Numerical analysis of multicomponent responses of surface-hole transient electromagnetic method

We calculate the multicomponent responses of surface-hole transient electromagnetic method. The methods and models are unsuitable as geoelectric models of conductive surrounding rocks because they are based on regular local targets. We also propose a calculation and analysis scheme based on numerical simulations of the subsurface transient electromagnetic fields. In the modeling of the electromagnetic fields, the forward modeling simulations are performed by using the finite-difference time-domain method and the discrete image method, which combines the Gaver–Stehfest inverse Laplace transform with the Prony method to solve the initial electromagnetic fields. The precision in the iterative computations is ensured by using the transmission boundary conditions. For the response analysis, we customize geoelectric models consisting of near-borehole targets and conductive wall rocks and implement forward modeling simulations. The observed electric fields are converted into induced electromotive force responses using multicomponent observation devices. By comparing the transient electric fields and multicomponent responses under different conditions, we suggest that the multicomponent-induced electromotive force responses are related to the horizontal and vertical gradient variations of the transient electric field at different times. The characteristics of the response are determined by the varying the subsurface transient electromagnetic fields, i.e., diffusion, attenuation and distortion, under different conditions as well as the electromagnetic fields at the observation positions. The calculation and analysis scheme of the response consider the surrounding rocks and the anomalous field of the local targets. It therefore can account for the geological data better than conventional transient field response analysis of local targets.

Nonlinear Optical Properties of Al-Doped nc-Si-SiO_2 Composite Films

The nonlinear optical properties of Al-doped nc-Si-SiO2 composite films have been investigated using the time-resolved four-wave mixing technique with a femtosecond laser. The off-resonant third-order nonlinear susceptibility is observed to be 1.0 × 10-10 esu at 800nm. The relaxation time of the optical nonlinearity in the films is as short as 60fs. The optical nonlinearity is enhanced due to the quantum confinement of electrons in Si nanocrystals embedded in the SiO2 films. The enhanced optical nonlinearity does not originate from Al dopant because there are no Al clusters in the films.

红色警戒

多年来,休斯敦火箭总是如国足一般,在人垂头丧气时勾起希望,等你真的有所期待时又当头浇下冷水。上赛季,火箭走到了西部决赛,今年夏天,在没有失去任何重要球员的同时引进了泰·劳森,这让人们对本赛季的火箭充满期待。然而,他们的开局之糟糕可能出乎很多人的预料。相信有很多球迷都会有我一样的想法吧。去年的火箭靠着一股拼劲干到了西决,给我们莫大的欣慰,我一直都有这么一个理想,希望能在有生之年,看到火箭夺冠。

完善分时电价政策 提高企业经济效益——杭州工业企业实行三费率分时电价政策情况调查与分析

本文对杭州市2003年实施三费率分时电价政策以来工业用户的响应情况进行了分析。列举了不同行业代表企业在实施三费率电价政策后产生的实效效果,对其在削峰填谷方面产生的作用以及经济效益进行了评价。并提出了进一步实施三费率分时电价政策的建议。

NUMERICAL SIMULATIONS OF EVOLUTIONS FROM WALL PULSE TO TURBULENT COHE RENT STRUCTURES

The high order compact d if ference method is developed for solving the perturbation equations based on Navi er Stokes equations, and is used in studying complex evolution processes from w all negative pulse to the turbulent coherent structure in the channel flow. Th is method contains three dimensional coupling difference scheme with high accur acy and high resolution, and the high order time splitting methods. Compared with the general spectral method, the method can be used to research turbule nt coherent structure under more general boundary conditions and in flow domains . In this paper, the generation and evolution of the turbulent coherent structur es ind uced by wall pulse in the channel flow are simulated, and the basic characterist ics and rules of the turbulent coherent structure are shown. Computational r esults indicate that a wall negative pulse is more convenient than the resonant three wave model.

