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Coupled Optical Solitons for Pulse Propagation in Multi-Level Media

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Chinese Physics Letters 2006年第4期23卷 834-837页

作者：黄国翔 jacob Szeftel Department of Physics East China Normal University Shanghai 200062 Laboratoire de Photonique Quantique et Moleculaire Ecole Normale Superieure de Cachan Cachan France

We investigate the shape-preserving propagation of N optical pulses in an （N ＋ 1）-level medium. We solve Maxwell-Schroedinger equations exactly and provide several types of explicit coupled soliton solutions, which... 详细信息

关键词： ELECTROMAGNETICALLY INDUCED TRANSPARENCY SELF-INDUCED TRANSPARENCY COLD3-STATE MEDIUM SLOW-LIGHT ULTRASLOW BRIGHT 3-LEVEL MEDIUM DARK SOLITONS LASER AMPLIFICATION QUANTUM

Prediction of Hydrothermal Copper, Gold, Silver and Lead-Zinc in Northwestern Yunnan Using Weight of Evidence Model

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Geo-Spatial Information Science 2005年第3期8卷 230-234页

作者： jacob Kporfor Institute of Geomatics and Information Technology Stale Laboratory for Earth Probe & Remote Sensing China University of Geosciences Wuhan 430074 China

This paper discusses the application of the model in predicting for hydrothermal Cu, Ag, Au and Pb-Zn occurrences in northwestern Yunnan. Geochemical, lineament and lithology data were the selected recognition criteria. The mentioned criteria varied against 75 known hydrothermal occurrences; the geochemical data had a weight of （W^＋= 1. 209 7, W^- =-0. 748 1） being the maximum among the three and the rest lineament and lithology have （W^＋= 0.7424, W^-= -0.449 6）, （W^＋= 0.378 7,W^-=-0.6243） respectively. The application was successful since the predicted results covers about 70% of the known deposits and predicted unknown areas.

关键词： weight of evidence favorability maps hydrothermal mineral occurrences conditional independence and exploration

Investigation on the freeze-thaw damage to the jointed plain concrete pavement under different climate conditions

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Frontiers of Structural and Civil Engineering 2018年第2期12卷 227-238页

作者： Shuaicheng GUO Qingli DAI jacob HILLER Department of Civil and Environmental Engineering Michigan Technological University 1400 Townsend Drive Houghton MI49931-1295 USA

Freeze-thaw damage is one of the main threats to the long time performance of the concrete pavement in the cold regions. This project aims to evaluate the influence of the freeze-thaw damages on pavement distresses under different climate conditions. Based on the Long-Term Pavement Performance （LTPP） data base, the freeze-thaw damage generated by four different kinds of climate conditions are considered in this project： wet-freeze, wet-non freeze, dry- freeze and dry-non freeze. The amount of the transverse crack and the joint spalling, along with the International Roughness Index （IR/） are compared among the test sections located in these four different climate conditions. The back calculation with the Falling Weight Deflectometer （FWD） test results based on the ERES and the Estimation of Concrete Pavement Parameters （ECOPP） methods are conducted to obtain concrete slab elastic modulus and the subgrade k-value. These two parameters both decrease with service time under freeze condition. Finally, MEPDG simulation is conducted to simulate the IR/development with service year. These results showed the reasonable freeze-thaw damage development with pavement service life and under different climate conditions.

关键词： LTPP elastic modulus k-value IRI MEPDG

Adsorption kinetics of the herbicide safeners,benoxacor and furilazole,to activated carbon and agricultural soils

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Journal of Environmental Sciences 2020年第3期32卷 23-34页

作者： Saraswati Poudel Acharya jacob Johnson Jennifer Weidhaas Civil and Environmental Engineering University of UtahSalt Lake CityUTUSA Center for Science and Mathematics Education University of Utah155 South 1452 EastSalt Lake CityUT 84112USA

Chloroacetamide herbicides,namely acetochlor and metolachlor,are common herbicides used on corn and soybean *** safeners,namely benoxacor and furilazole,are commonly used in formulations containing chloroacetamide *** reports on adsorption of chloroacetamide herbicides are available,yet little information exists regarding adsorption potential of co-applied ***,the adsorption and desorption characteristics of selected herbicide safeners to granular activated carbon(GAC) and in agricultural soils are ***,soil column studies were performed to understand the leaching behaviour of the herbicide Dual II *** sorption experiments of safeners to three agricultural soils and one GAC showed that adsorption was best fitted by the Freundlich *** Freundlich adsorption constant,Kf,for benoxacor and furilazole sorption onto three agricultural soils ranged from0.1 to 0.27 and 0.1 to 0.13(mg/g) x(mg/L)(1/n),*** Kf for benoxacor and furilazole to GAC was 6.4 and 3.4(mg/g) x(mg/L)(1/n),respectively,suggesting more favorable sorption of benoxacor to GAC than furilazole to *** sorption to soils was reversible as almost 40%-90% of both safeners was desorbed from three *** results were validated in four replicated soil column studies,where S-metolachlor was shown to leach similarly to the safener benoxacor,originating from the herbicide *** leaching of S-metolachlor and benoxacor was influenced by soil ***,these results show that safeners will move through the environment to surface waters similarly to the active ingredients in herbicides,but may be removed during drinking water treatment via GAC.

