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Effect of droplet characteristics on liquid-phase distribution in spray zone of internal mixing air-mist nozzle

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China Foundry 2024年第2期21卷 185-196页

作者： Wei-li Wu chang-gui Cheng Yang li Shi-fa Wei De-li Chen The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081China Hubei Provincial Key Laboratory for New Processes of Ironmaking and Steelmaking Wuhan University of Science and TechnologyWuhan 430081China Technology Center Fushun Special Steel Co.Ltd.Fushun 113001LiaoningChina

In continuous casting production,droplet characteristics are important parameters for evaluating the nozzle atomization quality,and have a significant impact on the secondary cooling effect and the slab *** order to study the behavior of atomized droplets after reaching the slab surface and to optimize the spray cooling effect,the influence of droplet diameter and droplet velocity on the migration behavior of droplets in the secondary cooling zone was analyzed by FLUENT *** show that the droplets in the spray zone and on the slab surface are mainly concentrated in the center,thus,the liquid volume fraction in the center is higher than that of either *** the droplet diameter increases,the region of high liquid volume fraction on the slab surface becomes wider,and the liquid phase distribution in the slab width direction becomes *** increasing the droplet velocity at the nozzle exit has little effect on droplet diffusion in the spray zone,the distribution becomes more uneven due to more liquid reaches the slab surface per unit time.A prediction formula of the maximum water flow rate on the slab surface for specific droplet characteristics was proposed based on dimensionless analysis and validated by simulated data.A nozzle spacing of 210 mm was recommended under the working conditions in this study,which ensures effective coverage of the spray water over the slab surface and enhances the distribution uniformity of water flow rate in the transverse direction.

关键词： continuous casting secondary cooling zone internal mixing air-mist nozzle droplet characteristics liquid phase distribution water flow rate

Synthesis of Planar-Chiral[2.2]Paracyclophane-Based Oxazole-Pyrimidine ligands and Application in Nickel-Catalyzed 1,2-Reduction ofα,β-Unsaturated Ketones

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Chinese Journal of Chemistry 2024年第7期42卷 705-710页

作者： Juan Wang Qing-Xian Xie Xiang li chang-Bin Yu Yong-gui Zhou School of Chemistry Dalian University of Technology2 Linggong RoadDalianLiaoning 116024China State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalianLiaoning 116023China

The planar-chiral ligands have been widely applied as a class of unique and significant ligands in asymmetric *** them,chiral[2.2]paracycyclophane has emerged as a privileged type of planar-chiral framework and has been utilized as an important toolbox due to their structural ***,we design and synthesize[2.2]paracyclophane-derived oxazole-pyrimidine ligands(abberviated as PYMCOX).These N,N-ligands with stable properties,rigid structure and large steric hindrance performed successfully in nickel-catalyzed asymmetric 1,2-reduction ofα,β-unsaturated ketones,affording the chiral allylic alcohols with up to 99%yield and 99%***,this reduction reaction could be conducted on gram-scale without loss of activity and enantioselectivity,and the chiral ligand could be conveniently recovered with high yield.

关键词： Oxazole-pyrimidine ligands Planar chirality Nickel Hydroboration Asymmetric synthesis

Orientation controlled photogenerated carriers on selfsupporting CdS/Ni_(3)S_(2) paper toward photocatalytic hydrogen evolution and biomass upgrading

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Rare Metals 2024年第5期43卷 2015-2025页

作者： Xiao-Yan liu Qing Cao gui-Xiang li Hui liu li-li Zeng li-li Zhao Bin chang Xi-Wen Wang Hong liu Wei-Jia Zhou Institute for Advanced Interdisciplinary Research School of Chemistry and Chemical EngineeringUniversity of JinanJinan 250022China Institute of Chemical Sciences and Engineering Ecole Polytechnique Federale de Lausanne1015LausanneSwitzerland KAUST Catalysis Center King Abdullah University of Science and TechnologyThuwal 23955-6900Kingdom of Saudi Arabia School of Environment and Energy South China University of TechnologyGuangzhou Higher Education Mega CenterGuangzhou 510006China State Key Laboratory of Crystal Materials Shandong UniversityJinan250100China School of Mechanical Engineering Xi'an Jiaotong UniversityXi'an 710054China

