Research Plan on the Strategic Development of High-value Eco-agriculture in the Middle-lower Reaches of Yangtze River

At present,high-value eco-agriculture research in China is till limited and controversial,theoretical innovation and practices on eco-agriculture should be conducted.The key problems which should be solved urgently on the development of high-value eco-agriculture in the middle-lower reaches of Yangtze River now including：the connotation and characteristics of high-value eco-agriculture,the construction of high-value eco-agriculture system and the policies of the development of high-value eco-agriculture.Therefore,the strategic development research on high-value eco-agriculture mainly includes the following aspects：development of agriculture modernization and theory and practices of eco-economics;theory of high-value eco-agriculture;practice of high-value eco-agriculture in the middle-lower reaches of Yangtze River;construction of high-value eco-agriculture in the middle-lower reaches of Yangtze River;development strategy and system innovation of high-value eco-agriculture in the lower and medium reaches of Yangtze River.

Construction of Energy Diagram of Ecological High-value Agriculture System and Emergry Evaluation Index System

Ecological high-value agriculture research, ecological high-value agricultural is the future of agriculture in China. In the emergy diagram was constructed based on emergy theory, and the mechanism and realization approach were well described. In addition, a set of evaluation index system of emergy was established to deter- mine contribution made by different resources of the system, providing references for further exploration of ecological high-value agricultural production system.

Boosting CO_(2) hydrogenation to high-value olefins with highly stable performance over Ba and Na co-modified Fe catalyst

CO_(2)hydrogenation has been considered to be a highly promising route for the production of high-value olefins(HVOs)while also mitigating CO_(2)emissions.However,it is challenging to achieve high selectivity and maintain stable performance for HVOs(ethylene,propylene,and linear a-olefins)over a prolonged reaction time due to the difficulty in precise control of carbon coupling and rapid catalyst deactivation.Herein,we present a selective Ba and Na co-modified Fe catalyst enriched with Fe_(5)C_(2)and Fe_(3)C active sites that can boost HVO synthesis with up to 66.1%selectivity at an average CO_(2)conversion of 38%for over 500 h.Compared to traditional NaFe catalyst,the combined effect of Ba and Na additives in the NaBaFe-0.5 catalyst suppressed excess oxidation of FeCxsites by H_(2)O.The absence of Fe3O4phase in the spent NaBaFe-0.5 catalyst reflects the stabilization effect of the co-modifiers on the FeCxsites.This study provides a strategy to design Fe-based catalysts that can be scaled up for the stable synthesis of HVOs from CO_(2)hydrogenation.

Genetic Bioengineering in the Achievement of Algae Biofuels and High-Value Bio-products

The dependence to fossil fuels has increased the amount of greenhouse gases in the atmosphere.That is why,the production of renewable and sustainable biofuels has gained a long-term importance for both scientific and political necessities.In this context,algae are promising in terms of alternative biofuels resources.For this reason,intensive scientific researches have been carried out in recent years on providing optimum efficiency in this regard.Bioengineering is a discipline that applies engineering principles of design and analysis to biological systems and biomedical technologies.Examples of bioengineering research include bacteria or microalgae engineered to produce valuable bioactive chemicals.Microalgae by target gene modification may serve as a promising source for the production of biofuels and bio-based chemicals.A lot of research has been carried out by applying microalgae genomic editing technique with the aim to produce numerous biotechnological products.Some successful previously reported research and production activities are still underway in this area.However,in order to produce the desired products efficiently with manipulated microalgae biorefinery,there is a need to overcome the problem of low biomass production despite high production costs.The aim of this work is to give special attention to the rich potential content of microalgae and to provide information on algal genetic manipulations to increase products by bioengineering methods.

Study on the Monitoring Malfunction of Water Pollution during Drought or Flood Period and Low-carbon and High-value Methodology--A Case Study of the Correlation Test of Water,Soil and Gas Pollution in Xiangxiang County

Based on the low-carbon and high-value methodology of chemical ecology and chemical informatics,combining theory and methods,taking saving,environmental protection,low carbon,high production,high value and circulation as values and aims,the relationship between human and land as a basis,ecosystem as a center,overall control as a goal and agricultural ecological engineering as a mean,environmental pollution detection,as one of bottlenecks for agricultural products and food security,should be solved firstly;through the field survey in dry years from 2009 to 2010 when drought and flood were frequent and the frequency of drought was higher than that of flood,plus the determination of surface water flow and water quantity in a small typical river basin,the correlation of local water,soil and gas in the county could be found,and the transfer of monitoring focus from water environment to atmospheric environment was possible and necessary.The study would promote the quantitative research on the correlation among water,soil and gas,and the results were in accordance with the conclusions of related studies.

