定挂玉钩 推转冰轮——访烟台冰轮集团董事长于元波

宋代大诗人陆游在《月下作》中写下了“玉钩定谁挂,冰轮了无辙”这一烩炙人口的诗句。 40多年来,冰轮集团经过几代人的努力,已从一个只能修修补补的小铁工厂发展成为今天技术装备精良。

他的岗位不仅在医院——记肇庆市人大代表黄元波

黄元波代表是高要市人民医院院长、党支部书记。从1993年当选为肇庆市八届人大代表的那一天起,黄元波就懂得,自己的岗位不仅仅在医院,同时也是在人民当中。他对自己提出了要求,既要当好院长,又要当好代表,尽职尽责,一言一行,无愧于党和人民。黄元波时刻不忘自己的身份。平时在医院,通过同医务人员和病人交谈。

渠道中涨落水时的测流分析

渠道正常供水时 ,上游调度影响下游分干渠流量的变化 ,从而影响测流的准确性 ,造成用水方与管水方的分歧。为了解决这个问题 ,首先分析了恒定流情况下涨水的流动分析 ,并得出了涨水时的沿程流速分布图。以此为基础 ,通过非恒定流缓慢涨水时的水力状态分析 ,得出结果 :距涨水源远的渠道沿程断面涨水流速与相同水深的恒定流具有相同流速。结论 :涨水时可以测流 。

LEAD SCREW LINEAR ULTRASONIC MOTOR USING BENDING VIBRATION MODES

The operating principle of a lead screw linear ultrasonic motor using bending vibration modes is analyzed. The simplified beam bending vibration model is used to analyze the dynamics characteristics of the motor. Motion trajectory equations are derived for driving points of the stator. The motor operation and driving mechanisms are investigated. The vibration modes and the construction of the motor are analyzed by using the finite element method （FEM）. A prototype motor is built and its stator dimension is 13 mm × 13 mm× 30 mm. The motor is experimentally characterized and the maximum output force of 5- 2 N is obtained.

断波及其在上荆江河段传播特性研究

三峡水库投入运行后,其下游荆江河段洪水传播特性发生了一系列变化,主要表现为洪水传播时间明显缩短。通过建立荆江河段水力学模型,对比分析不同类型洪水波的水力要素,模拟分析水库不同泄流条件时洪水波传播特性,揭示了水库调度对洪水波的影响规律。研究表明:洪水在荆江河段传播时间缩短的主要原因是洪水波波型的改变;当三峡水库下泄流量在较短时间内出现较大变化时,洪水波在荆江河段不同范围、不同程度地表现为断波特性;相同条件时,断波流量越大、维持时间越长,以断波特性向下游演进的距离越远,洪水传播时间缩短现象越明显。

Determination of Heavy Metals in Dendrobium candidium Wall.ex Lindl.by ICP-MS

[Objective] This research aimed to establish an inductively coupled plasma mass spectrometry （ICP-MS） method for determination of five kinds of heavy metals （Pb, Cd, Cu, As and Hg） in Dendrobium candidium Wall. ex Lindl. [Method] The samples were digested in HNO3-H202 acids system by closed vessel microwave di- gestion. At the same time, internal standard was added to avoid the matrix effect. [Result] The five kinds of heavy meals all showed good linear relationships, and the correlation coefficients ranged from 0.998 2 to 0.999 9. The detection limits of the five kinds of heavy metals were in the range of 0.008-0.750 μg/L, while the stan- dard recovery rates were in the range of 90.4%-96.9%. The relative standard devi- ations ranged from 1.6% to 8.2%. The heavy metals in the Ginseng and Astragalus national standard samples were determined by the established ICP-MS method, and the results were in conformity with the standard values. [Conclusion] The established method has simple and convenient operation and accurate and reliable results, and it meets the requirements by determination of heavy metals in Dendrobium candididium Wall. ex Lindl.

Wavefield simulation in porous media saturated with two immiscible fluids

Wavefields in porous media saturated by two immiscible fluids are simulated in this paper.Based on the sealed system theory,the medium model considers both the relative motion between the fluids and the solid skeleton and the relaxation mechanisms of porosity and saturation（capillary pressure）.So it accurately simulates the numerical attenuation property of the wavefields and is much closer to actual earth media in exploration than the equivalent liquid model and the unsaturated porous medium model on the basis of open system theory.The velocity and attenuation for different wave modes in this medium have been discussed in previous literature but studies of the complete wave-field have not been reported.In our work,wave equations with the relaxation mechanisms of capillary pressure and the porosity are derived.Furthermore,the wavefield and its characteristics are studied using the numerical finite element method.The results show that the slow P3-wave in the non-wetting phase can be observed clearly in the seismic band.The relaxation of capillary pressure and the porosity greatly affect the displacement of the non-wetting phase.More specifically,the displacement decreases with increasing relaxation coefficient.

