新疆灌溉用水定额分区初步研究

在综合分析新疆各地区地形地貌、气候特征、水资源状况、种植结构、农业灌溉用水现状和经济发展水平等因素基础上,采用共区优选法对新疆灌溉用水定额进行分区,并提出相应的改善措施。该结果可为提高新疆灌溉用水率和用水效率,以及为灌溉管理节水提供决策参考。     

不同穗型水稻产量与群体生理性状的关系

根据穗倾角穴穗颈节至穗尖的连线与茎秆延长线的夹角雪的大小,将参试的12个品种划分为直立穗型、半弯曲穗型、弯曲穗型3种类型,研究了不同穗型的群体形态生理性状与产量形成的关系。结果表明,弯曲穗型品种抽穗期干物重较高,直立穗型品种抽穗后和成熟期干物重较高,抽穗后干物重占成熟期干物重的百分比也较高,半弯曲穗型上述方面介于二者之间。直立穗型、半弯曲穗型和弯曲穗型的颖花/叶值相近,说明三者单位叶面积所负担的颖花数差异不大。就粒重/叶而言,直立穗型>半弯曲穗型>弯曲穗型。直立穗和半弯曲穗型品种抽穗后单个颖花拥有的干物质越多,成粒率越高。比叶重大的品种,抽穗后群体叶面积衰减缓慢,具有一定的群体叶面积,对干物质生产和产量的形成是十分有利的。     

The effect of anisotropic reflectance on imaging spectroscopy of snow properties

How does snow's anisotropic directional reflectance affect the mapping of snow properties from imaging spectrometer data? This sensitivity study applies two spectroscopy models to synthetic images of the spectral hemispherical-directional reflectance factor (HDRF) with prescribed snow-covered area and snow grain size. The MEMSCAG model determines both sub-pixel snow-covered area and the grain size of the fractional snow cover. The Nolin/Dozier model analyzes the ice absorption feature that spans wavelength λ≅1.03 μm to estimate snow grain radius when the pixel is fully snow-covered. Retrievals of subpixel snow-covered area with MEMSCAG are progressively more sensitive to the HDRF as grain size decreases, solar zenith angle increases, and fractional snow cover increases. The model overestimates snow cover in the forward reflectance angles by up to +20% and underestimates it in the backward reflectance angles by as much as −15%. Grain size retrievals from both MEMSCAG and Nolin/Dozier are more sensitive to anisotropy as grain size and solar zenith angle increase. MEMSCAG retrievals of grain size are insensitive to snow-covered area. The largest inferred grain sizes occur around a peak in the backward reflectance angles and the smallest generally occur at the largest view angles in the forward direction. Retrievals of albedo from MEMSCAG and Nolin/Dozier are similarly sensitive to anisotropy, with albedo errors up to 5% for a 30° solar zenith angle and up to 10% at 60°. The albedo differences between the two models are less than 0.015 for all grain sizes and solar zenith angles.     

High‐luminance 1‐m‐long plasma tubes for wall displays

Abstract— The plasma‐tube array is expected to realize a wall‐sized display. This method will realize an emissive‐type display with a flexible screen shape and an expandable screen size. The shape of the plasma tube was investigated to realize high luminance, high luminance efficacy, and high flexural strength. As the result, a cylindroid tube is proposed to satisfy these demands. An experimental display of 1 m × 128 mm has been developed with these cylindroid tubes and it demonstrated a high luminous efficacy of 3.1 lm/W.     

Estimation of individual feature surface area with the vertical spatial grid

The area of an individual bounded surface (e.g. the boundary of a properly sampled cell) can be estimated from an isotropic uniform random stack of parallel sections, or of non-invasive planar scans, using the well-known spatial grid. A standing problem was to estimate the area of an individual bounded surface with an arbitrary degree of accuracy from a vertical (i.e. not isotropic) stack of sections or scans. A new tool to do this, called the ‘vertical spatial grid’, is presented.     

