检索结果-南通市图书馆

Rare Metals 2024年第4期43卷 1580-1588页

作者： shabana shaheen shuai Xu ji Bian Amir Zada zi-Qing zhang Yang Qu li-Qiang jing Key Laboratory of Functional inorganic Materials Chemistry(Ministry of Education) International Joint Research Center and Lab for Catalytic TechnologySchool of Chemistry and Materials ScienceHeilongjiang UniversityHarbin150080China Department of Chemistry Abdul Wali Khan UniversityMardan23200Pakistan

it is highly desired to develop efficient photocatalysts with recycling property for practical application to degrade toxic ***,nanosheet-assembled NiFe_(2)O_(4)microspheres with commendable activity are successfully synthesized by a facile solvothermal reaction with NH4F as the modifier,and their photoactivities are further improved by coupling with NiO through an in situ growth *** optimized nickel oxide(NiO)/nickel ferrite(NiFe_(2)O_(4))microsphere composite(5NiO/NFO-4)exhibits a satisfactory photocatalytic activity for 2,4-dichlorophenol(2,4-DCP)degradation under visible-light irradiation,which is attributed to its wide visible-light response,well-designed hierarchical structure and enhanced charge transfer and separation by coupling NiO as a high-level energy platform to accept ***,it is found that the NiO/NiFe_(2)O_(4)microsphere photocatalysts can be easily collected and recycled owing to the distinctive magnetic *** work provides a feasible route to rational design visible-light-driven photocatalysts with high-activity for environmental remediation and purification with good recyclability.

关键词： NiFe_(2)O_(4) microspheres NiO/Fe_(2)O_(4) composite Charge separation Visible-light photocatalysis 2 4-Dichlorophenol degradation

implications for fault reactivation and seismicity induced by hydraulic fracturing

在线全文

学校读者我要写书评

暂无评论

Petroleum science 2024年第2期21卷 1081-1098页

作者： zi-Han sun Ming-Guang Che li-Hong Zhu shu-Juan zhang ji-Yuan Lu Chang-Yu jin Key Laboratory of Ministry of Education on safe Mining of Deep Metal Mines School of Resources and Civil Engineering and Key Laboratory of Liaoning Province on Deep Engineering and Intelligent TechnologyNortheastern UniversityShenyang110819LiaoningChina Research institute of Petroleum Exploration&Development PetroChina Company LimitedBeijing100084China The Exploration and Development Research institute of Daqing Oilfield limited Company Daqing163458HeilongjiangChina

Evaluating the physical mechanisms that link hydraulic fracturing(HF) operations to induced earthquakes and the anticipated form of the resulting events is significant in informing subsurface fluid injection operations. Current understanding supports the overriding role of the effective stress magnitude in triggering earthquakes, while the impact of change rate of effective stress has not been systematically addressed. in this work, a modified critical stiffness was brought up to investigate the likelihood, impact,and mitigation of induced seismicity during and after hydraulic fracturing by developing a poroelastic model based on rate-and-state fraction law and linear stability analysis. in the new criterion, the change rate of effective stress was considered a key variable to explore the evolution of this criterion and hence the likelihood of instability slip of fault. A coupled fluid flow-deformation model was used to represent the entire hydraulic fracturing process in COMsOL Multiphysics. The possibility of triggering an earthquake throughout the entire hydraulic fracturing process, from fracturing to cessation, was investigated considering different fault locations, orientations, and positions along the fault. The competition between the effects of the magnitude and change rate of effective stress was notable at each fracturing stage. The effective stress magnitude is a significant controlling factor during fracturing events, with the change rate dominating when fracturing is suddenly started or stopped. instability dominates when the magnitude of the effective stress increases(constant injection at each fracturing stage) and the change rate of effective stress decreases(the injection process is suddenly stopped). Fracturing with a high injection rate, a fault adjacent to the hydraulic fracturing location and the position of the junction between the reservoir and fault are important to reduce the Coulomb failure stress(CFs) and enhance the critical stiffness as