A Novel Matched Filter Structure with Neuron MOS Devices

Based on the principle of the neuron MOS device,a novel matched filter structure which is easily realized by neuron MOS is presented and the details of circuit performance is analyzed.Compared to the conventional structure,the number of circuit elements is decreased greatly for the same function.The test chip is fabricated in 0.35μm process,and the measured result shows that the system structure is feasible and effective.

The Determination of Heavy Metal Elements in Honey by MWD-ICP-AES

In order to build method for measuring of elements in honey, the contents of Ba, Cu, Pb, Cd, As, Hg, Cr, Mn, Se had been determined by microwave diges- tion （MWD） and actively coupled plasma atomic emission spectrometry （ICP-AES）. The results show that, the range of heavy metal elements were in the range of 0- 10.0 mg/L, with good linear relationship. In addition, all correlation coefficients kept higher than 0.999, and the recovery rate of ample added with standard solution was in 94.1%-110%. By comparison with the result of chemical experiment, the method was quickly accessible and convenient, widely used in the measurement of elements in honey, with satisfactory results.

NUMERICAL MODEL OF WAVE FORCES ON CONTINUOUS CYLINDER STRUCTURES

A numerical model of wave force upon continuous cylinder structures with a large diameter using the boundary element method (BEM) is presented. A numerical model of reflecting wave upon continuous cylinders was established on the basis of linear wave theory.The fundamental solution to the Helmholtz equation within an infinite strip area that explicitly satisfies two infinite parallel boundaries is used together with Radiation condition rather than the solution of an infinite area.According to the proposed theory and method,the computer programs have been composed in Visual C ++ Development Studio.Several examples show that the technique and its program are feasible and efficient.And the wave forces upon continuous cylinders can be decreased by as much as 14%～24% under a ratio of D/L= 0.09～0.19 compared with the square caissons.

WAVE TRANSFORMATION AND BREAKING OVER A RECTANGULAR STEP

An idealized numerical wave flume has been established by finite element method on the bases of Navier Stokes equations through prescribing the appropriate boundary conditions for the open boundary,incident boundary,free surface and solid boundary in this paper.The characteristics of waves propagating over a step have been investigated by this numerical model.The breaker wave height is determined depending on the kinetic criterion.The numerical model is verified by laboratory experiments,and the empirical formula for the damping of wave height due to breaking is also given by experiments.

MULTI-MATERIAL NUMERICAL SIMULATION OF MOVING SHOCK INTERACTING WITH CONSECUTIVE BUBBLES

Numerical simulations are performed on the interface with large deformation induced by the interaction between a moving shock and two consecutive bubbles. The high performance of the level set method for multi-material interfaces is demonstrated. Discontinuous Galerkin finite element method is used to solve Euleri- an equations. And the fifth-order weighted essentially non-oscillatory （WENO） scheme is used to solve the level set equation for capturing multi-material interfaces. The ghost fluid method is used to deal with the interfacial boundary condition. Results are obtained for two bubble interacting with a moving shock. The contours of the constant density and the pressure at different time are given. In the computational domain, three different cases are considered, i.e. two helium bubbles, a helium bubble followed by an R22 bubble in the direction of the moving shock, and an R22 bubble followed by a helium bubble. Computational results indicate that multi-mate- rial interfaces can be properly captured by the level set method. Therefore, for problems involving the flow of three different materials with two different interfaces, each interface separating two different materials can be similarly handled.

Mesh Generation for Finite Element Analysis of Electric Machines

This paper describes two modified methods for triangular and quadrilateral meshing for finite element analysis of 2D electric machines. One is coupling the classic Delaunay method and advancing front method to generate optimal triangulation; the other is coupling the classic paving and Delaunay triangulation for optimal quadrilateral meshing. Various electric machine models are meshed successfully to demonstrate the robustness and effectiveness of the methods.

