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Transient fuel performance analysis of UO_(2)–BeO fuel with composite SiC coated with Cr cladding based on multiphysics method

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Nuclear Science and Techniques 2023年第12期34卷 93-108页

作者： Chun‑yu Yin Shi‑Xin Gao sheng‑yu liu Rong liu Guang‑Hui Su Li‑Bo Qian School of Nuclear Science and Technology Xi’an Jiaotong UniversityXi’an 710049China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213China School of Electric Power South China University of TechnologyGuangzhou 510640China

The transient multiphysics models were updated in CAMPUS to evaluate the accident-tolerant fuel performance under accident *** is a fuel performance code developed based on *** simulated results of the UO_(2)–Zircaloy fuel performance under accident conditions were compared with those of the FRAPTRAN code and the experimental data to verify the correctness of the updated ***,multiphysics models of the UO_(2)–BeO fuel and composite SiC coated with Cr(SiC_(f)/SiC-Cr)cladding were implemented in ***,the fuel performance of the three types of fuel cladding systems under Loss of Coolant Accident(LOCA)and Reactivity Insertion Accident(RIA)conditions was evaluated and compared,including the temperature distribution,stress distribution,pressure evolution,and cladding failure *** results showed that the fuel temperature of the UO_(2) fuel under accident conditions without pre-irradiation was lower after being combined with SiC_(f)/SiC-Cr ***,the centerline and outer surface temperatures of the UO_(2)–BeO fuel combined with SiC_(f)/SiC-Cr cladding reduced further under accident *** cladding temperature increased after the combination with the SiC_(f)/SiC-Cr cladding under accident conditions with *** addition,the use of SiC_(f)/SiC-Cr cladding significantly reduced the cladding hoop strain and plenum pressure.

关键词： Accident condition Fuel performance UO2–BeO fuel SiCf/SiC-Cr cladding

Response characteristics of PWR primary circuit under SBLOCAs considering steam bypass discharging

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Nuclear Science and Techniques 2024年第6期35卷 189-201页

作者： Shuai Yang Xiang-Bin Li yu-sheng liu Jia-Ning Xu De-Chen Zhang School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy Beijing 102206China Nuclear and Radiation Safety Center MEPBeijing 100084China

Small-break superposed station blackout(SBO)accidents are the basic design accidents of nuclear power *** the condition of a small break in the cold leg,SBO further increases the severity of the accident,and the steam bypass discharg-ing system(GCT)in the second circuit can play an important role in guaranteeing core *** explore the influence of the GCT on the thermal-hydraulic characteristics of the primary circuit,RELAP5 software was used to establish a numerical model based on a typical pressurized water reactor nuclear power *** different small breaks in the cold-leg super-posed SBO were selected,and the impact of the GCT operation on the transient response characteristics of the primary and secondary circuit systems was *** results show that the GCT plays an indispensable role in core heat removal during an accident;otherwise,core safety cannot be *** GCT was used in conjunction with the primary safety injection system during the placement *** the break diameter was greater than a certain critical value,the core cooling rate could not be guaranteed to be less than 100 K/h;however,the core remained in a safe state.

关键词： Steam bypass discharging Pressurized water reactor SBLOCA Numerical simulation

Two‑parameter dynamical scaling analysis of single‑phase natural circulation in a simple rectangular loop based on dilation transformation

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Nuclear Science and Techniques 2022年第12期33卷 59-74页

作者： Jia‑Ning Xu Xiang‑Bin Li yu‑sheng liu Shuai Yang De‑Chen Zhang Qiao Wu School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy Beijing 102206China Nuclear and Radiation Safety Center MEEBeijing 100082China Department of Nuclear Engineering Oregon State UniversityCorvallisOR 97331USA

Scaling analysis is widely used to design scaled-down experimental facilities through which the prototype phenomena can be effectively *** a new method,dynamic system scaling(DSS)must be verified as a rational and applicable method.A DSS method based on dilation transformation was evaluated using single-phase natural circulation in a simple rectangular *** scaled-down cases were constructed based on two parameters—length ratio and dilation number—and the corresponding transient processes were simulated using the Relap5 computational *** results show that this DSS method can simulate the dynamic flow characteristics of scaled-down *** transient deviation of the temperature difference and mass flow rate of the scaled cases decrease with increases in the length ratio and dilation *** distortion of the transient temperature difference is smaller than that of the mass flow;however,the overall deviation is within a reasonable range.