关键词： Hydraulic fracturing Coulomb failure stress Rate-and-state fraction model linear stability analysis Critical stiffness seismically induced fault

stability analysis of intermittently jointed rock slopes based on the stepped failure mode

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain science 2024年第3期21卷 1019-1035页

作者： li Dejian FU junwen li Hekai CHENG Xiao ZHAO lianheng zhang Yingbin PENG Xinyan school of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China institute for Disaster Management and Reconstruction College of Architecture&EnvironmentSichuan UniversityChengdu 610065China school of Civil Engineering Key Laboratory of Heavy-Haul Railway Engineering StructureMinistry of EducationHunan Provincial Key Laboratory for Disaster Prevention and Mitigation of Rail Transit Engineering StructureCentral South UniversityChangsha 410075China

in practical engineering,due to the noncontinuity characteristics of joints in rock slopes,in addition to plane failure,stepped sliding failure may occur for intermittently jointed rock *** for intermittently bedding jointed rock slopes,the correlation and difference in strength parameters between joints and rock bridges,along with the various failure modes and intermittency of rock bridges,contribute to the complexity of stepped failure modes and the unpredictability of failure *** on the upper-bound limit analysis method and multi-sliders step-path failure mode,considering the shear and tensile failure of rock bridges and the weakened relationship between the strength parameters of rock bridges and jointed surfaces,by introducing the modified M-C failure criterion and the formula for calculating the energy consumption of tensile failure of rock bridges,two failure mechanisms are constructed to obtain the safety factor(F_(s))of intermittently jointed rock *** sequential quadratic programming method is used to obtain the optimal upper-bound solution for F_(s).The influence of multiple key parameters(slope height H,horizontal distance L,slope angleβ,shear strength parameters of the rock bridgeφr and cr,Dimensionless parameter u,weakening coefficients of the internal friction angle and cohesion between the rock bridges and joint surfaces Kφand Kc)on the stability analysis of intermittently jointed rock slopes under the shear failure mode of rock bridges as well as under the tensile failure mode is also *** reliability of the failure mechanisms is verified by comparative analysis with theoretical results,numerical results,and landslide cases,and the variation rules of F_(s)with each key parameter are *** results show that F_(s) varies linearly withφr and cr of the rock bridge and with K_(φ)and K_(c),whereas F_(s)changes nonlinearly with H and *** particular,with the increase in Kφand Kc,Fs increases by approximately 52.

关键词： Jointed rock slopes stepped sliding failure Weakening characteristics Modified M‒C failure criterion

Modulation of d-orbital to realize enriched electronic cobalt sites in cobalt sulfide for enhanced hydrogen evolution in electrocatalytic water/seawater splitting

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第2期43卷 511-521页

作者： jian-Peng sun Yu Zheng zi-sheng zhang Xiang-Chao Meng zi-Zhen li Key Laboratory of Marine Chemistry Theory and Technology(Ministry of Education) College of Chemistry and Chemical EngineeringOcean University of ChinaQingdao266100China shanxi institute of Energy Taiyuan030600China Department of Chemical and Biological Engineering Faculty of EngineeringUniversity of OttawaOttawaONK1N6 N5Canada

Herein,a novel single-atomic Pt doping and interface-rich Cos/Co(OH)_(2)(Pt-Cos/Co(OH)_(2)/C)electrocatalyst has been successfully *** from precise regulation of d-orbital electronic structure modulation on Co site,Pt-Cos/Co(OH)_(2)/C exhibited remarkable HER activity and high stability for hydrogen evolution in splitting both water(73 mV@10 mA·cm^(−2)) and seawater(87 mV@10 mA·cm^(−2)).Notably,atomic Pt doping was introduced into Cos/Co(OH)_(2),which could produce local unbalanced Coulombic force and significantly increased the number of s vacancies,and then expose abundant Co ***,Co(OH)_(2) in Pt-Cos/Co(OH)_(2)/C could act as the adsorption sites for H_(2)O in hydrogen evolution reaction *** functional theory results also proved that atomic Pt doping,s vacancies and Co(OH)_(2) coupling could result in the formation of enriched electronic Co sites and optimize d_(z2) orbital electronic structure,and then realize the depth upward shift of d-band center and enhance the adsorption of H*on Co sites.

