水橇在涌浪运动中诱振及其设计时的附加载荷

本文研究水橇及其有关构件在涌浪作用下的动响应及其在设计时的附加动载荷，推导出水橇的动力学方程，并进行分析计算，阐明水橇及其有关构件在涌浪作用下的周期性载荷，为其结构设计提供依据。

湖南稻鸭生态种养与频振式诱蛾灯技术示范成效与技术

湖南省近年试验示范推广的安全卫生优质食用稻米生产技术———稻鸭生态种养与频振式诱蛾灯技术 ,鸭子为水稻除草、治虫、中耕、施肥 ,稻田为鸭子提供大部分饲料 ,频振式诱蛾灯诱杀成虫 ,减少虫口基数 ,这样既增加了稻米产量和鸭子数量 ,又大幅度减少了农药、化肥、除草剂等的用量 ,减少了污染 ,降低了生产成本 ,提高了种稻效益 ,提高了稻米安全卫生品质。平均每季每667m2 纯收入增加162元。饲养蛋鸭,全年每667m2增纯收入达403元。

植保“三诱”技术应用研究

介绍广西隆安县大力推广"三诱"技术,即频振诱控技术、生态粘虫板诱杀技术、性信息素诱杀技术取得的显著成效,并对"三诱"技术在县域农业经济中的发展前景进行初步探讨,以促进"三诱"技术的推广应用。

昆虫带电特性及影响因子

本文对大袋蛾等昆虫的带电特性进行了定量测量 ,同时 ,由昆虫自身带电和与环境相互作用带电分析 ,给出了昆虫自身带电的分形特性。测定了在不同介质上静止爬行和振翅对大袋蛾雄蛾带电量。

重大农业害虫频振诱控技术研究与应用

频振诱控技术是根据重大农业害虫趋光、趋波特性而开发的以频振杀虫灯为核心的害虫诱控技术。经过15年的研究开发与推广应用,该技术逐步解决和提高了使用安全性、诱集选择性、诱控高效性、作物广泛性和环境适应性,并研究总结提出了在不同作物上推广应用的配套技术模式。通过全国各级农技推广和产品研发人员的共同努力,提出了有效的推广方法和机制,推广应用面积逐年扩大,对促进绿色植保事业和农业可持续发展做出了重要贡献。

Experimental Determination of the Vibrational Constants of FeS（X5 △） by Dispersed Fluorescence Spectroscopy

Based on previous laser-induced fluorescence excitation spectroscopy work, the vibrational constants of neutral FeS in the X5 △ electronic state were obtained by directly mapping the ground-state vibrational levels up to v＂=3 using conventional laser-induced dispersed fluorescence spectroscopy. The vibrational frequency of FeS（X5 △） （518±5 cm-1） agrees well with that reported in a recent PES measurement （520±30 cm-1） [J. Phys. Chem. A 107, 2821 （2003）] which is the only one prior experimental vibrational frequency value for the 5 △ state of FeS. Careful comparisons of our experimental results and those documented in the literature （mainly from theoretical predictions） suggest that the ground state of FeS is 5 △ state.

Adaptive rotor current control for wind-turbine driven DFIG using resonant controllers in a rotor rotating reference frame

This paper proposes an adaptive rotor current controller for doubly-fed induction generator (DFIG), which consists of a proportional (P) controller and two harmonic resonant (R) controllers implemented in the rotor rotating reference frame. The two resonant controllers are tuned at slip frequencies ωslip+ and ωslip-, respectively. As a result, the positive- and negative-sequence components of the rotor current are fully regulated by the PR controller without involving the positive- and negative-sequence decomposition, which in effect improves the fault ride-through (FRT) capability of the DFIG-based wind power generation system during the period of large transient grid voltage unbalance. Correctness of the theoretical analysis and feasibility of the proposed unbalanced control scheme are validated by simulation on a 1.5-MW DFIG wind power generation system.

