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Bending Failure Mode and Prediction Method of the Compressive Strain Capacity of A Submarine Pipeline with Dent Defects

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China Ocean Engineering 2024年第4期38卷 636-647页

作者： HOU fu-heng JIA Lu-sheng CHEN Yan-fei ZHANG Qi zhong Rong-feng WANG Chun-sha School of Mechanical and Transportation Engineering China University of PetroleumBeijingBeijing 102249China CNOOC Research Institute Ltd.Beijing 100028 China

A dent is a common type of defects for submarine *** submarine pipelines,high hydrostatic pressure and internal pressure are the main *** pipelines bend due to complex subsea conditions,the compression strain capacity may be *** into the local buckling failure and accurate prediction of the compressive strain capacity are important.A finite element model of a pipeline with a dent is *** buckling failure under a bending moment is investigated,and the compressive strain capacity is *** effects of different parameters on pipeline local buckling are *** results show that the dent depth,external pressure and internal pressure lead to different local buckling failure modes of the pipeline.A higher internal pressure indicates a larger compressive strain capacity,and the opposite is true for external *** the ratio of external pressure to collapse pressure of intact pipeline is greater than 0.1,the deeper the dent,the greater the compressive strain capacity of the *** as the ratio is less than 0.1,the opposite is *** the basis of these results,a regression equation for predicting the compressive strain capacity of a dented submarine pipeline is proposed,which can be referred to during the integrity assessment of a submarine pipeline.

关键词： submarine pipeline dent defect bending load local buckling compressive strain capacity

Identification of a novel mtDNA lineage B3 in chicken (Gallus gallus domesticus)

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Zoological Research 2017年第4期38卷 208-210页

作者： xun-he huang gui-mei li xing chen ya-jiang wu wei-na li fu-sheng zhong wen-zhi wang zhao-li ding school of life sciences jiaying universityMeizhou Guangdong 514015China kunming biological diversity regional center of large apparatus and equipments chinese academy of sciencesKunming Yunnan 650223China public technical service center kunming institute of zoologychinese academy of scienceKunming Yunnan 650223China state key laboratory of genetic resources and evolution kunming institute of zoologychinese academy of sciencesKunming Yunnan 650223China state key laboratory for conservation and utilization of bioresource in yunnan yunnan universityKunming Yunnan 650091China forensic science service of yunnan endangered species scientific commission Kunming Yunnan 650223China

DEAR EDITOR, In this study, we sequenced the complete mitochondrial DNA genome （mitogenome） of the Zhengyang Yellow chicken （Gallus gallus domesticus） by next-generation sequencing technology. Samples were taken from Zhumadian city, Henan Province, China. The complete mitogenome was 16 785 bp in size, and had a nucleotide composition of 30.3% （A）, 23.7% （T） 32.5% （C）, and 13.5% （G）, with a high AT content of 54.0%. The assembled mitogenome exhibited typical mitochondrial DNA （mtDNA） structure, including a non-coding control region, two rRNA genes, 13 protein-coding genes, and 22 tRNA genes. Phylogenetic analysis indicated that this mitogenome defined a novel sub-haplogroup B3 within haplogroup B. These results should provide essential information for chicken domestication and insiqht into the evolution of genomes.

关键词： DNA Identification of a novel mtDNA lineage B3 in chicken Gallus gallus domesticus

Influences of shale microstructure on mechanical properties and bedding fractures distribution

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Petroleum Science 2024年第3期21卷 1944-1954页

作者： Ming-Zhe Gu Mao sheng Shi-zhong Cheng Fan-Hao Gong Gen-sheng Li State Key Laboratory of Petroleum Resources and Engineering China University of Petroleum-BeijingBeijing2249China College of Petroleum Engineering China University of Petroleum-BeijingBeijing102249China Shenyang Center of China Geological Survey ShenyangLiaoning110034China