关键词： Electrocatalysts Hydrogen evolution reaction Pt-Cos/Co(OH)_(2) d-band center Electronic structure Water/seawater electrolysis

Discovery of the choristodere Hyphalosaurus baitaigouensis from the Lower Cretaceous jiufotang Formation of western liaoning,China and its paleobiogeographic significance

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2024年第3期13卷 547-562页

作者： li-Jun zhang shu-An ji Hai-Chun zhang south China sea Culture Museum Hainan Tropical Ocean UniversitySanya 572022Hainan ProvinceChina Key Laboratory of stratigraphy and Paleontology Ministry of Natural ResourcesInstitute of GeologyChinese Academy of Geological SciencesBeijing 100037China state Key Laboratory of Palaeobiology and stratigraphy Nanjing Institute of Geology and Palaeontology and Center for Excellence in Life and PaleoenvironmentChinese Academy of SciencesNanjing 210008Jiangsu ProvinceChina

The water-living reptile genus Hyphalosaurus was previously discovered in the Lower Cretaceous Yixian Formation bearing the middle Jehol Biota in western liaoning,*** complete skeletons of Hyphalosaurus are reported for the first time from the jiufotang Formation bearing the late Jehol Biota at two sites in western *** show the typical characteristics of Hyphalosaurus baitaigouensis in terms of the contact between some cranial bones and the number of cervical and dorsal vertebrae,and therefore are assigned to *** discovery extends the stratigraphic range of this species from the Yixian Formation to the overlying jiufotang *** paper further briefly compares the main characteristics of the two skeletons,summarizes the temporal and spatial distribution of Hyphalosaurus,and discusses the palaeogeographic evolution of western liaoning at the middle and late Jehol Biota stages based on the aquatic habits of Hyphalosaurus and the geological background of western *** analytical results show that the volcanic downwarped lakes,with distinct geographical divisions in western liaoning during the deposition of the Yixian Formation,had not completely disappeared till the deposition of the jiufotang *** palaeo-lake in the Fuxin-Yixian Basin underwent the process of generation,expansion and shrinkage during the depositional period of the Yixian Formation and finally merged into a large *** palaeo-Dalinghe River,which connected the main basins in western liaoning during the depositional period of the jiufotang Formation,was formed simultaneously.

关键词： Western liaoning Jehol biota jiufotang formation Hyphalosaurus baitaigouensis Palaeobiogeography

Threshold selection and Resource Allocation for Quantized identification

在线全文

学校读者我要写书评

暂无评论

Journal of systems science & Complexity 2024年第1期37卷 204-229页

作者： WANG Ying li Xin ZHAO Yanlong zhang ji-Feng Key Laboratory of systems and Control Institute of Systems ScienceAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China school of Mathematical sciences University of Chinese Academy of SciencesBeijing 100049China

This paper is concerned with the optimal threshold selection and resource allocation problems of quantized identification, whose aims are improving identification efficiency under limited resources. Firstly, the first-order asymptotically optimal quantized identification theory is extended to the weak persistent excitation condition. secondly, the characteristics of time and space complexities are established based on the Cramér-Rao lower bound of quantized systems. On these basis, the optimal selection methods of fixed thresholds and adaptive thresholds are established under aperiodic signals, which answer how to achieve the best efficiency of quantized identification under the same time and space complexity. in addition, based on the principle of maximizing the identification efficiency under a given resource, the optimal resource allocation methods of quantized identification are given for the cases of fixed thresholds and adaptive thresholds, respectively, which show how to balance time and space complexity to realize the best identification efficiency of quantized identification.

