检索结果-南通市图书馆

A Local Tb Theorem for Square Functions and Parabolic Layer Potentials

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第8期40卷 1941-1966页

作者： Zhi Dan WANG guo Ming zhang School of Physical and Mathematical Sciences Nanjing Tech UniversityNanjing 211816P.R.China Frontiers Science Center for Nonlinear Expectations Ministry of EductionResearch Center for Mathematics and Interdisciplinary SciencesShandong UniversityQingdao266237P.R.China

In this paper,we give a locally parabolic version of Tb theorem for a class of vector-valued operators with off-diagonal decay in L^(2) and certain quasi-orthogonality on a subspace of L^(2),in which the testing functions themselves are also *** an application,we establish the boundedness of layer potentials related to parabolic operators in divergence form,defined in the upper half-space Rn+2+:={(x,t,λ)∈R^(n+1)×(0,∞)},with uniformly complex elliptic,L^(∞),t,λ-independent coefficients,and satisfying the De Giorgi/Nash estimates.

关键词： Local Tb theorems Calderon-Littlewood-Paley family Parabolic layer potentials Carleson measure estimates

Tactile-sensing-based robotic grasping stability analysis

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2024年第6期67卷 1817-1828页

作者： huang YanJiang WANG HaoNan zhang XianMin Guangdong Provincial Key Laboratory of Precision Equipment and Manufacturing Technology South China University of TechnologyGuangzhou510640China

Tactile signals play a crucial role in enabling robots to successfully manipulate unfamiliar *** robots to grasp unknown objects securely and without causing damage,it is essential that they can analyze grasping stability in real time through tactile signals and respond *** study introduces a novel method for analyzing the stability of robotic hand grasping,utilizing the Wilcoxon signed rank *** efficacy of this method is demonstrated through its static and dynamic performance,and evaluated across a series of *** findings of this research highlight the method’s ability to accurately detect when an object begins to slip from the robot’s *** this method allows the gripper to maintain a secure hold on objects by applying the minimal necessary *** also enables the gripper to dynamically adjust the force it applies in real time,thus preventing the object from slipping during the movement of the robotic ***,the gripper demonstrates the ability to stably grasp objects of varied weights and with unknown characteristics,showcasing the versatility and effectiveness of the proposed method.

关键词： grasping stability manipulation tactile sensors

For Mega-Constellations: Edge Computing and Safety Management Based on Blockchain Technology

在线全文

学校读者我要写书评

暂无评论

China Communications 2024年第2期21卷 59-73页

作者： Zhen zhang Bing guo Chengjie Li College of Computer Science Sichuan UniversityChengdu 610064China The Key Laboratory for Computer Systems of State Ethnic Affairs Commission School of Computer Science and TechnologySouthwest Minzu UniversityChengdu 610225China National Key Laboratory of Science and Technology on Communications University of Electronic Science and Technology of ChinaChengdu 611731China

In mega-constellation Communication Systems, efficient routing algorithms and data transmission technologies are employed to ensure fast and reliable data transfer. However, the limited computational resources of satellites necessitate the use of edge computing to enhance secure *** edge computing reduces the burden on cloud computing, it introduces security and reliability challenges in open satellite communication channels. To address these challenges, we propose a blockchain architecture specifically designed for edge computing in mega-constellation communication systems. This architecture narrows down the consensus scope of the blockchain to meet the requirements of edge computing while ensuring comprehensive log storage across the network. Additionally, we introduce a reputation management mechanism for nodes within the blockchain, evaluating their trustworthiness, workload, and efficiency. Nodes with higher reputation scores are selected to participate in tasks and are appropriately incentivized. Simulation results demonstrate that our approach achieves a task result reliability of 95% while improving computational speed.

