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Dynamic Analysis of A Deepwater Drilling Riser with A New Hang-off System

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China Ocean Engineering 2024年第1期38卷 29-41页

作者： LI Yan-wei LIU Xiu-quan WANG Jin-long CHEN Guo-ming CHANG Yuan-jiang SHENG Lei-xiang Centre for Offshore Engineering and Safety technology China University of PetroleumQingdao 266580China national Engineering Laboratory of Offshore Geophysical and Exploration Equipment China University of PetroleumQingdao 266580China China CNOOC research Institute Co. Ltd.Beijing 100028China

The safety of risers in hang-off states is a vital challenge in offshore oil and gas engineering.A new hang-off system installed on top of risers is proposed for improving the security of *** approach leads to a challenging problem:coupling the dynamics of risers with a new hang-off system combined with multiple structures and complex *** accurately analyze the dynamic responses of the coupled system,a coupled dynamic model is established based on the Euler-Bernoulli beam-column theory and penalty function method.A comprehensive analysis method is proposed for coupled dynamic analysis by combining the finite element method and the Newmarkβ*** analysis program is also developed in MATLAB for dynamic *** simulation results show that the dynamic performances of the risers at the top part are significantly improved by the new hang-off system,especially the novel design,which includes the centralizer and articulation *** bending moment and lateral deformation of the risers at the top part decrease,while the hang-off joint experiences a great bending moment at the bottom of the lateral restraint area which requires particular attention in design and *** platform navigation speed range under the safety limits of risers expands with the new hang-off system in use.

关键词： deepwater drilling riser new hang-off system dynamic analysis finite element method penalty function method

high-Efficiency Dynamic Scanning Strategy for Powder Bed Fusion by Controlling Temperature Field of the Heat-Affected Zone

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 203-214页

作者： Xiaokang Huang Xiaoyong Tian Qi Zhong Shunwen He Cunbao Huo Yi Cao Zhiqiang Tong Dichen Li State Key Laboratory of Manufacturing Systems Engineering Xi’an Jiaotong UniversityXian 710049China

Improvement of fabrication efficiency and part performance was the main challenge for the large-scale powder bed fusion(PBF)*** this study,a dynamic monitoring and feedback system of powder bed temperature field using an infrared thermal imager has been established and integrated into a four-laser PBF equipment with a working area of 2000 mm×2000 *** heat-affected zone(HAZ)temperature field has been controlled by adjusting the scanning speed ***,the relationship among spot size,HAZ temperature,and part performance has been *** fluctuation of the HAZ temperature in four-laser scanning areas was decreased from 30.85℃to 17.41℃.Thus,the consistency of the sintering performance of the produced large component has been *** on the controllable temperature field,a dynamically adjusting strategy for laser spot size was proposed,by which the fabrication efficiency was improved up to 65.38%.The current research results were of great significance to the further industrial applications of large-scale PBF equipment.

关键词： Powder bed fusion Efficiency Large-scale Spot size Heat-affected zone(HAZ)

Identification of Motor Nuclei in the Medulla Oblongata of Carp for Biological Control

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Journal of Bionic Engineering 2024年第2期21卷 842-851页

作者： Yang Zhao Yong Peng Yudong Wen Lingjun Han Yanhong Yan Xueying Dong Hui Zhang Zheng Zhao Xiaoyue Liu School of Electrical Engineering Yanshan UniversityQinhuangdao066004China School of Mechanical Engineering Yanshan UniversityQinhuangdao066004China Key Laboratory of national Defense of Mechanical Structure and Material Science Under Extreme Conditions Yanshan UniversityQinhuangdao066004China Institute of Marine Science and Engineering Yanshan UniversityQinhuangdao066004China Shijiazhuang University Shijiazhuang050035China

Brain-controlled technology is the key technology in biological control,and the corresponding relationship between animal brain nuclei and motor behavior is the *** purpose of this study was to explore the motor nuclei of the medulla oblongata in *** carps were subjected to electrical stimulation and chemical stimulation experiments,respectively,in the water-free state,and the effective chemical stimulation sites were injected with the pontamine sky blue *** brain tissue sections were obtained by paraffin tissue section technology and the neutral red staining *** comparing the positions of the brain nuclei shown in earlier studies,the motor nerve nuclei in the medulla oblongata were *** brain electrode was implanted into the motor nucleus of the medulla oblongata,and the underwater control experiment and behavioral tests were carried out with different electrical stimulation *** results showed that the abducens nucleus(NVI)was the motor nucleus that controls the ipsilateral steering,and the facial nucleus(NVII)was the motor nucleus that controls the forward *** adjusting the stimulation voltage and the stimulation pulse number,the carp can be stably controlled to achieve a left–right steering motion of 30°–180°and a forward motion of more than 80 cm/*** study indicated that the quantitative control of the steering and forward behavior of the carp can be achieved by electrical stimulation of the NVI and NVII,which provided a certain experimental basis for the accurate control of the carp robot.

