of G , i.e., we do not have to decompress G r to propagate the changes. (3) Using real-life data, we experimentally verify that our compression techniques could reduce graphs in average by 95% for reachability and 57% for graph pattern matching, and that our incremental maintenance algorithms are efficient.
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7、A Study of the Temperature Characteristics of Low Speed Curved Surface Jet in the Lower Air Supply Area

摘要:1 online resource Abstract: Semi-cylindrical diffusers are widely popular in displacement ventilation and lower air supply systems. The big point of the air flow characteristics of the curved surface jet is the "Cold Lake Effect", arounding the ground. In this paper, we derive a theoretical model of this "Cold Lake Effect" to investigate semi-cylindrical diffusers. The temperature distribution of the air supply in the main section was calculated with different air flow rate and initial air supply temperature. The temperature distribution model was experimentally verified. It is a good agreement with the calculated results, whereby the maximum deviation is 0.812°C. The study of the temperature characteristics, is a reference for making indoor thermal environment comfort better, and it can provide technical measures for designing air distribution systems in displacement ventilation and lower air supply systems.
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8、An overview of Sirtuins as potential therapeutic target: Structure, function and modulator

9、Optimized transport properties of GaN MISHEMTs with thin AlN interlayer

摘要:The high electron mobility and carrier density induced by the AlGaN and GaN heterojunction has exhibited great promise for high frequency and high-power applications and has attracted numerous research efforts [1]. The AlGaN/GaN high electron mobility transistors (HEMT) with a traditional Schottky metal gate suffer from large gate leakage at positive biases, and as a result, MISHEMTs with an insulating layer of high-k dielectrics is usually adopted for improved interface and leakage properties [2,3]. Moreover, previous studies show that improved output performance and reliability properties can be realized by inserting a thin AlN in between the AlGaN and GaN heterojunction [4]. In this work, detailed studies of capacitance-voltage (CV), output current, interface properties, and breakdown voltage have been carried out, and by optimizing the interface properties from both high-κ dielectrics and the AlN layer, improved transport properties can be achieved for GaN MISHEMTs.
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10、Improved Interface Properties and Dielectric Breakdown in Recessed AlGaN/GaN MOS-HEMTs Using HfSiOx as Gate Dielectric

摘要:In this letter, we report optimized transport properties in gate recessed enhancement-mode GaN MOS-HEMTs by incorporating silicon into atomic layer deposited gate dielectric HfO2. Compared with commonly used HfO2 gate dielectric, the interface trap density can be reduced by nearly an order of magnitude and the fixed oxide traps inside reduces to almost half using the high quality passivation of HfSiOx. The MOS-HEMTs based on HfSiOx exhibit a threshold voltage of 1.5 V, excellent subthreshold swing of 65 mV/dec, a high on-off ratio of 3×1010. The incorporation of silicon in HfO2 can also increase dielectric breakdown property with maximum gate electric field of 2.85 MV/cm for 10-year time-dependent gate dielectric breakdown lifetime, which is 36 % higher than pure HfO2. The maximum breakdown voltage of HfSiOx MOS-HEMT is 742 V, which is 30% higher than HfO2 MOS-HEMT.
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11、Experimental Study on Measuring the Amount of Jet Entrainment by the Tracer Gas Concentration Method

摘要:The jet entrainment from motional air to the ambient stationary air is one of the important characteristics for jet airstream. Entrainment can change its internal distribution of temperature, velocity, jet flow, and energy distribution, which are closely related with the engineering design of ventilation and air conditioning. Thereby, it is significant to quantify the amount of jet entrainment which is caused by nozzle jet from the ambient air in an air-conditioning room. Basing on the basic theory of fluid mechanics, we had proposed a measurement method of jet entrainment by the tracer gas. In this paper, we have made an experimental study in a constant temperature and humidity laboratory to measure and calculate the entrainment for the air conditioning jet motion, compared the results to the traditional method of velocity measurement, and predicted the related factors of the jet entrainment.
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12、Lymphomatoid papulosis misdiagnosed as pityriasis lichenoides et varioliformis acuta: Two case reports and a literature review

摘要:The aim of this study was to improve the level of diagnosis and differential diagnosis of lymphomatoid papulosis (LyP). Two cases of type B LyP were identified and the literature was reviewed to summarize the clinical outcomes and pathology of LyP and its treatment. The two patients exhibited symptoms with papulonodular lesions, the centers of which gradually underwent ulceration and necrosis. CD30, a helper T‑cell marker specifically expressed in tumor cells was analyzed by immunohistochemical staining and the result showed that CD30‑negative or only scattered CD30‑positive cells were present. Therefore, a diagnosis of type B LyP was made. A fairly good curative effect was achieved following treatment with retinoic acid, glucocorticoids and immunomodulatory drugs. LyP is a type of low‑level malignant lymphoma and is easily misdiagnosed as pityriasis lichenoides et varioliformis acuta and other diseases. In order to avoid under diagnosis and misdiagnosis, doctors should evaluate suspected patients by histopathological and immunohistochemical examination.
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13、Dermatofibrosarcoma protuberans with pit-like lesions: A case report and literature review