The Determination of Heavy Metal Elements in Sipunculs nudus by MWD-ICP-AES

In order to develop a method for measuring of elements in Sipunculus nudus, the contents of Cu, Pb, Cd, Cr, Mn, As, Hg and Ba were determined by actively coupled plasma atomic emission spectrometry （MWD） and microwave digestion （ICP-AES）. The results showed that correlation coefficients al kept higher than 0.999 and the recovery rates of sample added standard solutions were in 98%-114%. The results indicated that the contents of Cu, Pb, Cd, Cr, Mn, As, Hg and Ba were 17.119, 3.781, 0.695, 7.351, 1997.982, 0.620, 0.144, 4.249 mg/kg respectively. The contents of Mn exceeded national limit by hundredfold, Cd sevenfold, Pd fourfold, Cd three-and-a-half-fold, and As onefold. Sipunculs nudus became seriously pol uted. Therefore, it is necessary to formulate robust policies to fol ow closely and pay close attention to coastal areas pol ution around Dongfang City.

锦城夜话(5) 重色时代当反思

最近有媒体报道，成都某大学一名男性学生在校园行凶杀人．死伤的同学与他并不相识，更无冤无仇，法官问其行凶原因．他冷静的回答令人十分惊讶。他嫌自己长得太丑，进大学以后．同学们也都不愿跟他相处，

FINITE ELEMENT-ARTIFICIAL TRANSMITTING BOUNDARY METHOD FOR WAVE SCATTERING FROM IRREGULAR CYLINDER

The finite element artificial transmitting boundary method is employed here to treat the near field scattering of a cylindrical wave from an irregular cylinder. A comparison is made between this method and the analytical one. And then examples are given to demonstrate the solution of several problems of the irregular object scattering. The method can not only produce clear physical pictures, but can efficiently handle many complicated scattering problems.

Filter algorithm based on cochlear mechanics and neuron filter mechanism and application on enhancement of audio signals

A filter algorithm based on cochlear mechanics and neuron filter mechanism is proposed from the view point of vibration.It helps to solve the problem that the non-linear amplification is rarely considered in studying the auditory filters.A cochlear mechanical transduction model is built to illustrate the audio signals processing procedure in cochlea,and then the neuron filter mechanism is modeled to indirectly obtain the outputs with the cochlear properties of frequency tuning and non-linear amplification.The mathematic description of the proposed algorithm is derived by the two models.The parameter space,the parameter selection rules and the error correction of the proposed algorithm are discussed.The unit impulse responses in the time domain and the frequency domain are simulated and compared to probe into the characteristics of the proposed algorithm.Then a 24-channel filter bank is built based on the proposed algorithm and applied to the enhancements of the audio signals.The experiments and comparisons verify that,the proposed algorithm can effectively divide the audio signals into different frequencies,significantly enhance the high frequency parts,and provide positive impacts on the performance of speech enhancement in different noise environments,especially for the babble noise and the volvo noise.

Self-contained in situ sediment acoustic measurement system based on hydraulic driving penetration

A novel self-contained in situ sediment acoustic measurement system based on hydraulic driving penetration is proposed to solve the problem of large disturbances to sediments of the in situ equipments already in existence. By using a hydraulic driving device, the system drives four acoustic probes into sediments at an even speed, and this decreases disturbances to sediments introduced by the penetration of acoustic probes. By means of the special design of the central control unit, the system can work full-automatically and the data are stored self-containedly, and this avoids the requirement of real-time remote controlling from the ship. Its operating water depth, measuring depth and measuring frequency is 500m, 1.0m and 30kHz respectively. A set of in situ sound speeds and attenuation coefficients of sediments are obtained at 40 stations using the system. The results confirm that the data obtained by the in situ sediment acoustic system are accurate and credible.

All Single Traveling Wave Solutions to （3＋1）-Dimensional Nizhnok-Novikov-Veselov Equation

Using elementary integral method, a complete classification of all possible exact traveling wave solutions to （3＋1）-dimensional Nizhnok-Novikov-Veselov equation is given. Some solutions are new.

SINS in-Flight Alignment Using Quaternion Error Models

The widely used conventional linearized error models or perturbation models are not effective to represent the nonlinear characteristics of SINS error propagation with large attitude errors.Error equations in terms of quaternion error are derived,and extended Kalman filter techniques are used to solve the in-flight alignment problems.In the case of small attitude errors,the nonlinear models can be reduced to conventional phi-angle models.The simulation results show that the proposed error models may improve the performance of alignment.