检索结果-南通市图书馆

Rare Metals 2024年第3期43卷 1309-1315页

作者： Long-Hua Ding ya-wen wang Qiu-wen Li Li-Li Zhang Ai-Zhu wang Institute for Advanced Interdisciplinary Research School of Chemistry and Chemical EngineeringUniversity of JinanJinan250022China HCA Florida Healthcare Westside/Northwest Hospital Internal Medicine PlantationFL33324USA

In this study,an electrochemical impedimetric sensor was established for imidacloprid(IMI)detection based on WO_(3)/MoS_(2)and molecular imprinted polymer(MIP)*** layer was prepared on electrode surface by electropolymerization of o-phenylenediamine(o-PD)in the presence of IMI template,which ensured the specific rec-ognization toward IMI.

关键词： electrochemical polymer polymerization

Unit Test Data Generation for C Using Rule-Directed Symbolic Execution

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2019年第3期34卷 670-689页

作者： Ming-Zhe Zhang Yun-Zhan Gong ya-wen wang Da-Hai Jin State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876China

Unit testing is widely used in software development. One important activity in unit testing is automatic test data generation. Constraint-based test data generation is a technique for automatic generation of test data, which uses symbolic execution to generate constraints. Unit testing only tests functions instead of the whole program, where individual functions typically have preconditions imposed on their inputs. Conventional symbolic execution cannot detect these preconditions, let alone converting these preconditions into constraints. To overcome these limitations, we propose a novel unit test data generation approach using rule-directed symbolic execution for dealing with functions with missing input preconditions. Rule-directed symbolic execution uses predefined rules to detect preconditions in the individual function, and generates constraints for inputs based on preconditions. We introduce implicit constraints to represent preconditions, and unify implicit constraints and program constraints into integrated constraints. Test data generated based on integrated constraints can explore previously unreachable code and help developers find more functional faults and logical faults. We have implemented our approach in a tool called CTS-IC, and applied it to real-world projects. The experimental results show that rule-directed symbolic execution can find preconditions (implicit constraints) automatically from an individual function. Moreover, the unit test data generated by our approach achieves higher coverage than similar tools and efficiently mitigates missing input preconditions problems in unit testing for individual functions.

关键词： automated unit testing program constraint symbolic execution static analysis

A Novel Multiscale Reinforcement by In-Situ Growing Carbon Nanotubes on Graphene Oxide Grafted Carbon Fibers and Its Reinforced Carbon/Carbon Composites with Improved Tensile Properties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2016年第5期32卷 419-424页

作者： Yunyu Li Ling-jun Guo ya-wen wang He-jun Li Qiang Song State Key Laboratory of Solidification Processing Northwestern Polytechnical University Center for Nano Energy Materials Northwestern Polytechnical University

In-situ growing carbon nanotubes （CNTs） directly on carbon fibers （CFs） always lead to a degraded tensile strength of CFs and then a poor fiber-dominated mechanical property of carbon/carbon composites （C/ Cs）. To solve this issue, here, a novel carbon fiber-based multiscale reinforcement is reported. To synthesize it, carbon fibers （CFs） have been first grafted by graphene oxide （GO）, and then carbon nanotubes （CNTs） have been in-situ grown on GO-grafted CFs by catalytic chemical vapor deposition. Characterizations on this novel reinforcement show that GO grafting cannot only nondestructively improve the surface chemical activity of CFs but also protect CFs against the high-temperature corrosion of metal catalyst during CNT growth, which maintains their tensile properties. Tensile property tests for unidirectional C/Cs with different preforms show that this novel reinforcement can endow C/C with improved tensile properties, 32% and 87% higher than that of pure C/C and C/C only doped with in-situ grown CNTs. This work would open up a possibility to fabricate multiscale C/Cs with excellent global performance.

关键词： Multiscale reinforcement Carbon fiber Graphene oxide Carbon nanotube Carbon/carbon composite Tensile property

Scientific workflow execution system based on mimic defense in the cloud environment

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2018年第12期19卷 1522-1536页

作者： ya-wen wang Jiang-xing WU Yun-fei GUO Hong-chao HU wen-yan LIU Guo-zhen CHENG National Digital Switching System Engineering Technology Research Center

With more large-scale scientific computing tasks being delivered to cloud computing platforms, cloud workflow systems are designed for managing and arranging these complicated tasks. However, multi-tenant coexistence service mode of cloud computing brings serious security risks, which will threaten the normal execution of cloud workflows. To strengthen the security of cloud workflows, a mimic cloud computing task execution system for scientific workflows is proposed. The idea of mimic defense contains mainly three aspects: heterogeneity, redundancy, and dynamics. For heterogeneity, the diversities of physical servers, hypervisors, and operating systems are integrated to build a robust system framework. For redundancy, each sub-task of the workflow will be executed simultaneously by multiple executors. Considering efficiency and security, a delayed decision mechanism is proposed to check the results of task execution. For dynamics, a dynamic task scheduling mechanism is devised for switching workflow execution environment and shortening the life cycle of executors, which can confuse the adversaries and purify task executors. Experimental results show that the proposed system can effectively strengthen the security of cloud workflow execution.