基于空-频域映射与虚警抑制的弱小目标检测算法

为了有效控制红外弱小目标检测过程中的虚警率,提高复杂云背景下的目标检测准确度,提出了基于空域-频域映射与虚警抑制的弱小目标检测算法。根据红外中心像素不同方向上的强度值,构建了方向最大中值滤波器,有效消除噪声;并利用中心像素与其邻域像素的强度差异,形成背景抑制滤波,充分增强弱小目标;考虑云区域的特有属性,联合非线性滤波,定义了云区域识别机制,提取空域映射;引入Butterworth差异低通滤波器,对去噪图像中的显著目标完成初步识别;基于其幅度信息,进行显著目标的精细检测;再利用细显著性检测结果,计算阈值,利用二值分割方法来获取去噪红外图像的频域映射;联合空域映射与频域映射,提取红外图像中的候选目标;根据真实动目标与虚警之间的运动特征差异,利用多尺度改进的管道滤波来抑制虚警,准确识别出真实目标。实验数据表明,相对于已有的弱小目标识别方案,所提方案能够准确地识别出真实目标,拥有更好的ROC特性曲线。     

Cutting Force Model for a Small-diameter Helical Milling Cutter

In the milling process, the major flank wear land area (two-dimensional measurement for the wear) of a small-diameter milling cutter, as wear standard, can reflect actual changes of the wear land of the cutter. By analyzing the wearing characteristics of the cutter, a cutting force model based on the major flank wear land area is established. Characteristic parameters such as pressure parameter and friction parameter are calculated by substituting tested data into their corresponding equations. The cutting force model for the helical milling cutter is validated by experiments. The computational and experimental results show that the cutting force model is almost consistent with the actual cutting conditions. Thus, the cutting force model established in the research can provide a theoretical foundation for monitoring the condition of a milling process that uses a small-diameter helical milling cutter.     

Effects of the surface morphologies of ZnO nanotube arrays on the performance of amperometric glucose sensors

Amperometric glucose sensors have been fabricated with glucose oxidase (GOx) immobilized on ZnO nanotubes (ZnONTs) by physical adsorption. The ZnONTs were formed through selective dissolution of ZnO nanorods (ZnONRs) which were hydrothermally synthesized on Au cylindrical spiral (AuCS) electrodes. With the etching temperature regulated, the surface morphologies of the ZnONT arrays were tailored and their effects on the performance of the corresponding glucose sensors were investigated. It is found that at 65 °C the as-prepared ZnONT arrays show a Gaussian rough surface with larger surface area and better hydrophilicity, and have an effective solid–liquid interface with GOx solution, which further results in desirable GOx immobilization. Therefore favorable performance of the ZnONT-based glucose sensor was obtained, such as the sensitivity 2.63 μA/(mM cm²), linear range 0–6.5 mM, low detection limit 8 μM (S/N=3) and Michaelis-Menten constant 5.24 mM, which are superior to that of the ZnONR-based one. Moreover, the ZnONT-based glucose sensor exhibits good long-term stability, and excellent anti-interference ability to uric acid and ascorbic acid. The results can also be used for the performance optimization and the process standardization of other ZnONT-based amperometric biosensors.     

Synthesis and evaluation of some amine compounds having surface active properties as H2S scavenger

In this work three H₂S scavengers were prepared by reacting monoethanolamine with formaldehyde in different ratios (1:1, 2:1 and 2:3) to give MF1, MF2 and MF3, respectively. The chemical structures of the prepared scavengers were confirmed by FT-IR spectroscopy. The effect of reaction time (the time required for completing the reaction between the scavenger and the H₂S gas) has been studied for the three prepared scavengers. The effects of concentration and temperature have been studied on the scavenging efficiency of H₂S using three prepared products and two commercial products EPRI-710 and EPRI-730. The surface and thermodynamic parameters of the prepared scavengers were determined at 25 °C including, surface tension (γ), and effectiveness, maximum surface excess (Γ_max) and minimum surface area (A_min). Also, the standard free energy of micellization and adsorption was recorded. The results show that the efficiency of scavengers increased with increasing reaction time up to 50 min. Also, as concentration of scavengers and temperature increased, the removal efficiency of the scavengers increased. By comparing the efficiency of the prepared products with the commercial products EPRI-710 and EPRI 730, it was found that, MF3 exhibited a similar efficiency comparing with the commercial scavenger EPRI 730 (currently used in the field) at different concentrations and temperatures.     

富县西部长2油层组储层控制因素分析

通过岩心薄片鉴定、扫描电镜和物性等分析资料,对富县西部长2段储层岩石学特征、孔隙类型和物性特征等进行研究,分析影响储层储集性能的主要控制因素。研究表明:以三角洲前缘的水下分流河道沉积的长2储层具有较低的成分成熟度和较高的结构成熟度,是控制储层发育的沉积因素;孔隙类型以粒间孔、溶蚀孔、微孔隙和裂隙为主,次生溶孔和微裂隙的存在为储层提供了储集空间和渗流通道;本区的成岩阶段已进入晚成岩A期,主要的成岩作用有压实-压溶、碳酸盐岩充填和溶解作用,不同成岩阶段的成岩作用对储层物性的改造不同,因此也控制着储层的储集性能。