Analysis of Quenching Resistor Effect to Improve Stability of TIA Circuit for APD-A Secondary Publication

In this paper,since the Avalanche Photo Diode(APD)for Light-to-Voltage LTV conversion uses a high voltage in the operating range unlike other Photo Diodes(PD),the quenching resistor must be connected in series to prevent overcurrent when using the Transimpedance Amplifier(TIA).In such a case,quenching resistance may affect the transfer function of the TIA circuit,resulting in serious stability.Therefore,in this paper,by analyzing the effect of APD quenching resistance on the voltage and current loop transfer function of TIA,we proposed a loop analysis and a method for determining the quenching resistance value to improve stability.A TIA circuit with quenching resistance was designed by the proposed method and its operational stability was verified through simulation and chip fabrication.

灵活接地系统中性点接地电阻投入暂态特征分析

灵活接地系统发生永久性单相接地故障后,通过延时闭合中性点接地电阻(并联小电阻)投切开关以期可靠切除故障。目前,基于稳态信息的灵活接地系统保护方法应用效果难以达到要求,而关于小电阻投入时的暂态特征分析尚未有完整结论,制约了灵活接地系统接地故障暂态保护理论的发展。文中建立基于线路分布参数的灵活接地系统并联小电阻投入暂态分析模型,研究系统内各元件间的谐振特性,并据此提出一种简化模型。针对低阻、高阻接地故障,分别给出暂态电流、电压的解析表达式,分析其谐振频率、衰减时间常数及最大幅值等主要特征值随系统参数及故障条件的变化规律,以及各线路暂态零序电流的分布特征,并与谐振接地阶段故障时刻的暂态特征作对比。最后,利用数字仿真及现场试验数据验证了所提暂态特征分析简化模型的正确性。

基于模糊PID的磁力搅拌器温度控制设计

针对磁力搅拌器的电阻炉盘具有大滞后、非线性以及无法精确获得数学模型的问题,在温度-电流串级控制的基础上提出了一种基于模糊PID的磁力搅拌器温度控制方法,能够更好地应对电阻炉盘的特性。通过模糊化输入和输出,利用模糊规则进行推理,根据实时的温度偏差和变化率来调整控制器的输出,以实现更快的响应并且减小超调的程度。PID控制器的比例、积分和微分部分也能够对系统进行精确调节,进一步提高温度控制的准确性。实验表明,在50~350℃的温控范围之间,系统的稳态误差在±1℃内,并且超调量小,可以满足磁力搅拌器的应用需求。

十进制量子电阻阵列研究综述

文章综述了十进制量子电阻阵列的制造难点和在电学计量标准化中的应用及前景。通过分析量子霍尔效应的核心原理,探讨了砷化镓(gallium arsenide,GaAs)与石墨烯两种材料在量子电阻阵列中的优势与差异。文章总结了实现十进制量化的关键技术,包括量子霍尔条的制备、载流子密度调控、超导互连与电路误差优化等。此外,文章还强调了量子电阻阵列在国际计量体系中的重要作用,尤其在欧姆与安培重新定义中的贡献,并展望了量子电阻设备的便携化与智能化发展趋势,不仅能够推动电学测量技术的进步,也能够为各类高精度测量应用提供了重要的技术支撑。

Recursion-transform approach to compute the resistance of a resistor network with an arbitrary boundary

We consider a profound problem of two-point resistance in the resistor network with a null resistor edge and an arbitrary boundary,which has not been solved before because the Green＇s function technique and the Laplacian matrix approach are invalid in this case.Looking for the exact solutions of resistance is important but difficult in the case of the arbitrary boundary since the boundary is a wall or trap which affects the behavior of a finite network.In this paper,we give a general resistance formula that is composed of a single summation by using the recursion-transform method.Meanwhile,several interesting results are derived by the general formula.Further,the current distribution is given explicitly as a byproduct of the method.

