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Spatial correlations in time and frequency domains between chlorophyll-a concentration and environmental factors in the Bohai Sea

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Journal of Oceanology and Limnology 2024年第4期42卷 1143-1156页

作者： wan XU Di MU Zhenteng YANG Dekui yuan Department of Mechanics Tianjin UniversityTianjin 300350China Engineering Research Center of Seawater Utilization of Ministry of Education School of Chemical Engineering and TechnologyHebei University of TechnologyTianjin 300130China State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China

Based on the reconstructed MODIS data and ECMWF reanalysis data from 2003 to 2021,spatial correlations between chlorophyll a(Chl a)and sea surface temperature(SST),photosynthetically available radiation(PAR),aerosol optical thickness(AOT),and wind speed(WS)in the Bohai Sea were analyzed from the perspective of time domain and frequency *** indicate that the frequency domain analysis was more conducive to revealing the correlations between Chl a and environmental *** spatial pattern of time-domain correlations was similar to the isobaths of the Bohai Sea,which was positive in shallow waters and negative in deep waters for SST,PAR,and AOT,and was reversed for ***-domain correlations were obtained by performing Fourier Transform and were higher than correlations in time *** spatial distributions indicated that the effects of SST and PAR on Chl a were greater than AOT and WS in the Bohai ***,cross-spectrum analysis was applied to explore the response relationships.A depth-dependent pattern was shown in correlations and time lags,indicating that the influential mechanism of environmental factors on Chl-a concentration is related to seawater depth.

关键词： chlorophyll a(Chl a) frequency domain spatial correlation Bohai Sea

Electrokinetic movement of multiple chlorobenzenes in contaminated soils in the presence of β-cyclodextrin

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Journal of Environmental Sciences 2007年第8期19卷 968-976页

作者： yuan Song-hu wan Jin-zhong LU Xiao-hua School of Environmental Science and Engineering Huazhong University of Science and Technology Wuhan 430074 China.

This study investigated the electrokinetic （EK） behavior of multiple chlorobenzenes, including 1,2,3,4-tetrachlorobenzene （TeCB）, 1,2,4,5-tetrachlorobenzene （i-TeCB）, and 1,2,3-trichlorobenzene （TCB） in contaminated clayed soils. The effect of β-cyclodextrin （β- CD） on the EK removal of the chlorobenzenes was studied. The largest removal was obtained when Na2CO3/NaHCO3 buffer was used as anodic purging solution without β-CD. The removal efficiencies were related to the aqueous solubilities of chlorobenzenes. With the same cumulative electroosmotic flow, greater solubility led to higher removal efficiency. The addition of β-CD inhibited the EK removal efficiency of all chlorobenzenes. The inhibition increased with the increase of β-CD concentration. With the same β-CD concentration, the inhibition increased with the rise of electric potential. It was found that the inclusion compounds between β-CD and chlorobenzenzes were less soluble than chlorobenzenes. The formation of the less soluble inclusion compounds reduced the aqueous solubility of chlorobenzenes and led to the partial immobilization of the chlorobenzenes that desorbed from soil. It was feasible to use the EK technology to remove chlorobenzenes in contaminated soils using water as the anodic flushing solution. The addition of β-CD was not recommended for the EK removal of chlorobenzenes.

关键词： chlorobenzenes electrokinetic soil remediation β-cyclodextrin (β-CD)

Development of component stiffness equations for thread-fixed one-side bolt connections to an enclosed rectangular hollow section column under tension

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Frontiers of Structural and Civil Engineering 2024年第4期18卷 568-586页

作者： Fu-wei WU yuan-Qi LI Department of Structural Engineering Tongji UniversityShanghai 200092China State Key Laboratory of Disaster Reduction in Civil Engineering Tongji UniversityShanghai 200092China

The derivation and validation of analytical equations for predicting the tensile initial stiffness of threadfixed one-side bolts(TOBs),connected to enclosed rectangular hollow section(RHS)columns,is presented in this *** unknown stiffness components are considered:the TOBs connection and the enclosed RHS ***,the trapezoidal thread of TOB,as an equivalent cantilevered beam subjected to uniformly distributed loads,is analyzed to determine the associated *** on the findings,the thread-shank serial-parallel stiffness model of TOB connection is *** analysis of the tensile stiffness of the enclosed RHS face due to two bolt forces,the four sidewalls are treated as rotation constraints,thus reducing the problem to a two-dimensional plate *** to the load superposition method,the deflection of the face plate is resolved into three components under various boundary and load *** to the plate deflection theory of Timoshenko,the analytical solutions for the three deflections are derived in terms of the variables of bolt spacing,RHS thickness,height to width ratio,***,the validity of the above stiffness equations is verified by a series of finite element(FE)models of T-stub *** proposed component stiffness equations are an effective supplement to the component-based method.