Impacts of mariculture practices on the temporal distribution of macrobenthos in Sandu Bay, South China

Sandu Bay is located in the East China Sea and is characterized by high-density fish farming and kelp culture. Despite this, little is known about the impacts of these different mariculture practices on the local environment. We investigated the temporal variation in macrobenthos and environmental conditions at three sites in the bay （fish farming site, kelp culture site, and a control site）. We collected water and sediment samples during nine cruises between May 2009 and February 2010. The density of macrobenthos peaked at the fish farming site in July （655 ind./mE） whereas density did not fluctuate as widely at the other two sites. Biomass varied significantly at both the control and kelp culture sites, but had only a single peak at the fish farming site in June （21.90 g/mE）. The dominant species varied throughout the study period at the control and kelp culture sites, whereas a single terebellid species （Lysilla pacifica） dominated the macrobenthos at the fish farming site. The diversity index H＇ increased at the control site beginning in February then decreased after May, whereas H＇ was low at the other sites in December. The mean dissolved oxygen level was highest at the control site （6.59 mg/L） and lowest at the fish farming site （5.54 mg/L）. DO levels were lowest at all sites in summer （July and August）. The sediment acid volatile sulfide content was higher at the fish farming site （1.46 mg/g dry weight） than those at the kelp culture and control sites （1.22 and 0.14 mg/g, respectively）. Our results suggest that mariculture practices have a clear impact on the benthic environment/ community in Sandu Bay.

Direct Observation of Singletππ*and nπ*Equilibrium State in 2-Amino-1,3,5-triazine Solution

1,3,5-Triazine molecules represent a class of molecules that may have been prebiotic information carriers in a primordial soup in early Earth and their excited state dynamics has received attention in recent years.In our previous study,one component with lifetime longer than100 ps was discovered in 2-amino-1,3,5-trainzine(2-AT),but its nature has not been revealed.In this study,excited state dynamics of 2-AT is studied in different solvents by using femtosecond time-resolved transient absorption and fluorescence upconversion spectroscopy.Interestingly,an equilibrium state consisting of the brightππ^(*)and dark nπ^(*)states in 2-AT is directly observed in aqueous solution and its dynamics is solvent sensitive.The whole picture of the excited state deactivation mechanism of 2-AT is proposed based on our spectroscopy results.

Reflection of thermo-elastic wave in semiconductor nanostructures nonlocal porous medium

The current work is an extension of the nonlocal elasticity theory to fractional order thermo-elasticity in semiconducting nanostructure medium with voids.The analysis is made on the reflection phenomena in context of three-phase-lag thermo-elastic model.It is observed that,four-coupled longitudinal waves and an independent shear vertical wave exist in the medium which is dispersive in nature.It is seen that longitudinal waves are damped,and shear wave is un-damped when angular frequency is less than the cut-off frequency.The voids,thermal and non-local parameter affect the dilatational waves whereas shear wave is only depending upon non-local parameter.It is found that reflection coefficients are affected by nonlocal and fractional order parameters.Reflection coefficients are calculated analytically and computed numerically for a material,silicon and discussed graphically in details.The results for local(classical)theory are obtained as a special case.The study may be useful in semiconductor nanostructure,geology and seismology in addition to semiconductor nanostructure devices.

Insights into Three-Dimensional Radiofrequency Circuits Connections

The authors state briefly the possibility of various simulators to handle propagation of electromagnetic waves along some interconnections, in 3D RF （Radio Frequency） circuits. The studies are first derived in the time domain： a Finite-Difference Time-Domain method is applied, taking spectra via FFTs （Fast Fourier Transform） as post-processors. Electric and magnetic field distributions, pulse propagations along stripline structures or vias are highlighted. The scattering parameters for various cases are extracted and compared. Some original issue of this work is an insight on crosstalk or shielding phenomena between lines.