关键词： blockchain consensus mechanism edge computing mega-constellation reputation management

Provenance of Conglomerate and Sandstone from Early Permian Shoushangou Formation in Xi Ujimqin,Inner Mongolia:Implications for Understanding Paleo-Asian Ocean Subduction

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2024年第1期98卷 10-31页

作者： zhang Yingli guo Xianqing MA Shouxian MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesCAGSBeijing 100037China Chinese Academy of Geological Sciences Beijing 100037China

During the Late Carboniferous to Early Permian,a rift was formed by post-collisional extension after ocean closure or an island arc-related basin formed by Paleo-Asian Ocean(PAO)subduction in the Xi Ujimqin ***,the closure time of the PAO is still under ***,to identify the origin of the PAO,the geochemistry and U-Pb age of zircons were analyzed for the extra-large deep marine,polymict clastic boulders and sandstones in the Shoushangou Formation within the *** analyses revealed magmatic activity and tectonic *** conglomerates include megaclasts of granite(298.8±9.1 Ma)and granodiorite porphyry(297.1±3.1 Ma),which were deposited by muddy debris *** of this study demonstrated that the boulders of granitoids have the geochemistry of typical I-type granite,characterized by low Zr+Nb+Ce+Y and low Ga/Al *** granitoid boulders were formed in island arc setting,indicating the presence of arc magmatism in the area that is composed of the Late Carboniferous to Early Permian subduction-related granitoid in southern Xi *** diagrams for determining sedimentary provenance using major and trace elements indicate that Shoushangou sediments originated from continental island arc-related felsic *** zircon U-Pb age cluster of 330–280 Ma was obtained,indicating input from granite,ophiolite,Xilin Gol complex,and Carboniferous sources to the *** basin was geographically developed behind the arc during the Early Permian period because the outcropped intrusive rocks in the Late Carboniferous to Early Permian form a volcanic *** comprehensive analyses of source areas suggest that Shoushangou sediments developed in a backarc basin in response to the northward subduction of the *** backarc basin and intrusive rocks,in addition to previously published Late Carboniferous to Early Permian magmatic rocks of arc unit in Xilin Gol,confirm the presence of an Early Permian trencharc-basin system in the region,r

关键词： provenance analysis backarc basin Shoushangou Formation Early Permian Central Asian Orogenic Belt

Aflibercept combined with triamcinolone acetonide in the treatment of diabetic macular edema:optical coherence tomography and optical coherence tomography angiography

在线全文

学校读者我要写书评

暂无评论

International Journal of Ophthalmology(English edition) 2024年第4期17卷 670-675页

作者： De-Shuang Li Hong-Xia Liao Chuan-He zhang Jian-guo huang Wei Chen Jing-Lin zhang Bo Qin Shenzhen Aier Eye Hospital Aier Eye HospitalJinan UniversityShenzhen 518031Guangdong ProvinceChina Department of Ophthalmology the University of Hong Kong-Shenzhen HospitalShenzhen 518000Guangdong ProvinceChina Guangzhou Aier Eye Hospital Jinan UniversityGuangzhou 510040Guangdong ProvinceChina

AIM:To analyze the relationship between optical coherence tomography(OCT)and OCT angiography(OCTA)imaging in patients with diabetic macular edema(DME)who are treated with a combination of aflibercept and triamcinolone acetonide(TA).METHODS:A total of 76 eyes newly diagnosed DME were included in this *** were randomly assigned to receive either aflibercept or a combination of aflibercept and *** once a month for a total of three *** macular thickness(CMT),number of hyperreflective foci(HRF),height of subretinal fluid(SRF),and area of foveal avascular zone(FAZ)were evaluated using OCT and OCTA at baseline and after each monthly ***:Both groups showed improvement in best corrected visual acuity(BCVA)and reduction in macular edema after treatment,and the difference in BCVA between the two groups was statistically significant after each treatment(P<0.05).The difference in CMT between the two groups was statistically significant after the first two injections(P<0.01),but not after the third injection(P=0.875).The number of HRF(1mo:7.41±8.25 vs 10.86±7.22,P=0.027;2mo:5.33±6.13 vs 9.12±8.61,P=0.034;3mo:3.58±3.00 vs 6.37±5.97,P=0.007)and height of SRF(1mo:82.39±39.12 vs 105.77±42.26μm,P=0.011;2mo:36.84±10.02 vs 83.59±37.78μm,P<0.01;3mo:11.57±3.29 vs 45.43±12.60μm,P<0.01)in combined group were statistically significant less than aflibercept group after each injection,while the area of FAZ showed no significant change before and after treatment in both ***:The combination therapy of aflibercept and TA shows more significant effects on DME eyes with decreased HRF and ***,both aflibercept and combination therapy show no significant change in the area of FAZ.