关键词： initial stiffness component based method thread-fixed one-side bolt rectangular hollow sections analytical equation

A computational model for capturing the distinct in-and out-of-plane response of lipid membranes

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Acta Mechanica Sinica 2021年第1期37卷 138-144,I0004页

作者： Pinjing Wen Xi wei yuan Lin Institute of Semiconductor Manufacturing Research Shenzhen UniversityShenzhen518060China College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen518060China Department of Mechanical Engineering The University of Hong KongHong KongSARChina

A computational framework was developed to capture the combined fluid-and solid-like behavior of lipid membranes in a unified ***,the in-plane diffusion of lipid molecules and the associated evolution of membrane tension were explicitly taken into account in the *** addition,the out-of-plane movement induced bending and shearing of membrane,along with its thermal undulations caused by bombardment of medium molecules,were also *** capability and validity of this approach were demonstrated by simulating the enforced deformation and shape fluctuations of a lipid vesicle under a variety of testing conditions as well as their comparison with corresponding theoretical *** model could serve a useful platform for investigating processes such as cell spreading and division where morphology evolution of the membrane and transport of lipids/transmembrane proteins are known to play key roles.

关键词： Cell membrane Thermal undulations Lipid diffusion Finite element method

Effects of osmotic pressure, temperature and stocking density on survival and sexual reproduction of Craspedacusta sowerbii

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Zoological Research 2016年第2期37卷 90-95页

作者： yuan-wei ZHANG Xiao-Fu PAN Xiao-Ai wanG wan-Sheng JIANG Qian LIU Jun-Xing YANG State Key Laboratory of Genetic Resources & Evolution Kunming Institute of Zoology Chinese Academy of Sciences University of Chinese Academy of Sciences

The effects of osmotic pressure, temperature and stocking density on medusae survival of Craspedacusta sowerbii were examined. The medusae were shown to be sensitive to the variations of osmotic pressure. And the survival time was 〈90 h at 34 mOsm/L and it declined rapidly with rising osmotic pressure. The peak survival time of 〉200 h was recorded at 0.2 mOsm/L. Comparing with 27℃ and 32 ℃ treatments, 23 ℃ treatment yielded lower activities at a range of 8-13/min. However, there was a longer survival time. A non-linear relationship existed between survival time and stocking density. Lower density resulted in larger body size. And sexual reproduction resumed after breeding for 〉22 days. Newly-formed polyps and medusae appeared subsequently but only in the higher-density groups of 10, 14 and 18 ind./L. It suggested that the number of newly-formed polyps and medusae was highly dependent on stocking density. That is, a higher stocking density produced more organisms. However, newly-formed medusae died within one month and none grew a diameter of 〉5 mm.

关键词： Craspedacusta sowerbfi Osmotic pressure Temperature Stocking density

Preliminary limits of a logarithmic correction to the Newtonian gravitational potential in binary pulsars

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Research in Astronomy and Astrophysics 2014年第10期14卷 1301-1306页

作者： Chang Lu Zi-wei Li Sheng-Feng yuan Zhen wan Song-He Qin Kai Zhu Yi Xie School of Astronomy and Space Science Nanjing University Key Laboratory of Modern Astronomy and Astrophysics Nanjing UniversityMinistry of Education

We obtain preliminary limits on a logarithmic correction to the Newtonian gravitational potential by using five binary pulsars： PSR J0737-3039, PSR B 1534＋12, PSR J 1756-2251, PSR B 1913＋ 16 and PSR B2127＋ 11C. This kind of correction may originate from fundamental frameworks, like string theories, effective models of grav- ity due to quantum effects and the non-local gravity scheme. We estimate the upper limit of the Tohline-Kuhn-Kruglyak parameter A and the lower limit of the Fabris- Campos parameter α, which parameterize the correction and are connected to each other by αλ = -1. By analyzing the advances of periastron of these binary pulsars, we find that the preliminary upper limit of a is 0.19 ± 0.14 kpc^-1 and the prelimi- nary lower limit of ）, is -5.2 4± 3.8 kpc. They are compatible with the bounds based on dynamics of spiral galaxies but quite different from those given by solar system dynamics. These results indicate that this logarithmic correction might be more ob- servable in current timings of binary pulsars than in motions of the solar system.

