检索结果-南通市图书馆

Journal of Materials Science & Technology 2021年第5期64卷 195-202页

作者： Lin Lu qianqian liu Corrosion and Protection Center University of Science and Technology BeijingBeijing100083China State Key Laboratory of Metal Material for Marine Equipment and Application Anshan114000China

This work aimed to study the comprehensive effects of photo-oxidation and biodegradation on different failure stages of polyester coatings,which were exposed to the tropical rainforest *** surface morphology,aging products,local aging characteristics and electrochemical behavior of the coatings were characterized with scanning electron microscope(SEM),fourier transform infrared spectroscopy(FTIR),electrochemical impedance spectroscopy(EIS)and high-resolution dispersive Raman *** results showed that the surface of coatings became rougher and fungal hyphae distributed more densely on surface with the increasing of exposure *** the aspect of polymer structure,the ultraviolet radiation destroyed the main chain of polyester through the photo-oxidation process,resulting in the breakage of aliphatic ester bonds and the formation of ***,the metabolites of fungi can promote the hydrolysis of oligomers produced by the *** a short,the photo-oxidation could facilitate the biodegradation of the *** the synergistic effect of UV photo-oxidation and fungal biodegradation,a rapid diffusion tunnel between the coating surface and the metal substrate was established at the pore defects of the coating,which finally accelerated the corrosion failure process of the *** main corrosion products includeα-Fe_(2)O_(3),ZnO and Zn_(5)(OH)_(6)(CO_(3))_(2).

关键词： Polyester coating Fungus Biodegradation Photo-oxidation Microbiologically influenced corrosion Tropical rainforest

Numerical Study of the Three Gorges Dam Influences on Chlorophyll-a in the Changjiang Estuary and the Adjacent East China Sea

在线全文

学校读者我要写书评

暂无评论

Journal of Ocean University of China 2021年第1期20卷 10-22页

作者： CHEN Dongxing liu qianqian YIN Kedong School of Marine Sciences/Guangdong Key Laboratory of Marine Resources and Coastal Engineering Sun Yat-sen UniversityGuangzhou 510275China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 510275China Department of Physics and Physical Oceanography University of North Carolina WilmingtonWilmingtonNC 28403USA

The impoundment of the Three Gorges Dam(TGD)has altered downstream hydrological characteristics and sediment discharge,and it has caused ecological impacts,such as changes in chlorophyll-a(Chl-a)in estuaries and coastal *** investigate the TGD's influence on Chl-a's interannual and seasonal variations in the Changjiang Estuary and the adjacent coastal East China Sea,a physical-biogeochemical model was developed with numerical experiments covering a decade,including TGD's preperiod(pre-TGD,1999–2003)and post-period(post-TGD,2004–2008).The modeling results demonstrate an annual increase in the regional average Chl-a from pre-to post-TGD,with the largest increase reaching up to 20.8%in spring in the nearshore region beyond the Changjiang *** spatial variations in Chl-a are high,with the largest variation being observed around the 20–40 m *** increase in Chl-a is influenced by improved light and nutrient conditions,which is attributed to dam construction and fertilization by human activities.A decline in nitrogen-phosphorus fertilizer usage ratio along the Changjiang River watershed after the TGD's impoundment is another factor that influences the Chl-a's *** modeling results also show severe NO3 and PO4 imbalances with a larger N/P ratio during the post-TGD period,especially in regions with large Chl-a ***,the greater increase in the usage of phosphorus fertilizer than nitrogen fertilizer influences Chl-a's variation and has potential promotion effects on the outbreak of harmful algal bloom events.

