查询词典 explicit difference schemes

The major implementations of the developed model include: Pseudo-spectral and finite-difference schemes are employed to approximate the spatial-differential operators in the horizontal and vertical directions, respectively. A second-order Runge-Kutta method is adopted to integrate in time for the velocity field and the free-surface elevation. The solenoidal condition of the velocity field is satisfied by solving the transformed pressure Poisson equation. A modified secant method is used to accelerate the iterative solution of the non-separable Poisson equation.

模式的主要数值方法包括：分别以拟频谱法以及二阶有限差分法近似控制方程与边界条件中的水平与垂直导数；以二阶Runge-Kutta法进行非稳态的自由液面位移与流场速度的时间积分；利用改良式割线叠代法求解计算区间中不可分离的压力Poisson方程式，以满足不可压缩流条件。

Dendrite growth has been simulated with the phase field method and finite difference schemes on a two dimensional rectangular domain with a uniform square mesh.

采用相场模型和有限差分方法，模拟了过冷纯金属熔体的枝晶生长，计算区域为二维正方形均匀网格。

At the same time, it has been calculated its truncation errors by using multi-dimensional Taylor formula and analyzed the stability by the discrete Fourier transform. At last, the conclusion of the stable difference schemes has been drawn.

同时，应用多维泰勒公式计算出它的截断误差，并在此基础上利用离散傅立叶方法分析了稳定性，得出此格式恒稳定的结论。

The local truncation error,stable conditions and positivity condition,for all these difference schemes areeasily given.

简便地给出了全部差分格式的局部截断误差，稳定性条件和正性条件。

The paper introduces the characteristics and performance of HGIS devices and their application in Bao'an Converter Station of GuiGuang II DC Project,and analyzes the abnormal condition that a 500 kV HGIS disconnector did not work correctly due to the difference between its framework and blueprint.Based on the analysis of the original blueprint,three design alternation schemes are presented and compared to compensate the mismatch,and the realization of a scheme in this station is discussed.In addition,some suggestions about design,commissioning and operation of an HGIS are proposed.

笔者首先简要介绍了HGIS设备的特点、性能以及国产500 kV HGIS开关设备在贵广II回直流工程宝安换流站的应用情况，接着分析了因隔离开关机构箱与设计图存在一些差别导致现场调试过程中出现隔离开关不能正常操作的情况，在分析原始设计图的设计原则的基础上，给出了3种设计变更方案及其优劣性对比，介绍了该站所选方案的具体实现情况，最后给出了在今后的HGIS设计、调试和运行过程中须注意的几点建议。

First, the mathematic models of equidistant and inequidistant difference schemes are founded. Then, the range of influence, criteria and process of damage location detection are obtained. The index is also used to detect concrete damage with microcrack, namely without macrocrack.

建立了基于等间距、不等间距差分格式的损伤应变模态差分数学模型及其损伤位置直接指标法，提出了损伤位置判定准则、判定步骤及损伤影响区确定方法。

Among all of the stateless broadcast encryption schemes, subset difference method is the most practical.

在无状态型广播加密机制中，目前最为可行的是子集差别方法。

Simultaneously, compared with the nine-point difference scheme which are widely applied , our new schemes have more advantageous on non-orthogonal grids, for example, the convergent accuracy, the fast-solving of the discrete system and so on.

同时与目前广泛使用的九点差分格式(文[1])作了对比实验，发现新建的三种对称有限体格式在对非正交网格的适应性、收敛精度以及相应离散化系统的快速求解等方面具有明显的优势。

Reference crop evapotranspiration (ET0) and new wetness index were both calculated and analyzed according to Penman-Monteith scheme recommended by FAO with routine meteorological data from 616 weather stations in China from 1975 to 2004. In terms of grades of wetness index from Chinese Climate Classification Criterion, China is classified into severe arid, arid, semi-arid, semi-humid and humid zones, respectively, which are compared with the demarcations from rainfall-based indices in order to reveal the similarity and difference in association with the two schemes under current global climate warming. Besides, the spatio-temporal analysis of climate wetness over the country in the past thirty years was performed.

依据中国616个地面气象台站1975年至2004年的日气象资料，利用联合国粮农组织推荐的参考蒸散计算方法，计算参考作物蒸散（ET0）和湿润指数，按照中国气候区划中的干湿指标把中国分为极干旱、干旱、半干旱、半湿润和湿润气候区，并与传统的降水量干湿指标进行对比，揭示在全球气候变化下两种干湿指标的异同，最后对中国近30 a干湿状况进行时空分析。

In conclusion, the results of multilevel model analysis showed that the GERD score of resident in Wuhan was relatively higher and had significant difference with that in Guangzhou, however, that in Shanghai, Beijing and Xi\'an had no significant difference compared with that in Guangzhou. That is to say, the prevalence of GERD in Wuhan was relatively higher compared with the other four survey sites; the residents'health status more worse, the GERD score more higher, and the influence of health status on GERD score was also effected by the region difference between Wuhan and Guangzhou; residents lived in rural region with lower education level, worse spirit status were more likely to suffer from GERD; Moreover, those residents who had family history of GI tumors or other GI diseases, some anamneses (such as dyspepsia, gastritis, rheumatic arthritis), and some diseases (such as irritable bowel syndrome and aerophagia) were also more likely to report GERD. However, no significant association was found between GERD and some other factors in this survey, such as sex, age, etc.

总之，多水平模型分析结果显示，与广州相比，上海、北京和西安居民的GERD总评分没有明显的差异，而武汉居民的GERD总评分则相对较高，即表示武汉的GERD发病率在5个调查城市中相对较高；居民的总体健康状况越差，其GERD总评分越高，且其对GERD总评分的影响受到武汉与广州之间地域差异的影响；农村居民、文化程度越低、精神状况越差者更容易患GERD；另外，那些有胃肠道疾病或肿瘤家族史，既往患有胃炎、消化不良、风湿性关节炎，现患有肠易激综合征、吞气症的人，患GERD的可能性更大，而性别、年龄等因素，本研究未发现其与GERD有显著的关系。

Objective:To compare the response control and attention of Schizophrenic patients with that of the healthy controls by Integrated Visual and Auditorycontinuous performance test. To quantitate the impairment of cognitive function in patients, and to explore the relationship between cognitive function and the severity of the disorder.

目的：探讨精神分裂症病人在IVA持续操作测试中的反应控制能力、注意力等，并与健康人进行比较，从而量化精神分裂症病人的认知功能损害，并进一步探讨其认知功能与疾病严重程度的关系。

Main effective factors including subcooling degree, mechanical vibration, gas hydrate reformation, environment temperature, noncondensing gas and surfactant are analyzed.

指出过冷度、机械振动、重复生成水合物、环境温度、不凝性气体、添加剂是影响气体水合物生成的主要因素，还对R152a水合物的放冷进行了实验研究。