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Research and Implementation of Credit Investigation Sharing Platform Based on double Blockchain

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Computers, Materials & Continua 2023年第6期75卷 5193-5211页

作者： Han Yanyan Wei Wanqi dou Kaili li Peng College of Information Engineering Xidian UniversityXi’an710071China Department of Electronic and Communication Engineering Beijing Electronic Science and Technology InstituteBeijing100070China Department of Cyberspace Security Beijing Electronic Science and Technology InstituteBeijing100070China

As the development of the modern economy is increasingly insep-arable from credit support,the traditional credit investigation mode has yet to meet this *** of the difficulties in conventional credit data sharing among credit investigation agencies,poor data portability,and centralized supervision,this paper proposes a data-sharing scheme for credit investigation agencies based on a double *** the problems such as difficult data sharing,difficult recovery of damaged data,and accessible data leakage between institutions and users with non-traditional credit inves-tigation data other than credit,this paper proposes a data-sharing scheme for credit investigation subjects based on the digital *** on the above two solutions,this paper designs a double blockchain credit data-sharing plat-form based on the“public chain+alliance chain”from credit investigation agencies’and visiting subjects’*** sharing platform uses the alliance chain as the management chain to solve the problem of complex data sharing between credit bureaus and centralized supervision,uses the public chain as the use chain to solve the problem of complex data sharing between the access subject and the credit bureaus,uses the interplanetary file system and digital envelope and other technologies to solve the problem of difficult recovery of damaged data,data leakage,and other *** the upload test,the average upload speed reaches 80.6 M/*** average download speed of the system is 88.7 M/s after the download *** multi-thread stress test tests the linkage port on the system package,and the average response time for the hypertext transfer protocol(HTTP)is 0.6 *** system performance and security analysis show that the sharing platform can provide safe and reliable credit-sharing services for organizations and users and high working efficiency.

关键词： Dual blockchain credit data sharing truffle framework digital envelope ipfs

B←N-containing azaacenes with propynyl groups on boron atoms

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Chinese Chemical Letters 2020年第5期31卷 1193-1196页

作者： linan li Ying Gao Chuandong dou Jun liu School of Chemistry and Environmental Engineering Changchun University of Science and TechnologyChangchun 130022China State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China

For organnoboron co mpounds,the substituents on boron atoms are very important because they not only impact on the molecular stability but also significantly modulate the electronic structu res and prope *** this manuscript,we synthesized two new B←N-co ntaining azaacenes with propynyl groups on boron atoms through one-step Grignard *** fluorine atoms by propynyl groups greatly impacts on the electronic energy levels,especially enhancing the HOMO levels,thus leading to the narrowed HOMO-LUMO *** B←N-containing azaacenes exhibit the NIR light-absorption(λabs=706 nm for 2 a and 762 nm for 2 b)and fluorescence properties(λem=740 nm for 2 a and802 nm for 2 b),as well as multiple reversible redox behaviors,which are significantly different from the analogs with fluorine *** study thus provides a functional substituent of boron atom,which may lead to new organoboron materials with fascinating properties.

关键词： Polyarene Azaacene B-N coordination bond N1R absorption Fluorescence

Numerical Simulation and Analysis of Solid-liquid Two-phase Flow in Centrifugal Pump

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Chinese Journal of Mechanical Engineering 2013年第1期26卷 53-60页

作者： ZHANG Yuliang li Yi CUI Baoling ZHU Zuchao dou Huashu The State Key Lab of Fluid Power Transmission and Control Zhejiang University The Province Key Lab of Fluid Transmission Technology Zhejiang Sci-Tech University

The flow with solid-liquid two-phase media inside centrifugal pumps is very complicated and the relevant method for the hydraulic design is still immature so far. There exist two main problems in the operation of the two-phase flow pumps, i.e., low overall efficiency and severe abrasion. In this study, the three-dimensional, steady, incompressible, and turbulent solid-liquid two-phase flows in a low-specific-speed centrifugal pump are numerically simulated and analyzed by using a computational fluid dynamics （CFD） code based on the mixture model of the two-phase flow and the RNG k-~ two-equation turbulence model, in which the influences of rotation and curvature are fully taken into account. The coupling between impeller and volute is implemented by means of the frozen rotor method. The simulation results predicted indicate that the solid phase properties in two-phase flow, especially the concentration, the particle diameter and the density, have strong effects on the hydraulic performance of the pump. Both the pump head and the efficiency are reduced with increasing particle diameter or concentration. However, the effect of particle density on the performance is relatively minor. An obvious jet-wake flow structure is presented near the volute tongue and becomes more remarkable with increasing solid phase concentration. The suction side of the blade is subject to much more severe abrasion than the pressure side. The obtained results preliminarily reveal the characteristics of solid-liquid two-phase flow in the centrifugal pump, and are helpful for improvement and empirical correction in the hydraulic design of centrifugal pumps.