关键词： gravitation -- relativity -- pulsars individual (PSR 0737-3039, PSRB 1534+12, PSR J1756-2251, PSR B1913+16, PSR B2127+11C)

Earthquake-induced collapse mechanism of two types of dangerous rock masses

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Earthquake Engineering and Engineering Vibration 2016年第2期15卷 379-386页

作者： wang wei yuan wei wang Qizhi Xue Kang School of Civil Engineering Shijiazhuang Railway Institute Geotechnical Institute Civil Engineering Department Tianjin University

As the economy of China develops, an increasing number of key traffic projects have been undertaken in the west of China, where there are high, steep rock slopes. The collapse of dangerous rock masses, especially following a strong earthquake, is one of common geological disasters known in rock slope engineering. Therefore, it is important to study the collapse mechanism of dangerous rock masses induced by an earthquake and the analysis approach of its stability. This study provides a simple and convenient method to determine the collapse mechanisms of two types of dangerous rock masses （i.e. cantilever and upright） associated with the definition and calculation of the safety factor, which is based on the flexure theory of a constant-section beam by combining with the maximum tensile-stress criterion to depict the process of crack propagation caused by seismic waves. The calculation results show that there are critical crack depths in each form of the dangerous rock masses. Once the accumulated depth of the crack growth during an earthquake exceeds the critical depth, the collapse will occur. It is also demonstrated that the crack extension amount of each step is not a constant value, and is closely associated with the current accumulated crack depth. The greater the cumulative crack depth, the more easily the crack propagates. Finally, the validity and applicability of the proposed method are verified through two actual engineering examples.

关键词： dangerous rock mass earthquake-induced collapse cantilever beam theory safety factor high-steep rock slope

QoS-Aware Virtual Machine Scheduling for Video Streaming Services in Multi-Cloud

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Tsinghua Science and Technology 2013年第3期18卷 308-317页

作者： wei Chen Junwei Cao Yuxin wan the Research Institute of Information Technology Tsinghua National Laboratory for Information Science and TechnologyTsinghua University

Video streaming services are trending to be deployed on cloud. Cloud computing offers better stability and lower price than traditional IT facilities. Huge storage capacity is essential for video streaming service. More and more cloud providers appear so there are increasing cloud platforms to choose. A better choice is to use more than one data center, which is called multi-cloud. In this paper a closed-loop approach is proposed for optimizing Quality of Service （QoS） and cost. Modules of monitoring and controlling data centers are required as well as the application feedback such as video streaming services. An algorithm is proposed to help choose cloud providers and data centers in a multi-cloud environment as a video service manager. Performance with different video service workloads are evaluated. Compared with using only one cloud provider, dynamically deploying services in multi-cloud is better in aspects of both cost and QoS. If cloud service costs are different among data centers, the algorithm will help make choices to lower the cost and keep a high QoS.

关键词： cloud computing dynamic scheduling data centers video streaming service computing performance evaluation Quality of Service (QoS)

An Optimized Cross Correlation Power Attack of Message Blinding Exponentiation Algorithms

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China Communications 2015年第6期12卷 22-32页

作者： wan Wunan YANG wei CHEN Jun Information Security Engineering College Chengdu University of Information Technology Institute of Applied Cryptography Chengdu University of Information Technology

The message blinding method is the most efficient and secure countermeasure against first-order differential power analysis(DPA).Although cross correlation attacks(CCAs) were given for defeating message blinding methods,however searching for correlation points is difficult for noise,misalignment in practical *** this paper,we propose an optimized cross correlation power attack for message blinding exponentiation *** attack method can select the more correlative power points of share one operation in the modular multiplication by comparing variances between correlation *** we demonstrate that the attack method is more efficient in experiments with hardware implementation of RSA on a crypto chip *** addition to the proposed CCA method can recovery all 1024 bits secret key and recognition rate increases to 100%even when the recorded signals are noisy.

关键词： side channel attack correlationpower analysis cross correlation attacks module exponentiation.