检索结果-南通市图书馆

地形影响的水平相关模型在CMA-MESO中的应用

在线全文

学校读者我要写书评

暂无评论

应用气象学报 2024年第4期35卷 414-428页

作者：庄照荣李兴良王瑞春高郁东中国气象局地球系统数值预报中心北京100081 中国气象科学研究院灾害天气国家重点实验室北京100081 中国气象局地球系统数值预报重点开放实验室北京100081 重庆市气象科学研究所重庆401147 致灾降水数值模式与人工智能融合预报关键技术研究重点实验室重庆401147

在背景误差水平相关模型中引入地形作用,研究复杂地形下近地面观测资料同化对分析和预报的影响。CMAMESO三维变分系统中背景误差水平相关关系采用高斯相关模型描述,观测信息在高度追随坐标的模式面上各向同性传播。然而在地形复杂的近... 详细信息

在背景误差水平相关模型中引入地形作用,研究复杂地形下近地面观测资料同化对分析和预报的影响。CMAMESO三维变分系统中背景误差水平相关关系采用高斯相关模型描述,观测信息在高度追随坐标的模式面上各向同性传播。然而在地形复杂的近地面层,观测信息传播受到山脉阻挡,因而其背景误差协方差非均匀且各向异性,观测信息传播应随地形高度变化。为此,采用美国国家气象中心NMC方法统计复杂地形下背景误差水平相关结构,构建包含地形高度和地形梯度影响的高斯相关模型,并将改进的水平相关模型应用于CMA-MESO三维变分分析。理想试验表明:考虑地形项的水平相关模型方案使观测信息以随地形高度变化的各向异性形式传播,越过大地形观测信息影响明显减弱,分析增量更加合理。我国北方一次强降水过程分析预报试验表明:随地形高度变化的水平相关模型方案使地面观测信息各向异性传播,削弱了大地形处近地面的分析增量,对降水预报略有正贡献。针对华东地区降水过程进行5 d逐小时快速更新分析预报循环试验结果表明,随地形变化的水平相关模型方案对10 m风场和24 h时效内降水预报有正贡献。

关键词：背景误差水平相关模型地形三维变分 CMA-MESO

基于奇异值分解消噪原理的多通道卷积神经网络算法在石油勘探数据质量控制上的研究与实践检验

在线全文

学校读者我要写书评

暂无评论

智能计算机与应用 2024年第8期14卷 165-168页

作者：徐振李兴亮龙军中国石油吐哈油田分公司勘探开发研究院新疆哈密839000

在石油勘探中,数据常常受噪声干扰影响,精度和准确性变差,数据的可信度降低,进而影响油气勘探的成效,因此数据处理是油气勘探中的重要环节。奇异值分解(SVD)是一种常用的信号处理方法,能有效降低数据噪声。本文提出的基于SVD的多通道卷... 详细信息

在石油勘探中,数据常常受噪声干扰影响,精度和准确性变差,数据的可信度降低,进而影响油气勘探的成效,因此数据处理是油气勘探中的重要环节。奇异值分解(SVD)是一种常用的信号处理方法,能有效降低数据噪声。本文提出的基于SVD的多通道卷积神经网络算法,有针对性地解决石油勘探数据中的噪声问题,为石油勘探数据的消噪和质量的提升提供了新的思路和方法,具有良好的推广应用前景。

关键词：奇异值分解多通道卷积神经网络算法石油勘探数据噪声处理

适用于非静力大气模式的近似黎曼求解器应用研究

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

气象学报 2024年第3期82卷 371-384页

作者：魏杰姝陈春刚张寅钲唐杰沈学顺肖锋李兴良中国气象科学研究院北京100081 中国气象局地球系统数值预报中心北京100081 西安交通大学西安710049 成都市温江区气象局成都610072 东京工业大学机械工程系东京152-8850

基于多矩非静力大气模式,开展了3类垂向近似黎曼求解器应用研究。多矩非静力大气模式具有高精度与数值守恒特性,其垂向采用守恒的有限差分格式进行数值离散,而网格单元边界通量计算是通过求解黎曼问题来实现的,因此采用合适的近似黎曼... 详细信息