The difference in microstructure leads to the diversity of shale mechanical properties and bedding fractures distribution *** this paper,the microstructure and mechanical properties of Longmaxi marine shale and Qingshankou continental shale were studied by X-ray diffractometer(XRD),field emission scanning electron microscope(FE-SEM)with mineral analysis system,and ***,the typical bedding layers area was properly stratified using Focused Ion Beam(FIB),and the effects of microstructure and mechanical properties on the distribution patterns of bedding fractures were *** results show that the Longmaxi marine shale sample contains more clay mineral grains,while the Qingshankou continental shale sample contains more hard brittle mineral grains such as *** Longmaxi marine shale sample,hard brittle minerals with grain sizes larger than 20μm is18.24%and those with grain sizes smaller than 20μm is 16.22%.For Qingshankou continental shale sample,hard brittle minerals with grain sizes larger than 20μm is 40.7%and those with grain sizes smaller than 20μm is 11.82%.In comparison to the Qingshankou continental shale sample,the Longmaxi marine shale sample has a lower modulus,hardness,and *** shales are formed by alternating coarse-grained and fine-grained layers during *** average single-layer thickness of Longmaxi marine shale sample is greater than Qingshankou continental shale *** two types of shale have similar bedding fractures distribution patterns and fractures tend to occur in the transition zone from coarse-grained to fine-grained *** orientation of the fracture is usually parallel to the bedding plane and detour occurs in the presence of hard brittle *** fracture distribution density of the Longmaxi marine shale sample is lower than that of the Qingshankou continental shale sample due to the strong heterogeneity of the Qingshankou continental *** current resea

关键词： Shale Nanoindentation Microstructure Mechanical property Fracture

Nucleophiles promotes the decomposition of electrophilic functional groups of tetracycline in ZVI/H_(2)O_(2) system: Efficiency and mechanism

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Chinese Chemical Letters 2024年第10期35卷 414-420页

作者： Xin Li Wanting fu Ruiqing Guan Yue Yuan Qinmei zhong Gang Yao sheng-Tao Yang Liandong Jing Song Bai Key Laboratory of Pollution Control Chemistry and Environmental functional Materials for Qinghai-Tibet Plateau of the National Ethnic Affairs Commission School of Chemistry and EnvironmentSouthwest Minzu UniversityChengdu 610041China Key Laboratory of General Chemistry of the National Ethnic Affairs Commission School of Chemistry and EnvironmentSouthwest Minzu University.Chengdu 610041China Institute of Environmental Engineering RWTH Aachen UniversityAachen 52062Germany

When zero-valent iron(ZVI)is prepared and applied under neutral conditions,it is easy to form oxides or hydroxides on its surface,which hinders the electron release of *** this end,a nucleophile was introduced into the ZVI system to inhibit the precipitation of iron ions,improve the conductivity of the solution,and promote the removal efficiency of electrophilic functional groups in organic *** this study,the addition of nucleophiles such as ethylenediamine,methylamine and dimethylamine to the ZVI/H_(2)O_(2)system resulted in an enhanced removal efficiency of tetracycline(TC)under neutral condition,while electrophiles such as EDTA-2Na and oxalic acid dihydrate impeded the removal of *** results demonstrated that the presence of nucleophiles could effectively promote the release of iron ions and increase the proportion of ferrous in both aqueous solution and solid surface of *** and theoretical calculation results revealed that the electrophilic functional group was eliminated in the TC molecule,and the toxicity of the treated solution was reduced ***,this work provides a selection of the conditions and pollutants applicable to ZVI under neutral pH conditions.

关键词： ZVI Nucleophiles Tetracycline Electrophilicfunctionalgroup Electronic transfer

Relative position of seeds driven the seedling growth are mediated by root-leaf traits

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Journal of Plant Ecology 2024年第2期17卷 24-35页

作者： Jing Zhu Xue-Lin Wang Xing Jin Lan Jiang Hong-Yu Lin Yang Hu Jin-fu Liu zhong-sheng He College of Forestry Fujian Agriculture and Forestry UniversityFuzhou 350002China Key Laboratory of fujian Universities for Ecology and Resource Statistics Fujian Agriculture and Forestry UniversityFuzhou 350002China Zhenjiang Natural Resources and Planning Bureau Economic and Technological Development Zone Branch Zhenjiang 212132China