关键词： Dynamical system scaling analysis Single-phase natural circulation Transient scaling deviation Dilation transformation

Dynamic scaling characteristics of single-phase natural circulation based on different strain transformations

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Nuclear Science and Techniques 2023年第9期34卷 128-141页

作者： Jia-Ning Xu Xiang-Bin Li Zhong-Yi Wang yu-sheng liu De-Chen Zhang Qiao Wu School of Nuclear Science and Engineering North China Electric Power UniversityBeijing 102206China Beijing Key Laboratory of Passive Safety Technology for Nuclear Energy Beijing 102206China China Institute of Nuclear Industry Strategy BeijingChina Nuclear and Radiation Safety Center MEEBeijing 100082China Department of Nuclear Engineering Oregon State UniversityCorvallisOR 97331USA

To understand the dynamical system scaling(DSS)analysis theory,the applicability of DSSβ-andω-strain transformation methods for the scaling analysis of complex loops was explored.A simplified model consisting of two loops was established based on the primary and secondary sides of a nuclear reactor,andβ-andω-strain transformation methods were used to ana-lyze the single-phase natural circulation in the primary *** comparison with the traditional method,simplified DSSβ-andω-strain methods were developed based on the standard scaling *** strain parameters in these four methods were modified to form multiple groups of scaled-down *** transient process of the natural circulation was simulated using the Relap5 code,and the variation in the dynamic flow characteristics with the strain numbers was obtained using different scaling *** results show that both the simplified and standard DSS methods can simulate the dynamic characteristics of natural circulation in the primary *** scaled-down cases in the simplified method exhibit the same geometric scaling and correspond to small core power *** contrast,different scaled-down cases in the standard DSS method correspond to different geometric scaling criteria and require more *** dynamic process of natural circula-tion can be simulated more accurately using the standard DSS method.

关键词： Dynamical system scaling analysis β-strain transformation ω-strain transformation Natural circulation

Mechanism of anomalous low friction phenomenon in deep block rock mass

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Mining Science and Technology 2009年第4期19卷 409-419页

作者： WU Hao FANG Qin ZHANG Ya-dong LU yu-sheng liu Jin-chun Engineering Institute of Engineering Corps PLA University of Science and Technology Nanjing Jiangsu 210007 China

Deep rock mass has the unique ＂self-stressed＂ block-hierarchical structure, anomalous low friction （ALF） was one of the typical nonlinear get-mechanical and dynamic responses in deep block rock mass, which occurred as the result of movements of large-scale get-blocks under the impact of external pulses （such as a deep confined explosion, earthquakes, rock bursts and etc.）. ALF phenomenon obtained its name to describe the curious phenomenon that the friction between interacting get-blocks qua- si-periodically disappears at some discrete points in time along the direction orthogonal to the direction of the external pulse. With the objective to confirm the existence of the ALF phenomenon and study the get-mechanical conditions for its occurrence experi- mentally and theoretically, laboratory tests on granite and cement mortar block models were carried out on a multipurpose testing system developed independently. The ALF phenomenon was realized under two loading schemes, i.e., blocks model and a working block were acted upon jointly by the action of a vertical impact and a horizontal static force, as well as the joint action of both ver- tical and horizontal impacts with differently delayed time intervals. We obtained the rules on variation of horizontal displacements of working blocks when the ALF phenomenon was realized in two tests. The discrete time delay intervals, corresponding to local maxima and minima of the horizontal displacement amplitudes and residual horizontal displacements of the working block, satis- fied canonical sequences multiplied by （√2）＇. Some of these time intervals satisfied the quantitative expression （√2）＇ ,alva. At last, 1D dynamic theoretical model was established, the analytical results agreed better with the test data, while the quantitative expression drawn from test data was not validated well in theoretical analyses.

关键词： deep block rock mass block-hierarchical structure optical fiber displacement meter anomalous low friction canonical sequence

Theoretical Studies on the Structures and Reactions of Halocarbenoids(Ⅰ)Structures and Stability of Chlorocarbenoid CHCl_2

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Chemical Research in Chinese Universities 1997年第3期13卷 256-261页

作者： Li LI Ji-hai, FENG sheng-yu,liu Wei (Chemical College,Shandong University,Jinan, 250100) SHANDONG UNIV CHEM COLLJINAN 250100PEOPLES R CHINA

The chlorocarbenoid , CHCl2Li , was studied by means of ab initio molecular or- bital theory. Three equilibrium structures and two isomerization transition states were located. The calculations showed that the three-membered ring structure is the most stable. The 'classical tetrahedral' structure is not the local minimum on the potential energy surface.