关键词： centrifugal pump solid-liquid two-phase particle property hydraulic performance abrasion numerical simulation

Abnormal State Detection of OLTC Based on Improved Fuzzy C-means Clustering

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Chinese Journal of Electrical Engineering 2023年第1期9卷 129-141页

作者： Hongwei li lilong dou Shuaibing li Yongqiang Kang Xingzu Yang Haiying Dong School of Automation and Electrical Engineering Lanzhou Jiaotong UniversityLanzhou 730070China School of New Energy and Power Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

An accurate extraction of vibration signal characteristics of an on-load tap changer(OLTC)during contact switching can effectively help detect its abnormal ***,an improved fuzzy C-means clustering method for abnormal state detection of the OLTC contact is ***,the wavelet packet and singular spectrum analysis are used to denoise the vibration signal generated by the moving and static contacts of the ***,the Hilbert-Huang transform that is optimized by the ensemble empirical mode decomposition(EEMD)is used to decompose the vibration signal and extract the boundary spectrum ***,the gray wolf algorithm-based fuzzy C-means clustering is used to denoise the signal and determine the abnormal states of the OLTC *** analysis of the experimental data shows that the proposed secondary denoising method has a better denoising effect compared to the single denoising *** EEMD can improve the modal aliasing effect,and the improved fuzzy C-means clustering can effectively identify the abnormal state of the OLTC *** analysis results of field measured data further verify the effectiveness of the proposed method and provide a reference for the abnormal state detection of the OLTC.

关键词： On-load tap changer singular spectrum analysis Hilbert-Huang transform gray wolf optimization algorithm fuzzy C-means clustering

Thermospheric mass density derived from CHAMP satellite precise orbit determination data based on energy balance method

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Science China Earth Sciences 2017年第8期60卷 1495-1506页

作者： li RuoXi LEI JiuHou WANG XiJing dou XianKang JIN ShuangGen School of Earth and Space Science University of Science and Technology China Key Laboratory for Fault Diagnosis and Maintenance of Spacecraft In-orbit Shanghai Astronomical Observatory Chinese Academy of Sciences

In this article, the energy balance method is used to retrieve thermospheric mass density from CHAMP satellite precise orbit determination(POD) data during 2007–2009. The retrieved thermospheric mass densities are compared with those from accelerometer data and an empirical model. The main conclusions are as follows:(1) Thermospheric mass density can be retrieved from POD data by the energy balance and semi-major axis decay methods, whose results are consistent.(2) The accuracy of the retrieved densities depends on the integration time period, and the optimal period for CHAMP density retrieval from POD data is about 20 minutes.(3) The energy balance method can be used to calibrate accelerometer data.(4) The accuracy of retrieving thermospheric density from POD data varies with satellite altitude and local time.

关键词： Thermospheric mass density Satellite orbit Semi-major axis Energy balance Accelerometer

Stress corrosion cracking failure of X80 carbon steel U-b end cause d by Desulfovibrio vulgaris biocorrosion

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Journal of Materials Science & Technology 2024年第7期174卷 95-105页

作者： Zhong li Jike Yang Shihang Lu Wenwen dou Tingyue Gu Corrosion&Protection Center University of Science&Technology BeijingBeijing 100083China Institute of Marine Science and Technology Shandong UniversityQingdao 266237China Department of Chemical and Biomolecular Engineering Institute for Corrosion and Multiphase TechnologyOhio UniversityAthensOH 45701USA

Sulfate reducing bacteria(SRB)are widely present in oil and gas industry,causing pitting corrosion on pipeline *** corrosion cracking(SCC)often occurs in the presence of mechanical stress before pit-ting perforation failure,leading to economic losses and even catastrophic *** this study,stress distribution simulation using the finite element method(FEM),corrosion analysis techniques and elec-trochemical corrosion measurements were employed to investigate the SCC mechanism of X80 pipeline steel caused by Desulfovibrio vulgaris,which is a common SRB strain used in microbiologically influenced corrosion(MIC)*** was found that *** MIC caused sharp microcracks on an X80 U-bend coupon after only 2 weeks of immersion at 37℃in the deoxygenated ATCC 1249 culture medium inocu-lated with *** X80 U-bend coupon’s weight loss-based uniform corrosion rate for the 12 cm^(2)surface was 60%of that for the unstressed flat square coupon(2.3 mg cm^(−2)vs.3.8 mg cm^(−2)).This was likely because the square coupon had wide MIC pits,providing a larger effective surface area for more sessile cells(4.2×10^(8)cells cm^(−2)on square coupon vs.2.4×10^(8)cells cm^(−2)on U-bend coupon)to attach and harvest more *** SCC failure occurred on an X80 U-bend pre-cracked at the outer bottom after a 6-week immersion in the *** *** from MIC damage,this could also be because *** metabolism increased the availability hydrogen atoms on the steel surface,and promoted the diffusion of hydrogen atoms into the metal lattice,thus increasing the brittleness of the steel.