关键词： Biological control Carp Medulla oblongata motor nucleus Electrical stimulation technique Chemical stimulation technique

Disruption of PABPN1 phase separation by SNRPD2 drives colorectal cancer cell proliferation and migration through promoting alternative polyadenylation of CTNNBIP1

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Science China(Life Sciences) 2024年第6期67卷 1212-1225页

作者： Zhijie Hu Mengxia Li Yufeng Chen Liutao Chen Yuting Han Chengyong Chen Xin Lu Nan You Yawen Lou Yingye Huang Zhanfeng Huo Chao Liu Cheng Liang Susu Liu Ke Deng Liangfu Chen Shangwu Chen Guohui Wan Xiaojian Wu Yonggui Fu Anlong Xu State Key Laboratory of Biocontrol Guangdong Province Key Laboratory of Pharmaceutical Functional GenesDepartment of BiochemistrySchool of Life SciencesSun Yat-sen UniversityGuangzhou 510275China Department of General Surgery(Colorectal Surgery)&Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases&Biomedical Innovation Center The Sixth Affiliated HospitalSun Yat-sen UniversityGuangzhou 510655China national-Local Joint Engineering Laboratory of Druggability and New Drug Evaluation National Engineering Research Center for New Drug and Druggability(cultivation)Guangdong Province Key Laboratory of New Drug Design and EvaluationSchool of Pharmaceutical SciencesSun Yat-sen UniversityGuangzhou 510006China School of Life Sciences Beijing University of Chinese MedicineBeijing 100029China

Generally shortened 3′UTR due to alternative polyadenylation(APA)is widely observed in cancer,but its regulation mechanisms for cancer are not well ***,with profiling of APA in colorectal cancer tissues and poly(A)signal editing,we firstly identified that the shortened 3′UTR of CTNNIBP1 in colorectal cancer promotes cell proliferation and *** found that liquid-liquid phase separation(LLPS)of PABPN1 is reduced albeit with higher expression in cancer,and the reduction of LLPS leads to the shortened 3′UTR of CTNNBIP1and promotes cell proliferation and ***,the splicing factor SNRPD2 upregulated in colorectal cancer,can interact with glutamic-proline(EP)domain of PABPN1,and then disrupt LLPS of PABPN1,which attenuates the repression effect of PABPN1 on the proximal poly(A)*** results firstly reveal a new regulation mechanism of APA by disruption of LLPS of PABPN1,suggesting that regulation of APA by interfering LLPS of 3′end processing factor may have the potential as a new way for the treatment of cancer.

关键词： alternative polyadenylation colorectal cancer CTNNBIP1 PABPN1 liquid-liquid phase separation SNRPD2

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An efficient and mild recycling of waste melamine formaldehyde foams by alkaline hydrolysis

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Green Energy & Environment 2024年第5期9卷 919-926页

作者： Shaodi Wu Ning Zhang Chizhou Wang Xianglin Hou Jie Zhao Shiyu Jia Jiancheng Zhao Xiaojing Cui Haibo Jin Tiansheng Deng Shanxi Engineering research Center of Biorefinery Institute of Coal ChemistryChinese Academy of Sciences27 South Taoyuan RoadTaiyuan030001China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing100049China Department of Chemistry and Chemical Engineering Taiyuan Institute of TechnologyTaiyuanShanxi030008China Beijing Key Laboratory of Fuels Cleaning and Advanced Catalytic Emission Reduction technology/College of New Materials and Chemical Engineering Beijing Institute of Petrochemical TechnologyBeijing102617China

Melamine formaldehyde foam(MFF)generates many poisonous chemicals through the traditional recycling methods for organic resin ***,a high MFF degradation ratio of ca.97 wt.%was achieved under the mild conditions(160℃)in a NaOH–H2O system with ammelide and ammeline as the main degradation *** alkaline solvent had an obvious corrosion effect for MFF,as indicated by scanning electron microscopy(SEM).The reaction process and products distribution were studied by Fourier-transform infrared spectroscopy(FTIR),X-ray photoelectron spectroscopy(XPS),and ^(13)C nuclear magnetic resonance(NMR).Besides,the MFF degradation products that have the similar chemical structures and bonding performances to those of melamine can be directly used as the raw material for synthesis of melamine urea-formaldehyde resins(MUFs).Moreover,the degradation system demonstrated here showed the high degradation efﬁciency after reusing for 7 *** degradation process generated few harmful pollutants and no pre-or post-treatments were required,which proves its feasibility in the safe removal or recovery of waste MFF.

