检索结果-南通市图书馆

Acta Geochimica 2016年第4期35卷 445-462页

作者： Xingxing Cao pan Wu Zhenxing Cao College of Resource and Environmental Engineering Guizhou University Graduate School of Science and Technology Shizuoka University

This study presents bulk chemical compositions of the Tongmuling soil profile, which developed on dolostone, and the overlying strata covering the bedrock in the central Guizhou province(southern China). The chemical weathering characteristics of the studied profile were investigated and the inheritance relationships between the terra rossa and overlying strata were discussed. The results show that there is no remarkable variation in the major elements and weathering indices from the rock–soil interface to the topsoil, indicating that the studied profile was not typical for in situ crustal chemical weathering. The terra rossa were mainly composed of Si O_2, Al_2O_3 and Fe_2O_3. Compared with the insoluble residues and overlying strata, the terra rossa are characterized by an enrichment of Y and Cs and depletion of Ba and Sr. The subsoil shows a notable Ce negative anomaly, characterized by heavy rare earth element enrichment(L/h = 1.55–3.74), whereas the topsoil shows a positive Ce anomaly with light rare earth element enrichment(L/h = 5.93–9.14). According to Laterite-forming capacity estimates, the terra rossa could not have only been formed from acid-insoluble residues from the bedrock; Al_2O_3 versus Fe_2O_3and Nb plotted against Ta show significant positive correlations between the terra rossa and overlying strata. The Eu/Eu* versusGd_N/Yb_Nand ternary diagrams for Sc, Th, Zr, and Ta suggest that the overlying strata could also provide parent materials for the genesis of terra rossa.

关键词： Terra rossa Dolomite Parent materials Guizhou China

Lightning Activity and Its Relation to the Intensity of Typhoons over the Northwest Pacific Ocean

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2014年第3期31卷 581-592页

作者： pan Lunxiang QIE Xiushu WANG Dongfang Key Laboratory of the Middle Atmosphere and Global Environment Observation Institute of Atmospheric Physics Chinese Academy of Sciences Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science & Technology

ABSTRACT Data from the World Wide Lightning Location Network （WWLLN） were used to analyze the lightning activity and the relationship between maximum sustained wind and lightning rate in 69 tropical cyclones over the Northwest Pacific Ocean from 2005 to 2009. The minimum lightning density was observed in the category 2 typhoon Kong-Rey （2007）, with a value of only 1.15 d-1 （100 kin）-2. The maximum lightning density occurred in the category 2 typhoon Mitag （2007）, with a value of 510.42 d-1 （100 km）-2. The average lightning density decreased with radius from the typhoon center in both weak （categories 1-3） and super （categories 4-5） typhoons. The average lightning density in the inner core of super typhoons was more than twice as large as that for weak typhoons. Both groups of typhoons showed a near-monotonic decrease in lightning density with radius. Results also showed that lightning activity was more active in typhoons that made landfall than in those that did not. The mean correlation coefficient between the accumulated flashes within a 600-kin radius and the maximum wind speed in the weak typhoons and super typhoons was 0.81 and 0.74, respectively. For more than 78% （56%） of the super （weak） typhoons, the lightning activity peaked before the maximum sustained wind speed, with the most common leading time being 30 （60） h. The results suggest that, for the Northwest Pacific Ocean, lightning activity might be used as a measurement of the intensification of typhoons.

关键词： lightning typhoon intensity WWLLN

2D photocatalysts for hydrogen peroxide synthesis

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第12期35卷 15-32页

作者： Liyong Ding Zhenhua pan Qian Wang Graduate School of Engineering Nagoya UniversityFuro-choChikusa-kuNagoya 464-8603Japan College of Chemical and Material Engineering Quzhou UniversityQuzhou 324000China Institute for Advanced Research Nagoya UniversityFuro-choChikusa-kuNagoya 464-8601Japan Department of Applied Chemistry Graduate School of EngineeringUniversity of HyogoHimejiHyogo 671-2280Japan