3D prestack reverse time migration of ground penetrating radar data based on the normalized correlation imaging condition

The reverse time migration(RTM)of ground penetrating radar(GPR)is usually implemented in its two-dimensional(2D)form,due to huge computational cost.However,2D RTM algorithm is difficult to focus the scattering signal and produce a high precision subsurface image when the object is buried in a complicated subsurface environment.To better handle the multi-off set GPR data,we propose a three-dimensional(3D)prestack RTM algorithm.The high-order fi nite diff erence time domian(FDTD)method,with the accuracy of eighth-order in space and second-order in time,is applied to simulate the forward and backward extrapolation electromagnetic fi elds.In addition,we use the normalized correlation imaging condition to obtain pre-stack RTM result and the Laplace fi lter to suppress the low frequency noise generated during the correlation process.The numerical test of 3D simulated GPR data demonstrated that 3D RTM image shows excellent coincidence with the true model.Compared with 2D RTM image,the 3D RTM image can more clearly and accurately refl ect the 3D spatial distribution of the target,and the resolution of the imaging results is far better.Furthermore,the application of observed GPR data further validates the eff ectiveness of the proposed 3D GPR RTM algorithm,and its fi nal image can more reliably guide the subsequent interpretation.

像雪一样飘(组诗)

一颗药片像雪一样飘进她的身体 雪终于落下的时候 隔壁传来激动的声响 第一场雪踏上南方的道路 以狂欢的名义，狂欢 哪怕是濒临死亡的病房 这18楼12床离地面太远 衰竭的肾脏像失去重力的吸盘 悬浮的物质 偶然感到下垂的力量。

跳投战队 NBA最好的跳投阵容

在篮球场上,让人热血沸腾的惊天暴扣并不常见,相比之下,那些普普通通的跳投却是攻城拔寨的常规武器,而且,它也是最简洁有效、最节省体力的攻击方式——迈克尔·乔丹的10次得分王,有一半都是依靠跳投完成的,这足以说明问题。因此,我们决定在劳资纠纷仍然乱成一锅粥的时候,谈谈有关联盟最让人朝思暮想的东西——我心目中的最佳跳投阵容。当然,他们中某些人的跳投是堪称教科书,而且我们选中的都是他们投篮最准的时期。斯蒂芬·库里Stephen Curry控球后卫｜G428｜FG%.473｜3P%.441就投篮精准度和保持机器人般完美、肘曲于球正下的动作的能力——无论在投三分时还是在罚球线附近投篮假动作一库里可以被看作是纳什的继承人。快速的投篮出手和与之不匹配的空心命中的数量,库里的入选根本不用多想。

总决赛第四场 四星王者的诞生

0比3,历史上没有球队能够在0比3的情况下翻盘,骑士能吗?詹姆斯还想试一试.但是法国人帕克没有答应,他要带领马刺9年4次封王,他要把总冠军作为结婚礼物。

留言飞语

关于那个篮球的梦想……(1)记得还是在上高二的时候才迷上的篮球,那时的我瘦得和火柴棒似的,根本没有和别人对抗的能力。于是从那时开始,我养成了在三分线外飙三分的习惯。久而久之,我有远投能力有了逐步的提高,虽然大家都说我投三分时的姿势很难看。难看就难看吧,只要投得进,难看又有什么关系呢?渐渐地,我对篮球的热爱变成了酷爱,进而更是发展成一发而不可收拾。高考在即,我依旧没有放下这份对篮球的热情,每天的黄昏,

A single camera volumetric particle image velocimetry and its application

Volumetric particle image velocimetry(VPIV) refers to a PIV-based technique which can obtain full velocity components in a three-dimensional measurement volume.A new VPIV method with a single lens was developed.A three-vision prism was used to make viewing from different angles using one camera.The technique was tested and successfully applied to a three-dimensional three-component(3D3C) measurement of a zero-net-mass-flux jet flow.The accuracy of the measurement was investigated,specifically in steps of calibration,self-calibration and particle triangulation.Time sequence of a vortex ring development was presented.It was shown that the measurement has high accuracy with validation rate of velocity vector reaching about 95%.The flow with vortex ring passing the measurement volume was studied using both swirl strength and vorticity magnitude criteria.Through comparison,the swirl criterion was found to be superior to the criterion of vorticity in differentiating the rotation motion and the free shear.