关键词： Melamine formaldehyde foam Degradation Alkaline hydrolysis Recycling

Responses of soil stoichiometry and soil enzyme activities in the different distance around opencast coal mine of the Hulun Buir Grassland of China

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International Journal of Coal Science & technology 2024年第1期11卷 221-231页

作者： Yinli Bi Nan Guo Yanxu Zhang Xianglei Li Ziheng Song State Key Laboratory for Fine Exploration and Intelligent development of Coal Resources China University of Mining and Technology(Beijing)Beijing100083China Institute of Ecological Environment Restoration in Mine Areas of West China Xi’an University of Science and TechnologyXi’an710054China

The objectives of this study were to explore the changes in soil stoichiometry and enzyme activities at different distances from an opencast coal mine in the Hulun Buir Grassland of China. Four transects were established on north and east sides of the opencast coal mining area, and samples were collected at 50 m, 550 m, and 1550 m from the pit on each transect. Control samples were collected from a grassland station 8 km from the opencast coal mining area that was not disturbed by mining. Four replicate soil samples were collected at each point on the four transects. Soil physicochemical properties and enzyme activities were determined, and correlations between soil properties and stoichiometric ratios and enzyme activities were explored using redundancy analysis. The increase in distance from mining did not significantly affect soil properties, although soil urease activity was significantly lower than that of the control area. Soil properties 1550 m from the mine pit were similar to those at the grassland control. In addition, soil total nitrogen had the greatest effect on soil stoichiometry, and soil total potassium had the greatest effect on soil enzyme activities. Coal dust from opencast mining might be the main factor affecting soil stoichiometry and enzyme activities. The results of this study provide direction for the next step in studying the influence of mining areas on soil properties and processes.

关键词： Opencast coal mine Soil stoichiometry Soil enzyme activities Distance Grassland

Preparation of high-purity fluorite and nanoscale calcium carbonate from low-grade fluorite

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International Journal of Minerals,Metallurgy and Materials 2024年第6期31卷 1198-1207页

作者： Qianqian Lu Haisheng Han Wenjuan Sun Xingfei Zhang Weiwei Wang Bilan Zhang Wensheng Chen Qin Zou School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China Hunan Nonferrous Chenzhou Fluoride Chemical Co. Ltd.Chenzhou 423000China State Key Laboratory of Baiyunobo Rare Earth Resource researches and Comprehensive Utilization Baotou Research Institute of Rare EarthsBaotou 014030China Hunan Shizhuyuan Nonferrous Metal Co. Ltd.Chenzhou 423000China

Flotation separation of calcite from fluorite is a challenge on low-grade fluorite flotation that limits the recovery and purity of fluorite concentrate.A new acid leaching–flotation process for fluorite is proposed in this *** innovative process raised the fluor-ite’s grade to 97.26wt%while producing nanoscale calcium carbonate from its leachate,which contained plenty of calcium *** the production of nanoscale calcium carbonate,the impacts of concentration,temperature,and titration rate were *** modifying the process conditions and utilizing crystal conditioning agents,calcite-type and amorphous calcium carbonates with corresponding particle sizes of 1.823 and 1.511μm were *** influence of the impurity ions Mn^(2+),Mg^(2+),and Fe^(3+)was demonstrated to reduce the particle size of nanoscale calcium carbonate and make crystal shape easier to manage in the fluorite leach solution system compared with the calcium chloride *** combination of the acid leaching–flotation process and the nanoscale calcium carbonate preparation method improved the grade of fluorite while recovering calcite resources,thus presenting a novel idea for the effective and clean usage of low-quality fluorite resources with embedded microfine particles.