关键词： Scientific workflow Mimic defense Cloud security Intrusion tolerance

Automated String Constraints Solving for Programs Containing String Manipulation Functions

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2017年第6期32卷 1125-1135页

作者： Xu-Zhou Zhang Yun-Zhan Gong ya-wen wang Ying Xing Ming-Zhe Zhang State Key Laboratory of Networking and Switching Technology Beijing University of Posts and Telecommunications Beijing 100876 China Automation School Beijing University of Posts and Telecommunications Beijing 100876 China

The ability to solve various constraints is a principal factor of automatic constraint solvers. Most object-oriented languages treat a character string as a primitive data type which is manipulated by string library functions. Most constraint solvers have limitations on their input constraints, such as strong restrictions on the expressiveness of constraints or lack of the ability to solve hybrid constraints. These limitations hinder applying automated constraint solvers on program analysis techniques for programs containing strings and string manipulation functions. We propose an approach to automatically solve program constraints involving strings and string manipulation functions. Based on the character array model, we design a constraint language which contains primitive operations to precisely describe the constraints of commonly used string manipulation functions. The translated string constraints together with numeric constraints are then solved by a two- phase test generation procedure： firstly, a partial solution is obtained to satisfy the arithmetic constraints of the position variables, and the solution is utilized to simplify the string constraints into pure character array constraints; secondly, the pure array constraints are solved by an off-the-shelf array-specific theory based constraint solver. We integrate the approach into an automated testing tool to support the generation of string test cases, and then perform experiments. The results of the experiments prove that the integration of the proposed approach promotes the testing coverage of the existing testing tool, and the integrated tool has an advantage of handling specific string manipulation functions compared with an existing string solver.

关键词： string constraints solving satisfaction module theory program analysis software testing automated testinput generation

Passivity breakdown of 13Cr stainless steel under high chloride and CO_2 environment

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2019年第3期26卷 329-336页

作者： Hui-xin Li Da-peng Li Lei Zhang ya-wen wang Xiu-yun wang Min-xu Lu Institute for Advanced Materials and Technology University of Science and Technology Beijing Safetech Research Institute (Beijing) Co. Ltd. CRRC Beijing Locomotive Co. Ltd.

Herein, the effect of high chloride ion(Cl^-) concentration on the corrosion behavior and passive film breakdown of 13Cr martensitic stainless steel under CO_2 environment was demonstrated. The Cl^- concentration was varied from 30 to 150 g/L and cyclic potentiodynamic polarization was conducted to investigate the influence of the Cl^- concentration on the corrosion potential(E_(corr)), passive breakdown potential(E_(pit)), and repassivation potential(E_(rep)). The results of the polarization curves revealed that 13Cr stainless steel is susceptible to pitting under high Cl^- concentration. The passive breakdown potential and repassivation potential decreased with the increase of Cl-concentration. The semiconducting behavior of the passive film was investigated by Mott-Schottky analysis and the point defect model(PDM). It was observed that the iron cation vacancies and oxygen vacancies were continuously generated by autocatalytic reactions and the higher Cl^- concentration resulted in higher vacancies in the passive film. Once the excess vacancies condensed at the metal/film interface, the passive film became locally detached from the metal, which led to the breakdown of the passive film.

关键词： 13Cr stainless steel electrochemical characterization pitting corrosion high chloride concentration passive film breakdown

Carbon quantum dots/Bi_(4)O_(5)Br_(2) photocatalyst with enhanced photodynamic therapy:killing of lung cancer(A549)cells in vitro

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2022年第1期41卷 132-143页

作者： Bing He Hai-yan Jin ya-wen wang Cai-Mei Fan Yun-Fang wang Xiao-Chao Zhang Jian-Xin Liu Rui Li Jue-wen Liu College of Chemistry and Chemical Engineering Taiyuan University of TechnologyTaiyuan 030024China Department of Chemistry University of WaterlooWaterlooON N2L 3G1Canada

Inorganic photocatalysts have been regarded as a promising candidate in the domain of tumor photodynamic therapy(PDT)due to their inspirational photocatalytic *** this study,a Bi_(4)O_(5)Br_(2)photocatalyst was synthesized and it exhibited effective photo-killing activity of A549 cells(a human lung carcinoma epithelial cell line)in *** this basis,we modified Bi_(4)O_(5)Br_(2)with carbon quantum dots(CQDs)via a hydrolysis method at room temperature,which resulted in an improved photo-killing effect of Bi_(4)O_(5)Br_(2)to A549 *** samples and the interaction between samples and cells were fully *** has been found that the loading of CQDs on Bi_(4)O_(5)Br_(2)can reduce the hydration ratio,increase the cellular uptake and improve the photogenerated reactive oxygen species(ROS)as compared with pristine Bi_(4)O_(5)Br_(2).Electron spin resonance(ESR)analysis and radical-trapping experiments manifested that the ROS contributed to PDT may be·O^(2-)and ·*** study may provide a useful strategy to ameliorate the penetrability,cell compatibility and PDT effect upon cancer cells of other inorganic photocatalysts.