Variations in plant traits are indicative of plant adaptations to forest environments,and studying their relationships with tree growth provides valuable insights into forest *** spatial arrangement of plant seeds within the forest litter or soil critically infuences the variations of root-leaf traits,thereby affecting the adaptive strategies of emerging ***,our current understanding of the impacts of individual root-leaf traits on seedling growth in different relative position,and whether these traits together affect growth,remains *** study focuses on the dominant tree species,Castanopsis kawakamii,within the Sanming *** Nature Reserve of *** present experiment aimed to examine the variations in root-leaf traits of seedling,focus on the relative positions of seeds within different layers:beneath or above the litter layer,or within the bare soil layer(without litter).Our fndings provided evidence supporting a coordinated relationship between root and leaf traits,wherein leaf traits varied in conjunction with root traits in the relative positions of ***,we observed that seedlings exhibited higher values for specifc leaf area and average root diameter,while displaying lower root tissue *** mixed model explained 86.1%of the variation in root-leaf traits,surpassing the variation explained by the relative ***,soil nitrogen acted as a mediator,regulating the relationship between seedling growth and root-leaf traits,specifcally leaf dry matter content and root tissue ***,future studies should consider artifcially manipulating tree species diversity based on root-leaf traits characteristics to promote forest recovery.

关键词： relative growth rate coordination leaf traits root traits soil nitrogen content seed relative positions

Energy modeling and optimization of building condenser water systems with all-variable speed pumps and tower fans:A case study

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Building Simulation 2024年第7期17卷 1085-1111页

作者： Yong Cao Chuang Wang sheng Wang Xiao fu Xinguo Ming School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Air-Conditioning Equipment and System Energy Conservation Zhuhai 519070China GREE Electric Appliances Inc.of ZhuhaiZhuhai 519070China School of Environment and Energy Engineering Beijing University of Civil Engineering and ArchitectureBeijing 100044China Beijing Advanced Innovation Centerfor future Urban Design Beijing University of Civil Engineering and ArchitectureBeijing 100044China

The emergence of building condenser water systems with all-variable speed pumps and tower fans allows for increased efficiency and flexibility of chiller plants in partial load operation but also increases the control complexity of condenser water *** study aims to develop an integrated modeling technique for evaluating and optimizing the energy performance of such a condenser water *** proposed system model is based on the semi-physical semi-empirical chiller,pump,and cooling tower models,with capabilities of fully considering the hydraulic and thermal interactions in the condenser water loop,being solved analytically and much faster than iterative solvers and supporting the explicit optimization of the pump and tower fan frequency.A mathematical approach,based on the system model and constrained optimization technique,is subsequently established to evaluate the energy performance of a typical dual setpoint-based variable speed strategy and find its energy-saving potential and most efficient operation by jointly optimizing pumps and tower *** all-variable speed chiller plant from Wuhan,China,is used for a case study to validate the system model’s accuracy and explore its *** results showed that the system model can accurately simulate the condenser water system’s performance under various operating *** optimizing the frequencies of pumps and tower fans,the total system energy consumption can be reduced by 12%–13%compared to the fixed dual setpoint-based strategy with range and approach setpoints of 4℃and 2℃.In contrast,the energy-saving potential of optimizing the cooling tower sequencing is insignificant.A simple joint speed control method for optimizing the pumps and tower fans emerged,i.e.,the optimal pump and fan frequency are linearly correlated(if both are non-extremes)and depend on the chiller part load ratio only,irrespective of the ambient wet-bulb temperature and chilled water supply *** was also foun

关键词： all-variable speed chiller plant model-based optimization hydraulic and thermal coupling analytical solution dual setpoint-based variable speed control optimal joint speed control

Effect of Mo and cold forging deformation on strength and ductility of cobalt-based alloy L605

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Journal of Iron and Steel Research International 2024年第7期31卷 1811-1823页

作者： zhong-lin Wang Zhi-hua Gong Quan Li Han-sheng Bao School of Materials and Metallurgy Inner Mongolia University of Science and TechnologyBaotou 014017Inner MongoliaChina Institute of Special Steels Central Iron and Steel Research Institute Co.Ltd.Beijing 100081China

Mo element was added to cobalt-based alloy L605,and cold forging deformation was *** effects of the addition and cold forging deformation on the microstructure and mechanical properties of the alloy were studied by thermodynamic calculation,electron backscatter diffraction,transmission electron microscopy,and X-ray *** stacking fault energy(SFE)of the alloy decreased after the addition,and the formation of stacking faults and intersections were promoted to improve the strength and *** tensile strength of the alloy with Mo increased from 1190 to 1702 MPa after 24%cold deformation,producing significant work *** strengthening mechanism is strain-induced martensitic transformation(SIMT)and deformation *** alloy,combined with Mo and after 24%deformation,had both high strength and ductility in comparison with the original cobalt-based alloy *** is attributed to the lower SFE which caused the increase in stacking fault *** the tensile process,theε-hcp phase was easily generated at the stacking fault to reduce the stress concentration and increase the *** SIMT by adjusting the density of stacking faults can improve the mechanical properties of cobalt-based ***ε-hcp phase,the interaction between deformation twins and dislocations,and the interaction between e-hcp phases during cold forging deformation caused local stress concentration,lowering ductility and toughness.