关键词： fluorite calcite nanoscale calcium carbonate waste recovery

Telomere-to-telomere genome of the allotetraploid legume Sesbania cannabina reveals transposon-driven subgenome divergence and mechanisms of alkaline stress tolerance

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Science China(Life Sciences) 2024年第1期67卷 149-160页

作者： Haofei Luo Xiaofei Wang Changqing You Xuedan Wu Duofeng Pan Zhiyao Lv Tong Li Dongmei Zhang Zhongbao Shen Xiaodong Zhang Guodao Liu Kaixuan He Qingtong Ye Yajun Jia Qinghua Zhao Xian Deng Xiaofeng Cao Xianwei Song Gai Huang State Key Laboratory of Plant Genomics and national Center for Plant Gene research Institute of Genetics and Developmental BiologyChinese Academy of SciencesBeijing 100101China Hainan Yazhou Bay Seed Lab Sanya 572025China University of Chinese Academy of Sciences Beijing 100049China Institute of Forage and Grassland Sciences Heilongjiang Academy of Agricultural SciencesHarbin 150086China Shandong Academy of Agricultural Sciences Jinan 250100China national Center of technology Innovation for Comprehensive Utilization of Saline-Alkali Land Dongying 257345China Shandong Green Manure Ecological technology Co. LtdDongying 257345China State Key Laboratory of Tropical Crop Breeding Chinese Academy of Tropical Agricultural SciencesHaikou 571101China

Alkaline soils pose an increasing problem for agriculture worldwide,but using stress-tolerant plants as green manure can improve marginal ***,we show that the legume Sesbania cannabina is very tolerant to alkaline conditions and,when used as a green manure,substantially improves alkaline *** understand genome evolution and the mechanisms of stress tolerance in this allotetraploid legume,we generated the first telomere-to-telomere genome assembly of *** spanning~2,087 *** assembly included all centromeric regions,which contain centromeric satellite repeats,and complete chromosome ends with telomeric *** genome analysis distinguished A and B subgenomes,which diverged approximately 7.9 million years *** genomic analysis revealed that the chromosome homoeologs underwent large-scale inversion events(>10 Mb)and a significant,transposon-driven size expansion of the chromosome 5A *** further identified four specific alkali-induced phosphate transporter genes in ***;these may function in alkali tolerance by relieving the deficiency in available phosphorus in alkaline *** work highlights the significance of *** as a green tool to improve marginal lands and sheds light on subgenome evolution and adaptation to alkaline soils.

关键词： Sesbania cannabina alkaline stress telomere-to-telomere genome legume green manure phosphate transporter allotetraploid

Geobacter sulfurreducens promoted the biosynthesis of reduced graphene oxide and coupled it for nitrobenzene reduction

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Journal of Environmental Sciences 2024年第4期138卷 458-469页

作者： Shoujuan Zhang Qi Liu Linrui Zhong Jianhong Jiang Xiaozhe Luo Xingxin Hu Qian Liu Yue Lu College of Environmental Science and Engineering Hunan UniversityChangsha 410082China Shenzhen research Institute Hunan UniversityShenzhen 510082China Key Laboratory of Environment Biology and Pollution Control Hunan UniversityMinistry of EducationChangsha 410082China China Machinery International Engineering Design&research Institute Co. LtdChangsha 410007China Hunan Engineering research Center for Water Treatment Process&Equipment Changsha 410007China

In order to explore an efficient and green method to deal with nitrobenzene(NB)pollutant,reduced graphene oxide(r GO)as an electron shuttle was applied to enhance the extracellular electron transfer(EET)process of Geobacter sulfurreducens,which was a typical electrochemically active bacteria(EAB).In this study,r GO biosynthesis was achieved via the reduction of graphene oxide(GO)by *** PCA within 3 ***,the r GOPCA combining system completely reduced 50-200μmol/L of NB to aniline as end product within one *** characterization revealed that PCA cells were partly wrapped by rGO,and therefore the distance of electron transfer between strain PCA and r GO material was ***,the ID/IGof GO,r GO,and r GO-PCA combining system were 0.990,1.293 and 1.31,***,highest currents were observed in r GO-PCA-NB as 12.950μA/-12.560μA at -408 m V/156 m V,attributing to the faster electron transfer efficiency in EET ***,the NB reduction was mainly due to:(I)direct EET process from *** PCA to NB;(II)r GO served as electron shuttle and accelerated electron transfer to NB,which was the main degradation ***,the biosynthesis of r GO via GO reduction by Geobacter promoted the NB removal process,which provided a facile strategy to alleviate the problematic nitroaromatic pollution in the environment.

关键词： Reduced graphene oxide Geobacter Nitrobenzene Removal Extracellular electron transfer