植保常用扇形雾喷头系列型谱模型研究

[目的]为了实现植保常用扇形雾喷头的数字化管理及生成,促使喷头设计与生产向协调、统一、择优、简化方向发展。[方法]对常用扇形雾喷头的结构组成、性能特征、喷雾质量进行了理论分析,对不同终端型式的扇形雾喷头进行了雾型分布试验。[结果]雾型分布受喷嘴终端型式影响较大。最终建立了不同系列喷头的型谱模型,制定了扇形雾喷头谱系结构。[结论]此研究为相关软件开发与数据库建立提供了支持与参考,便于喷头的快速检索与参数化设计,研发和生产新型植保喷头。

Spectrum Sensing Model for Wireless Internet of Things

In the last few years, the number of devices operating in wireless Internet of Things （IoT） has experienced tremendous growth. On the other hand, the growth results in spectrum scarcity. Cog- nitive Radio （CR） systems have been proposed to efficiently exploit the spectra that have been assigned but are underutilized. In this paper, a spectrum sensing model based on Markov chain is proposed to predict the spectrum hole for CR in wireless IoT. Theoretical analysis and simulation results have been evaluated that a Markov model with two- state or four-state works well enough in wireless loT whereas a model with more states is not necessary for it is complex.

Effect of Energy Transfer on UV Spectra of “H-shaped” Azobenzene Derivatives

A series of “H-shaped” organic dimers （azobenzene derivatives） exhibit linear absorption red shift compared with their corresponding monomers experimentally. Dipolar interaction model is not appropriate for the azobenzene derivatives due to the small distance between two “D-π-A” chains. Energy transfer model is suggested for explanation of the absorption red shift. Two necessary conditions for energy transfer were verified. In addition, bi-exponential florescence-delay behavior of the dimer as well as Bella＇s quantum chemistry calculation shows evidence of energy transfer.

Development and validation of global prediction models for monitoring the manufacturing process of herbal medicine by ultraviolet spectroscopy

Objective: Process monitoring for traditional Chinese medicine(TCM) preparations is necessary to ensure the quality of the product. A typical pharmaceutical process of TCM preparations consists of multiple manufacturing units, such as ethanol precipitation, concentration, and water precipitation, among others. Compared with the traditional practice of one prediction model for one unit, the global model covers the variation from samples with different backgrounds or processes and can be used to monitor intermediates from substeps.Methods: We used ultraviolet(UV) spectroscopy to establish global models for a typical TCM preparation-Danhong injection.The concentrations of danshensu, protocatechualdehyde, rosmarinic acid, salvianolic acid A, salvianolic acid B, and hydroxyl safflor yellow A and the total phenolic and total sugar contents were quantified for every intermediate from operation units of Danhong injection. New samples prepared by mixing different intermediates were introduced for the calibration set to cover more variations. An accuracy profile was employed to validate the developed method from the aspects of specificity, trueness, precision,accuracy, linearity, and robustness.Results: The developed models showed a high determination coefficient(R2) value up to 0.97 and a low root-mean-square error of the prediction set. Five components of the models passed all validation tests, whereas the total sugar was not suitable for modeling with UV and did not apply to the whole process.Conclusions: This study indicates that the global models of UV spectroscopy for the quantitative determination of phenolic acids are feasible and reliable with a simple, rapid, and non-destructive method.Graphical abstract: http://links.lww.com/AHM/A22.

Transitional Description of Diatomic Molecules in U（4） Vibron Model

U(3)-O(4) transitional description of diatomic molecules in the U(4) vibron model is studied by usingthe algebraic Bethe ansatz, in which the O(4) limit is a special case of the theory. Vibrational band-heads of sometypical diatomic molecules are fitted by both transitional theory and the O(4) limit within the same framework. Theresults show that there are evident deviations from the O(4) limit in description of vibrational spectra of some diatomicmolecules.

Construction of lake bathymetry from MODIS satellite data and GIS from 2003 to 2011

In recent years, sedimentation conditions in Dongting Lake have varied greatly because of signifi cant changes in runoff and sediment load in the Changjiang(Yangtze) River following the construction of Three Gorges Dam. The topography of the lake bottom has changed rapidly because of the intense exchange of water and sediment between the lake and the Changjiang River. However, time series information on lake-bottom topographic change is lacking. In this study, we introduced a method that combines remote sensing data and in situ water level data to extract a record of Dongting Lake bottom topography from 2003 to 2011. Multi-temporal lake land/water boundaries were extracted from MODIS images using the linear spectral mixture model method. The elevation of water/land boundary points were calculated using water level data and spatial interpolation techniques. Digital elevation models of Dongting Lake bottom topography in different periods were then constructed with the multiple heighted waterlines. The mean root-mean-square error of the linear spectral mixture model was 0.036, and the mean predicted error for elevation interpolation was-0.19 m. Compared with fi eld measurement data and sediment load data, the method has proven to be most applicable. The results show that the topography of the bottom of Dongting Lake has exhibited uneven erosion and deposition in terms of time and space over the last nine years. Moreover, lake-bottom topography has undergone a slight erosion trend within this period, with 58.2% and 41.8% of the lake-bottom area being eroded and deposited, respectively.

Simple single field inflation models and the running of spectral index

The BICEP2 experiment confirms the existence of primordial gravitational wave with the tensor-to-scalar ratio r = 0 ruled out at 70- level. The consistency of this large value of r with the Planck data requires a large negative running n＇s of the scalar spectral index. Herein we propose two types of the single field inflation models with simple potentials to study the possibility of the consistency of the models with the BICEP2 and Planck observations. One type of model suggested herein is realized in the supergravity model building. These models fail to provide the needed n＇s even though both can fit the tensor-to-scalar ratio and spectral index.