摘要:The present study describes a case of pit-like dermatofibrosarcoma protuberans (DFSP) with the clinical manifestations, histopathological features and criteria for diagnosis. The study also reviews the relevant literature in order to raise awareness among dermatologists with regard to the specific behavior of DFSP. A 27???year???old female presented with subcutaneous nodules on the left side of the neck that had been apparent for 5??years and which had gradually begun caving in during the last year. Histopathological examination revealed that the tumor was composed of a large number of spindle cells arranged in a whirlpool???like pattern. Immunohistochemical studies revealed positive staining for cluster of differentiation 34, vimentin and lysozyme, which could be used as diagnostic markers of DFSP. The patient was finally diagnosed with DFSP by pathological and immunohistochemical analyses. The DFSP was treated with an extended resection followed by adjacent skin repair. The patient responded well and no relapse occurred during the 8???month clinical follow???up. Thus, the current study describes a unique pit???like clinical manifestation of DFSP with typical immunohistochemical and pathological features. In addition, histopathological examination revealed a downward depression in the epidermis. Therefore, histopathological examination should be considered as an essential diagnostic tool for DFSP.
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14、Trim9 Regulates Activity-Dependent Fine-Scale Topography in Drosophila

摘要:Topographic projection of afferent terminals into 2D maps in the CNS is a general strategy used by the nervous system to encode the locations of sensory stimuli. In vertebrates, it is known that although guidance cues are critical for establishing a coarse topographic map, neural activity directs fine-scale topography between adjacent afferent terminals [1-4]. However, the molecular mechanism underlying activity-dependent regulation of fine-scale topography is poorly understood. Molecular analysis of the spatial relationship between adjacent afferent terminals requires reliable localization of the presynaptic terminals of single neurons as well as genetic manipulations with single-cell resolution in vivo. Although both requirements can potentially be met in Drosophila melanogaster [5, 6], no activity-dependent topographic system has been identified in flies [7]. Here we report a topographic system that is shaped by neuronal activity in Drosophila. With this system, we found that topographic separation of the presynaptic terminals of adjacent nociceptive neurons requires different levels of Trim9, an evolutionarily conserved signaling molecule [8-11]. Neural activity regulates Trim9 protein levels to direct fine-scale topography of sensory afferents. This study offers both a novel mechanism by which neural activity directs fine-scale topography of axon terminals and a new system to study this process at single-neuron resolution.• Nociceptive afferents in Drosophila larva form fine-scale topography • Neural activity regulates larval nociceptive topography • Trim9 directs the fine-scale topography of larval nociceptive afferents • Neural activity regulates Trim9 expression to direct fine-scale topographyThe segregation of presynaptic terminals of same-type neurons is important for topographic projections of sensory afferents. Yang et al. report that nociceptive afferents in Drosophila larva form fine-scale topography. In this system, neural activity regulates Trim9 protein levels to direct fine-scale topography.
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15、The feasibility and challenges of energy self-sufficient wastewater treatment plant 2017

摘要:1 online resource Highlights: Various influencing factors of energy use in WWTPs are characterized. Benchmark energy consumption in WWTPs in different countries are highlighted. Energy recovery or saving technologies in WWTPs are summarized. Recent advances in optimization of energy recovery technologies are highlighted. Feasibility and challenges of energy self-sufficient WWTPs are explored. Abstract: Energy efficiency optimization is crucial for wastewater treatment plants (WWTPs) because of increasing energy costs and concerns about global climate change. Energy efficiency optimization can be achieved through a combination of energy recovery from the wastewater treatment process and energy saving-related technologies. Through these two approaches energy self-sufficiency of WWTPs is achievable, and research is underway to reduce operation costs and energy consumption and to achieve carbon neutrality. In this paper, we analyze energy consumption and recovery in WWTPs and characterize the factors that influence energy use in WWTPs, including treatment techniques, treatment capacities, and regional differences. Recent advances in the optimization of energy recovery technologies and theoretical analysis models for the analysis of different technological solutions are presented. Despite some challenges in implementation, such as technological barriers and high investment costs, particularly in developing countries, this paper highlights the potential for more energy self-sufficient WWTPs to be established in the future.
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16、Molecular dynamics study on the nucleation of Al–Si melts on sheet substrates at the nanoscale

17、Channel Engineering of Normally-OFF AlGaN/GaN MOS-HEMTs by Atomic Layer Etching and High- \kappa Dielectric

摘要:In this letter, normally-OFF AlGaN/GaN metal–oxide–semiconductor high-electron-mobility transistors with a threshold voltage of 2.2 V have been achieved by an atomic layer etching technique. Combined with surface passivation by atomic layer deposition of composite HfSiO high- \kappa gate dielectric, a well-controlled gate-recess process with minimized surface damage results in improved interface properties with a low interface trap density of 2.8⨉ 10^{11} eV−1cm−2 and suppressed gate leakage current with a high current on/off ratio over 1011. A maximum current density of 518 mA/mm with an ON-resistance of 10.1 \Omega \cdot \textsf {mm} and a high breakdown voltage of 1456 V at an OFF-state current density of 1~ \text{A} /mm are also achieved. In the meantime, the dynamic {\text {R} \mathrm {on}} is only 1.2 times the static {\text {R} \mathrm {on}} after OFF-state drain voltage stress of 120 V and 2.6 times after 300-V stress.
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18、High-Performance CVD Bernal-Stacked Bilayer Graphene Transistors for Amplifying and Mixing Signals at High Frequencie