关键词： physical-biogeochemical model Chl-a coastal ecosystem East China Sea

Highly efficient single-crystalline NaNb_(1-X)Ta_(X)O_(3)(X=0.125)wires:The synergistic effect of tantalum-doping and morphology on photocatalytic hydrogen evolution

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2020年第19期54卷 20-30页

作者： qianqian liu Quan Zhang Lu Zhang Wei-Lin Dai School of Chemistry Biology and Materials EngineeringSuzhou University of Science and TechnologySuzhou 215009China Department of Chemistry and Shanghai Key Laboratory of Molecular Catalysis and Innovative Materials Fudan UniversityShanghai 200433China

For the first time in this work,we manage to synthesize single-crystalline NaNb_(0.875)Ta_(0.125)O_(3) wires by combining the advantages of one-dimensional(1 D)nanostructure and heteroatom doping *** Ta doping was performed to figure out the correlation between morphological and structural evolution as well as the photocatalytic performance towards H2 *** was found that,the as-prepared NaNb_(0.875)Ta_(0.125)O_(3) wires presented a highest and stable photocatalytic performance,which was appropriately 41 and 2 folds higher than that of bare Na TaO_(3) and Na *** optical activity was mainly ascribed to the synergistic effect between appropriate Ta doping and perfect 1 D wire-like morphology,which resulted in fewer defects,improved charge transfer efficiency and higher reduction capability of *** the other hand,a possible photocatalytic mechanism of photocatalytic H_(2) production was proposed in *** work creates a new perspective into designing multi-component materials and understanding the mechanism of H_(2) evolution,which offers new opportunities for solar-energy conversion.

关键词： NaNb_(0.875)Ta_(0.125)O_(3)wires Single crystal Ta-doping effect Photocatalytic H2 production Mechanism

Quantum properties of fermionic fields in multi-event horizon spacetime

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2023年第12期66卷 56-62页

作者： qianqian liu Shu-Min Wu Cuihong Wen Jieci Wang Department of Physics Key Laboratory of Low-Dimensional Quantum Structures and Quantum Control of Ministry of EducationSynergetic Innovation Center for Quantum Effects and ApplicationHunan Normal UniversityChangsha 410081China Department of Physics Liaoning Normal UniversityDalian 116029China

We investigated the properties of quantum entanglement and mutual information in the multi-event horizon Schwarzschild-de Sitter(Sd S)spacetime for massless Dirac *** the first time,we obtained the expression for the evolutions of the quantum state near the black hole event horizon(BEH)and cosmological event horizon(CEH)in the Sd S *** the Nariai limit,the physically accessible entanglement and mutual information are maximized,and the physically inaccessible correlations are *** the increase in temperature of either horizon,the physically accessible correlations experience ***,the initial state remains entangled and can be utilized in entanglement-based quantum information processing tasks,which differs from the scalar field ***,the degradation of physically accessible correlations is more pronounced for small-mass black *** contrast,the physically inaccessible correlations separated by the CEH monotonically increase with the radiation temperature,and such correlations are not decisively influenced by the effect of particle creation at the ***,a similar phenomenon is observed for the inaccessible correlations separated by the *** result differs from the single event spacetime,in which the physically inaccessible entanglement is a monotonic function of the Hawking temperature.

关键词： multi-event horizon spacetime Dirac field SdS spacetime quantum entanglement

Efficacy of electroacupunture at Zusanli(ST36)on jumping-injured muscle based on transcriptome sequencing and genes analysis

在线全文

学校读者我要写书评

暂无评论

Journal of Traditional Chinese Medicine 2023年第2期43卷 322-328页

作者： HAN Rui CHANG Junzhao liu qianqian liu Haitao LI Junwei School of Physical Education and Sport Henan UniversityKaifeng 475001China Kidney Department Xindu Hospital of Traditional Chinese MedicineChengdu 610500China Intensive Care Unit the Third Affiliated Hospital of Henan University of Chinese MedicineDiagnostics Facultythe Third School of Clinical Medicine of Henan University of Chinese MedicineZhengzhou 450053China