关键词： Cobalt-based alloy-Stacking fault energy Strain-induced martensitic transformation Deformation twin Cold forging deformation

CP violation of baryon decays with Nπrescatterings

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Chinese Physics C 2024年第10期48卷 1-10页

作者： Jian-Peng Wang fu-sheng Yu MOE Frontiers Science Center for Rare Isotopes and School of Nuclear Science and TechnologyLanzhou UniversityLanzhou 730000China

There is a long-standing puzzle that the CP violation(CPV)in the baryon systems has never been wellestablished in experiments,while the CPV of mesons have been observed by *** this paper,we propose thatthe CpV of baryon decays can be generated with the rescatterings of a nucleon and a pion into some final states,i.e Nπ→Nπor Nππ.Benelited by the fruitful data of Nπscatterings,we can model-independently analyse the strongphases of b-baryon decays using the partial wave amplitudes of Nπ*** the most difficult problemof non-perturbative dynamics,it makes a great advantage to predict the CpV of baryon decays with a relatively *** understanding of the decay *** study the processes of∧_(b)^(0)→(pπ^(+)π^(-))h^(-)and(pπ^(0))h^(-)with h=πor *** is found that the global CPV of the above processes in the invariant mass regions of Nπscatterings are at theorder of several *** importantly,the local CPV in some regions of the Dalitz plots can reach the order of 10%,or be even *** the predicted results and the experimental data samples,we strong suggest tomeasure the CPV of∧_(b)^(0)→(pπ^(+)π^(-))K^(-),which has a large possibility to achieve the first observation of CPV in thebaryon system.

关键词： CP violation baryon decays Nπscatterings

Distribution and geochemical significance of alkylbenzenes for crude oil with different depositional environments and thermal maturities

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Petroleum Science 2024年第2期21卷 777-790页

作者： Bing-Kun Meng Dao-fu Song Yuan Chen sheng-Bao Shi School of Petroleum Engineering and Environmental Engineering Yan'an UniversityYan'an716000ShaanxiChina State Key Laboratory of Petroleum Resources and Prospecting College of GeosciencesChina University of PetroleumBeijing102249China

A total of 45 alkylbenzenes were detected and identified in crude oils with different depositional environments and thermal maturities from the Tarim Basin,Beibuwan Basin,and Songliao Basin using comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry(GC×GCTOFMS).By analyzing the distribution characteristics of C0-C5alkylbenzenes,it is found that the content of some alkylbenzenes varies greatly in crude *** on the distribution characteristics of 1,2,4,5-tetramethylbenzene(Te MB)and 1,2,3,4-Te MB,the ratio of 1,2,4,5-Te MB to 1,2,3,4-Te MB is proposed to indicate the organic matter origin and depositional environment of ancient *** samples originated mainly from lower hydrobiont,algae,bacteria and source rocks deposited under reducing/anoxic conditions have low 1,2,4,5-/1,2,3,4-Te MB values(less than 0.6),while oil samples originated mainly from terrestrial higher plants and source rocks deposited under oxic/sub-oxic conditions have higher 1,2,4,5-/1,2,3,4-Te MB values(greater than 1.0).The significant difference of 1,2,4,5-/1,2,3,4-Te MB values is controlled by 1,2,4,5-Te MB content.1,2,4,5-Te MB content in oils derived from source rocks deposited in oxidized sedimentary environment(greater than 1.0 mg/g whole oil)is higher than that in oils from source rocks deposited in reduced sedimentary environment(less than 1.0 mg/g whole oil).1,2,4,5-/1,2,3,4-Te MB ratio might not or slightly be affected by evaporative fractionation,biodegradation and thermal maturity.1,2,4,5-/1,2,3,4-Te MB ratio and 1,2,4,5-Te MB content can be used as supplementary parameter for the identification of sedimentary environment and organic matter *** should be noted that compared to the identification of organic matter sources,the 1,2,4,5-/1,2,3,4-Te MB parameter is more effective in identifying sedimentary environments.

关键词： 1 2 4 5-Tetramethylbenzene GC×GC-TOFMS Organic matter origin Depositional environment