The appropriate regulation of band structure is an effective strategy in constructing efficient photocatalytic *** photocatalytic system mainly employs powder photocatalysts,which makes their recovery reliant on expensive separation processes and severely limits their industrial ***,we constructed a novel CdS/Ni_(3)S_(2)heterostructure using free-standing and flexible nickel fiber paper as the *** regulated energy band structure achieves effective electron–hole *** as-synthesized flexible photocatalyst exhibits considerable photocatalytic activity toward the H_(2)evolution reaction under visible-light irradiation,with an H_(2)production rate of5.63μmol·cm^(-2)·h^(-1)(14.1 mmol·g^(-1)cat·h^(-1)according to the catalyst loading content).Additionally,the otherwisewasted excited holes simultaneously drive organic transformations to yield value-added organic products,thus markedly improving the photocatalytic H_(2)evolution *** a photocatalytic system is scaled up further,where a self-supported 20 cm×25 cm sample achieves a champion H_(2)production rate of 60-80μmol·h^(-1)under practical sun *** newly developed self-supported photocatalyst produces opportunities for practical solar H2production with biomass upgrading.

关键词： Self-supporting photocatalyst CdS/Ni_(3)S_(2) heterojunction Hydrogen evolution Biomass upgrading Large-scaleapplication

Evolutionary mechanisms and practical significance of reproductive success and clonal diversity in unisexual vertebrate polyploids

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Science China(life Sciences) 2024年第3期67卷 449-459页

作者： Meng Lu li Zhou Jian-Fang gui State Key Laboratory of Freshwater Ecology and Biotechnology Hubei Hongshan Laboratorythe Innovation Academy of Seed DesignInstitute of HydrobiologyChinese Academy of SciencesWuhan 430072China University of Chinese Academy of Sciences Beijing 100049China

Unisexual reproduction is generally relevant to polyploidy, and unisexual vertebrates are often considered an evolutionary “dead end” due to the accumulation of deleterious mutations and absence of genetic diversity. However, some unisexual polyploids have developed strategies to avoid genomic decay, and thus provide ideal models to unveil unexplored evolutionary mechanisms, from the reproductive success to clonal diversity creation. This article reviews the evolutionary mechanisms for overcoming meiotic barrier and generating genetic diversity in unisexual vertebrates, and summarizes recent research advancements in the polyploid Carassius complex. Gynogenetic gibel carp(Carassius gibelio) is a unique amphitriploid that has undergone a recurrent autotriploidy and has overcome the bottleneck of triploid sterility via gynogenesis. Recently, an efficient strategy in which ploidy changes, including from amphitriploid to amphitetraploid, then from amphitetraploid to novel amphitriploid, drive unisexual-sexual-unisexual reproduction transition and clonal diversity has been *** on this new discovery, multigenomic reconstruction biotechnology has been used to breed a novel strain with superior growth and stronger disease resistance. Moreover, a unique reproduction mode that combines both abilities of ameiotic oogenesis and sperm-egg fusion,termed as ameio-fusiongensis, has been discovered, and it provides an efficient approach to synthesize sterile allopolyploids. In order to avoid ecological risks upon escape and protect the sustainable property rights of the aquaculture seed industry, a controllable fertility biotechnology approach for precise breeding is being developed by integrating sterile allopolyploid synthesis and gene-editing *** review provides novel insights into the origin and evolution of unisexual vertebrates and into the attempts being made to exploit new breeding biotechnologies in aquaculture.

关键词： unisexual vertebrates polyploidy reproduction transition clonal diversity precise breeding genomic reconstruction controllable fertility

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Potential evaluation of saline aquifers for the geological storage of carbon dioxide: A case study of saline aquifers in the Qian-5 member in northeastern Ordos Basin

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China Geology 2024年第1期7卷 12-25页

作者： Yan li Peng li Hong-jun Qu gui-wen Wang Xiao-han Sun chang Ma Tian-xing Yao Guoneng Jinjie Energy Co. Ltd.Shenmu 719319China Department of Geology Northwest UniversityXi’an 710069China Carbon Neutrality College(Yulin) Northwest UniversityXi’an 710069China National&Local Joint Engineering Research Center of Carbon Capture and Storage Technology Xi’an 710069China