关键词： Quantized output resource allocation system identification threshold selection.

Microplastic exposure disturbs sleep structure,reduces lifespan,and decreases ovary size in Drosophila melanogaster

在线全文

学校读者我要写书评

暂无评论

Zoological Research 2024年第4期45卷 805-820页

作者： Wei Yan zi-jie li zi-Yi lin shu-Qin ji William Ka Fai Tse Zhi-Qiang Meng Chang liu Lei li shenzhen-Hong Kong institute of Brain science Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong 518000China CAs Key Laboratory of Brain Connectome and Manipulation the Brain Cognition and Brain Disease InstituteShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong 518000China Laboratory of Developmental Disorders and Toxicology Center for Promotion of International Education and ResearchFaculty of AgricultureKyushu UniversityFukuokaFukuoka 819-0395Japan shenzhen Key Laboratory of Drug Addiction the Brain Cognition and Brain Disease InstituteShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong 518000China Guangdong Provincial Key Laboratory of Brain Connectome and Behavior Brain Cognition and Brain Disease InstituteShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong 518000China

The organ-specific toxicity resulting from microplastic(MP)exposure has been extensively explored,particularly concerning the gut,liver,testis,and ***,under natural conditions,these effects are not restricted to specific organs or *** whether MP exposure presents a systemic threat to an entire organism,impacting factors such as lifespan,sleep,and fecundity,is *** this study,we investigated the effects of dietary exposure to two different doses of MPs(1–5μm)using the terrestrial model organism Drosophila *** indicated that the particles caused gut damage and remained within the digestive *** MP exposure significantly shortened the lifespan of adult *** short-term exposure disrupted sleep patterns,increasing the length of daytime sleep ***,one week of MP exposure reduced ovary size,with a trend towards decreased egg-laying in mated *** MPs did not penetrate the brain or ovaries,transcriptome analysis revealed altered gene expression in these *** the ovary,Gene Ontology(GO)analysis indicated genotoxic effects impacting inflammation,circadian regulation,and metabolic processes,with significant impacts on extracellular structure-related *** the brain,GO analysis identified changes in pathways associated with proteolysis and carbohydrate ***,this study provides compelling evidence of the systemic negative effects of MP exposure,highlighting the urgent need to address and mitigate environmental MP pollution.

关键词： Microplastics sleep lifespan Reproduction Risk assessment Drosophila melanogaster

Photocaged activity-based probes for improved monitoring of protein s-sulfenylation in living cells

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第2期35卷 451-454页

作者： jiahao zhang Haiyue Peng zi'an Chen Guorui li jing Huang state Key Laboratory of Chemo/Biosensing and Chemometrics Hunan Provincial Key Laboratory of Animal Models and Molecular MedicineSchool of Biomedical SciencesHunan UniversityChangsha 410082China

Protein s-sulfenylation(protein sulfenic acid),as one of the most significant oxidative post-translational modifications(OxiPTMs),plays a vital role in regulating protein function.A variety of activity-based probes have been developed to profile sulfenic acid in living ***,due to the transient presence and low content of sulfenic acid in living cell,high doses of probes are needed to achieve efficient *** importantly,current probes have no temporal control over sulfenic acid *** overcome these limitations,two caged cysteine sulfenic acid probes DYn-2-ONB and DYn-2-Cou with either an o-nitrobenzyl or coumarin protecting group were developed in this *** probes can be efficiently uncaged via irradiation to produce the active C-nucleophile probe *** assay in living cells demonstrated DYn-2-ONB exhibited better labeling capacity compared with DYn-2,providing it as a powerful tool for improved monitoring of protein s-sulfenylation in living cells.

