Using precise data sets on farming and pesticide properties to verify a diffuse pollution hydrological model for predicting pesticide concentration.

Verification of a diffuse pollution model involves comparing results actually observed with those predicted by precise model inputs. Acquisition of precise model inputs is, however, problematic. In particular, when the target catchment is large and substantial estimation uncertainty exists, not only model verification but also prediction is difficult. Therefore, in this study, rice-farming data were collected for all paddy fields from all farmers in a catchment and pesticide adsorption and degradation rates in paddy field soil samples were measured to obtain precise model inputs. The model inputs successfully verified the model's capability to predict pesticide concentrations in river water. Sensitivity analyses of the model inputs elucidated the processes significantly affecting pesticide runoff from rice farms. Pesticide adsorption and degradation rates of the soil did not significantly affect pesticide concentrations, although pesticide discharge to river water accounted for less than 50% of the total quantity of pesticide applied to fields, possibly owing to pesticide adsorption and degradation. The timing of increases in pesticide concentrations in river water was affected mostly by the farming schedule, including the time of pesticide application and irrigation, and secondarily by rainfall events.     

High-speed and large noise margin tolerance E/D logic gates withLDD structure DMTs fabricated using selective RIE technology

The authors describe a novel design concept for enhancement (E) and depletion (D) mode FET formation using i-AlGaAs/n-GaAs doped-channel hetero-MISFET (DMT) and a novel self-aligned gate process technology for submicrometer-gate DMT-LSIs based on E/D logic gates. 0.5-μm gate E-DMTs (D-DMTs) with a lightly doped drain (LDD) structure show an average V_t of 0.18 (-0.46) V, a V_t standard deviation of 22.6 (24.9) mV, and a maximum transconductance of 450 (300) mS/mm. The V_t shift is less than 50 mV with a decrease in gate length down to 0.5 μm. The gate forward turn-on voltage V_f is more than 0.9 V, i.e. about 1.6 times that for MESFETs. This superiority in V _f, preserved in the high-temperature range, leads to an improvement in noise margin tolerance by a factor of three. In addition, 31-stage ring oscillators operate with a power consumption of 20 (1.0) mW/gate and a propagation delay of 4.8 (14.5) ps/gate. Circuit simulation based on the experimental data predicts 140 ps/gate and 1 mW/gate for DMT direct-coupled FET logic circuits under standard loading conditions. DMTs and the technology developed here are very attractive for realizing low-power and/or high speed LSIs     

Adiabatic shear bands on the titanium side in the titanium/mild steel explosive cladding interface: Experiments, numerical simulation, and microstructure evolution

The microstructure and microtexture in adiabatic shear bands (ASBs) on the titanium side in the titanium/mild steel explosive cladding interface are investigated by means of optical microscopy, scanning electron microscopy/electron backscattered diffraction (SEM/EBSD), and transmission electron microscopy (TEM). Highly elongated subgrains and fine equiaxed grains with low dislocation density are observed in the ASBs. Microtextures (25 deg, 75 deg, 0 deg), (70 deg, 45 deg, 0 deg), and (0 deg, 15 deg, 30 deg) formed within the ASBs suggest the occurrence of the recrystallization. The grain boundaries within ASBs are geometrically necessary boundaries (GNBs) with high angles. Finite element computations are performed to obtain the effective strain and temperature distributions within the ASBs under the measured boundary conditions. The rotation dynamic recrystallization (RDR) mechanism is employed to describe the kinetics of the nanograins’ formation and the recrystallized process within ASBs. During the deformation time (about 5 to 10 μs), the following processes take place: dislocations accumulate to form elongated cell structures, cell structures break up to form subgrains, and subgrains rotate and finally form recrystallized grains. The small grains within ASBs are formed during the deformation and do not undergo significant growth by grain boundary migration after deformation.     

广水市:一盘棋规划 "两线一片"推进

广水市位于湖北省东北部，地处大别山与桐柏山交汇处南麓，地跨长江、淮河两大流域，国土面积2647km^2,是湖北省38个山区县市之一。     

Reliability Modeling and Analysis of Communication Networks with Dependent Failures

This paper presents a new model to study the reliability of communication networks in which link failures are statistically dependent. The approach tries to identify and model explicitly the events that cause communication link failures. No conditional probabilities are needed, and so two major difficulties inherent to them, namely, an exponential number of conditional probabilities to deal with and a consistency requirement to satisfy, are avoided. For reliability computations, some existing algorithms for finding network reliability can be used with minor modifications and no significant increase in computational complexity.     

Finite element formulation by parametrized hybrid variational principles: Variable stiffness and removal of locking

In this paper, a new one-parameter hybrid functional is obtained as a special case of Felippa and Militello's parametrized variational principles. The functional contains stress, strain and compatible displacement as the primary fields. It will be proved that some of the existing variable stiffness formulations fall into the framework of the new functional. Novel applications of the functional are also suggested, mainly for removal of locking. Solid element, destabilized 8-node and stabilized 9-plate elements are designed. All of them can handle thin plate/shell analysis. In particular, a prominent method is devised for constructing stabilization vectors. The vectors are explicit linear functions of the nodal coordinates and can be implemented without resorting to Gram–Schmidt orthogonalization or numerical integration. Results of the new elements in popular benchmark tests are encouraging.     

Characterization of Al-doped n-type ZnSe prepared under a zinc-rich growth condition by low-pressure organometallic chemical vapor deposition

High conductivity n-type ZnSe with = 0.01 ωcm and n = 2.4 × 10¹⁸ cm⁻³ is obtained on (100) GaAs substrates by low pressure organometallic chemical vapor deposition. The 14 meV full width at half maximum of the 77 K photoluminescence near-band-edge emission shows a high quality of as-grown Al-doped ZnSe epilayers. With a suitable Al doping level, a strong photoluminescence intensity of near-band-edge emission is obtained. The behavior of near-band-edge emission and of self-activated emission related to the incorporation of aluminum are discussed in this paper.     

The dominance of the K I-field for a crack under stress wave loading

The extent of the dominant singular field is investigated for a finite crack under stress wave loading. Using a boundary integral equation method the complete solution as well as the near field solution is determined. A comparison of the two fields indicates that the singular field dominates within a small domain at the crack tip. The size of the dominance region in the dynamic case may be very different from that in the static case.