佳多农林病虫害自动测控系统(ATCSP)开发与应用前景

佳多农林病虫害自动测控系统集成了病虫害实时监测预警、预警遥控和频振生物诱控3个子系统,通过信息化管理、自动化控制和无害化防治,为有效解决农林害虫防控依赖化学农药这一世界性难题奠定了技术基础。

Comparison of vibrations induced by excavation of deep-buried cavern and open pit with method of bench blasting

The measured data of vibrations induced by excavation of deep-buried cavern and open pit with method of bench blasting were analyzed by Fourier Transform and Wavelet Transform,and the characteristics of vibrations induced under these two circumstances were studied.It is concluded that with the similar rock condition and drilling-blasting parameters,vibration induced by bench blasting in deep-buried cavern has a higher main frequency and more scattered energy distribution than that in open pit.The vibration induced by bench blasting in open pit is mainly originated from the blast load,while the vibration induced by bench blasting in deep-buried cavern is the superposition of vibrations induced by blast load and transient release of in-situ stress.The vibration induced by transient release of in-situ stress increases with the stress level.

Modeling of fluid-induced vibrations and identification of hydrodynamic forces on flow control valves

Dynamics and vibration of control valves under flow-induced vibration are analyzed. Hydrodynamic load characteristics and structural response under flow-induced vibration are mainly influenced by inertia, damping, elastic, geometric characteristics and hydraulic parameters. The purpose of this work is to investigate the dynamic behavior of control valves in the response to self-excited fluid flow. An analytical and numerical method is developed to simulate the dynamic and vibrational behavior of sliding dam valves, in response to flow excitation. In order to demonstrate the effectiveness of proposed model, the simulation results are validated with experimental ones. Finally, to achieve the optimal valve geometry, numerical results for various shapes of valves are compared. Rounded valve with the least amount of flow turbulence obtains lower fluctuations and vibration amplitude compared with the flat and steep valves. Simulation results demonstrate that with the optimal design requirements of valves, vibration amplitude can be reduced by an average to 30%.

Strong ground movement induced by mining activities and its effect on power transmission structures

Surface mining activities may introduce damages to nearby infrastructure. Concerns are put forward by the power company about structural integrity of electric power transmission structures in areas where coal mining activities cause strong ground vibrations. Common practice in the power industry is to limit ground motion by specifying maximum Peak Particle Velocity. So far, there is a lack of industry-wide recognized guidelines on how ground vibration limits should be set for the transmission structures. In order to develop a defense strategy to protect power transmission lines against strong ground motions in mining areas, a systematic research work was conducted to establish strong ground vibration characteristics and to study impacts of ground excitations on transmission pole structures. Ground movements were recorded using geophones and wireless tri-axial sensing units. The process of generating ground motion response spectra via analyzing actual ground motion measurements is described in the paper. These spectra developed based on peak particle velocities were used as a basis for spectral analysis performed using validated Finite Element models to obtain structural displacements, reactions and stress states of the transmission pole structures in the mining sites. A quantitative ground motion limit was established by comparing structural responses with the corresponding design requirements.

Surface-Induced Dissociation of Low Energy H_2^(+) Impact on a Carbon Surface: A Monte Carlo Simulation

A Monte Carlo simulation based on the classical binary collision approximation is performed to investigate the interaction of W2 ions with the carbon target. The incident H2^＋ ion is characterized by its translational energy, eigenenergy and population of the vibrational state, and orientation of the ion with respect to the target surface. It is shown that experimentally determined energy resolved mass spectrum of H＋ can be nicely reproduced with the help of the proposed model. These simulations predict that translational to vibrational （T → V） energy transfer efficiency increases nonlinearly with translational energy of the incident ion. T → V energy transfer efficiency along with the initial vibrational energy of the incident H＋ ion found to play an important role in dissociation. Our simulations also show that the fraction of absorbed, reflected, and dissociated ions depends on the translational energy. The average vibrational energy of reflected H＋ increases with its initial translational energy. Moreover, average number of collisions required for dissociation varies inversely with the initial translational energy of the H2^＋.