关键词： Cysteine sulfenic acid Activity-based probe Photocage light activation Protein s-sulfenylation

Channel estimation-based time-frequency neural network for post-equalization in underwater visible light communication

在线全文

学校读者我要写书评

暂无评论

Chinese Optics Letters 2024年第6期22卷 116-122页

作者： Haoyu zhang li Yao Chaoxu Chen Yuan Wei Chao shen ji.nyang shi junwen zhang ziwei li Nan Chi Key Laboratory for information science of Electromagnetic Waves(MoE) Department of Communication Science and EngineeringSchool of Information Science and TechnologyFudan UniversityShanghai 200433China shanghai CiC of LEO satellite Communication Technology Fudan UniversityShanghai 200433China shanghai ERC of LEO satellite Communication and Application Fudan UniversityShanghai 200433China

This Letter proposes a post-equalizer for underwater visible light communication(UVLC) systems that combines channel estimation and joint time-frequency analysis, named channel-estimation-based bandpass variable-order time-frequency network(CBV-TFNet). By utilizing a bandpass variable-order loss function with communication prior knowledge, CBVTFNet enhances communication performance and training stability. it enables lightweight implementation and faster convergence through a channel estimation-based mask. The superior performance of the proposed equalization method over Volterra and deep neural network(DNN)-based methods has been studied experimentally. Using bit-power loading discrete multitone (DMT) modulation, the proposed method achieves a transmission bitrate of 4.956 Gbps through a 1.2 m underwater channel utilizing only 38.15% of real multiplication calculations compared to the DNN equalizer and achieving a bitrate gain of440 Mbps and a significantly larger dynamic range over the LMs-Volterra equalizer. Results highlight CBV-TFNet's potential for future post-equalization in UVLC systems.

关键词： underwater visible light communication channel estimation post-equalizer neural network

Effects of drought on non-structural carbohydrates and C,N,and P stoichiometric characteristics of Pinus yunnanensis seedlings

在线全文

学校读者我要写书评

暂无评论

Journal of Forestry Research 2024年第1期35卷 90-102页

作者： Zhijuan Zhao lina Wang Yuanxi liu jianli sun jiandong Xiao Qiong Dong lianfang li Wanjie zhang Chao Wang junwen Wu College of Forestry Southwest Forestry UniversityKunming 650224YunnanPeople’s Republic of China

To study non-structural carbohydrate character-istics and nutrient utilization strategies of Pinus yunnanen-sis under continuous drought conditions,2-year-old seed-lings were planted in pots with appropriate water,light and moderate and severe drought treatments[(80±5),(65±5),(50±5),and(35±5)%of field water-holding capacity].Non-structural carbohydrates,carbon(C),nitrogen(N),and phosphorus(P)concentrations were measured in each plant *** results show that:(1)With increasing drought,non-structural carbohydrates gradually increased in leaves,stems,and coarse roots,while gradually decreased in fine roots;(2)C concentrations of all were relatively stable under different stress *** utilization of each component increased under light and moderate drought conditions,while N and P utilization efficiency of each plant component decreased under severe *** was mainly restricted by N,first decreasing and then increasing with increased drought;(3)There was a correlation between the levels of non-structural carbohydrates and C,N,and P in each *** in N concentration affected the interconversion between soluble sugar and starch,which play a regulatory role in the fluctuation of the concentration of non-structural carbohydrates;and,(4)Plasticity analysis showed that *** seedlings responded to drought mainly by altering starch concentration,the ratio of soluble sugar to starch in leaves and stems,and further by alter-ing N and P utilization ***,these results suggest that the physiological activities of all organs of *** seedlings are restricted under drought and that trade-offs exist between different physiological indicators and *** findings are helpful in understanding non-structural carbohydrate and nutrient adaptation mechanisms under drought in *** seedlings.

关键词： Pinus yunnanensis seedlings Drought Non-structural carbohydrates C,N,P stoichiometric characteristics