METHODS:In the present study,female SpragueDawley rats were randomly divided into four groups with 6 of each,including normal control group(NC),jumpinginduced muscle injury model group(JI),JI with electroacupuncture stimulation treatment group(EA),and JI with non-electroacupuncture stimulation group(NEA).Transmission electron microscopy,transcriptome sequencing and analysis,prediction of protein interaction networks,real-time polymerase chain reaction verification,and Western blotting were performed on the gastrocnemius muscle of ipsilateral lower ***:The structural repair of injured gastrocnemius myofibers following jumping training in EA rats was better than that of NEA rats.A total of 136 genes were differentially expressed in EA rats relative to JI rats,with 55 genes upregulated and 81 genes *** to results of transcriptome analysis,and prediction of protein mutual interaction by the online STRING database,Heat shock protein beta-7(Hspb7)and myozenin2(Myoz2)genes were *** of Hspb7 and Myoz2 mRNAs were increased in EA rats relative to JI rats(P<0.05).The expression of Hspb7 protein was upregulated in EA rats relative to that in NC,JI,and NEA rats(P<0.01,<0.05,and<0.05,respectively).The expression of Myoz2 protein was upregulated in EA rats relative to that in NC and JI rats(both P<0.01,respectively).CONCLUSIONS:The present results suggest that electroacupuncture stimulation at Zusanli(ST36)could improve muscle healing following jumping-induced muscle injury,owing to the upregulation of Hspb7 and Myoz2 proteins.

关键词： electroacupuncture stimulation skeletal muscle wounds and injuries gene expression profiling sequence analysis Hspb7 Myoz2

The assessment of extactable tidal energy and the effect of tidal energy turbine deployment on the hydrodynamics in Zhoushan

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2015年第5期34卷 86-91页

作者： HOU Fang BAO Xianwen LI Benxia liu qianqian National Marine Environmental Forecasting Center College of Physical and Environmental Oceanography Ocean University of China Graduate School of Oceanography University of Rhode Island

In this study, we construct one 2-dimensional tidal simulation, using an unstructured Finite Volume Coastal Ocean Model （FVCOM）. In the 2-D model, we simulated the tidal turbines through adding additional bottom drag in the element where the tidal turbines reside. The additional bottom drag was calculated from the relationship of the bottom friction dissipation and the rated rotor efficiency of the tidal energy turbine. This study analyzed the effect of the tidal energy turbine to the hydrodynamic environment, and calculated the amount of the extractable tidal energy resource at the Guishan Hangmen Channel, considering the rotor wake effect.

关键词： extractable tidal energy resource rotor wake effect tidal energy turbine

Metadata as a Methodological Commons:From Aboutness Description to Cognitive Modeling

在线全文

学校读者我要写书评

暂无评论

Data Intelligence 2023年第1期5卷 289-302页

作者： Wei liu Yaming Fu qianqian liu Shanghai Library(Institute of Scientific and Technical Information of Shanghai) No.1555 Huaihai Middle Road Xuhui DistrictShanghai 200031China School of Information Management at Nanjing University No.163 Xianlin AvenueNanjingJiangsu 210093China

Metadata is data about data,which is generated mainly for resources organization and description,facilitating finding,identifying,selecting and obtaining *** the advancement of technologies,the acquisition of metadata has gradually become a critical step in data modeling and function operation,which leads to the formation of its methodological commons.A series of general operations has been developed to achieve structured description,semantic encoding and machine-understandable information,including entity definition,relation description,object analysis,attribute extraction,ontology modeling,data cleaning,disambiguation,alignment,mapping,relating,enriching,importing,exporting,service implementation,registry and discovery,monitoring *** operations are not only necessary elements in semantic technologies(including linked data)and knowledge graph technology,but has also developed into the common operation and primary strategy in building independent and knowledge-based information *** this paper,a series of metadata-related methods are collectively referred to as'metadata methodological commons',which has a lot of best practices reflected in the various standard specifications of the Semantic *** the future construction of a multi-modal metaverse based on Web 3.0,it shall play an important role,for example,in building digital twins through adopting knowledge models,or supporting the modeling of the entire virtual world,***-based description and coding obviously cannot adapted to the UGC(User Generated Contents)and AIGC(AI Generated Contents)-based content production in the metaverse *** automatic processing of semantic formalization must be considered as a sure way to adapt metadata methodological commons to meet the future needs of Al era.