关键词： CQDs/Bi_(4)O_(5)Br_(2) Photocatalyst PDT A549 cell Reactive oxygen species

How to Wear Beautifully？ Clothing Pair Recommendation

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2018年第3期33卷 522-530页

作者： Yu-Jie Liu Yong-Biao Gao Ling-yan Bian wen-ya wang Zong-Min Li College of Computer and Communication Engineering China University of Petroleum (East China) Qingdao 266580 China

In this paper, we present a practical system to automatically suggest the most pairing clothing items, given the reference clothing （upper-body or low-body）. This has been a challenge, due to clothes having a variety of categories. Clothing is one of the most informative cues for human appearance. In our daily life, people need to wear properly and beautifully to show their confidence, politeness and social status in various occasions. However, it is not easy to decide what to wear and how to coordinate their own clothes. To address this problem, we propose a recommendation approach that includes clothing region detection, clothing pair recommendation and distance fusion. Clothing region detection based on Faster R-CNN is used to detect clothing region. Clothing pair recommendation consists of a quadruple network architecture, where one dual network of the architecture adopts Siamese convolution neural network architecture. Training examples are pairs of upper-body and low-body clothing items that are either compatible or incompatible. The other dual network is used to learn clothing style features of the input image. This framework is designed to learn a feature transformation from the images of clothing items into two latent spaces, which we call them compatible space and style space respectively. After training the two dual networks, we use a distance fusion method to fuse the features extracted from the compatible and style dual networks. To acquire an optimized model and verify our proposed method, we expand an existing large clothing dataset WoG （Weather-to-Garment）, and the resulted dataset is called ＂How to Wear Beautifully＂（H2WB）. Experiments on the H2WB dataset demonstrate that our approach is effective with clothing region detection and clothing pair recommendation as well as distance fusion.

关键词： clothing recommendation clothing pair style learning

A flexible electrochemical sensor for paracetamol based on porous honeycomb-like Ni Co-MOF nanosheets

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rare Metals 2023年第10期42卷 3311-3317页

作者： Xiu-Li Liu Jia-Wei Guo ya-wen wang Ai-Zhu wang Xin Yu Long-Hua Ding Institute for Advanced Interdisciplinary Research School of Chemistry and Chemical EngineeringUniversity of JinanJinan250022China

The overdose of 4-aminophenol(AP) threatens human health,and the determination of AP is ***,we report a flexible electrochemical sensor for highly sensitive and precise determination of *** ultrathin honeycomblike NiCo-MOF nanosheets were in situ grown on freestanding flexible carbon cloth(CC) *** porous structure among nanosheets and rich porosity of NiCoMOF shorten the transport path of electrolyte ions and reactants,ensuring fast electron transport.

关键词： porous precise porosity

Study of glue extrusion after endoscopic N-butyl-2-cyanoacrylate injection on gastric variceal bleeding

在线全文

学校读者我要写书评

暂无评论

World Journal of Gastroenterology 2009年第39期15卷 4945-4951页

作者： yan-Mei wang Liu-Fang Cheng Nan Li Kai Wu Jun-Shan Zhai ya-wen wang Department of Gastroenterology the Second Affiliated Hospital of PLA General Hospital Beijing 100091 China

AIM:To investigate glue extrusion after endoscopic N-butyl-2-cyanoacrylate injection on gastric variceal bleeding and to evaluate the long-term efficacy and safety of this ***:A total of 148 cirrhotic patients in our hospital with esophagogastric variceal bleeding(EGVB) were included in this study.N-butyl-2-cyanoacrylate was mixed with lipiodol in a 1:1 ratio and injected as a bolus of 1-3 mL according to variceal *** underwent endoscopic follow-up the next week,fourth week,second month,fourth month,and seventh month after injection and then every 6 mo to determine the cast *** abdominal X-ray fi lm and ultrasound or computed tomographic scan were also carried out in order to evaluate the time of variceal disappearance and complete extrusion of the *** average follow-up time was 13.1 ***:The instantaneous hemostatic rate was 96.2%.Early re-bleeding after injection in 9 cases(6.2%) was estimated from rejection of *** re-bleeding occurred in 12 patients(8.1%) at 2-18 *** glue cast was extruded into the lumen within one month in 86.1% of patients and eliminated within one *** erosion was seen at the injection position and mucosa edema in the second *** glue casts were extruded in 18 patients(12.1%) after one week and in 64 patients(42.8%) after two *** kinds of glue clumping shapes and colors on endoscopic examination were observed in 127 patients(86.1%) within one month,including punctiform,globular,pillar and *** one patients(27.9%) had glue extrusion after 3 mo and 28 patients(28.9%) after six *** extrusion time was not related to the injection volume of *** was seen in 70.2%(104 cases) *** main complication was re-bleeding resulting from *** prognosis of the patients depended on the severity of the underlying liver ***:Endoscopic injection of cyanoacrylate is highly effective for gastric varices *** glue clump

关键词： Gastric variceal bleeding Glue extruded N-butyl-2-cyanoacrylate Portal hypertension