Photocatalytic hydrogen peroxide(h_(2)O_(2))synthesis,driven by solar energy,offers a sustainable and cleaner alternative for producing green h_(2)O_(2)from water and oxygen.2D photocatalysts have emerged as powerful materials for this purpose due to their unique physiochemical properties such as a flexible planar structure and large surface *** review provides a comprehensive overview of the latest advances in 2D photocatalytic materials employed in h_(2)O_(2)synthesis,including metal oxides,metal chalcogenides,bismuth-based materials,graphitic carbon nitrides(g-C_(3)N_(4)),metal-organic frameworks(MOFs),and covalent organic frameworks(COFs).Beginning with an extensive introduction to possible reaction routes for photocatalytic h_(2)O_(2)synthesis,we summarize the common methods for h_(2)O_(2)detection,crucial for obtaining reliable results in h_(2)O_(2)***,we highlight molecular-level modification strategies for 2D photocatalysts,such as surface modification,ion doping,defect engineering,and heterojunction construction,which promote high-efficiency solar-to-chemical conversion for sustainable h_(2)O_(2)***,we discuss key issues and provide perspective outlooks for the efficient and sustainable generation of h_(2)O_(2)in scale-up industrial *** review offers in-depth insights into different reaction pathways of h_(2)O_(2)synthesis and provides design principles for 2D photocatalysts to enhance h_(2)O_(2)production,guiding the development of efficient photocatalysts for h_(2)O_(2)synthesis.

关键词： Photocatalysis hydrogen peroxide production 2D photocatalysts Oxygen reduction reaction Water oxidation reaction

Extraction hydrolysates from Larimichthys Polyactis Swim Bladder Using Enzymatic hydrolysis

在线全文

学校读者我要写书评

暂无评论

Journal of Renewable Materials 2021年第6期9卷 1099-1109页

作者： Ling pan Yubo Tao Peng Li College of Material Science and Engineering Northeast Forestry UniversityHarbin150040China State Key Laboratory of Biobased Material and Green Papermaking Qilu University of TechnologyShandong Academy of SciencesJinan250353China

As a kind of biopolymer,hydrolysates of fish swim bladder,safer than those of land mammals,are widely used in food,cosmetics as well as pharmaceutical and biomedical fields for their biocompatibility,biodegradability,and weak *** enhance hydrolysate production,in this paper,the papain and alcalase hydrolysis processes of larimichthys polyactis swim bladder were optimized with orthogonal *** 89.5%hydrolysate yield,the optimal processing conditions for alcalase were solid-liquid ratio of 1:30,enzyme concentration of 0.7%,and extraction time of 6 *** for papain,under the optimal processing conditions:solid-liquid ratio of 1:20,enzyme concentration of 0.5%,and extraction time of 8 h,the hydrolysate yield was 65.1%.To obtain higher hydrolysate yields,the ultrasonic pretreatments were implemented before the optimal enzyme hydrolysis *** ultrasonic waves of 100 W for 50 min,the hydrolysate yields were increased 2.1%(alcalase)and 4.5%(papain),*** Fourier Transform Infrared(FTIR)spectroscopic analysis revealed that the hydrolysates extracted by papain exist in triple-helical *** Ultra-Violet(UV)absorption spectra indicated that the aromatic amino acids in the hydrolysates had strong absorptions in the wavelength range of 240 nm–300 *** results of this research demonstrate that the alcalase hydrolysates have better solubility in water and the solution is more stable under ambient ***,the hydrolysates extracted by papain have a gel property and are insoluble in weak acid at room temperature,which is more suitable for applications in feedstock of biomedical.

关键词： Swim bladder enzymatic hydrolysis ultrasonic-assisted extraction hydrolysates analysis

Characterizing model uncertainty of upper-bound limit analysis on slopes using 3D rotational failure mechanism

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

Rock Mechanics Bulletin 2023年第1期2卷 38-43页

作者： X.Z.Li h.Jiang Q.J.pan L.h.Zhao School of Civil Engineering Central South UniversityNo.22Shaoshan South RoadChangshaHunan Province410075People's Republic of China Department of Resources and Environment Hunan Nonferrous Metals Vocational and Technical CollegeZhuzhouHunan412006People's Republic of China

The slope stability assessment is a classical problem in geotechnical *** topic have attracted many researcher’s attention and various theoretical models for predicting critical slope heights or safety factors in the light of the limit equilibrium(LE)method and the kinematical approach of limit analysis(LA)***,a large number of experimental studies have been conducted to check the slope *** centrifuge testing results,this paper aims to employ Bayesian method to characterize the model uncertainties of the classical three-dimensional rotational failure mechanism proposed by Michalowski and Drescher(2009)to predict critical slope heights in frictional soils,by incorporating the test uncertainties and parameter *** obtained results show that the LA three-dimensional rotational failure mechanism overestimates the critical slope height compared with the LE method,and the experimental observational uncertainty has negligible influences on the posterior statistics of model uncertainty.