关键词： Herbicide safener Dual Ⅱ magnum Adsorption Granular activated carbon Soil column transport

Effects of irrigation and weed-control methods on growth of weed and rice

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International Journal of Agricultural and Biological Engineering 2014年第5期7卷 22-33页

作者： jacob Jeremiah Towa Guo Xiangping Key Laboratory of High-Effective Irrigation and Drainage and Agricultural Water and Soil Environment in Southern China Ministry of EducationHohai UniversityNanjing 210098China Irrigation and Technical Services Division Ministry of AgricultureFood Security and CooperativeDar es Salaama9192Tanzania

A field experiment was conducted to study the effects of weeds control methods and an irrigation model on rice growth as well as water consumption and weed quantity in the paddy *** conventional paddy rice production,one of the most important irrigated crops,a significant amount of irrigation water is lost due to percolation and evaporation.A new irrigation model called the Rain-Catching and Controlled Irrigation(RCCI)model has been developed as a viable water-saving technology in the production of paddy *** this study the performance of the RCCI model has been analyzed under mulching,hand weeding and weedy conditions in Jiangsu Province of *** experiment was laid out in Randomized Complete Block Design(RCBD)with three replications and nine *** three replicates consisted of three water management regimes:high dry high flooding(HD-HF),high dry low flooding(HD-LF),and shallow and frequent irrigation(SF)water *** RCCI model was adopted in HD-HF and HD-LF while Flooding Irrigation(CFI)was adopted in SF as a *** nine treatments were equally divided under mulching,hand weeding and weedy *** lowest and maximum irrigation water delivery was 244.86 mm in mulching and 429.22 mm in hand weeding,respectively at *** the lowest and maximum irrigation water delivery was 300.1 mm in the mulching field and 680.72 mm under hand weeding,respectively at *** Nanjing 44 rice variety was *** was observed that weed density and dry weight were significantly influenced by the amount of irrigation water in all the mulching,hand weeding and weedy *** yield and the number of irrigations,the RCCI model produced better results than *** under RCCI was an effective method to control weeds and reduce labor *** addition,mulching decreases the use of herbicides and the risk of *** the other hand,mulching could improve yield and save water.

关键词： irrigation weed control mulching hand weeding RCCI weed population agronomy traits paddy rice

Ecological correlates of sport and exercise participation among Thai adolescents:A hierarchical examination of a cross-sectional population survey

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Journal of Sport and Health Science 2023年第5期12卷 592-605页

作者： Areekul Amornsriwatanakul Leanne Lester Fiona C.Bull Michael rosenberg College of Sports Science and Technology Mahidol University999 Phutthamonthon Sai 4 SalayaPhutthamonthon DistrictNakhon Pathom 73170Thailand School of Human Sciences(Exercise and Sport Science) The University of Western Australia35 Stirling HighwayNedlandsPerthWA 6009Australia Centre for Built Environment and Health School of Human SciencesThe University of Western Australia35 Stirling HighwayNedlandsPerthWA 6009Australia

Background:Understanding factors influencing adolescents’ sport/exercise participation(S/EP) is vital to developing effective interventions,but currently,evidence from less developed countries is *** purpose of this study was to examine correlates of S/EP across individual,interpersonal,and environmental levels in a nationally representative sample of Thai ***:Data from 4617 Thai adolescents aged 14-17 years old were obtained from recruited schools across *** on S/EP(outcome variable),and psychosocial,home,and community environment covariates were collected from individual adolescents using the Thailand Physical Activity Children Survey,Student *** environmental data were collected at the school level using a School Built Environment *** regressions taking into account school clustering effects were applied for data ***:At the individual level,age and body mass index were independently and strongly correlated with S/*** with high preference for physical activity(PA)(odd ratio(OR)=1.71,p 3 types of parental support(OR=1.43,p=0.005) and who received siblings’(OR=1.26,p=0.004) and friends’(OR=1.99,p <0.001) support had a greater chance of high S/*** the environmental level,adolescents’ S/EP was greater when there were at least 3-4 pieces of home sport/exercise equipment(OR=2.77,p=0.003),grass areas at school(OR=1.56,p <0.001),and at least 1-2 PA facilities in the community(OR=1.30,p=0.009).Conclusion:Multiple factors at different levels within an ecological framework influencing Thai adolescents’ S/EP were generally similar to those found in developed countries,despite some *** those interested in promoting and supporting Thai adole

