硅及热处理参数对低合金奥-贝钢组织与性能的影响

研究了硅及热处理因素对中碳低合金贝氏体钢的力学性能及组织的影响.实验结果表明：含硅量为0.7-1.7%的实验钢在280-320℃范围内等温适当的时间,获得贝氏体＋奥氏体组织,具有优良的综合机械性能;含2.7%硅时获得的组织为粗大的粒状贝氏体,因而使奥-贝实验钢的性能下降;而对合2.7%硅的奥-贝实验钢经空冷及空冷回火后,得到的组织为先共析铁素体加珠光体组织,因而其性能明显次于等温淬火的实验钢.     

奥氏体——贝氏体球铁的组织与性能

本文研究了一种新型高强度球墨铸铁——奥氏体——贝氏体球铁.与铁素体及珠光体球铁相比,它不仅具有高强度,σ_b>100Kgf/mm~2,σ_(-1)>33kgf/mm~2,而且有高的塑性和韧性,δ_5>6%,K_(IC)=280Kgf/mm~(3/2).同时,其疲劳门坎值▽K_(tk)较高,而疲劳裂纹扩展速率(da)/(dN)较低.它的出现,扩大了球铁的使用范围,是球铁强韧化的一个重要发展.本文还探讨了奥氏体——贝氏体球铁的性能和组织间的关系.     

球墨铸铁接触疲劳试验第一阶段小结

表面剥落是等温贝氏体球铗齿轮失效的主要方式。为提高球铁齿轮的使用寿命,必需研究球铁接触疲劳破坏的规律和寻找提高球铁抗剥落能力的措施。本文是球铁接触疲劳试验第一阶段工作小结。使用ZYS—6型接触疲劳试验机测定了经完全奥氏体化(奥氏体化温度910℃)与部分奥氏体化(奥氏体化温度880℃)等温淬火的普通球铁以及经上述两种奥氏体化温度等温淬火的低硫球铁的接触疲劳曲线和接触疲劳极限;研究了当试验用的工作轮由等温贝氏体球铁改为GCr15钢时,普通球铁接触疲劳极限的变化;研究了等温贝氏体球铁基体组织与接触疲劳极限之间的关系;并用金相法研究了球铁的接触疲劳破坏过程。     

15MnMoVNRE钢的粒状贝氏体组织对裂纹扩展与塑韧性影响的研究

本文通过电镜动态拉伸和冲击断口形貌,研究了热轧15MnMoVNRE钢粒状贝氏体组织对塑韧性影响的因素。结果表明,在外力作用下,该钢粒状贝氏体组织中裂纹萌生及扩展,主要是在铁素体基体中进行。(M—A)岛的存在阻止裂纹的扩展,并使其改变方向,对塑韧性有利。但如果奥氏体岛分解成珠光体,则对塑韧性不利。     

SCL—90和EPQ对282例大学生心理健康状况的测评分析

采用SCL - 90及EPQ等量表对 2 82例大学生进行心理健康现状测试 ,结果 :SCL - 90阳性 5 6例 ,因子均分明显高于常模 ,其中以强迫 (1 95± 0 71 )、人际敏感(1 87± 0 5 1 )、抑郁 (1 84± 0 48)、敌对 (1 83± 0 5 5 )得分较高 ,与全国大学生水平相比 ,敌对 (1 83± 0 5 5 )、焦虑 (1 78± 0 5 9)、精神症 (1 71± 0 43)、恐怖 (1 5 7± 0 37)四项因子显著偏高 (P <0 0 1 )。被测试者中情绪稳定型、不稳型和中间型人数比例为 2∶2∶1。     

B→(K+,K0)η(′)衰变与新物理企鹅图贡献

1999年 8月 ,美国 CELO实验组在对 1 .9× 1 0 7个 B介子衰变事例进行分析的基础上 ,给出了对 4个B→ Kη(′) 衰变道衰变分枝比的新实验测量结果 :B( B → K η′) =( 80 10-9± 7)× 1 0 -6B( B0→ K0η′) =( 88 18-16± 9)× 1 0 -6( 1 )B( B→ K η) <6.9× 1 0 -6B( B0→ K0η) <9.3× 1 0 -6( 2 )在所考虑的参数空间范围内 ,对 B → K η和 B0 → K0 η衰变道 ,采用次领头阶对数近似 ( N LO)有效哈密顿和因子化方法的标准理论预言值分别为 ( 3- 6)× 1 0 -6和 ( 2 - 5)× 1 0 -6,与 ( 2 )式所示 CLEO实验上限值符…     

预热与焊后回火对铸钢基体双金属梯度堆焊锻模堆焊层组织与性能的影响

为解决大型锻模的高成本、低寿命等问题,提出铸钢基体表面堆焊制备大型液压机用锻模新方法,针对其中的焊前预热与焊后回火工艺,将有限元分析与试验分析相结合,研究预热温度与焊后回火对堆焊层组织与力学性能的影响机理。研究结果表明:常温堆焊时,堆焊熔合区组织为马氏体+碳化物+残留奥氏体;随着预热温度的升高,冷却时间不断延长,组织呈现马氏体→贝氏体→珠光体转变趋势,显微硬度逐渐降低;当预热温度为400℃时,熔合区组织为铁素体+珠光体;焊后550℃/2 h回火后,堆焊层及热影响区硬度下降,基体中析出大量碳化物,堆焊层冲击韧性显著提高,断裂方式以韧窝断裂为主,母材性能在回火后无明显变化,说明预热与焊后热处理使堆焊层获得了较好的综合力学性能。     

Nb离子注入Ti—Al合金的氧化性能研究

研究了不同注量Nb离子注入的Ti－Al合金（Al的原子分数为48％）在900,950℃静止空气中的恒温氧化行为．研究发现：注量为3×1017cm(-2)的Nb可以显著改善该合金的高温抗氧化能力;随注量的增加（3×1015→3×10(17)cm(-2)）,其改善能力得到增强;离子注入Nb是通过改变氧化反应初期的氧化形式和Ti－Al合金氧化层的显微结构而发挥作用的．     

淬火速度对厚壁高压容器钢组织性能的影响

研究了35CrNi3MoV厚壁高压容器钢经不同速度淬火后的组织与性能，结果表明，淬火速度小于1000℃／h时，形成马氏体＋贝氏体混合组织。淬火速度在30-240℃／h时，由于大量的粒状小氏体及上贝氏体形成．使强度及冲击韧性降低，40℃冲击断口出现准解理特征．然而，淬火速度在380～1000℃／h时．少量的下贝氏体形成（贝氏体相对量小于30％），屈服强度和-40℃冲击断口（韧窝花样）则得到改善。初步分析了显微组织对力学性能的影响。     

8-羟基喹啉合钴(Ⅲ)·甲醇加合物的晶体结构

合成了8-羟基喹啉合钴(Ⅲ)@甲醇加合物并测定其晶体结构.该晶体属于单斜晶系的P2(1)/n空间群.a＝1.091 8(±2)mm,b＝1.3136(±8)nm,c＝1.669 9(±3)nm,β＝97.58(±3)°,V＝2.374 0(±8)nm3,Z＝4,F(000)＝1 080.8-羟基喹啉合钴(Ⅲ)配合物中钴原子为六配位的变形八面体构型,它的甲醇加合物通过氢键形成了二维超分子晶体结构.     

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.