用于气象探测的低辐射误差温度传感器设计

为了降低太阳辐射对温度传感器测量精度的影响,提出了一种低辐射误差温度传感器设计。该传感器系统包括不同涂层外壳的铂电阻探头、信号调理电路、嵌入式处理系统及误差修正算法构成。在不同太阳辐射强度下,利用不同涂层传感器的温升比值不变,推算出真实的大气温度。采用计算流体动力学方法(CFD)仿真计算出的辐射温升比值为2.31,实测比值为2.23。实验结果表明,通过低辐射误差温度传感器推算的温度值与真实大气温度值误差在0.09~0.26℃之间。与传统气象站使用的温度传感器相比,这种低辐射误差温度传感器具有精度高、响应速度快、体积小等优点。     

探空温度传感器的动态性能分析

为了研究探空温度传感器的动态性能,提出利用计算流体动力学(CFD)方法分析探空温度传感器从地面到32 km高空不同气压和不同上升速度条件下的热响应时间常数;并利用该方法对不同海拔高度下温度传感器的气流温度阶跃响应特性进行分析。仿真结果表明,探空温度传感器的热响应时间常数与海拔高度呈正相关,与探空仪上升速度呈反相关。通过拟合获得不同上升速度下,气流温度阶跃变化后的传感器温度变化与海拔高度、时间的函数关系。这种数值方法和分析结果对探空温度传感器的动态性能分析有潜在的指导意义。     

具有辐射误差修正功能的自动气象站

太阳辐射引起的气象站温度测量误差可达0.8 K以上,制约了气候变化监测和天气预报精度的提高。设计了一种具有辐射误差修正功能的自动气象站,主要由高反射率温度传感器探头、辐射传感器、风速风向传感器、高精度信号调理电路以及嵌入式处理系统等部分组成。用该气象站和强制通风温度传感器搭建了试验平台。以强制通风温度传感器作为参考,测量不同风速、不同辐射强度下的辐射误差值,利用Levenberg-Marquardt(L-M)算法拟合出用辐射强度和风速计算辐射误差的修正方程,可实现辐射误差的实时修正。实验结果表明,在一定的辐射强度和风速范围内,辐射误差平均值降低到0.021 K,显著提高了气象站气温测量精度。     

一种自然通风防辐射罩的设计与研究

为了降低太阳直接辐射、散射辐射、下垫面反射辐射等对现有气象站中温度传感器的影响,本文设计了一种多导管式球形防辐射罩。首先对防辐射罩外形结构进行设计;然后通过计算流体动力学(Computational Fluid Dynamics, CFD)方法对风速、太阳辐射强度、太阳高度角等不同环境参数下传感器的辐射误差进行量化;接着,采用支持向量机(Support Vector Machine, SVM)算法训练预测模型;最后,利用外场辐射误差实验平台对其辐射屏蔽效果及算法预测精度进行验证。实验结果表明,辐射误差精度可降至0.05 ℃量级。可见,此防辐射罩降低辐射效果显著。     

基于PSO-BP神经网络的探空湿度太阳辐射误差修正

采用计算流体动力学(CFD)软件仿真太阳辐射偏干误差可获得无线探空仪的湿度修正因子,提高了湿度廓线的精度,有助于提升天气预报、气候预测及气象灾害预报预警能力。但湿度修正因子存在明显的时空分布特性,采用CFD方法对每条湿度廓线进行修正计算量庞大。针对这一问题,以CFD软件仿真出典型气压、太阳辐射量和太阳高度角下的温度误差作为数据样本,通过粒子群优化(PSO)的BP神经网络构建预测模型,对探空湿度太阳辐射温度误差进行预测,并利用饱和水汽压逼近公式推算湿度测量的修正因子。研究结果表明,以南京探空站某一天的探空数据作为测试对象,CFD计算和PSO-BP预测的湿度测量太阳辐射误差吻合度较好,说明PSO-BP神经网络预测方法能够对湿度廓线的太阳辐射偏干误差进行有效修正,而且可显著提高修正效率。     

回填空气间隙对水平埋管换热性能的影响

建立了未夯实土壤初始温度数值计算模型,利用CFD软件求解,得到未夯实土壤初始温度数值计算结果,并将未夯实土壤初始温度数值计算结果与夯实情况下的理论计算值和实验测试数据进行比较,在该实验工况下,未夯实回填导致埋深2.2m处的土壤初始温度比夯实回填状况增大1℃左右.以未夯实土壤和夯实土壤的初始温度作为边界条件,建立埋深为2.2m的水平埋管耦合数值计算模型,利用CFD软件求解,得到土壤在未夯实和夯实情况下水平埋管换热器进出口温度及平均传热系数随时间的变化值,并与实验运行测试结果进行对比,在该实验条件下,土壤未夯实会使水平埋管进出口温度升高,系统效率降低,平均传热系数从2.71 W/(m·℃)下降到2.22 W/(m·℃).     

