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Jet Characteristics and Optimization of a Cavitation Nozzle for Hydraulic Fracturing Applications

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Fluid Dynamics & Materials Processing 2024年第1期20卷 179-192页

作者： Yu Gao zhenqiang xu Kaixiang Shen Shenzhen South China Sea Oil Economic Development Co. Ltd.Shenzhen518000China Guangzhou Marine Geological Survey China Geological SurveyGuangzhou511458China National Engineering Research Center of Gas Hydrate Exploration and Development Guangzhou511458China

Hydraulic jetting is a form of fracturing that involves using a high-pressure jet of water to create fractures in the reservoir rock with a nozzle serving as the central component of the hydraulic sandblasting perforation *** this study,the flow behavior of the nozzle is simulated numerically in the framework of a SST k-ωturbulence *** results show that the nozzle structure can significantly influence the jet performance and related cavitation *** orthogonal experiments,the nozzle geometric parameters are optimized,and the following configuration is found accordingly:contraction angle 20°,contraction segment length 6 mm,cylindrical segment diameter 6 mm,cylindrical segment length 12 mm,spread segment length 10 mm,and spread angle 55°.

关键词： Cavitation jet angle nozzle hydraulic characteristics nozzle parameters

Effect of Skeleton Grain Size on the Saturation of Gas Hydrate in Natural Sediments

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Peroxyacetyl nitrate observed in Beijing in August from 2005 to 2009

中国海洋大学学报（自然科学英文版） 2024年第3期 676页

作者： xu zhenqiang LI Yang

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Journal of Environmental Sciences 2014年第10期26卷 2007-2017页

作者： Tianyu Gao Li Han Bin Wang Guang Yang zhenqiang xu Limin Zeng Jianbo Zhang State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and EngineeringPeking University

Measurements of peroxyacetyl nitrate（PAN） were made at a Beijing urban site each August from2005 to 2009. Over this 5-year period, the average PAN concentration for August in each year increased from 3（2005） to 11.7 μg/m3（2007）; however, it decreased rapidly in 2008（4.1 μg/m3）.Generally, the variation over the 5 years showed a rise in the first part of the study period,followed by a decline. We considered two categories of local and regional air masses in this study, which revealed that the PAN concentration in Beijing was affected mainly by southeastern air masses. The August PAN variation was influenced predominantly by local air masses in 2005,but by 2009 regional air masses had become more important. This study showed the level and variation of PAN in the month of August in 5 consecutive years for the first time, and proved that control measures are useful in decreasing photochemical pollution; hence, these measures are probably feasible for other megacities too. Furthermore, this method of analyzing regional and local impacts might be useful for other studies as well.

关键词： PAN Beijing Transport Local Regional

ImmunoCytTM and cytology for diagnosis of bladder carcinoma：a meta analysis

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Chinese Medical Journal 2014年第4期127卷 758-764页

作者： Yang Minggen Zheng Zhouda Zhuang Zhiming Zhao Xiaokun xu zhenqiang Lin Haili Department of Urology Zhangzhou Affiliated Hospital Fujian Medical University Zhangzhou Fujian 363000 China Department of Urology The Second Xiangya Hospital Central South University Changsha Hunan 410011 China

Background Currently,cystoscopy and urine cytology are standard modalities in therapy monitoring and follow-up of bladder carcinoma （BC）.Cystoscopy is an invasive and uncomfortable procedure while cytology has a limited value because it is operator-dependent and has low *** study was to assess the accuracy of ImmunoCyt in detecting BC by comparing it with cytology using systemic analyses of studies published in both English and *** Cochrane systematic evaluation was used to search through MEDLINE,EMBASE,Cochrane Library,CMCC,and CNKI for studies regarding ImmunoCyt and cytology for detection of *** were extracted and analyzed by the software MetaDiSc *** In total 42 relevant studies were searched,of which 15 were enrolled and 12 491 patients were ***,except for threshold effects,was found within these studies.A meta-analysis was performed using the random effect *** accuracy indicators like sensitivity,specificity,and diagnostic odds ratio of ImmunoCytTM and cytology were 0.75 （0.73-0.77） vs.0.45 （0.43-0.48）,0.73 （0.72-0.74） vs.0.97 （0.96-0.97）,and 10.97 （7.53-15.99） vs.16.40 （10.57-25.46）,*** sensitivity of both was increased with the increase of tumor grade and *** area under summary receiver operating characteristics curve was 0.834 4 and 0.853 4 and the Q index 0.766 7 and 0.785 3 for ImmunoCyt and cytology,*** of both can obviously improve the accuracy of *** ImmunoCyt has a high sensitivity in detecting BC,but its specificity is *** an important adjunct,ImmunoCytTM can not replace cytology,but combined with cytology it could improve sensitivity with high specificity in the detection and postoperative monitoring of BC.