关键词： diabetic macular edema optical coherence tomography optical coherence tomography angiography hyperreflective foci subretinal fluid foveal avascular zone aflibercept

Improving benzene catalytic oxidation on Ag/Co_(3)O_(4) by regulating the chemical states of Co and Ag

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第9期143卷 201-212页

作者： Hao guo Tao guo Mengqi Zhao Yaxin zhang Wenfeng Shangguan Yinnian Liao State Key Laboratory of Chemistry and Utilization of Carbon Based Energy Resources Xinjiang UniversityXinjiang 830017China Xinjiang Key Laboratory of Coal Clean Conversion&Chemical Engineering Process Xinjiang UniversityXinjiang 830017China School of Chemical Engineering and Technology Xinjiang UniversityXinjiang 830017China Research Center for Combustion and Environmental Technology Shanghai Jiao Tong UniversityShanghai 200240China School of Applied Chemistry and Materials Zhuhai College of Science and TechnologyGuangdong 519041China

Silver(9 wt.%)was loaded on Co_(3)O_(4)-nanofiber using reduction and impregnation methods,*** to the stronger electronegativity of silver,the ratios of surface Co^(3+)/Co^(2+) on Ag/Co_(3)O_(4) were higher than on Co_(3)O_(4),which further led to more adsorbed oxygen species as a result of the charge ***,the introducing of silver also obviously improved the reducibility of Co_(3)O_(4).Hence the Ag/Co_(3)O_(4) showed better catalytic performance than Co_(3)O_(4) in benzene *** with the Ag/Co_(3)O_(4) synthesized via impregnation method,the one prepared using reduction method(named as Ag Co-R)exhibited higher contents of surface Co^(3+) and adsorbed oxygen species,stronger reducibility,as well as more active surface lattice oxygen ***,Ag Co-R showed lowest T_(90) value of 183℃,admirable catalytic stability,largest normalized reaction rate of1.36×10^(-4)mol/(h·m^(2))(150℃),and lowest apparent activation energy(E_(a))of 63.2 kJ/*** analyzing of in-situ DRIFTS indicated benzene molecules were successively oxidized to phenol,o-benzoquinone,small molecular intermediates,and finally to CO_(2) and water on the surface of Ag *** last,potential reaction pathways including five detailed steps were proposed.

关键词： Reduction method Co_(3)O_(4)-supported Ag catalyst,VOCs Benzene oxidation Reaction mechanism

Mechanism of acupuncture in attenuating cerebral ischaemia-reperfusion injury based on nuclear receptor coactivator 4 mediated ferritinophagy

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medicine 2024年第2期44卷 345-352页

作者： zhang Xinchang huang Zheng huang Peiyan YANG Mengning zhang Zhihui NI Guangxia College of Acupuncture-Moxibustion and Tuina Nanjing University of Chinese MedicineNanjing 210023China Key Laboratory of Acupuncture and Medicine Research of Ministry of Education Nanjing University of Chinese MedicineNanjing 210023China

OBJECTIVE:To explore the effect of acupuncture treatment on cerebral ischaemia-reperfusion injury(CIRI)and reveal the underlying mechanism of the effect based on nuclear receptor coactivator 4(NCOA4)mediated ***:Sprague-Dawley male rats were divided into four groups:the sham group,model group,acupuncture group,and sham acupuncture *** 2 h of middle cerebral artery occlusion(MCAO),reperfusion was performed for 24 h to induce *** rats were treated with acupuncture at the Neiguan(PC6)and Shuigou(GV26)*** neurological function was evaluated by taking their Bederson scores at 2 h after ischaemia and 24 h after *** chloride staining was applied to assess the cerebral infarct volume at 24 h after *** malondialdehyde(MDA)and ferrous iron(Fe^(2+))levels were observed after 24 h of reperfusion using an assay *** blotting was performed to detect the expression of NCOA4 and ferritin heavy chain 1(FTH1)at 24 h after ***,the colocalization of ferritin with neurons,NCOA4 with microtubule-associated protein 1 light chain 3(LC3),and NCOA4 with ferritin was visualized using immunofluorescence ***:Acupuncture significantly improved neurological function and decreased cerebral infarct volume in the acupuncture *** CIRI,the expression of NCOA4,LC3 and FTH1 was increased,which enhanced ferritinophagy and induced an inappropriate accumulation of Fe^(2+)and MDA in the ischaemic ***,acupuncture dramatically downregulated the expression of NCOA4,LC3 and FTH1,inhibited the overactivation of ferritinophagy,and decreased the levels of MDA and Fe^(2+).CONCLUSIONS:Acupuncture can inhibit NCOA4-mediated ferritinophagy and protect neurons against CIRI in a rat model.

