Numerical modeling of the 2D time-domain transient electromagnetic secondary field of the line source of the current excitation

To effectively minimize the electromagnetic field response in the total field solution, we propose a numerical modeling method for the two-dimensional （2D） time- domain transient electromagnetic secondary field of the line source based on the DuFort- Frankel finite-difference method. In the proposed method, we included the treatment of the earth-air boundary conductivity, calculated the normalized partial derivative of the induced electromotive force （Emf）, and determined the forward time step. By extending upward the earth-air interface to the air grid nodes and the zero-value boundary conditions, not only we have a method that is more efficient but also simpler than the total field solution. We computed and analyzed the homogeneous half-space model and the fiat layered model with high precision--the maximum relative error is less than 0.01% between our method and the analytical method--and the solution speed is roughly three times faster than the total-field solution. Lastly, we used the model of a thin body embedded in a homogeneous half-space at different delay times to depict the downward and upward spreading characteristics of the induced eddy current, and the physical interaction processes between the electromagnetic field and the underground low-resistivity body.

写月二首

写月二首孟德会（一）捧出亘古的话题不管它的完整与残缺只有品不尽的千年余韵还应感激诗仙的飘逸他粗算的歌喉唱穿了历史的隧道从古至今无论是多情的人种亦或是无情的风物总能感应到它永远丰盈的诗情如果容你开怀畅仗相信你助长的诗兴将会写意在这有月的夜空（二）从遥远...

古诗情

去年九月十日晚,在街口散步不慎从台阶滑下跌倒,造成右胳膊肩肘粉碎性的骨折。医生给打夹板捆扎治疗,整个胳膊吊起来,不许动,不仅是难受,而且疼痛难忍。白天还好过,夜晚睡觉,只能左侧躺,仰卧或翻身都不行。真是一失足跌成夜夜痛。 骨折是右胳膊,人活动最多是靠右手,而手一动就心连心的痛,想拿书报读十分不便,真气煞人。不禁想起南宋大诗人陆游诗云:“儿扶一老候溪边。

Uniaxial compressive behavior of equal channel angular pressing Al at wide temperature and strain rate range

Uniaxial compressive experiments of ultrafine-grained Al fabricated by equal channel angular pressing(ECAP) method were performed at wide temperature and strain rate range. The influence of temperature on flow stress, strain hardening rate and strain rate sensitivity was investigated experimentally. The results show that both the effect of temperature on flow stress and its strain rate sensitivity of ECAPed Al is much larger than those of the coarse-grained Al. The temperature sensitivity of ultrafine-grained Al is comparatively weaker than that of the coarse-grained Al. Based on the experimental results, the apparent activation volume was estimated at different temperatures and strain rates. The forest dislocation interactions is the dominant thermally activated mechanism for ECAPed Al compressed at quasi-static strain rates, while the viscous drag plays an important role at high strain rates.

DIMENSIONLESS ANALYSIS AND LOCATION OF ELECTRIC FIELD INDUCED BY MAGNETIC COIL

A model of magnetic stimulation is presented for analysis of the spatial distributions of the electric field induced by magnetic coils.Dimensionless analysis is introduced and makes the factors influencing the magnitude of electric field into two parts:c (represents the stimulation conditions),and E 0 (reflects the geometry of coil).By 3 D simulation of the induced electric field of two kinds of coils,the effect of magnetic stimulation can be demonstrated and the factors influencing stimulating focality and depth are identified.The principles for determining the electric field magnitude,focality and magnetic stimulation depth when designing a reasonable coil and stimulator and achieving ideal stimulating effect are discussed.

Apoptosis induction with polo-like kinase-1 antisense phosph-orothioate oligodeoxynucleotide of colon cancer cell line SW480

AIM： To investigate the effects of polo-like kinase-1 （PLK1） antisense phosphorothioate oligodeoxynucleotide （ASODN） on apoptosis and cell cycle of human colon cancer cell line SW480. METHODS： After SW480 colon cancer cells were transfected with PLK1 ASODN, Northern and Western blot analyses were used to examine PLK1 gene expression in cancer cells. We studied apoptosis using terminal uridine deoxynucleotidyl nick end labeling. Apoptosis and cell cycle of SW480 cells were examined by fluorescence-activated cell sorter scan. RESULTS： The levels of PLK1 mRNA and protein were greatly inhibited by PLK1 ASODN in SW480 cancer cells transfected with PLK1 ASODN. Apoptosis index （AI） induced PLK1 ASODN in a time- and dose-dependent manner. Results from FLM showed that sub-2N DNA content of transfected cancer cells was significantly increased and arrested at G2/M compared with control groups. CONCLUSION： PLK1 ASODN can induce apoptosis of human colon cancer cell line SW480.