高空大型无人机下投探空观测资料分析

基于2020年8月2日在南海开展的中国首次高空大型无人机观测试验获取的下投探空观测资料、邻近站点常规探空资料和ERA5再分析资料,通过分析资料间的误差、平均绝对误差、均方根误差、相关系数、标准差和变化趋势,研究了下投探空资料的质量水平及其与ERA5再分析资料间的差异,并讨论了引起下投探空观测误差的原因,结果表明：各组下投探空之间温度一致性最优,好于湿度,明显好于风向风速;以常规探空为标准进行对比,下投探空温度、湿度、风速误差水平接近WMO CIMO的精度要求,风向受探空仪下落速度和下垫面差异影响导致误差较大;ERA5的温度、中下层湿度与下投探空偏差较小,风向相差较大,风速在1 000～2 000 m高度区间偏差较大,下投探空上层湿度明显偏干;探空仪高速下落对湿度、风向、风速测量准确度影响明显,湿度还受传感器测量性能影响,可能受环境温度突变影响.     

微波冷冻干燥过程中光纤测温技术的研究

分析了半导体吸收波长随温度的变化特性,选用红外发光二极管作为信号光源,光纤采用石英光纤,设定这类半导体吸收式光纤温度传感器的基本参数,建立了半导体材料ＧａＡｓ的透过率与温度关系的数学模型．采用一种基于双波长原理的输送回路来减少测量误差,研制成功了一套半导体吸收式光纤测温系统．在０～１００℃内进行了实验测试．结果表明,改进后的光纤温度传感器可以替代传统的热电偶在微波场中进行实时测温     

液体火箭发动机羽烟三维紫外辐射仿真研究

针对液体火箭发动机羽烟紫外辐射的空间分布问题,建立三维数值计算模型.该模型采用标准κ-ε湍流模型和PDF模型仿真羽烟流场的状态参数,根据HITRAN数据库计算流场内吸收系数分布,并利用离散坐标法求解辐射传输方程,计算三维空间的紫外辐射分布.测试结果表明:三维紫外辐射模型的计算结果与实验数据一致,能够反应不同视角下液体火箭发动机羽烟紫外辐射强度的空间变化.     

温度传感器非线性误差的理论分析及其实验研究

通过导出的温度传感器的温度－电压特性线性化电路参数Ｒｓ和Ｒｆ应满足的方程组，在（Ｒｓ，Ｒｆ）变数平面内对该方程组的性质进行了分析，并提出了求解这一方面组的数值计算方法和计算传感器非线性误差的理论公式，其理论计算与实验结果吻合较好。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

An Index mechanism for multi-scale view in spatial databases

There are numerous geometric objects stored in the spatial databases. An importance function in a spatial database is that users can browse the geometric objects as a map efficiently. Thus the spatial database should display the geometric objects users concern about swiftly onto the display window. This process includes two operations:retrieve data from database and then draw them onto screen. Accordingly, to improve the efficiency, we should try to reduce time of both retrieving object and displaying them. The former can be achieved with the aid of spatial index such as R-tree, the latter require to simplify the objects. Simplification means that objects are shown with sufficient but not with unnecessary detail which depend on the scale of browse. So the major problem is how to retrieve data at different detail level efficiently. This paper introduces the implementation of a multi-scale index in the spatial database SISP (Spatial Information Shared Platform) which is generalized from R-tree. The difference between the generalization and the R-tree lies on two facets: One is that every node and geometric object in the generalization is assigned with a importance value which denote the importance of them, and every vertex in the objects are assigned with a importance value,too. The importance value can be use to decide which data should be retrieve from disk in a query. The other difference is that geometric objects in the generalization are divided into one or more sub-blocks, and vertexes are total ordered by their importance value. With the help of the generalized R-tree, one can easily retrieve data at different detail levels.Some experiments are performed on real-life data to evaluate the performance of solutions that separately use normal spatial index and multi-scale spatial index. The results show that the solution using multi-scale index in SISP is satisfying.     

海南岛地体及其毗邻陆缘晚中生代—新生代古地磁研究和构造演化

本文叙述了对海南岛及其毗邻大陆边缘白垩纪到第四纪地层岩石进行古地磁研究的全部工作过程。通过分析岩石中剩余磁矢量的磁偏角及磁倾角的变化,提出海南岛白垩纪以来经历的构造演化模式如下:早期伴随顺时针旋转而向南迁移,后期伴随逆时针转动并向北运移。联系该地区及邻区的地质、地球物理资料,对海南岛上述的构造地体运动提出以下认识:北部湾内早期有一拉张作用,主要是该作用使湾内地壳显著伸长减薄,形成北部湾盆地。从而导致了海南岛的早期构造运动,而海南岛后期的构造运动则主要是受南海海底扩张的影响。海南地体运动规律的阐明对于了解北部湾油气盆地的形成演化有重要的理论和实际意义。     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that