Three Gorges Dam stability monitoring with time-series InSAR image analysis

In this paper,we carried out a combination of permanent scatterer and quasi permanent scatterer time-series InSAR image analyses to extract geometric information over the area of the Three Gorges Dam.For the first time,we measured and analyzed the deformation of the Three Gorges Dam and its surrounding area using 40 SAR images acquired from 2003 to 2008.Our results indicate that the temporal deformation of the left part of the dam has ceased and that the deformation of the dam was influenced by the changing level of the Yangtze River.Seasonal deformation due to varying temperature is also observed.The obtained results agree well with the published results of the Three Gorges Dam deformation obtained by employing conventional survey methods.We also found that there is an area of abnormal subsidence near Zigui County.This paper demonstrates the potential of time-series InSAR image analysis in the monitoring of dam stability and measurement of subsidence.

Analysis of the effect of regional lateral inflow on the flood peak of the Three Gorges Reservoir

The Three Gorges Region(TGR),located at the lower reach of the Upper Yangtze River Basin(UYRB) in China,suffers from heavy rainstorm frequently.The runoff generated from TGR composes an important part of the total flood at the famous Three Gorges Reservoir(TGRe).During the severe flood period in 1954,for example,the water from TGR accounted for up to 13.2% of the 30-days maximum flood volume of the UYRB.Considering the short and steep tributaries with rapid concentration,the regional lateral inflow(RLI) may induce more serious effect on the flood peak of the TGRe than the volume.However,hydrological data of the sparse gauge stations is too insufficient to evaluate the effect of RLI.This paper studied the impact by analyzing 880 flood events during 1956-2000.By comparing the observed hydrograph and simulated hydrograph with HEC-RAS software regarding no RLI,the effect of RLI on flood peak value and timing properties was identified and quantified.The variability of this effect among floods of different magnitudes was also analyzed.To evaluate the analysis uncertainty associated with the parameter of roughness coefficient,four sets of roughness coefficients from different research groups were employed in this study.The results showed that RLI contributes discharge of 3524 m3/s to flood peaks of the TGRe on average,with the contribution ratio of 15.9%.RLI contributes 12000 m3/s to the flood peaks larger than 50000 m3/s on average,with 25000 m3/s as its upper bound,while the contribution ratio can reach up to 50%,with an average of 20%.The variability of this effect is great among different events.Statistical analysis showed that to larger flood peak of the TGRe,RLI contributes more discharge with higher variability,and the contribution ratio and its variability are slightly larger,and events with higher contribution ratio occur more frequently.RLI can reshape the hydrograph,leading to earlier appearance of flood peak.This effect and its variability increase with the contribution ratio.This study has revealed that RLI plays an important role in large flood peak of the TGRe,which calls for more reliable flood forecasting methods to prolong the forecast lead time and improve the accuracy for the safety of the Three Gorges Dam and the protection of its lower reaches during severe flood disaster period.

Landslide monitoring with high-resolution SAR data in the Three Gorges region

Employing the well-known D-InSAR technique,we investigated landslide monitoring in the Three Gorges region using TerraSAR-X data.The experiment demonstrates that using both the amplitude and differential phase allows us to identify the precise location,deformation and time range of occurrence of certain landslides.To overcome the atmospheric effect on D-InSAR results,a time-series analysis was also carried out.The observed nonlinear relationship between the deformation and water level suggests that reservoir water level fluctuation is one of the major causes of landslides,which is significant in terms of issuing landslide warnings.In addition,the comparison of TerraSAR-X and C-band ASAR data results indicates that TerraSAR-X data provide far more reasonable deformation measurements because of their high temporal and spatial resolutions.