基于多矩非静力大气模式,开展了3类垂向近似黎曼求解器应用研究。多矩非静力大气模式具有高精度与数值守恒特性,其垂向采用守恒的有限差分格式进行数值离散,而网格单元边界通量计算是通过求解黎曼问题来实现的,因此采用合适的近似黎曼求解器对准确模拟非静力大气垂直运动显得十分关键。LLF(Local Lax-Friedrich)、LMARS(Low Mach Approximate Riemann Solver)和HLLC(Harten-Lax-van Leer Contact)为计算流体力学(CFD)中常用的3种近似黎曼求解器,它们的计算代价和复杂程度逐渐增加。一维标准数值试验表明:LLF计算最为经济,但具有较强的耗散;LMARS具有适用于大气流动的假设,对于数值粘性的控制较好且计算量不大;HLLC建立的三波模型可以避免对中间特征场的过度数值耗散。基于LLF近似黎曼求解器计算经济的特点,通过优化LLF近似黎曼求解器各特征波动的粘性系数,能够实现与LMARS、HLLC近似黎曼求解器相同的性能,且计算代价最小。二维非静力数值试验表明,优化的LLF近似黎曼求解器能够规避常规LLF近似黎曼求解器的数值耗散过大问题,正确模拟小尺度非静力垂直运动,达到更复杂的LMARS、HLLC近似黎曼求解器模拟效果且并未增加计算量,这为非静力大气数值模式提供了良好的参考价值。

关键词：近似黎曼求解器守恒型有限差分方法多矩约束有限体积方法非静力大气模式

An Adaptive Nonhydrostatic Atmospheric Dynamical Core Using a Multi-Moment Constrained Finite Volume Method

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2022年第3期39卷 487-501页

作者： Pei HUANG Chungang CHEN xingliang li Xueshun SHEN Feng XIAO State Key Laboratory for Strength and Vibration of Mechanical Structures Xi’an Jiaotong UniversityXi’an 710049China Center of Numerical Weather Prediction China Meteorological AdministrationBeijing 100081China Department of Mechanical Engineering Tokyo Institute of TechnologyTokyo 226-8502Japan

An adaptive 2 D nonhydrostatic dynamical core is proposed by using the multi-moment constrained finite-volume(MCV) scheme and the Berger-Oliger adaptive mesh refinement(AMR) algorithm. The MCV scheme takes several pointwise values within each computational cell as the predicted variables to build high-order schemes based on single-cell reconstruction. Two types of moments, such as the volume-integrated average(VIA) and point value(PV), are defined as constraint conditions to derive the updating formulations of the unknowns, and the constraint condition on VIA guarantees the rigorous conservation of the proposed model. In this study, the MCV scheme is implemented on a height-based, terrainfollowing grid with variable resolution to solve the nonhydrostatic governing equations of atmospheric dynamics. The AMR grid of Berger-Oliger consists of several groups of blocks with different resolutions, where the MCV model developed on a fixed structured mesh can be used directly. Numerical formulations are designed to implement the coarsefine interpolation and the flux correction for properly exchanging the solution information among different blocks. Widely used benchmark tests are carried out to evaluate the proposed model. The numerical experiments on uniform and AMR grids indicate that the adaptive model has promising potential for improving computational efficiency without losing accuracy.

关键词： adaptive mesh refinement multi-moment constrained finite-volume method nonhydrostatic model dynamical core high-order methods

Complexation between uranyl(Ⅵ)and CMPO in a hydroxyl-functionalized ionic liquid:An extraction,spectrophotography,and calorimetry study

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2022年第7期33卷 3451-3455页

作者： Baihua Chen Jun liu Hongyuan Wei Yuchuan Yang xingliang li Shuming Peng Yanqiu Yang Institute of Nuclear Physics and Chemistry CAEPMianyang 621900China

The extraction complexes of uranyl(Ⅵ)in HNO_(3)to a hydroxyl-functionalized ionic liquid(IL)phase,HOEtmimNTf2bearing CMPO,were *** possibly successive extraction complexes,UO_(2)L^(2+)(L=CMPO),UO2L_(2)^(2+) and UO_(2)L_(3)^(2+),were detected based on variable U/L ***(Ⅵ)prefers to be extracted as complex UO_(2)L_(3)^(2+),combining with the ions from HOEtmimNTf_(2) to construct a solid material through *** thermodynamics of complexes,UO_(2)L_(j)^(2+)(j=1-3),were studied by spectrophotometry and *** the formation reactions are principally driven by entropy,although a small part of the driving force of complexes UO_(2)L_(2)^(2+)and UO_(2)L_(3)^(2+) comes from *** on the thermodynamic properties for complex UO_(2)L_(3)^(2+),we provide a possible coordination mode in HOEtmim NTf_(2):the first CMPO molecule coordinates with UO_(2)^(2+) in a bidentate fashion while the others do in a monodentate *** results offer a thermodynamic insight into the formation behaviors of the uranyl(Ⅵ)/CMPO complexes involving the special IL HOEtmimNTf_(2),which is of significance to advance the novel IL extraction strategy.