关键词： Stress corrosion cracking Microbiologically influenced corrosion Sulfate reducing bacteria X80 U-bend steel Tensile stress

High molecular karyotype variation revealed in indigenous Elymus nutans in the Qinghai Plateau

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Plant Diversity 2017年第3期39卷 117-122页

作者： Quanwen dou Feng Yu Yuan li Yanyan Zhao Ruijuan liu Laboratory of Adaptation and Evolution of Plateau Biota Northwest Plateau Institute of BiologyChinese Academy of Sciences Xining 810001 China Graduate University of Chinese Academy of Sciences Beijing 100049 China

The karyotypes of 27 individuals of Elymus nutans from eight wild populations in the Qinghai Plateau were analyzed using sequential FISH and GISH. High FISH pattern polymorphism and karyotype variation were detected within and among populations. The chromosome variations were mainly characterized as repeat deletions and amplifications along with inter-genomic translocations. The chromosomes of the St and Y genomes demonstrated higher polymorphism than those of the H genome. Six different intergenomic translocations were identified in 33.3% of individuals; type Ⅰ and Ⅱ translocations were detected with higher frequency. Further analysis revealed that type Ⅰ and Ⅱ translocations were distributed in different geographic regions. The origin of high karyotype variation of E. nutans in the Qinghai plateau is further discussed.

关键词： Elymus nutans Karyotype variation Inter-genomic translocation

L-proline feeding for augmented freeze tolerance of Camponotus japonicus Mayr

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Science Bulletin 2019年第23期64卷 1795-1804页

作者： Mengjia dou Yazhou li Ziqiao Sun Lei lia Wei Rao C4S Key Laboratory of Cryogenics Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China School of Energy and Power Engineering Beihang UniversityBeijing 100191China Beijing Engineering Research Center of Sustainable Energy and Buildings Beijing University of Civil Engineering and ArchitectureBeijing 100044China School of Future Technology University of Chinese Academy of SciencesBeijing 100049China Beijing Key Laboratory of Cryo-Biomedical Engineering Beijing 100190China

The successful cryopreservation of organs is a strong and widespread demand around the world but faces great challenges. The mechanisms of cold tolerance of organisms in nature inspirit researchers to find new solutions for these challenges. Especially, the thermal, mechanical, biological and biophysical changes during the regulation of freezing tolerance process should be studied and coordinated to improve the cryopreservation technique and quality of complex organs. Here the cold tolerance of the Japanese carpenter ants, Camponotus japonicus Mayr, was greatly improved by using optimal protocols and feeding on L-proline-augmented diets for 5 days. When cooling to -27.66 ℃, the survival rate of frozen ants increased from 37.50% ± 1.73% to 83.88% ± 3.67%. Profiling of metabolites identified the concentration of whole-body L-proline of ants increased from 1.78 to 4.64 ng g-1 after 5-day feeding. High Lproline level, together with a low rate of osmotically active water and osmotically inactive water facilitated the prevention of cryoinjury. More importantly, gene analysis showed that the expression of ribosome genes was significantly up-regulated and played an important role in manipulating freezing tolerance. To the best of our knowledge, this is the first study to link genetic variation to the enhancement of ants’ cold tolerance by feeding exogenous cryoprotective compound. It is worth noting that the findings provide the theoretical and technical foundation for the cryopreservation of more complex tissues,organs, and living organisms.

关键词： L-proline Cryopreservation Freeze tolerance Metabolomics Gene expression

Numerical and Experimental Investigation on Aerodynamic Performance of Small Axial Flow Fan with Hollow Blade Root

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Journal of Thermal Science 2013年第5期22卷 424-432页

作者： Zhang li Jin Yingzi1 dou Huashu Jin Yuzhen Faculty of Mechanical Engineering & Automation Zhejiang Sci-Tech University Department of Application & Engineering Zhejiang Economic & Trade Polytechnical

To reduce the influence of adverse flow conditions at the fan hub and improve fan aerodynamic performance, a modification of conventional axial fan blades with numerical and experimental investigation is presented. Hollow blade root is manufactured near the hub. The numerical and experimental results show that hollow blade root has some effect on the static performance. Static pressure of the modified fan is generally the same with that of the datum fan, while, the efficiency curve of the modified fan has a different trend with that of the datum fan. The highest efficiency of the modified fan is 10% greater than that of the datum fan. The orthogonal experimental re- suits of fan noise show that hollow blade root is a feasible method of reducing fan noise, and the maximum value of noise reduction is about 2 dB. The factors affecting the noise reduction of hollow blade root are in the order of importance as follows： hollow blade margin, hollow blade height and hollow blade width. The much smoother pressure distribution of the modified fan than that of the datum fan is the main mechanism of noise reduction of hollow blade root. The research results will provide the proof of the parameter optimization and the structure de- sign for high performance and low noise small axial fans.

关键词： small axial flow fan hollow blade root performance noise reduction mechanism