Sensory-motor responses to mechanical stimulation of the esophagus after sensitization with acid

AIM: Sensitization most likely plays an important role in chronic pain disorders, and such sensitization can be mimicked by experimental acid perfusion of the esophagus.The current study systematically investigated the sensory and motor responses of the esophagus to controlled mechanical stimuli before and after sensitization.METHODS: Thirty healthy subjects were included.Distension of the distal esophagus with a balloon was performed before and after perfusion with 0.1 mol/L hydrochloric acid for 30 min. An impedance planimetry system was used to measure cross-sectional area,volume, pressure, and tension during the distensions. A new model allowed evaluation of the phasic contractions by the tension during contractions as a function of the initial muscle length before the contraction (comparable to the Frank-Starling law for the heart). Length-tension diagrams were used to evaluate the muscle tone before and after relaxation of the smooth muscle with butylscopolamine.RESULTS: The sensitization resulted in allodynia and hyperalgesia to the distension volumes, and the degree of sensitization was related to the infused volume of acid. Furthermore, a nearly 50% increase in the evoked referred pain was seen after sensitization. The mechanical analysis demonstrated hyper-reactivity of the esophagus following acid perfusion, with an increased number and force of the phasic contractions, but the muscle tone did not change.CONCLUSION: Acid perfusion of the esophagus sensitizes the sensory pathways and facilitates secondary contractions.The new model can be used to study abnormal sensorymotor mechanisms in visceral organs.

Automatic separation system for marine meiobenthos based on laser-induced fluorescence technology

An automatic system for marine meiobenthos separation was developed by using laser-induced fluorescence tech- nology. Rose Bengal was used as organism dye and the spectrums of Rose Bengal were measured. Laser-induced fluorescence system was established to detect marine meiobenthos in sediments. Data obtained from experiments were analyzed by using a mathematical model. The results showed that laser-induced fluorescence technology worked well in the system. The system could select the meiobenthos efficiently and precisely.

Effect of Fe content on microstructure and mechanical properties of Cu-Fe-based composite coatings by laser induction hybrid rapid cladding

To select the proper composition and obtain an overall material?microstructure?property relationship for Cu?Fe alloy, theeffect of Fe content on microstructure and properties of Cu?Fe-based composite coatings by laser induction hybrid rapid claddingwas investigated. Microstructure characterization of the composite coatings was tested utilizing SEM, XRD and EDS. Microhardnessmeasurement was executed to evaluate the mechanical properties of the composite coatings. The results show that for low Fe content,the composite coating presents a feature that Fe-rich equiaxed dendrites are embedded in the Cu-rich matrix. With increasing Fecontent, the Fe-rich particles are dispersed in the Cu-rich matrix. With further increasing Fe content, large amounts of Cu-richparticles are homogeneously dispersed in the interdendrite of the Fe-rich matrix. Correspondingly, the average microhardness of thecomposite coatings increases gradually with the increase of Fe content and the microhardness of Cu14.5Fe83Si2C0.5 coating is muchtwice higher than that of the substrate.

Pressure-Induced Shifts of R1 and R2 Lines of YAG：Cr3＋

By means of improved ligand-field theory, the ＂pure electronic＂ pressure-induced shifts （PS＇s） and the PS＇s due to electron-phonon interaction （EPI） of R1 line and R2 line of YAG：Cr^3＋ have been calculated, respectively. The calculated results are in very good agreement with the experimental data. It is demonstrated that the admixture of │t^2 2（^3T1）e^4T2〉 and │t^3 2 ^2E〉 bases in the wavefunction of RI level of YAG：Crs＋ and its change with pressure play a key role for the PS of RI line. The behaviors of the ＂pure electronic＂ PS of RI line and the PS of RI line due to EPI are different. It is the combined eEect of them that gives rise to the total PS of R1 line, which has satisfactorily explained the experimental results. The systematic analyses and comparisons between the feature of R1-line PS of YAG：Cr^3＋ and the ones of three laser crystals （GSGG：Cr^3＋, GGG：Cr^3＋ and ruby） have been made, and the origin of the difference between them has been revealed.