关键词： bladder carcinoma ImmunoCytTM cytology

Wind-sand flow simulation and radius optimization of highway embankment under different vertical curve radius

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Journal of Mountain Science 2024年第8期21卷 2533-2546页

作者： LI Liangying LI Qi WANG xu XIN Guowei WANG zhenqiang School of Civil Engineering Lanzhou Jiaotong UniversityLanzhou 730070China

It is of great practical value to explore the correlation between the vertical curve radius of desert highway and the increase of sand accumulation in local lines,and to select the appropriate vertical curve radius for reducing the risk of sand *** this study,three-dimensional models of desert highway embankments with different vertical curve radii were constructed,and Fluent software was used to simulate the wind-sand flow field and sand accumulation distribution of vertical curve *** results show that:(1)Along the direction of the road,the concave and the convex vertical curve embankments have the effect of collecting and diverging the wind-sand flow,*** the radius of the concave vertical curve is 3000 m,5000 m,8000 m,10000 m and 20000 m,the wind velocity in the middle of the vertical curve is 31.76%,22.58%,10.78%,10.53%and 10.44%,higher than that at both *** the radius of the convex vertical curve is 6500 m,8000 m,10000 m,20000 m and 30000 m,the wind velocity at both ends of the vertical curve is 14.06%,9.99%,6.14%,3.22%and 2.41%,higher than that in the *** diversion effect also decreases with the increase of the radius.(2)The conductivity of the concave and convex vertical curve embankments with different radii is greater than 1,which is the sediment transport *** conductivity increases with the increase of radius and gradually tends to be *** the radius of the concave and convex vertical curves reaches 8000 m and 20000 m respectively,the phenomenon of sand accumulation is no longer *** the same radius condition,the concave vertical curve embankment is more prone to sand accumulation than the convex one.(3)Considering the strength of the collection and diversion of the vertical curve embankment with different radii,and the sand accumulation of the vertical curve embankment in the desert section of Wuma Expressway,the radius of the concave vertical curve is not less than 8000 m,and the r

关键词： Highway engineering Vertical curve Numerical simulation Embankment wind-sand flow Radius optimization

Feed conversion ratio,residual feed intake and cholecystokinin type A receptor gene polymorphisms are associated with feed intake and average daily gain in a Chinese local chicken population

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Journal of Animal Science and Biotechnology 2018年第4期9卷 794-802页

作者： Zhenhua Yi Xing Li Wen Luo zhenqiang xu Congliang Ji Yan Zhang Qinghua Nie Dexiang Zhang Xiquan Zhang Department of Animal Genetics Breeding and ReproductionCollege of Animal ScienceSouth China Agricultural UniversityGuangzhou 510642GuangdongChina Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding and Key Laboratory of Chicken Genetics Breeding and ReproductionMinistry of AgricultureGuangzhou 510642GuangdongChina Wen’s Nanfang Poultry Breeding Co.Ltd Yunfu 527400GuangdongChina

Background: The feed conversion ratio(FCR) and residual feed intake(RFI) are common indexes in measuring feed efficiency for livestock. RFI is a feed intake adjusted for requirements for maintenance and production so these two traits are related. Similarly, FCR is related to feed intake and weight gain because it is their ratio. Cholecystokinin type A receptor(CCKAR) plays an important role in animal digestive process. We examined the interplay of these three parameters in a local Chinese chicken ***: The feed intake(FI) and body weights(BW) of 1,841 individuals were monitored on a daily basis from 56 to 105 d of age. There was a strong correlation between RFI and average daily feed intake(ADFI) and a negative correlation between the FCR and daily gain(r=-0.710). Furthermore, we identified 51 single nucleotide polymorphisms(SNPs) in the CCKAR and 4 of these resulted in amino acid mutations. The C334A mutation was specifically associated with FI and the expected feed intake(EFI)(P < 0.01) and significantly associated with the average daily gain(ADG)(P < 0.05). G1290A was significantly associated with FI and EFI(P < 0.05).Conclusion: FCR is apply to weight selecting, and RFI is more appropriate if the breeding focus is feed intake. And C334A and G1290A of the CCKAR gene can be deemed as candidate markers for feed intake and weight gain.