A wideband metamaterial absorber based on a magnetic resonator loaded with lumped resistors

A wideband metamaterial absorber （MA） based on a magnetic resonator loaded with lumped resistors is presented. It is composed of a one-dimensional periodic array of double U-shaped structured magnetic resonators loaded with lumped resistors, a dielectric substrate, and a metal plate. We simulated, fabricated, measured, and analyzed the MA. The experimental results show that the reflectance （S11） is below -10 dB at normal incidence in the frequency range of 7.7 GHz 18 GHz, and the peak value is about -20 dB. Simulated power loss density distributions indicate that wideband absorption of the MA is mainly attributable to the lumped resistors in the magnetic resonator. Further investigations indicate that the distance between two unit cells along the magnetic field direction significantly influences the performance of the MA.

Failure Behaviors and Mechanisms of High-Ohmic Resistors Protected by PF/EP Paint in Heat and Humid Environment

Phenolic formaldehyde(PF)and epoxy(EP)resins are commonly used in electronic packaging. In this paper, high-ohmic resistors(2.2 M?, ±0.5%,)with Cr-Si film were coated by PF/EP paint, and the resulting coated resistors were used for heat and humid(HH)experiments. The experimental results show that the corrosion of bandlike resistive films is selective and isotropic, and that the corrosion spots in resistive films all form along grooves and extend in the same direction. It is revealed that OH^- ions are generated due to the electrochemical reactions of resistive film in HH experiments, so a NaOH aqueous solution with pH about 10 was used to study the effects of absorbed water and OH^- ions on PF/EP polymer film. The results indicates that the color of some part on PF/EP polymer film changes due to corrosion, and that the corrosion part of the polymer film is easy to be peeled off. It can be inferred that OH^- ions generated in HH experiments may play a catalytic role in the chemical reactions between polymer film and the absorbed water, which accelerates the degradation of PF/EP protection film for a resistor.

Hybrid functional IrO_2-TiO_2 thin film resistor prepared by atomic layer deposition for thermal inkjet printheads

IrO2-TiO2 thin films were prepared by atomic layer deposition using Ir（EtCp）（COD） and titanium isopropoxide （TTIP）. The resistivity of IrO2-TiO2 thin films can be easily controlled from 1 500 to 356.7 μΩ·cm by the IrO2 intermixing ratio from 0.55 to 0.78 in the IrO2-TiO2 thin films. The low temperature coefficient of resistance（TCR） values can be obtained by adopting IrO2-TiO2 composite thin films. Moreover, the change in the resistivity of IrO2-TiO2 thin films was below 10% even after O2 annealing process at 600 ℃. The step stress test results show that IrO2-TiO2 films have better characteristics than conventional TaN08 heater resistor. Therefore, IrO2-TiO2 composite thin films can be used as a heater resistor material in thermal inkjet printhead.

Thin Film Chip Resistors with High Resistance and Low Temperature Coefficient of Resistance

High resistance thin film chip resistors(0603 type) were studied,and the specifications are as follows:1 k? with tolerance about ±0.1% after laser trimming and temperature coefficient of resistance(TCR) less than ±15×10-6/℃.Cr-Si-Ta-Al films were prepared with Ar flow rate and sputtering power fixed at 20 standard-state cubic centimeter per minute(sccm) and 100 W,respectively.The experiment shows that the electrical properties of Cr-SiTa-Al deposition films can meet the specification requirements of 0603 ty...

Interaction of RuO₂and Lead-Silicate Glass in Thick-Film Resistors

Results of investigation of X-ray diffraction, infrared and optical spectra of powders of the ruthenium dioxide, lead-silicate glass as well as their mixture before and after sintering are reported. Sintering conditions typical for thick film resistors were used. Intensity of main lines of RuO2 in X-ray diffraction patterns of sintered mixtures decreases and they slightly shift towards small angles. No new reflexes appear in these patterns. Absorbance of RuO2 in the range of 2.5-100 μm is proportional to and featureless. Infrared spectrum of lead-silicate glass has absorption bands of [SiO4]4- tetrahedra and Pb-O bonds only. Optical spectrum of RuO2 has wide absorption bands at 950 and 370 nm. Spectra of the mixture of RuO2 and glass powders before and after sintering are different indicating that there is interaction between them during the sintering process. Concentration of free charge carriers estimated from the optical spectra is about 1021 cm-3.

