稻田生物群落的能流参数

为了从能流动态来研究稻田生物群落,本文用田间调查和实验室测定等方法,取得了晚稻田生物群落的物种数量、生物量、热值、呼吸量、生产力、同化效率、摄食量等数据。据此,进一步估算了晚稻田生物群落的能量流动参数。根据其能量收支,用能量金字塔总结了晚稻田生物群落各类种群间的能量关系。

聚光能流参数对背接触电池阵列输出特性的影响

主要研究了聚光能流特性对槽式聚光热电联供系统电输出性能的影响。通过CCD相机测量不同距离和不同镜面开口宽度焦平面上的能流分布图获取能流值分布矩阵,提取能流参数,包括相对平均能流值、不均匀度、峰值偏离度和能流利用率。通过引入聚光条件下电池内部复合机制和寄生电阻,建立了聚光电池阵列的双指数等效电路模型,模拟结果与实验结果吻合得较好。结果表明,短路电流和相对最大功率随相对平均能流值的增加而增加,两者的增大率分别因复合机制的增强和寄生电阻欧姆损失的增大而减小;开路电压随不均匀度和峰值偏离度的增大而减小;相对平均能流值因寄生电阻欧姆损失对填充因子影响最大;电池的效率由能流利用率和相对平均能流值决定。以6片串联2cm×2cm的背接触电池阵列为例,当镜面开口宽度为157cm、距焦平面2cm时,平面上的能流分布最适合电池阵列的性能输出。

基于能流界面参数的氧化铝溶出过程节能优化

针对氧化铝生产过程中能耗过高的问题,提出一种基于能流界面参数的节能降耗单元优化方法。该方法利用分层递阶控制理论,从界面参数分析入手,确定相邻工序之间、同一工序内相邻生产单元之间以及同一生产单元的相邻设备之间的能流界面,通过分析能流界面参数与生产全过程能耗指标之间的关系,提出以能流界面参数为约束,整个生产过程能耗最小为目标的操作参数优化算法,并进行分析检验。检验结果证明:该方法提高了系统火用效率,减少了系统火用损失,实现了各生产单元优化匹配、协调运行、整个流程的节能降耗。

Effect of working parameters on performance characteristics of hydrostatic turntable by using FSI-thermal model

Effects of working parameters on performance characteristics of hydrostatic turntable are researched by applying the fluid-structure-thermal coupled model.Fluid-structure interaction(FSI)technique and computational fluid dynamics(CFD)method are both employed by this new model,and thermal effects are also considered.Hydrostatic turntable systems with a series of oil supply pressures,various oil recess depth and several surface roughness parameters are studied.Performance parameters,such as turntable displacement,system flow rate,temperature rise of lubrication,stiffness and damping coefficients,are derived from different working parameters(rotational speed of turntable and exerted external load)of the hydrostatic turntable.Numerical results obtained from this FSI-thermal model are presented and discussed,and theoretical predictions are in good agreement with the experimental data.Therefore,this developed model is a very useful tool for studying hydrostatic turntables.The calculation results show that in order to obtain better performance,a rational selection of the design parameters is essential.

Evaluating the Performances of GAMIL1.0 and GAMIL2.0 during TWP-ICE with CAPT

CAPT and Atmospheric （Climate Change Prediction Radiation Measurement Program Program （CCPP-ARM） Parameterization Testbed） has been a valu- able tool to assess climate models in recent years, and the Tropical Warm Pool-International Cloud Experiment （TWP-ICE） has collected comprehensive measurements to verify its physical parameterizations. The present study evaluates the performances of the two GAMIL （grid-point atmospheric model of lAP LASG） versions during TWP-ICE using CAPT. The results indicate that GAMIL2.0 reproduced better shifts of clouds and rainfall during three distinct monsoon phases than GAMIL1.0, although both of them simulated the large-scale dynamical states well, which are mainly attributable to the different convective parameterizations.

Run-to-run Optimization for Fed-batch Fermentation Process with Swarm Energy Conservation Particle Swarm Optimization Algorithm

An iterative optimization strategy for fed-batch fermentation process is presented by combining a run-to-run optimization with swarm energy conservation particle swarm optimization (SEC-PSO). SEC-PSO, which is designed with the concept of energy conservation, can solve the problem of premature convergence frequently appeared in standard PSO algorithm by partitioning its population into several sub-swarms according to the energy of the swarm and is used in the optimization strategy for parameter identification and operation condition optimization. The run-to-run optimization exploits the repetitive nature of fed-batch processes in order to deal with the optimal problems of fed-batch fermentation process with inaccurate process model and unsteady process state. The kinetic model parameters, used in the operation condition optimization of the next run, are adjusted by calculating time-series data obtained from real fed-batch process in the run-to-run optimization. The simulation results show that the strategy can adjust its kinetic model dynamically and overcome the instability of fed-batch process effectively. Run-to-run strategy with SEC-PSO provides an effective method for optimization of fed-batch fermentation process.

Properties analysis of a large flow-rate safety valve test device

In order to solve the problem of property test of large flow-rate safety, the property parameter of safety valve test system was analyzed, and a device for property oflarge flow-rate safety valve test was designed.The device used accumulators as power source and a united function cylinder, which can realized the large flow-rate output for the test system.Analyzed the test data and made a particular research on the test device by testing different flow-rate safety valves;it verifies that the test device can be used tode-sign larger flow-rate safety valve test system and can make the flow-rate test and analysis and dynamic characteristics for the large-flow safety valve.