关键词： Model uncertainty Slope stability Upper-bound limit analysis Bayesian analysis Centrifuge testing

A Schwarz Lemma at the Boundary of hilbert Balls

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

Chinese Annals of Mathematics,Series B 2018年第4期39卷 695-704页

作者： Zhihua ChEN Yang LIU Yifei pan Department of Mathematics Tongji UniversityShanghai 200092 China. Corresponding author. Department of Mathematics Zhejiang Normal University Jinhua 321004Zhejiang China. Department of Mathematical Sciences Indiana University-Purdue University Fort Wayne Fort Wayne IN 46805-1499 USA School of Mathematics and Informatics Jiangxi Normal University Nanchang 330022 China.

In this paper, the authors prove a general Schwarz lemma at the boundary for the holomorphic mapping f between unit balls B and B＇ in separable complex hilbert spaces h and h＇, respectively. It is found that if the mapping f ∈ C^1＋α at z0 ∈ B with f（zo） = wo ∈ OB＇, then the Fr＆het derivative operator Df（z0） maps the tangent space Tz0（ B^n） to Tw0（ B＇）, the holomorphic tangent space Tz0^（1,0） to Tw0（1,0）（ B＇）,respectively.

关键词： Boundary Schwarz lemma Separable hilbert space holomorphic mapping Unit ball

Testing the Coincidence Problem with Strong Gravitational Lens,Type Ia Supernovae and hubble Parameter Observational Data

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2022年第11期22卷 214-222页

作者： Jingwang Diao Yu pan Wenxiao Xu School of Science Chongqing University of Posts and TelecommunicationsChongqing 400065China

In this paper,we use three different kinds of observational data,including 130 strong gravitational lensing(SGL)systems,type Ia supernovae(SNeIa:pantheon and Union2.1)and 31 hubble parameter data points(h(z))from cosmic chronometers to constrain the phenomenological model(ρ_(x)∝ρ_(m)a^(ξ)).By combining these three kinds of data(Union2.1+SGL+h(z)),we get the parameter value at the confidence interval of 2σ,Ω_(X,0)=0.69±0.34,ω_(x)=−1.24±0.61,ξ=3.8±3.9 and h_(0)=70.22±0.86 kms^(−1) Mpc^(−1).According to our results,we find that theΛCDM model is still the model which is in best agreement with the observational data at present,and the coincidence problem is not *** addition,the Ω_(X) and Ω_(m) have the same order of magnitude in 0he transition redshift z_(T)=*** the transition occurs in z>0.645,it is necessary to introduce the dark energy interacting with dark matter.

关键词： (cosmology:)cosmological parameters (cosmology:)dark energy cosmology:observations

Assessment for soil loss by using a scheme of alterative sub-models based on the RUSLE in a Karst Basin of Southwest China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2017年第2期16卷 377-388页

作者： ChEN hao Takashi Oguchi WU pan School of Political Science and Public Administration Huaqiao University Quanzhou 362021 P.R. China Department of Natural Environment Studies The University of Tokyo Kashiwa 277-8568 Japan Center for Spatial Information Science The University of Tokyo Kashiwa 277-8568 Japan College of Resources and Environmental Engineering Guizhou University Guiyang 550025 P.R. China