Systematic design method for PI controller with Virtual Resistor-based Active Damping of LCL filter

The Virtual Resistor based Active Damping(VR-AD) is widely employed in converters connected to the grid via LCL filters in order to mitigate the inherent resonance of the filters. Nevertheless, in digitally controlled systems, the PWM and the calculating delays modify the system characteristics in terms of frequency and phase, thus destabilizing the system and degrading the VR-AD performances, mainly in low switching frequencies. Moreover, the stability of the system is greatly affected under weak grid operation characterized by large grid impedance variation. This paper solves these problems by proposing a systematic, robust and optimized design procedure of voltage oriented PI control(VOC) with VRAD. The considered design procedure ensures robust control(sufficient stability margins) and high quality of grid current(reduced steady-state error and minimized THD value) despite the negative impact of digital time delay, grid impedance variation and filter parameters change. Simulation and experimental results are presented to show robustness and efficiency of the suggested design procedure.

Fabrication of integrated resistors in printed circuit boards

In order to utilize integrated passive technology in printed circuit boards （PCBs）, manufacturing processing for integrated resistors by lamination method was investigated. Integrated resistors fabricated from Ohmega technologies in the experiment were 1 408 pieces per panel with four different patterns A, B, C and D and four resistance values of 25, 50, 75 and 100 fL Six panel per batch and four batches were performed totally. The testing was done for 960 pieces of integrated resistors randomly selected with the same size. The value distribution ranges and the relative standard deviation （RSD） show that the scatter degree of the resistance decreases with the resistor size increasing and/or with the resistance increasing. Patterns D with resistance of 75 and 100% for four patterns have the resistance value variances less than 10%. Patterns C and D with resistance of 100 Ω have the manufacturing tolerance less than 10%. The process capabilities are from about 0.6 to 1.6 for the designed testing patterns, which shows that the integrated resistors fabricated have the potential to be used in multilayer PCBs in the future.

Sensorless Control of Permanent Magnet Synchronous Motor Based on New Sliding Mode Observer with Single Resistor Current Reconstruction

To solve the chattering problem caused by discontinuous switching function in traditional sliding mode observer,a piecewise square root switching function with continuously varying characteristics is designed,and its stability is analyzed by using Lyapunov stability criterion.Secondly,according to the relationship among bus current,switching state and phase current,a single bus resistance sampling current reconstruction scheme without current sensors is adopted,which effectively reduces the cost of motor system.Finally,the feasibility and effectiveness of the proposed scheme are verified by simulation.

PF/EP/Nano-SiO_2 Composite Paint for Resistor

Phenolic resin(PF) and nano-SiO2 were used to improve the curing property and high humidity resistance of epoxy resin (EP) and methyl nadic anhydride (MNA) resistor paint, respectively. Hydrogen bonds, formed between phenolic resin and nano-SiO2 in alcohol, made nano-SiO2 disperse easily in EP/MNA paint through phenolic resin without being treated by supersonic vibration. When the mass ratio of PF to EP in paint is 3:7, the formed composite paint film can be cured in 2 min at 170 ℃ . When the mass ratio of nano-SiO2 to PF in paint is 3:100, the property of high humidity resistance of the composite paint is the best, meeting the requirement of varying ratio of resistance less than 0.1% after experiment on high humidity resistance. SEM analysis shows the surface of the composite paint film is smooth, glassy, tight and homogeneous, without acicular air holes.

Preparation of Lead-free Thick-film Resistor Pastes

The preparation of lead-free thick-film resistors are reported:using RuO 2 and ruthenates as conductive particles,glass powders composed of B 2 O 3,SiO 2,CaO and Al2 O 3 as insulating phase,adding organic matter which mainly consists of ethyl cellulose and terpineol to form printable pastes.Resistors were fabricated and sintered by conventional screen-printing on 96%Al 2 O 3 substrates,and then sintering in a belt furnace.X-ray diffraction(XRD) and electron scanning microscopy(SEM) have been used to characterize the conductive particles.The resistors exhibit good refiring stability and low temperature coefficient of resistance.Sheet resistance spans from about 80Ω/□ to 600Ω/□.The resistors prepared are qualified for common use.