A Magnetic Induction Tomography System for Prospective Industrial Processing Applications

Magnetic induction tomography(MIT) is one of the newest industrial process imaging techniques.Main industrial applications of the MIT imaging are in high conductive flow imaging.However,recently it has been shown that the MIT may be useful for low conductive process imaging.This paper presents a cost effective hardware design for MIT in industrial applications,called Bath-MKI industrial MIT system.The system comprises 8 inductor coils and has the possibility of expansion to 16 coils.The excitation signals and the measured voltages are generated and measured using a LabView based system.Two 16 by 1 multiplexers are used to select between the coils.Measurements,excitation and multiplexing are all controlled by a National Instrument(NI) USB based DAQ:USB-6259 and a signal generator.Using the same electronics,the prototype is tested with two different coil arrays;one is a small scale ferrite core coil and one larger scale air cored coil.Experimental image reconstruction results are shown using both small scale and large scale coil arrays.

Effect of processing parameters on flow behaviors and microstructure during high temperature deformation of GH4586 superalloy

The apparent activation energy for deformation(Q)and strain rate sensitivity(m)of GH4586 superalloy are calculated and the variation trend is reasonably explained by the microstructure observations.Constitutive modelling of this superalloy is established and the processing maps at different strains are constructed.The results show that the Q value is in the range of 751.22−878.29 kJ/mol.At a temperature of 1060°C,strain rate of 0.001 s^(−1),and strain of 0.65,the m value of GH4586 superalloy reaches a maximum of 0.42.The optimal processing parameter of GH4586 superalloy is at a deformation temperature of 1050°C and a strain rate of 0.001 s^(−1).The domains of flow instability notably expand with increasing strain during high temperature deformation of GH4586 superalloy.

Studies of Stability in Electrical Property and Sensitivity of Polypyrrole Conductive Fabrics Used for Intelligent Flexible Sensors

Electrically conducting fabrics used as flexible sensors can be produced by vacuumed vapor deposition.The research of what impacts the wide and reliable application of the flexible sensors shows that the stability of flexible sensors is one of the critical issues.The electrical performance of weft knitted fabrics in course and wale direction does not show significant differences under different ambient conditions,which include time,temperature,and relative humidity.Tests of stimuli responding sensitivity of conductive fabrics indicate that the sensitivity keeps at a constant level and the average sensitivity is stable over 38 days.

Propagation of Light in an Ensemble of Tripod Level Atoms

We study the propagation of a quantum probe light in an ensemble of tripod level atoms when the atoms are coupled to two other classical control fields. First we calculate the dispersion properties, such as susceptibility and group velocity, of the probe light within such an atomic medium under the case of three-photon resonance via the dynamical algebra method of collective atomic excitations. Then we calculate the dispersion of the probe light in the case that two classical control fieMs have the different detunings to the relative atomic transitions. Our results show that in both cases the phenomenon of electromagnetically induced transparency can occur. Especially under the second case, we can find two transparency windows for the probe light.

Fructose-1,6-diphosphate-added total parenteral nutrition in septic animals and stressed patients

Objective To investigate the roles of fructose-1,6-diphosphate(FDP)-added total parenteral nutrition (TPN)in septic animals and stressed patients.Methods Thirteen adult dogs were randomly assigned to one of two study groups 6 hours after the induction of severe intra-abdominal infection.Group TPN(n =6)received 70 kcal· kg-1· d-1 of nonprotein calorie(NPC)and 0.56 g· kg-1· d-1 of nitrogen.1 g/kg of FDP was also infused to the animals in group TPN + FDP(n = 7)everyday.In the clinical study,the control group received routine TPN,while the study group(n = 16)was treated with TPN plus FDP(5 g,two times a day)for 7 days.Results In dogs with TPN support,plasma ATP levels were not changed significantly,while the value in the TPN + FDP group increased significantly from 0.18 μmol/L to 0.46 μmol/L at 24 h and 0.51 μmol/L at 48 h(P ＜ 0.01).Muscular ATP increased markedly in the TPN + FDP group.Muscular creatine phosphate alues were not significantly changed in the TPN group,but the values increased in the TPN + FDP group from 4.06 μmol/g·wt at the beginning to 4.93 μmol/g· wt at 24 h and 5.60 μmol/g·wt at 48 h(P ＜ 0.05),with a cytochrome oxidase increase in immunohistochemistry stain.In the clinical study,plasma ATP levels increased and urinary 3-methylhistidine production significantly decreased with an improved value for positive accumulative nitrogen balance in the FDP-infused group.Conclusion Our results suggest that total parenteral nutrition support with the supplement of fructose-1,6-diphosphate has a positive role in body energy production and protein metabolism in septic animals and stressed patients.