Statistical modelling for effect of mix-parameters on properties of high-flowing sand-concrete

The high-flowing sand-concrete （HFSC） containing natural sands as aggregate was carried out. The high fluidity and stability of HFSC can be achieved by tailoring the mix design parameters, such as fine to coarse sand ratio, dosage of additions, water to binder ratio and dosage of admixtures. Mini-cone slump test, v-fl.mnel time test and viscosity model parameters were used to characterize the behaviour of HFSC in fresh state. The mechanical compressive strength in 28 d was also determined. A factorial design approach was used to establish models highlighting the effect of each mix-parameter on measured properties of HFSC. The derived models are valid for mixtures made with 0 to 0.3 of dune sand to total sand ratio, 82 to 418 kg/m3 of marble powder, 0.42 to 0.46 of water/binder ratio and 1.3% to 1.9% of superplasticizer high water-reducer. The results show that the derived models constitute very efficient means for understanding the influence of key mix-parameters on HFSC properties and are useful in selecting the optimum mix proportions, by simulating their impact on fluidity, stability and compressive strength.

Optimizing Geothermal Energy Resource

Unlike other types of renewable energy resources, geothermal energy provides a stable source of energy as it can be exploited regardless of meteorological conditions. Using organic cycle, geothermal energy can be utilized for power generation. In such systems, the heat is exchanged between the surrounding rock mass and transport fluid. Consequently, the temperature of extracted geofluid from the well decreases with the time in accordance with the working parameters. Those parameters includeenergy extraction rate, temperature difference between inlet and outlet of the well, and the thermal conductivity of the ground. Current work, aims to develop a reliable computer model to specify the optimal working parameters so that the geofluid temperature will not reach a low value that is not acceptable for electricity generation, and the energy availability of geothermal resource is maximized. In the current study the ground thermal properties, the geothermal gradient and well dimensions are based on realistic data in Qatar and neighboring countries. The proposed model was developed for different heat extraction rate, different ground thermal properties, and for varied temperature difference between inlet and outlet of the well. Simulation shows that selecting the optimal working parameters can increase the availability of geothermal resource significantly.

Physics issues in diffraction limited storage ring design

Diffraction limited electron storage ring is considered a promising candidate for future light sources,whose main characteristics are higher brilliance,better transverse coherence and better stability.The challenge of diffraction limited storage ring design is how to achieve the ultra low beam emittance with acceptable nonlinear performance.Effective linear and nonlinear parameter optimization methods based on Artificial Intelligence were developed for the storage ring physical design.As an example of application,partial physical design of HALS(Hefei Advanced Light Source),which is a diffraction limited VUV and soft X-ray light source,was introduced.Severe emittance growth due to the Intra Beam Scattering effect,which is the main obstacle to achieve ultra low emittance,was estimated quantitatively and possible cures were discussed.It is inspiring that better performance of diffraction limited storage ring can be achieved in principle with careful parameter optimization.

Parametric study on hydraulic performance of an inlet plenum in a printed-circuit heat exchanger

Hydraulic performance of an inlet plenum in a printed-circuit heat exchanger has been analyzed using three-dimensional Reynolds-Averaged Navier-Stokes equations. The numerical model of the inlet plenum was constructed through grid dependency test, calculation domain tests, and turbulence model and numerical scheme selections. Shear stress transport turbulence model was used for analysis of turbulence. Non-uniformity of the flow in zigzag flow channels was evaluated for the reference case. Parametric studies have been performed with the angle of the inlet plenum wall, radius of curvature of the inlet plenum wall, and width of the inlet pipes. The effects of these parameters on the flow uniformity and friction performance were evaluated.

The study of key design parameters effects on the vortex tube performance

In this paper, energy separation effect in a vortex tube has been investigated using a CFD model. Thenumerical simulation has been done due to the complex structure of flow. The governing equationshave been solved by FLUENT code in 2D and 3D compressible and turbulent model. The effects ofgeometrical and thermo-physical parameters have been investigated. The results have shown that theoptimum length to diameter ratio is from 25 to 35. Increasing the number of nozzles from 2 to 4 withconvergent shape is found to be an efficient configuration for the swirl generator. The optimum valueof orifice diameter to tube diameter ratio, for the maximum cold air temperature difference and efficiency,has been determined to be around 0.58. The results show that if the inlet pressure increases upto a critical value, the efficiency will increase. Nevertheless, if it increases to higher values, the efficiencywill decrease. Moreover, it is found out that increasing the cold fraction decreases the coldtemperature difference and efficiency.

Analysis on the process of ZAO films by DC magnetron reactive sputtering

The ZAO (ZnO:Al) thin films were prepared by DC reactive magnetron sputtering technique. The relationship between the process parameters and the organizational structure,optical and electrical properties was studied. Through optimizing the process parameters,an optimal preparation parameter can be obtained. Using the optimal parameters to prepare the ZAO thin films,the resistivity of the ZAO film is as low as 4.5×10-4 Ω·cm and the average transmissivity in the visible region is around 80%,the optical and electrical properties meet the application requirements.