关键词： Uranyl(Ⅵ) CMPO Ionic liquid Solvent extraction Complexation Thermodynamics

An Improved Dynamic Core for a Non-hydrostatic Model System on the Yin-Yang Grid

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2015年第5期32卷 648-658页

作者： li Xiaohan PENG Xindong li xingliang State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences Center of Numerical Weather Prediction China Meteorological Administration

A 3D dynamic core of the non-hydrostatic model GRAPES（Global/Regional Assimilation and Prediction System） is developed on the Yin-Yang grid to address the polar problem and to enhance the computational efficiency. Three-dimensional Coriolis forcing is introduced to the new core, and full representation of the Coriolis forcing makes it straightforward to share code between the Yin and Yang subdomains. Similar to that in the original GRAPES model, a semi-implicit semi-Lagrangian scheme is adopted for temporal integration and advection with additional arrangement for cross-boundary transport. Under a non-centered second-order temporal and spatial discretization, the dry nonhydrostatic frame is summarized as the solution of an elliptical problem. The resulting Helmholtz equation is solved with the Generalized Conjugate Residual solver in cooperation with the classic Schwarz method. Even though the coefficients of the equation are quite different from those in the original model, the computational procedure of the new core is just the same. The bi-cubic Lagrangian interpolation serves to provide Dirichlet-type boundary conditions with data transfer between the subdomains. The dry core is evaluated with several benchmark test cases, and all the tests display reasonable numerical stability and computing performance. Persistency of the balanced flow and development of both the mountain-induced Rossby wave and Rossby–Haurwitz wave confirms the appropriate installation of the 3D Coriolis terms in the semi-implicit semi-Lagrangian dynamic core on the Yin-Yang grid.

关键词： Yin-Yang grid semi-implicit semi-Lagrangian nonhydrostatic dynamic core

Cross-resistance and genetics of field-evolved resistance to chlorfenapyr in Plutella xylostella

在线全文

学校读者我要写书评

暂无评论

Insect Science 2024年第2期31卷 533-541页

作者： Cheng Qian Jialin li Shuwen Wu Yihua Yang Yidong Wu xingliang Wang Sanya Institute of Nanjing Agricultural Universty SanyaHainanChinaand College of Plant Protection Nanjing Agricultural UniversNanjingChina

Chlorfenapyr is a broad-spectrum halogenated pyrrole insecticide with a unique mode of *** to the misuse and overuse of this chemical,resistance has been reported in several arthropods,including Plutella xylostella,which is one of the most destructive insect pests afflicting crucifers worldwide.A better understanding of the cross-resistance and genetics of field-evolved chlorfenapyr resistance could effectively guide resistance management ***,the chlorfenapyr resistance of a fieldderived population of P xylostella was introgressed into the susceptible IPP-S strain using a selection-assisted multigenerational backcrossing *** constructed nearisogenic strain,TH-BCsF2,shared 98.4%genetic background with the recurrent parent IPP-S *** TH-BCsF2 strain showed 275-fold resistance to chlorfenapyr,but no significant cross-resistance to spinosad,abamectin,chlorpyrifos,β-cypermethrin,indoxacarb,chlorantraniliprole,or broflanilide(no more than 4.2-fold).Genetic analysis revealed that resistance was autosomal,incompletely dominant,and conferred by 1 major gene or a few tightly linked *** synergism of metabolic inhibitors(PBO,DEM,and DEF)to chlorfenapyr was very weak(lic enzyme activities in the TH-BCsF2 strain were not significantly elevated compared with the IPP-S *** results enhances our understanding of the genetic traits of chlorfenapyr resistance,and provides essential information for improving resistance management strategies.

