Release rates of tetradecen-1-ol acetates from polymeric formulations in relation to temperature and air velocity

An apparatus was developed for investigating the release rates of pheromone formulations at temperatures and air velocities that correspond with those in the field. Polyurethane foam proved an excellent adsorbent for the recovery of tetradecen-1-ol acetates, allowing high air flows at low differential pressure and without breakthrough of these compounds. The experimental setup and procedures are described. The release rates of all formulations investigated were almost proportional to the square root of air velocity, and their logarithms were proportional to the reciprocal of temperature (K). When temperature is increased from 15°C to 25°C, the release rates increase by about 2-2.5 ×. Both relationships were combined into one equation that allows a reliable estimate to be made of the actual release rates of a formulation, under varying conditions, on the basis of its specific parameters and the relevant meteorological data.     

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。     

Field response ofDendroctonus brevicomis toexo-brevicomin,frontalin, and myrcene released at two proportions and three levels

Racemicezo-brevicomin, racemic frontalin, and myrcene were released at two proportions (51400 and 111), each at three levels (1 ×, 10 ×, and 100 ×) in a ponderosa pine forest in central California. The 51400 mix was based on an estimate of the relative amounts released from a ponderosa pine under attack by the western pine beetle,Dendroctonus brevicomis. MoreD. brevicomis were trapped at a source of the three compounds released at 51400 than were trapped at a source released at 111, at all three levels, but this difference was statistically significant only at the 1 × and 10 × levels. Sex ratio of trapped beetles and distribution of catch at the source of attractant and 5 m away apparently did not differ between relative release rates.Coleoptera: Scolytidae.Trade names are mentioned solely for information. No endorsement by the U.S. Department of Agriculture is implied.     

Boundary feedback stabilization of the telegraph equation: Decay rates for vanishing damping term

We study a semilinear mildly damped wave equation that contains the telegraph equation as a special case. We consider Neumann velocity boundary feedback and prove the exponential stability of the closed loop system. We show that for vanishing damping term in the partial differential equation, the decay rate of the system approaches the rate for the system governed by the wave equation without damping term. In particular, this implies that arbitrarily large decay rates can occur if the velocity damping in the partial differential equation is sufficiently small.     

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.     

H.264/SVC mode decision based on mode correlation and desired mode list

Design of video encoders involves implementation of fast mode decision (FMD) algorithm to reduce computation complexity while maintaining the performance of the coding. Although H.264/scalable video coding (SVC) achieves high scalability and coding efficiency, it also has high complexity in implementing its exhaustive computation. In this paper, a novel algorithm is proposed to reduce the redundant candidate modes by making use of the correlation among layers. A desired mode list is created based on the probability to be the best mode for each block in base layer and a candidate mode selection in the enhancement layer by the correlations of modes among reference frame and current frame. Our algorithm is implemented in joint scalable video model (JSVM) 9.19.15 reference software and the performance is evaluated based on the average encoding time, peak signal to noise ration (PSNR) and bit rate. The experimental results show 41.89% improvement in encoding time with minimal loss of 0.02 dB in PSNR and 0.05% increase in bit rate.     

烟丝整丝率变化率对卷烟卷接质量控制的影响研究

长期以来,烟丝的物理特征都被认为是影响卷烟质量的主要因素。随着生产工艺和企业烟丝标准的不断提高,如今烟丝的物理特征对卷烟质量的影响不再显著。研究人员转而将目光转向了烟丝的整丝率变化率。     

基于平衡采样的轻量级广告点击率预估方法

类似Google AdSense这样的定向广告投放系统在过去十年得到了长足的发展和进步, 在定向广告投放系统中, 机器学习方法在广告点击率预估扮演着重要角色。目前, 广告点击率预估模型中的训练数据逐渐呈指数级增长, 越来越大的训练数据给模型的扩展性带来了极大的不便。很多有用的特征以及复杂的模型受限制于训练集规模而无法加入到模型之中。借鉴类别不平衡问题中的平衡采样策略, 通过多次采样的负样本数据和集成学习, 缩短训练时间, 改善学习准确率。实验证明在采用了平衡采样之后, 点击率预估效果和线上资源消耗都得到了优化。     

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.     

化学镀镍-磷合金机理的研究

通过对化学镀Ni—P合金过程中线性极化电阻及沉积速度的测量,得出极化电阻的倒数1/Rp与电流密度i呈线性关系。用阳极极化曲线的方法,较详细地研究了次磷酸钠在镍电极上的氧化过程。提出了化学镀Ni—P合金是按电化学机理进行的。