普钙产品转化率的数值计算方法

对影响普钙产品转化率的各种因素进行了分析,利用MATLAB 软件包得到了转化率的计算公式,提出了确定未分解磷矿的比例和由倍半氧化物引起的有效磷退化幅度的方法,为生产系统的预测和调整提供了一种途径。     

Apparatus and procedure for measuring release rates from formulations of lepidopteran semiochemicals

An apparatus was developed wherein a vacuum source was used to pull air across a controlled-release-formulation dispenser or a planchet containing a known quantity of a semiochemical and into a collector filled with a polymeric adsorbent. After a set time, the semiochemical was eluted with solvent and was quantified by gas-liquid chromatography (GLC). High percentages of known quantities of the lepidopteran semiochemicals (Z)-7-dodecen-l -ol acetate (Z7DDA), boiling point (bp) 275 ° C/1 atm, (Z)-9-tetradecen-1-ol formate (Z9TDF), bp 289 °C/1 atm, and (Z,Z)-3,13-octadecadien-1-ol acetate (ZZODDA), bp 490 °C/1 atm, were recovered. The semiochemicals did not oxidize and were recovered quantitatively from the adsorbent. The release rates of Z9TDF from a controlled-release dispenser were found to be directly proportional to the airflow rates. Release rate measurements on the Z9TDF dispensers were made for the purpose of estimating the method's precision. The method was shown to give internally consistent results by measurements on another Z9TDF formulation. The accuracy of the method is discussed.Mention of a commercial or proprietary product in this paper does not constitute an endorsement by the USDA.     

An analysis,design and tuning of Cascade Control Systems in the presence of constraints in actuator and process outputs

In the presence of rate constraints in actuator, design of cascade controller based on the primary controller conditional integration can result into closed-loop system oscillations. Stability analysis, performed by the describing function technique and confirmed by simulation, demonstrates that the solution based on the Anti-Reset Windup Cascade Control System (ARW CCS) structure is successful. Design and tuning of the ARW CCS secondary controller is a standard ARW single-input single-output problem. In the present paper tuning is proposed for the ARW CCS primary controller. For the serial process modeling simple rules are derived and confirmed by experimental results, obtained on a drum type boiler of a 210 MWe lignite coal fired unit. General design of the ARW CCS is based on the parallel process modeling and optimization of the primary controller. Optimization is performed in the frequency domain, under constraints on the maximum sensitivity, multiplicative uncertainty bound and sensitivity to measurement noise. Simulation and experimental results on a laboratory thermal plant demonstrate effectiveness of the proposed optimization.     

抗氧剂3114合成反应热力学和动力学的研究

研究了常温溶剂法合成抗氧剂3114反应热力学和动力学过程。控制温度在117±2℃,研究结果表明,反应是零级反应,反应速率常数k=1.91×10-3/min,反应的平衡常数K=138.4(mol/L)-6,反应活化能Ea=1366.2J/mol。     

电解法处理利福霉素SV钠废渣分离液的研究

根据电化学原理，采用电解法，利用铁屑与炭粒作电极，处理利福霉素SV钠药渣分离液，讨论各种因素对分离液污染物作效果的影响，COD去除率可达91．8％左右，脱色率可达95％左右。     

基于主成分分析中的几类问题的计算公式及结论

讨论了主成分分析中的几类问题的计算方法,重点揭示在协方差矩阵中对角元素相同时的第一主成分及贡献率和对角元素不同时的主成分贡献率．经讨论后给出有关计算公式,并说明这些计算公式在多元统计分析中的实际作用     

Molten salts/ceramic-foam matrix composites by melt infiltration method as energy storage material

A new type of high temperature energy storage material was obtained through the melt infiltration method, using compounding SiC ceramic foam as matrix and Na₂SO₄ as phase change material. The resulting composite material was measured by XRD, SEM, TG-DSC methods. The experimental results indicate that the composite is composed of silicon carbide, sodium sulfate and square quartz, and no chemical reactions occurs between Na₂SO₄ and SiC matrix. Na₂SO₄ has a good bonding with the SiC ceramic foam matrix. As the composite material is characterized by high thermal energy storage density and high thermal conductivity, it is suit for energy storage under high temperature. Funded by the “863” Hi-Tech Research and Development Program of China (2008AA05Z418)     

An improvement to the simulation of phase-change heat-transfer during soil freezing and thawing

A new variable time step method, which is called the backwards calculating time step method, is presented in this paper. It allows numerical simulation of soil freezing and thawing while avoiding "phase change missing and overflowing". A sensitive heat capacity model is introduced through which the calculation errors are analyzed. Then the equation using the self-adjusted time step is presented and solved using finite differences. Through this equation, the time needed for a space cell to reach the phase change point temperature is calculated. Using this time allows the time step to be adjusted so that errors caused by "phase change missing and overflowing" are successfully eliminated. Above all, the obvious features of this method are an accelerated rate for adjusting the time step and simplifing the computations. An actual example proves that this method can accurately calculate the temperature fields during soil freezing and thawing. It is an improvement over traditional methods and can be widely used on com- plicated multi-dimensional phase change problems.     

大变幅扬程多机组泵站并联运行水泵性能分析

分析了大变幅扬程下灌溉泵站并联运行水泵机组性能,提出了提高泵站装置效率的方法。     

Progress and recent trend in MILD combustion

Moderate or intense low oxygen dilution(MILD)combustion plays a significant role in the mitigation of combustion-generated pollutants and greenhouse gases whilst meeting thermal efficiency needs.However,due to the lack of the fundamental knowledge on this combustion,there is a misconception that MILD combustion should be established by high preheating of the air,which has limited its application.Our research and development on this combustion has been performed for several years. We have found that the requ...