关键词： CCKAR Chicken FCR RFI SNP

Dual-additives enable stable electrode-electrolyte interfaces for long life Li-SPAN batteries

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Chinese Chemical Letters 2024年第5期35卷 459-465页

作者： zhenqiang Guo Huicong Yang Qian Wei Shengjun xu Guangjian Hu Shuo Bai Feng Li School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Department of Biochemistry and Molecular Biology College of Life ScienceChina Medical UniversityShenyang 110122China Dalian National Laboratory for Clean Energy Dalian 116023China Shenyang King Power Technology Co. Ltd.Shenyang 110016China

Sulfurized polyacrylonitrile(SPAN)is proposed as a promising cathode material for lithium sulfur ***,the continuous side reactions at the electrolyte-electrode interfaces as well as the slow redox kinetics of SPAN cathode deteriorate the electrochemical *** this study,an electrolyte with dual-additives comprising 2-fluoropyridine(2-FP)and lithium difluorobis(oxalato)phosphate(LiDFBOP)was used to improve the performance of Li||SPAN cells.2-FP has a lower lowest occupied molecular orbital energy than that of the solvents in the electrolyte,leading to its prior reduction.A LiF-rich film can be formed on the electrode,effectively improving the stability of the electrolyte-electrode interfaces and prolonging the ***,LiDFBOP could form an electrolyte-electrode interface film containing a large amount of Li_(x)PO_(y)F_(z) species,compensating for the kinetic deterioration caused by the lower ionic conductive of LiF formed at the electrolyte-electrode ***,an electrode-interface film with good chemical stability and high Li^(+) transport was established by LiF and Li_(x)PO_(y)F_(z)-rich *** Li||SPAN cell with the electrolyte containing dual-additives demonstrates an excellent capacity retention of 97.5%after 200 cycles at 1.0 C,25℃,comparing to 56.2%capacity retention without ***,the rate capacities of cells with dual-additives can reach 1128.1 mAh/g at 5 C,comparing to only 813.5 mAh/g using electrolyte without *** results shown that the dual-additives in electrolyte provide a promising strategy for practical application of lithium sulfur batteries with SPAN cathodes.

关键词： Sulfurized polyacrylonitrile Lithium metal Interface film 2-Fluoropyridine Difluorobis(oxalato)phosphate

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基于SCI的生物气溶胶文献计量学研究

北京大学学报（自然科学版） 2010年第3期46卷 327-338页

作者：徐振强要茂盛北京大学环境科学与工程学院、北京大学环境模拟与污染控制国家重点联合实验室北京100871

通过运用HistCite和Endnote等文献计量工具对生物气溶胶的研究工作进行了系统的计量学分析与评价,识别出具有引领意义的刊物、文章、研究机构和国家等;通过对关键词的词频统计,初步揭示出生物气溶胶的研究动态。研究所获得的信息有助于... 详细信息

通过运用HistCite和Endnote等文献计量工具对生物气溶胶的研究工作进行了系统的计量学分析与评价,识别出具有引领意义的刊物、文章、研究机构和国家等;通过对关键词的词频统计,初步揭示出生物气溶胶的研究动态。研究所获得的信息有助于国内相关领域的科技工作者熟悉生物气溶胶研究进度与动态,同时为从事生物气溶胶的大气化学和健康效应研究人员提供文献参考。

关键词： SCI(科学引文索引) 生物气溶胶文献计量

A high-speed true random number generator based on Ag/SiNx/n-Si memristor

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Frontiers of physics 2024年第1期19卷 241-250页

作者： Xiaobing Yan Zixuan Zhang Zhiyuan Guan Ziliang Fang Yinxing Zhang Jianhui Zhao Jiameng Sun xu Han Jiangzhen Niu Lulu Wang Xiaotong Jia Yiduo Shao Zhen Zhao zhenqiang Guo Bing Bai Institute of Life Science and Green Development Key Laboratory of Brain-Like Neuromorphic Devices and Systems of Hebei ProvinceCollege of Electron and Information EngineeringHebei UniversityBaoding 071002China

The intrinsic variability of memristor switching behavior can be used as a natural source of randomness,this variability is valuable for safe applications in hardware,such as the true random number generator(TRNG).However,the speed of TRNG is still be further ***,we propose a reliable Ag/SiNx/n-Si volatile memristor,which exhibits a typical threshold switching device with stable repeat ability and fast switching *** volatile-memristor-based TRNG is combined with nonlinear feedback shift register(NFSR)to form a new type of high-speed dual output ***,the bit generation rate reaches a high speed of 112 kb/*** addition,this new TRNG passed all 15 National Institute of Standards and Technology(NIST)randomness tests without post-processing steps,proving its performance as a hardware security *** work shows that the SiNx-based volatile memristor can realize TRNG and has great potential in hardware network security.

关键词： volatile memristor true random number generator(TRNG) delay time threshold switching device