The well-developed coal electricity generation and coal chemical industries have led to huge carbon dioxide(CO_(2))emissions in the northeastern Ordos *** geological storage of CO_(2) in saline aquifers is an effective backup way to achieve carbon *** this case,the potential of saline aquifers for CO_(2) storage serves as a critical basis for subsequent geological storage *** study calculated the technical control capacities of CO_(2) of the saline aquifers in the fifth member of the Shiqianfeng Formation(the Qian-5 member)based on the statistical analysis of the logging and the drilling and core data from more than 200 wells in the northeastern Ordos Basin,as well as the sedimentary facies,formation lithology,and saline aquifer development patterns of the Qian-5 *** results show that(1)the reservoirs of saline aquifers in the Qian-5 member,which comprise distributary channel sand bodies of deltaic plains,feature low porosities and permeabilities;(2)The study area hosts three NNE-directed saline aquifer zones,where saline aquifers generally have a single-layer thickness of 3‒8 m and a cumulative thickness of 8‒24 m;(3)The saline aquifers of the Qian-5 member have a total technical control capacity of CO_(2) of 119.25×10^(6) *** the largest scale and the highest technical control capacity(accounting for 61%of the total technical control capacity),the Jinjie-Yulin saline aquifer zone is an important prospect area for the geological storage of CO_(2) in the saline aquifers of the Qian-5 member in the study area.

关键词： Carbon burial Carbon neutral CO_(2) storage in saline aquifer Distributary channel sand body Potential evaluation Technical control capacity CO_(2)geological storage engineering Ordos Basin

Effect of Ti and Ta content on the oxidation resistance of Co-Ni-based superalloys

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 351-361页

作者： Yuheng Zhang Zixin li Yunwei gui Huadong Fu Jianxin Xie Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology BeijingBeijing 100083China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China Key Laboratory for Advanced Materials Processing(MOE) University of Science and Technology BeijingBeijing 100083China Beijing Laboratory of Metallic Materials and Processing for Modern Transportation University of Science and Technology BeijingBeijing 100083China

Co-Ni-based superalloys are known for their capability to function at elevated temperatures and superior hot corrosion and thermal fatigue ***,these alloys show potential as crucial high-temperature structural materials for aeroengine and gas turbine hot-end *** previous work elucidated the influence of Ti and Ta on the high-temperature mechanical properties of ***,the intricate interaction among elements considerably affects the oxidation resistance of *** this paper,Co-35Ni-10Al-2W-5Cr-2Mo-1Nb-xTi-(5−x)Ta alloys(x=1,2,3,4)with varying Ti and Ta contents were designed and compounded,and their oxidation resistance was investigated at the temperature range from 800 to 1000℃.After oxidation at three test conditions,namely,800℃for 200 h,900℃for 200 h,and 1000℃for 50 h,the main structure of the oxide layer of the alloy consisted of spinel,Cr_(2)O_(3),and Al_(2)O_(3)from outside to *** consisting of Ta,W,and Mo formed below the Cr_(2)O_(3)*** interaction of Ti and Ta imparted the highest oxidation resistance to 3Ti2Ta ***,an excessive amount of Ti or Ta resulted in an adverse effect on the oxidation resistance of the *** study reports the volatilization of W and Mo oxides during the oxidation process of Co-Ni-based cast superalloys with a high Al content for the first time and explains the formation mechanism of holes in the oxide *** results provide a basis for gaining insights into the effects of the interaction of alloying elements on the oxidation resistance of the alloys they form.

关键词： Co-Ni-based superalloys high-temperature oxidation Ti and Ta elements formation mechanism of holes

Thermal fatigue and wear of compacted graphite iron brake discs with various thermomechanical properties

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China Foundry 2024年第3期21卷 248-256页

作者： gui-quan Wang Zhuo Xu Zhong-li liu Xiang Chen Yan-xiang li School of Nuclear Equipment and Nuclear Engineering Yantai UniversityYantai 264005ShandongChina School of Materials Science and Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of EducationBeijing 100084China

The increase in payload capacity of trucks has heightened the demand for cost-effective yet high performance brake *** this work,the thermal fatigue and wear of compacted graphite iron brake discs were investigated,aiming to provide an experimental foundation for achieving a balance between their thermal and mechanical *** graphite iron brake discs with different tensile strengths,macrohardnesses,specific heat capacities and thermal diffusion coefficients were produced by changing the proportion and strength of *** peak temperature,pressure load and friction coefficient of compacted graphite iron brake discs were analyzed through inertia friction *** morphology of thermal cracks and 3D profiles of the worn surfaces were also *** is found that the thermal fatigue of compacted graphite iron discs is determined by their thermal properties.A compacted graphite iron with the highest specific heat capacity and thermal diffusion coefficient exhibits optimal thermal fatigue *** of the matrix at low temperatures significantly weakens the function of alloy strengthening in hindering the propagation of thermal *** the reduced hardness,increasing the ferrite proportion can mitigate wear loss resulting from low disc temperatures and the absence of abrasive wear.