关键词： chlorfenapyr cross-resistance mode of inheritance near-isogenic line Plutellaxylostella

Improvement of the Semi-Lagrangian Advection Scheme in the GRAPES Model:Theoretical Analysis and Idealized Tests

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2014年第3期31卷 693-704页

作者： HUANG Bo CHEN Dehui li xingliang li Chao Chinese Academy of Meteorological Sciences Numerical Weather Prediction Center China Meteorological Administration University of Chinese Academy of Sciences

ABSTRACT The Global/Regional Assimilation and PrEdiction System （GRAPES） is the newgeneration numerical weather predic- tion （NWP） system developed by the China Meteorological Administration. It is a fully compressible non-hydrostatical global/regional unified model that uses a traditional semi-Lagrangian advection scheme with cubic Lagrangian interpola tion （referred to as the SL_CL scheme）. The SL_CL scheme has been used in many operational NWP models, but there are still some deficiencies, such as the damping effects due to the interpolation and the relatively low accuracy. Based on Reich＇s semi-Lagrangian advection scheme （referred to as the R2007 scheme）, the Re_R2007 scheme that uses the low- and high-order B-spline function for interpolation at the departure point, is developed in this paper. One- and two-dimensional idealized tests in the rectangular coordinate system with uniform grid cells were conducted to compare the Re..R2007 scheme and the SL_CL scheme. The numerical results showed that：（1） the damping effects were remarkably reduced with the Re_R2007 scheme; and （2） the normalized errors of the Re_R2007 scheme were about 7.5 and 3 times smaller than those of the SL_CL scheme in one- and two-dimensional tests, respectively, indicating the higher accuracy of the Re..R2007 scheme. Furthermore, two solid-body rotation tests were conducted in the latitude-longitude spherical coordinate system with non uniform grid cells, which also verified the Re_R2007 scheme＇s advantages. Finally, in comparison with other global advection schemes, the Re_R2007 scheme was competitive in terms of accuracy and flow independence. An encouraging possibility for the application of the Re_R2007 scheme to the GRAPES model is provided.

关键词： numerical models semi-Lagrangian method advection scheme numerical accuracy spline interpolation

在线全文

学校读者我要写书评

暂无评论

4种矮化自根砧对宫藤富士苹果抗盐性的影响

中国果树 2024年第4期 23-28,44页

作者：周佳李兴亮李民吉周贝贝杨雨璋张强魏钦平张军科北京市农林科学院林业果树研究所北京市落叶果树工程技术研究中心100093

比较了盐胁迫对不同矮化自根砧宫藤富士苹果生长的影响,为土壤盐碱化地区苹果矮化自根砧木的选用与抗盐机理研究提供参考。以SH6、M9T337、G935、G114种矮化自根砧宫藤富士苹果2年生盆栽苗为试材,浇灌0.5%NaCl、1.0%NaCl溶液进行胁迫处... 详细信息

比较了盐胁迫对不同矮化自根砧宫藤富士苹果生长的影响,为土壤盐碱化地区苹果矮化自根砧木的选用与抗盐机理研究提供参考。以SH6、M9T337、G935、G114种矮化自根砧宫藤富士苹果2年生盆栽苗为试材,浇灌0.5%NaCl、1.0%NaCl溶液进行胁迫处理,以浇灌去离子水为对照,在持续处理60 d后调查盐害指数,测定生长、矿质元素含量等指标。结果表明:G11矮化自根砧宫藤富士植株盐害指数最高,其次为SH6矮化自根砧和M9T337矮化自根砧,G935矮化自根砧宫藤富士植株盐害指数最低,表现最为抗盐;盐胁迫下各矮化自根砧植株生长均受到显著抑制,生物量积累以G935矮化自根砧宫藤富士植株最高,G11矮化自根砧宫藤富士植株最低。在1.0%NaCl胁迫处理下,G11矮化自根砧富士叶片Na^(+)含量升高程度最大,为对照叶片的34.4倍;而G935矮化自根砧宫藤富士叶片Na^(+)含量升高程度最低,仅为对照叶片的2.4倍。4种矮化自根砧宫藤富士植株的抗盐性由强到弱依次为G935>M9T337>SH6>G11,抗盐矮化自根砧能够有效维持宫藤富士植株地上部低钠水平可能是其抗盐性形成的关键因素。

关键词：苹果矮化自根砧宫藤富士盐胁迫 Na+运输