关键词： acupuncture ferritinophagy ferroptosis ferritin nuclear receptor coactivator 4 cerebral ischaemia-reperfusion injury

同方期刊数据库

Glacial-interglacial cycles recorded in clay minerals from the eastern Tibetan Plateau over the last 800 ka and their indications

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2024年第7期67卷 2162-2177页

作者： Xiaoyan zhang Chunxia zhang Yan ZHAO Bin HU Zhengtang guo Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China College of Earth Science and Engineering Shandong University of Science and TechnologyQingdao 266590China Key Laboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China

Clay mineral proxies have been widely used to reconstruct changes in provenance and the ***,high-altitude clay mineral indications and long-term and orbital variations have not been fully ***,we present an800-ka clay-mineral record from a lacustrine sediment core(ZB13-C2)from the Zoige Basin on the eastern Tibetan Plateau(TP).X-ray diffraction and scanning electron microscopy were used to identify the clay mineral assemblages and their micromorphological characteristics of core *** results revealed that the clay minerals in core ZB13-C2 are mainly illite,with small amounts of chlorite,kaolinite,and smectite(including irregular mixed-layers of illite-smectite(I/S)and chloritesmectite(C/S)).The clay mineral assemblages and proxies exhibit three stages of change,which are mainly controlled by the Zoige watershed range under different climate *** watershed was limited to the southeastern region with altitudes ranging from~3500 to~4200 meters above sea level(m a.s.l.),and glacial-interglacial hydraulic erosion controlled the input of bedrock debris during 800-621 ka *** expanded to higher altitudes(~4200 to~4700 m a.s.l.)due to stronger seasonal freezethaw weathering without significant glacial-interglacial variations under a cooling and drying climate during 621-100 ka ***,it expanded to its highest altitudes of~4700 to~5200 m *** of the watershed after 100 ka BP,and hydraulic erosion increased obviously under a warm climate of the interstadial MIS 3 on the *** watershed underwent two major expansions under different climatic conditions at~621 ka and 100 ka BP,with the wet/dry alternation became strong at~621 ka *** results reveal that long-term temperature changes and the wet/dry alternation at high altitudes controlled the watershed range and degree of the physical erosion,and that the indications of clay minerals should be carefully clarified before they are used as climate indicators,especi

关键词： Quaternary Zoige Basin Lacustrine sediments Paleoenvironment Weathering

同方期刊数据库

Density functional theory study of B- and Si-doped carbons and their adsorption interactions with sulfur compounds

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2024年第2期6卷 195-208页

作者： Peng guo Hong zhang Shuliang Dong Libao An College of Mechanical Engineering North China University of Science and TechnologyTangshanHebeiChina College of Life Sciences North China University of Science and TechnologyTangshanHebeiChina

Understanding the adsorption interactions between carbon materials and sulfur compounds has far-reaching impacts,in addition to their well-known important role in energy storage and conversion,such as lithium-ion *** this paper,properties of intrinsic B or Si single-atom doped,and B-Si codoped graphene(GR)and graphdiyne(GDY)were investigated by using density functional theory-based calculations,in which the optimal doping configurations were explored for potential applications in adsorbing sulfur *** showed that both B or Si single-atom doping and B-Si codoping could substantially enhance the electron transport properties of GR and GDY,improving their surface ***,B and Si atoms displayed synergistic effects for the codoped configurations,where B-Si codoped GR/GDY exhibited much better performance in the adsorption of sulfurcontaining chemicals than single-atom doped *** addition,results demonstrated that,after B-Si codoping,the adsorption energy and charge transfer amounts of GDY with sulfur compounds were much larger than those of GR,indicating that B-Si codoped GDY might be a favorable material for more effectively interacting with sulfur reagents.

关键词： adsorption density functional theory doping graphdiyne graphene sulfur compounds