关键词： compacted graphite iron brake disc thermomechanical properties thermal fatigue wear

内蒙古自治区东部草原达乌尔黄鼠携带重要病原体的分布研究

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中国媒介生物学及控制杂志 2024年第3期35卷 374-380页

作者：李晋宇白雪峰闫文喆李轲汪子豪石圆鲁亮李贵昌温红玲赵宁刘起勇山东大学齐鲁医学院公共卫生学院微生物检验学系新发突发传染病防控与生物安全山东省高等学校重点实验室媒介生物控制学系山东济南250012 传染病溯源预警与智能决策全国重点实验室中国疾病预防控制中心传染病预防控制所媒介生物控制室世界卫生组织媒介生物监测与管理合作中心北京102206 锡林郭勒盟疾病预防控制中心内蒙古锡林浩特026099 南京医科大学公共卫生学院江苏南京211166

目的对内蒙古自治区(内蒙古)东部草原达乌尔黄鼠及其携带重要病原体的种类和分布进行调查,为当地啮齿动物源疾病的控制和病原体监测提供依据。方法2021年5、7和9月分别在内蒙古8个样地捕获达乌尔黄鼠。使用荧光定量PCR(qPCR)/反转录qPCR... 详细信息

目的对内蒙古自治区(内蒙古)东部草原达乌尔黄鼠及其携带重要病原体的种类和分布进行调查,为当地啮齿动物源疾病的控制和病原体监测提供依据。方法2021年5、7和9月分别在内蒙古8个样地捕获达乌尔黄鼠。使用荧光定量PCR(qPCR)/反转录qPCR(RT-qPCR)法对达乌尔黄鼠肝脏标本检测莫氏立克次体、嗜吞噬细胞无形体、恙虫病东方体、土拉弗朗西斯菌、巴尔通体、致病性钩端螺旋体、大别班达病毒和汉坦病毒8种重要病原体。使用χ^(2)检验进行样地、季节、性别和不同体表寄生虫(蜱、螨、蚤)携带状态间达乌尔黄鼠病原体阳性率差异性分析。结果共捕获达乌尔黄鼠181只,捕获率为1.44%,寄生虫携带率为77.35%。肝脏病原检测结果显示,巴尔通体阳性率为39.23%(71/181),其余7种病原体阳性率为0~8.84%。巴尔通体阳性率季节间差异有统计学意义(χ^(2)=26.795,P0.05)。除巴尔通体外的其他病原体感染率不同月份(季节)、样地、性别和体表寄生虫携带状态间差异均无统计学意义(均P>0.05)。同时感染≥2种病原体的复合感染阳性率为8.84%。结论调查发现达乌尔黄鼠可携带多种病原体,并且存在多种病原体的复合感染,其中巴尔通体最值得关注。在南北走向的样线上,由北向南气温逐渐升高,巴尔通体阳性率逐渐降低;在东西走向的样线上,由西向东湿度逐渐增大,巴尔通体阳性率逐渐上升。初秋是当地达乌尔黄鼠防控的重点季节。

关键词：达乌尔黄鼠病原体检测巴尔通体分布

Neighbor Sum Distinguishing Total Choosability of Planar Graphs with Maximum Degree at Least 10

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Acta Mathematicae Applicatae Sinica 2024年第1期40卷 211-224页

作者： Dong-han Zhang You Lu Sheng-gui Zhang li Zhang School of Mathematics and Statistics Northwestern Polytechnical UniversityXi’an710129China School of Mathematics and Computer Application Shangluo UniversityShangluo726000China

A neighbor sum distinguishing(NSD)total coloringφof G is a proper total coloring of G such thatΣz∈EG(u)U{u}φ(z)≠Σz∈EG(v)U{v}φ(z)for each edge uv∈E(G),where EG(u)is the set of edges incident with a vertex *** 2015,Pilśniak and Wozniak conjectured that every graph with maximum degreeΔhas an NSD total(Δ+3)-***,Yang et *** that the conjecture holds for planar graphs withΔ≥10,and Qu et *** that the list version of the conjecture also holds for planar graphs withΔ≥*** this paper,we improve their results and prove that the list version of the conjecture holds for planar graphs withΔ≥10.

关键词： planar graphs neighbor sum distinguishing total choosibility combinatorial nullstellensatz discharging method