热源位置对室内自然对流换热影响的数值分析

利用热和流体流动控制方程,以室内局部加热(集中热源)的自然对流换热现象为研究对象,分析讨论了不同瑞利数Ra(Ra=103～106)、不同热源位置时的室内流体流线、等温线分布特征以及平均努赛尔数Nu的变化.分析结果表明:针对某一固定热源位置情况,随着Ra的增大,室内的热传输形式由热传导逐渐变为对流换热,等温线和流线形状随着Ra的增大发生变化,流线逐渐变得"紊乱";Nu与Ra呈幂数关系,拟合后其线性相关性可达93%.     

不同Ra数下隔板Rayleigh-Bénard对流系统的流动和增强传热特性

本文计算研究Ra数对隔板对流系统的流动和增强传热特性的影响.对于无量纲的狭缝高度d=0.02,传热通道的无量纲速度U和温度TD数随Ra数的变化有两个阶段,低Ra数时U随Ra数增高而上升, TD数变化不大,高Ra数时U变化不大, TD数随Ra数增高而下降.传热Nu数随Ra增高而增大,低Ra时Nu数随Ra数快速上升, Nu～Ra~(1.1),高Ra时Nu数增大变缓, Nu～Ra~(0.14).与无隔板对流系统Nuno～Ra~(0.29)对比, Nu数呈现先快速增大而后变缓的过程,出现增强传热区间和Nu数增强最大值Nuq,为7×10~5≤Ra≤5×10~9, Nuq≈3Nuno,对应Ra|Nuq≈10~7.不同狭缝高度d时速度U和TD数及Nu数随Ra数的变化特性曲线特征保持不变,但会改变特性曲线对应于Ra数的位置.狭缝高度d增大,特性曲线向低Ra数方向移动.不同d将改变隔板对流系统Ra数的传热增强区间.三个不同狭缝高度的Nu数增强最大值都是Nuno的3倍左右,狭缝高度d越大,对应的Ra数越低.     

团簇Co3NiB2异构化反应的动力学与热力学研究

为确定团簇Co₃NiB₂最终能稳定存在的优化构型并探究不同异构化反应在不同温度下与平衡常数、指前因子之间的关系,基于密度泛函理论与过渡态理论在B3LYP/Lanl2dz水平下结合范特荷夫方程与阿伦尼乌斯方程,分别从化学动力学与化学热力学角度对团簇Co₃NiB₂的异构化反应进行深入讨论.研究结果表明:构型1⁽⁴⁾～4⁽⁴⁾能大量稳定存在,且连串反应7⁽⁴⁾→5⁽⁴⁾→4⁽²⁾→1⁽²⁾最容易发生; 依据范特荷夫方程积分式可知平衡常数的对数ln K与1/T呈线性关系,依据阿伦尼乌斯方程的衍生公式可知ln A与1/T同样呈线性关系; 当T=298.15 K时,ln K与反应物和生成物的能量差ΔE呈正相关关系,且同时满足线性方程ln K(T)=0.404 31ΔE+0.388 26.研究预测团簇各个优化构型所能发生异构化反应的平衡常数K的取值范围为0.946 0～9.431 9×10¹⁹.     

关于Diophantine方程x3±23m=3Dy2

设m是正整数,D是无平方因子正整数.证明了:当m＞1时,如果D不能被3或6k+1之形素数整除,则方程x³±2^3m=3Dy²没有适合gcd(x,y)=1的正整数解(x,y).三     

不定方程x3±133=y2的整数解

利用Pell方程的解的基本性质、同余理念、因式分解等相关知识，证明了不定方程x³-13³=y²仅有整数解(x,y)=(13,0),不定方程x³+13³=y²仅有整数解(x,y)=(-13,0)。     

封闭方腔自然对流的涡结构和传热特性

为研究封闭方腔自然对流的涡结构和传热特性,对普朗特数,Pr=0.71,方腔高长比A=H/L=1,瑞利数Ra=1.58×109的二维封闭方腔自然对流进行了直接数值模拟. 给出了水平边界层发展阶段和垂直边界层转捩阶段的流场结构以及Nu数分布. 结果表明,压力梯度对方腔的水平速度变化起着决定性的作用;高Ra数下的自然对流在逆压梯度作用下水平方向形成一系列的涡,这些涡使得水平边界层流动形成分层结构;壁面Nu数与速度梯度?v/?y有着密不可分的关系.      

局部高温壁面下复合腔体内传热传质

为研究局部高温壁面下,复合腔体内自然对流及传热传质规律,采用一区域模型整体对腔内温度场、浓度场和流场进行求解.高温壁面无量纲长度A=0.5(A=a/H),局部壁面温度为Th,浓度为Ch;右侧垂直壁面分别为Tc和Cc.对局部高温壁面的相对位置B、多孔结构的孔隙率ε、瑞利数Ra的影响进行综合的数值计算,由数值计算结果得出:局部高温壁面位置不同,腔内流体流动及传热传质不同,B值在0.6附近时对应的平均努赛尔数Nu和平均舍伍德数Sh最大;ε=0.7时Nu出现最小值;Ra对传热传质影响也较大.     

两个连续正整数平方和中的素数方幂

设x,n是正整数,p是素数,证明了当p>10⁹时, 如果 x²+(x+1)²= pⁿ,则必有n=1或2.     

榆神矿区导水裂隙带高度多因素影响规律及保水采煤分区

通过融合数理统计、多元回归与空间分析方法，分析了导水裂隙带发育高度受多种因素影响规律，构建了综采导水裂隙带高度与煤层采高、采深、开采推进速度多因素之间的非线性统计关系式；基于导水裂隙带经验公式及保水采煤阈值，将榆神矿区划分为五类，工况一条件下矿区内基于水资源保护的安全开采区域(WRSE)面积为4.24×10⁹ m²,占比为82%;基于水资源保护的非安全开采区域(Non-WRSE)的面积为920 835 911.3 m²,占比为18%;工况二条件下矿区内WRSE的面积为3.87×10⁹ m²,占比为77%;Non-WRSE的面积为1.14×10⁹ m²,占比为23%;工况三条件下矿区内WRSE的面积为3.78×10⁹ m²,占比为73%;Non-WRSE的面积为1.38×10⁹ m²,占比为27%;对比研究3种工况预测的保水采煤分区数据，以保水采煤分...     

阳离子标准熵、 水合焓与配分函数的相关性

根据独立共同可别粒子体系的熵与配分函数关系, 建立70种固体化合物中阳离子标 准熵［Ｓ⁰_m／(J·mol^-1·K^-1)］与 其相对原子质量(A_r,i)、 电子层数（n_i）的数学模型： Ｓ⁰ _m=-0.51＋3.59·(1.5ln A_r,i)^1.4-0.31 (ln n_i)², R=0.9996. 对于独立共同不可别粒子体系的焓与配分函数的关系, 建立51种金属离子水合 热［Δ_hH_m／（kJ·mol^-1）］与其基态能量(ε_i )的回归方程为： -Δ_hH_m =46.93＋525.49ε_i , R=0.9920. 以上模型的计算值与实验值都基本吻合.     

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.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

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.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

A computer generator for randomly layered structures

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

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。     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.