Effect of Mass Ratio on Hydrodynamic Response of a Flexible Cylinder

The effect of the mass ratio on the flow-induced vibration （FIV） of a flexible circular cylinder is experimentally investigated in a towing tank. A Tygon tube with outer and inner diameters of 7.9 mm and 4.8 mm, respectively, was employed for the study. The tube was connected to a carriage and towed from rest to a steady speed up to 1.6 m/s before slowing down to rest again over a distance of 1.6 m in still water. Reynolds number based on the cylinder＇s outer diameter was 800-13,000, and the reduced velocity （velocity normalized by the cylinder＇s natural frequency and outer diameter） spanned from 2 to 25. When connected, the cylinder was elongated from 420 mm to 460 mm under an axial pre-tension of 11 N. Based on the cylinder＇s elongated length, the aspect ratio （ratio of the cylinder＇s length to outer diameter） was calculated as 58. Three mass ratios （ratio of the cylinder＇s structural mass to displaced fluid mass, m＊） of 0.7, 1.0, and 3.4 were determined by filling the cylinder＇s interior with air, water, and alloy powder （nickel-chromium-boron matrix alloy）, respectively. An optical method was adopted for response measurements. Multi-frequency vibrations were observed in both in-line （IL） and cross-flow （CF） responses; at high Reynolds number, vibration modes up to the 3rd one were identified in the CF response. The mode transition was found to occur at a lower reduced velocity for the highest tested mass ratio. The vibration amplitude and frequency were quantified and expressed with respect to the reduced velocity. A significant reduced vibration amplitude was found in the IL response with increasing mass ratios, and only initial and upper branches existed in the IL and CF response amplitudes. The normalized response frequencies were revealed to linearly increase with respect to the reduced velocity, and slopes for linear relations were found to be identical for the three cases tested.

Experimental study of traffic-induced vibration of the new CCTV headquarters building

The traffic-induced vibrations of the new CCTV Headquarters building are studied stages. In the first stage when the through experiments in two 30th floor of the northwest tower and the 38th floor of the southeast tower were finished, the traffic flows on the roads surrounding the building were investigated, and 27 setups of accelerations were measured at the roadside, on the pile cap and on the 9th floor. In the second stage when the whole steel structure was completed, l 5 setups of accelerations were measured at the roadside, on the pile cap and on the 37th and the 48th floors. The accelerations of the building under different traffic flows, in different positions are analyzed in both time domain and frequency domain. The damping ratios are estimated by the upgraded half-power bandwidth method.

The Research Progress on Assessment and Reduction of Ground-Borne Vibrations Induced by Railway Traffic

Railway induced vibrations and noises are a growing matter of environmental concern. The rapid development of transportation and increases in vehicle speeds and vehicle weights have resulted in higher vibration and noise levels. In the meantime vibrations and noises that seem to have been tolerated in the past, are now more often considered to be a nuisance. Methodology of assessing ground-borne vibrations for railway traffic is presented based on the Federal Railway Administration （FRA） Guidance Manual-High-Speed Ground Transportation Noise and Vibration Impact Assessment. Effectiveness of wave barriers such as open trench, in-filled trench, and piers for reduction of vibrations induced by railways and the procedure for barrier selection are discussed. Finally, an example of vibration assessing of Suvarnabhumi Airport Rail Link is presented to demonstrate the methodology.

植保新技术在农业中的应用

一、杀虫灯技术杀虫灯技术是利用“频振式杀虫灯”的“频振诱控”技术理念,通过灯的频振来吸引害虫并将其杀灭。杀虫灯可有效灭除半翅目、直翅目、同翅目及鞘翅目等相关害虫,且不会对人、畜、田地造成负面影响。杀虫灯技术的广泛应用,可以部分取代喷洒农药等传统灭虫技术,能有效降低生态农业的污染指数。值得一提的是,杀虫灯技术还具有诱集成效,可有效预测病虫害的发展趋势,进而制定应对病虫害的应急方案。