关键词： Chlorocarbenoid isomeric structure Ab initio molecular orbital calcu- lation

ON SINIAN MICRO-FLORA IN YENLIAO REGION OF CHINA AND ITS GEOLOGICAL SIGNIFICANCE

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地质学报 1973年第1期 52-64页

作者： SIN yu-sheng liu KUI-ZHIH

The Sinian system of northern China is well-developed in Yenliao region, especially in Chih County of Hopei, where one finds a complete stratigraphical sequence showing distinct contacts with both the overlying and underlying strata as well as rather clear subdivisions of three series and ten formations. It is considered the type section of the Sinian system of *** 1962 a systematic study of micro-flora (bacteria, algae and their spores) in Chih County of Hopei and in Penchsi County of eastern Liaotung has been carried on by the authors. A description of 7 genera, 33 species and 1 variety are new. The new genera named are Pseudozonosphaera gen. n., Dictyosphaera gen. n., Quadratimorpha gen. n., Triangumorpha gen. n., Polynucella gen. n., Polyporata gen. n. and Cornutosphaera gen. *** study has revealed a regularity of vertical distribution of these microplant remains which is considered one of the criteria for the stratigraphic subdivision and correlation of the Sinian system. An attempt is made in correlating the Sinian type section in Chih County with its equivalent strata in other regions. It is indicated that the assemblage of mieroplant remains in the Chuanlingkou formation of the lower Sinian in Chih County bears resemblance to those in the lower and middle parts of the Riphean group of southern Urals and the Diabaig formation in the lower part of the Torridonian series of Scotland, while the assemblage of mieroplant remains in the Hsiamaling formation of the upper Sinian in Chih County is similar to that in the Vendian complex, especially its upper part, i.e., the Valdainian series of the Russian *** relationship between the Sinian and Pre-sinian micropalaeo-flora and origin of combustible organic deposits is discussed. It is pointed out that sapromyxite, oil shale, oil and natural gas, all of great economic significance, could come into being in the Sinian period or at an even earlier time and that the Sinian strata may serve not only as

关键词： ON SINIAN MICRO-FLORA IN YENLIAO REGION OF CHINA AND ITS GEOLOGICAL SIGNIFICANCE PI 微古植物群邢裕盛燕辽地区 ITS

基于所得税的设备赁购问题在线策略与竞争分析

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系统管理学报 2017年第5期26卷 842-849,856页

作者：余昇刘静中南财经政法大学工商管理学院武汉430074

由于所得税在企业租赁和购买设备时影响成本的方式不同导致实际设备使用费发生变化,因此,需要在市场环境下考虑所得税对企业设备赁购行为决策的影响。将所得税概念引入经典在线租赁问题,提出了基于所得税的在线设备赁购问题。给出了该... 详细信息

由于所得税在企业租赁和购买设备时影响成本的方式不同导致实际设备使用费发生变化,因此,需要在市场环境下考虑所得税对企业设备赁购行为决策的影响。将所得税概念引入经典在线租赁问题,提出了基于所得税的在线设备赁购问题。给出了该问题的离线最优解,设计了在线赁购策略RBS和租赁策略RS并进行竞争分析得到策略竞争比和问题下界。当设备寿命期内一直租赁费用与设备购置费用比值小于与所得税税率相关的函数值时,证明了策略RS是最优在线策略。最后,通过算例,结合实际中一般居民企业、小型微利企业和高新技术企业等3种不同类型企业缴纳的不同所得税税率,证实了所得税税率高低会影响企业的在线设备赁购决策和技术更新行为。

关键词：在线理论竞争比设备租赁所得税

MicroRNA-155 as a potential biomarker for breast cancer screening: a systematic review and meta-analysis

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TMR Cancer 2020年第5期3卷 187-198页

作者： yu-Rong Wang Xiao-Qian Hao Qian Xiang yu-sheng liu Jie-Yan Wu College of traditional Chinese Medicine Jinan UniversityGuangzhou 510632China

Background:It is aimed to evaluate the clinical significance of miR-155 on diagnosing human breast ***:Eligible studies were identified through multiple search *** search was updated up until April 10,***’s nomogram,publication bias,meta-regression,sensitive analysis,area under the summary receiver operating characteristic(AUC),diagnostic odds ratio as well as pooled sensitivity and specificity were utilized to assess the capacity of miR-155 for *** meta-analysis was conducted and the origin of the heterogenic property was investigated by Stata SE 12.0 and Meta-Disc ***:The meta-analysis contained 9 articles totally with the AUC,diagnostic odds ratio,specificity,pooled sensitivity of 0.90(95%CI,0.88–0.93),28.63(95%CI,11.22–73.04),0.82(95%CI,0.72–0.89)and 0.86(95%CI,0.76–0.93)*** negative and positive likelihood ratios were 0.14 and ***,the heterogeneity was apparent but resulted from neither sensitivity analyses nor threshold ***:The evidence from this study indicates that miR-155 exhibits satisfactory performance on diagnosis for breast cancer.

关键词： Diagnosis MicroRNA-155 Biomarker Breast cancer