关键词： National survey Noncommunicable diseases Physical activity Policy Thailand youthTagedEnd

Experimental and finite element analysis on determining the fatigue life of pb-free solder joint(Sn-0.5Cu-3Bi-1Ag)used in electronic packages under harmonic loads

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International Journal of Modeling, Simulation, and Scientific Computing 2020年第3期11卷 60-67页

作者： Jayesh S jacob Elias Department of Mechanical Engineering School of Engineering Cochin University of Science and Technology KochiKerala-682022India

Electronic packages that are used these days are exposed to different types of vibration loadings in their usage *** vibration exposure can be categorized as harmonic and random *** reliability assessment of modern electronic systems is considered,vibration loading has an important role to *** of the biggest challenges facing today is the accurate and rapid assessment of fatigue life under the vibration *** solder joints were made of lead-tin *** to many environment legislations and rules,lead is prohibited as an ingredient in the solder *** reason for the prohibition of the usage of the lead is that it poisons the *** this study,Sn-0.5Cu-3Bi-1Ag is used as the lead-free solder *** life prediction of electronic package containing SAC405 is conducted with the aid of vibration testing and Finite element analysis under harmonic vibration loading.A specially designed Plastic Ball Grid Array Package(PBGA)component is mounted on Printed Circuit Board(PCB).It is taken as a test vehicle for the vibration *** test vehicle is excited by a sinusoidal *** frequency of this excitation equals the fundamental frequency of the test vehicle and it is continued till the component *** the solder balls are very small for direct measurement,Finite Element analysis(FEA)is used for noting down the *** stress versus failures cycles(S-N)curve is made by relating both the stresses on the solder balls obtained and the number of failure cycles from vibration *** fatigue life of the component can be estimated from the generated S-N *** is analyzed that the methodology is effective in predicting the component’s ***,the reliability of electronic package can be improved.

关键词： PCB lead free solder joint FEA PBGA S-N curve

A review of late-stage tungsten fuzz growth

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Tungsten 2022年第3期4卷 184-193页

作者： jacob A.R.Wright Department of Materials Science and Metallurgy University of CambridgeCambridgeCB30FSUK

Tungsten will be used as the plasma-facing divertor material in the International Thermonuclear Experimental Reactor(ITER)fusion *** high temperatures and high ion fluxes,a‘fuzz’nanostructure forms on the tungsten surface with dramatically different properties and could contaminate the *** simulations and experimental observations have provided understanding of the initial fuzz formation process,there is debate over whether tungsten or helium migration is rate-limiting during late-stage growth,and the mechanisms by which tungsten and helium migrations ***,the proposed mechanisms are considered in *** is concluded that tungsten migration occurs by adatom diffusion along the fuzz *** helium migration through the porous fuzz to the tungsten bulk is also required for fuzz growth,for continued bubble growth and *** likely migrates due to ballistic penetration,although diffusion may *** is difficult to determine the limiting process,which may switch from helium penetration to tungsten adatom diffusion above a threshold *** for further research to clarify the mechanisms are then considered.A greater understanding of the fuzz formation mechanism is key to the successful design of plasma-facing tungsten components,and may have applications in forming porous tungsten catalysts.

关键词： Tungsten Tungsten fuzz Plasma-material interactions Fusion reactors

An Iterative Pose Estimation Algorithm Based on Epipolar Geometry With Application to Multi-Target Tracking

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IEEE/CAA Journal of Automatica Sinica 2020年第4期7卷 942-953页

作者： jacob H.White Randal W.Beard the Brigham Young University ProvoUtah 84058 USA

This paper introduces a new algorithm for estimating the relative pose of a moving camera using consecutive frames of a video sequence. State-of-the-art algorithms for calculating the relative pose between two images use matching features to estimate the essential matrix. The essential matrix is then decomposed into the relative rotation and normalized translation between frames. To be robust to noise and feature match outliers, these methods generate a large number of essential matrix hypotheses from randomly selected minimal subsets of feature pairs, and then score these hypotheses on all feature pairs. Alternatively, the algorithm introduced in this paper calculates relative pose hypotheses by directly optimizing the rotation and normalized translation between frames, rather than calculating the essential matrix and then performing the decomposition. The resulting algorithm improves computation time by an order of magnitude. If an inertial measurement unit(IMU) is available, it is used to seed the optimizer, and in addition, we reuse the best hypothesis at each iteration to seed the optimizer thereby reducing the number of relative pose hypotheses that must be generated and scored. These advantages greatly speed up performance and enable the algorithm to run in real-time on low cost embedded hardware. We show application of our algorithm to visual multi-target tracking(MTT) in the presence of parallax and demonstrate its real-time performance on a 640 × 480 video sequence captured on a UAV. Video results are available at https://***/Hh K-p2 h XNn U.

关键词： Aerial robotics epipolar geometry multi-target tracking pose estimation unmanned aircraft systems vision-based flight