平遥辅佐京城、汇通天下

平遥之为金:五行与身体器官的对应 中,金主呼吸系统,在五行之性中,金 主义,其性刚,其情烈,金盛之人为人 刚毅果断,疏财仗义,深知廉耻。在很 长的时间里,平遥就是一个巨大的呼 吸系统,吞吐着天下财富,而这个系统 中的“喉舌”,就是票号。

Characteristics of the induced voltage between deep brain stimulation(DBS) device electrodes by a transcranial magnetic stimulation(TMS) device

The combination of deep brain stimulation(DBS) and transcranial magnetic stimulation(TMS) is expected to provide additional insights into the pathophysiology of some brain diseases. However, when using TMS in patients with DBS implants, the induced voltage between DBS electrodes presents the greatest risk of brain damage. This paper describes the characteristics of the induced DBS electrode voltage due to TMS. We first examined the TMS stimulus signal and the DBS output impedance characteristics, and then experimentally investigated the induced DBS electrode voltage for various DBS and TMS conditions. The results show that many factors impact the induced electrode voltage. The induced electrode voltage with DBS device working in the unipolar mode is greater than that with DBS device working in the bipolar mode. No matter DBS device is turned on or turned off, the induced electrode voltage is almost the same, but it can provide a significant addition to the original stimulus waveform. There are no significant differences in the induced DBS electrode voltage when the DBS system is working at different stimulus intensities. Lowering the TMS stimulus intensity could effectively reduce the induced DBS electrode voltage. The induced electrode voltage is also strongly related to the position of the TMS coil relative to the DBS lead. This study provides further information about the characteristics of the induced DBS electrode voltage in TMS applications and a reference for the combined use of DBS and TMS.

Application of fiber Bragg grating based strain sensor in pipeline vortex-induced vibration measurement

The vortex-induced vibrations(VIV)is an important topic of study in many different scientific and engineering fields.While VIV can be of benefit in some cases,oftentimes,it is an undesirable phenomenon that can be quite dangerous.In particular for offshore pipelines,VIV can lead to fatiguing of the pipe structure and can cause disastrous consequences if left unchecked.A number of different methods have been applied to the measurement of VIV,especially for the elongated,thin cylindrical structures.The use of fiber optic fiber Bragg gratings(FBGs)in particular has gained popularity over the recent years due to their distinct properties.However,FBGs are also very fragile and are susceptible to failure when placed in harsh environments without protection.In this paper,56 FBGs encapsulated in stainless steel tubes were applied to the measurement of VIV in a28-m model pipeline under controlled and uncontrolled conditions.Tests show that the encapsulated sensors possessed good sensitivity as well as fatigue life(>80000 cycles).The measurements from FBGs were also high enough to allow frequency domain analysis of the pipeline VIV under the two conditions.The authors conclude that the encapsulated FBGs are a viable tool for the study of VIV in pipeline structures.

Laser beam induced current microscopy and photocurrent mapping for junction characterization of infrared photodetectors

For non-destructive optical characterization, laser beam induced current(LBIC) microscopy has been developed into as a quantitative tool to examine individual photodiodes within a large pixel array. Two-dimensional LBIC microscopy, also generally called photocurrent mapping(PC mapping), can provide spatially resolved information about local electrical properties and p-n junction formation in photovoltaic infrared(including visible light) photodetectors from which it is possible to extract material and device parameters such as junction area, junction depth, diffusion length, leakage current position and minority carrier diffusion length etc. This paper presents a comprehensive review of research background, operating principle, fundamental issues, and applications of LBIC or PC mapping.