Accurate assessment of soil loss caused by rainfall is essential for natural and agricultural resources management. Soil erosion directly affects the environment and human sustainability. In this work, the empirical and contemporary model of revised universal soil loss equation （RUSLE） was applied for simulating the soil erosion rate in a karst catchment using remote sensing data and geographical information systems. A scheme of alterative sub-models was adopted to calculate the rainfall erosivity （R）, soil erodibility （K）, slope length and steepness （LS）, cover management （C） and conservation practice （P） factors in the geographic information system （GIS） environment. A map showing the potential of soil erosion rate was produced by the RUSLE and it indicated the severe soil erosion in the study area. Six classes of erosion rate are distinguished from the map： 1） minimal, 2） low, 3） medium, 4） high, 5） very high, and 6） extremely high. The RUSLE gave a mean annual erosion rate of 30.24 Mg ha-1 yr-1 from the 1980s to 2000s. The mean annual erosion rate obtained using RUSLE is consistent with the result of previous research based on in situ measurement from 1980 to 2009. The high performance of the RUSLE model indicates the reliability of the sub-models and possibility of applying the RUSLE on quantitative estimation. The result of the RUSLE model is sensitive to the slope steepness, slope length, vegetation factors and digital elevation model （DEM） resolution. The study suggests that attention should be given to the topographic factors and DEM resolution when applying the RUSLE on quantitative estimation of soil loss.

关键词： soil erosion RUSLE GIS Karst Basin

A switchable concentrating photovoltaic/concentrating solar power(CPV/CSP)hybrid system for flexible electricity/thermal generation

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2023年第8期66卷 2332-2345页

作者： pan XinYu YUAN MengDi JU Xing XU Chao Key Laboratory of Power Station Energy Transfer Conversion and System of Ministry of Education School of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing 102206China

Due to the intermittency and indeterminacy of solar irradiance,balancing energy supply and load demand remains a *** paper proposed a switchable hybrid system that combines concentrating photovoltaic/concentrating solar power(CPV/CSP)technology with thermal energy storage(TES)to achieve flexible electricity and thermal generation by adjusting the incident solar flux of photovoltaic(PV).The hybrid system can directly transfer surplus solar energy into high-quality heat for storage using a rotatable PV/heat *** simulated results demonstrated that the hybrid system effectively improves power generation,optimally utilizes TES capacity,and reduces the levelized cost of electricity(LCOE).Over a selected seven-day period,the single-junction(1J)Ga As solar cells used in the hybrid system sustainably satisfied the load demand for more than five days without grid supplement,outperforming the CSP plant by an additional two *** hybrid system utilizing the 1J Ga As with the base configuration of solar multiple(SM)of 1.26 and TES capacity of 5 h improved the annual power production and renewable penetration(RP)by 20.8%and 24.8%compared with the conventional CSP plant,*** hybrid plant with monosilicon and a configuration of SM(1.8),PV ratio(1),and TES capacity(6 h)achieved an optimal LCOE of11.52$ct/k Wh and RP of 75.5%,which is 8.8%lower and 12.1%higher than the CSP plant,respectively.

关键词： concentrated photovoltaic concentrated solar power hybrid system flexible electricity/thermal ratio techno-economic analysis

同方期刊数据库

Low temperature catalytic oxidation of NO over different-shaped CeO2

在线全文

学校读者我要写书评

暂无评论

Journal of Rare Earths 2018年第6期36卷 588-593页

作者： Wenhuan Wang Ruitang Guo Weiguo pan Guoxin hu School of Mechanical and Power Engineering Shanghai Jiaotong UniversityShanghai 200240China School of Energy Source and Mechanical Engineering Shanghai University of Electric PowerShanghai 200090China Shanghai Engineering Research Center of Power Generation Environment Protection Shanghai 200090China

To investigate the effect of CeOnanomaterial morphology on its performance for NO catalytic *** kinds of CeOnanomaterials including CeOnanorods,nanospheres and nanoparticles were prepared by hydrothermal method and used for catalytic oxidation of NO at low temperature. The experimental results show that CeOnanorods are of the best catalytic performance. Characterization techniques including TEM, XRD, h-TPR, NO-TPD and XPS were used to determine the relationship between the morphology of CeOnanomaterial and its catalytic performance. TEM images show that CeOnanorods predominantly exposed(110) and(10 0) planes, while CeOnanospheres and CeOnanoparticles predominantly exposed(111) plane. The excellent catalytic performance of CeOnanorods could be ascribed to the low crystallinity, high reducibility, strong NO adsorption ability and the presence of more surface chemisorbed oxygen.

关键词： CeO_2 nanomaterials Catalytic oxidation NO Characterization Rare earths