关键词： Metadata Methodological Commons Content Architecture Data Modeling Ontology Semantic Web Semantic Formalization Web3.0 Metaverse

Performance of FCC Catalyst Improved with Vanadium Trapping Components

在线全文

学校读者我要写书评

暂无评论

China Petroleum Processing & Petrochemical Technology 2014年第2期16卷 8-11页

作者： Ren Fei liu qianqian Zhu Yuxia Research Institute of Petroleum Processing SINOPEC

The vanadium species were contaminated on FCC catalysts by using the Mitchell method. After the hydrothermal deactivation of the FCC catalysts, the cracking reaction was performed on these catalyst samples. The test results revealed that the conversion of feedstock and the gasoline yield obtained over the FCC catalysts with vanadium trapping components were obviously higher than those without addition of vanadium trapping components. The results also showed that the dry gas and coke selectivity on the FCC catalysts containing vanadium trapping components was improved. The X-Ray diffraction results proved that the zeolite crystal structure was well protected by the vanadium trapping components during its hydrothermal deactivation step. The results of SEM-EDX mapping disclosed that the vanadium was enriched on the vanadium trapping components which verified the positive function of vanadium trapping components.

关键词： catalytic cracking vanadium trapping components distribution vanadium poisoning

Partitioning tree water usage into storage and transpiration in a mixed forest

在线全文

学校读者我要写书评

暂无评论

Forest Ecosystems 2021年第4期8卷 961-973页

作者： Ziqiang liu qianqian liu Zijun Wei Xinxiao Yu Guodong Jia Jiang Jiang Co-Innovation Center for Sustainable Forestry in Southern China Nanjing Forestry UniversityNanjing 210037China Key Laboratory of Soil and Water Conservation and Desertification Combating of Ministry of Education Beijing Forestry UniversityBeijing 100083China

Background:Water migration and use are important processes in ***,it is possible to overestimate transpiration by equating the water absorbed through the plant roots to that diffused back to the atmosphere through stomatal ***,it is necessary to quantify the water transpired and stored in ***:The δ^(2)H/δ^(18)O technique and heat ratio method were used to explore the water usage of coniferous and broad-leaved tree species,including the proportions of water used for transpiration and water ***:Platycladus orientalis and Quercus variabilis had strong plasticity in their water usage from different *** orientalis primarily used groundwater(30.5%)and the 60-100-cm soil layer(21.6%)throughout the experimental period and was sensitive to precipitation,absorbing water from the 0-20-cm layer(26.6%)during the rainy *** variabilis absorbed water from all sources(15.7%-36.5%)except from the 40-60-cm soil layer during the dry *** addition,it did not change its water source but increased its groundwater uptake during the rainy *** annual mean water fluxes of *** and *** were 374.69 and 469.50 mm·year−1,with 93.49% and 93.91% of the water used for transpiration,***,nocturnal sap flow in *** and *** was mainly used for water storage in the trunk rather than transpiration,which effectively alleviated drought stress and facilitated the transport of ***:The water stored in both species comprised 6%-7% of the total water fluxes and,therefore,should be considered in water balance models.

关键词： Water migration Water uptake Nocturnal sap flow Transpiration

WiFi CSI Gesture Recognition Based on Parallel LSTM-FCN Deep Space-Time Neural Network

在线全文

学校读者我要写书评

暂无评论

China Communications 2021年第3期18卷 205-215页

作者： Zhiling Tang qianqian liu Minjie Wu Wenjing Chen Jingwen Huang Guangxi Key Laboratory of Wireless Broadband Communication and Signal Processing Guilin University of Electronic TechnologyGuilin 541004China

In this study,we developed a system based on deep space–time neural networks for gesture *** users change or the number of gesture categories increases,the accuracy of gesture recognition decreases considerably because most gesture recognition systems cannot accommodate both user differentiation and gesture *** overcome the limitations of existing methods,we designed a onedimensional parallel long short-term memory–fully convolutional network(LSTM–FCN)model to extract gesture features of different *** can learn complex time dynamic information,whereas FCN can predict gestures efficiently by extracting the deep,abstract features of gestures in the spatial *** the experiment,50 types of gestures of five users were collected and *** experimental results demonstrate the effectiveness of this system and robustness to various gestures and individual *** analysis of the recognition results indicated that an average accuracy of approximately 98.9% was achieved.

关键词： signal and information processing parallel LSTM-FCN neural network deep learning gesture recognition wireless channel state information