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1.
真空和堆载两种预压法的室内试验研究   总被引:2,自引:0,他引:2  
通过室内试验模拟真空预压法和堆载预压法加固不同深度的土体,对两种预压法下土体前后的物理力学性质指标、土体的沉降量、排水量等进行了分析,认为两种方法均能使土体的物理力学性质改善,就渗透性而言,真空预压优于堆载预压,但就压缩性而言,堆载预压优于真空预压;堆载预压下试样的轴向位移远大于真空预压下的轴向位移,且比真空预压下的沉降收敛慢;真空预压下的排水量大约是堆载预压下排水量的1.8倍;在真空预压和堆载预压下,浅层土体的排水量均大于深层土体的排水量。  相似文献   

2.
张霞 《化工矿产地质》2013,(1):47-51,64
对电感耦合等离子体质谱法与一米光栅发射光谱法在化探样品中的痕量银测定进行对比,实验表明,两种方法都具有高精密度和准确度,检出限也符合区域化探的要求,但是在大批量的化探测定及多元素同时测定方面,质谱法操作简单、快速、准确、成本低,优于一米光栅发射光谱法,更适合应用于批量化探样品中银的测定。  相似文献   

3.
王欣  王健  张举  傅力浦  孟勇  张欣 《地质科学》2013,48(4):1295-1301
Oktavites spiralis是志留纪兰多维列统特列奇阶的笔石带化石之一,具有重要的地层意义。为更精确地描述这一属种,对产自陕西岚皋地区的Cyrtograptus lapworthi笔石带的O.spiralis不同发育阶段的标本进行了详细研究,从而对其始部发育情况有了更深入的认识。同时,对O.spiralis发育过程的研究也可以成为对该属进行精确厘定的手段之一。  相似文献   

4.
黄晶 《地质与勘探》2002,38(4):67-70
将冶金地质系统50年来积累的地矿资源数据集中起来,便于管理和合理使用有用信息,建立矿产资源数据仓库是很重要的一种手段,数据仓库技术能将集成的数据置入多维空间,供地质人员从不同工作视角获取信息,综合分析数据,以指导找矿工作,在此,简要介绍了如何建立矿产资源数据仓库的过程。  相似文献   

5.
上扬子区寒武系蒸发岩沉积相及成钾潜力分析   总被引:1,自引:0,他引:1  
寒武纪是世界上重要的成钾时代之一。早寒武世成钾的西伯利亚涅帕钾盐矿床是世界上特大型钾盐矿床之一;印度一巴基斯坦在“始寒武世”地层成钾;伊朗在寒武纪地层也有钾盐发现。与其它大陆成盐强度相比,寒武系成盐成钾成为“亚洲现象”。中国地处东亚,已发现越来越多寒武系成盐盆地。本文着重介绍上扬子区寒武系蒸发岩发育特点,指出在上扬子陆块之上,发育面积达20万km2的蒸发岩盆地,并首次圈定两个膏盐岩聚集区(次盐盆地):泸州一江津区与巫溪一建南区,该区具备有利成盐找钾条件,值得今后进一步研究探索。  相似文献   

6.
A suite of schists—one from the garnet zone, 19 from thestaurolite zone, 2 from the kyanite isograd, and one from thekyanite zone—were separated into their constituent minerals.Chemical analyses of one chlorite and of 23 sets of coexistingbiotites and garnets were carried out by photometric and titrametricprocedures. Plots of garnet-biotite tie-lines from divariantassemblages on appropriate phase diagrams result in intersectingtie-lines which cannot be ascribed to experimental error. Theoreticalconsiderations argue that at equilibrium, at the same pressureand temperature or at constant pressure and varying temperature,tie-lines of divariant assemblages should not intersect. Possibleexplanations require that diffusion equilibrium of Fe and Mgbe restricted to volumes smaller than that of a hand specimenor that P as well as T varies considerably. Emission spectrographicdeterminations of Fe and Mg in biotite indicate that the Fe/Mgratio varies among biotites little more than a centimeter apart.Such a variation would argue more in favor of a lack of diffusionequilibrium.  相似文献   

7.
400余米深单孔波速测试体会   总被引:1,自引:0,他引:1  
蒋传琳  蒋传志  吕鑫方 《物探与化探》2005,29(2):183-184,188
介绍了测试400余米深井效果情况。实践表明了采取一定措施单孔检层法测试PS波可以突破百米的禁界,使此项技术推向更广泛的应用领域。  相似文献   

8.
用新老两台高频大地电磁仪,在同一测点上进行一致性试验研究.结果表明:新款仪器在50Hz频率的陷波能力较强,老款仪器陷波能力相对较弱.在200~63100Hz频段上两台仪器一致性较好.两台仪器在同一测点同时观测时相互之间存在干扰.  相似文献   

9.
Mantle plumes and plate motions   总被引:3,自引:0,他引:3  
This paper elaborates the hypothesis that convection plumes may be rising from the lower mantle to spread out in the asthenosphere and drive lithospheric plates about and thus possibly provide the primary mechanism which governs the behaviour of the earth's surface. The paper notes some characteristics of plumes and identifies more than thirty by the hot spots which overlie them. Most lie close to mid-ocean ridges and have produced aseismic ridges trending away from them on either plate. A few have been overridden by plates to produce single, isolated chains of seamounts and islands. One plume may have uplifted the Colorado Plateau. Such distinctions serve to identify five types of hot spots.Most plates are in motion over the lower mantle. They are considered to be driven by the plumes, but their paths are influenced by interactions with other plates. Some temporarily become more or less stationary relative to the lower mantle. It is held that stationary plates, of which Africa and Southeast Asia may be present examples, develop special characteristics among which much volcanism, epeirogenic uplift, rifting and the development of basins and swells are diagnostic.It is well-known that if two plates approach one another at a subduction zone that a continental plate generally overrides an oceanic one. It is here suggested that the question of which plate is more nearly stationary over the mantle is important and determines the character of the continental margin. It is held that, if a continental plate advances over an oceanic one which is fixed over the mantle, a migrating marginal trench and mountains of Andean type with huge batholiths will form on the leading edge of the continent. On the other hand, if a continental plate is fixed and one or more oceanic plates are advancing and sliding under it, island arcs (and, when a collision with another continent occurs, mountains of Appalachian type) will form along each coast towards which a plate is advancing.  相似文献   

10.
鄂尔多斯盆地周边地区野外溶蚀试验结果讨论   总被引:1,自引:3,他引:1  
2003到2004年,在国土资源部地质调查项目“鄂尔多斯盆地地下水勘查”工作中,作者在鄂尔多斯盆地周边地区建立了8个野外溶蚀试验站,采用不同岩石的600多枚试片开展了为期1年的野外溶蚀试验观测。通过试验并结合前人的野外溶蚀试验成果分析,得出了如下几个重要的结论: ( 1)试验区灰岩较白云岩的溶蚀量大20%以上; ( 2)与我国南方的试验结果相反,即北方土下碳酸盐岩样品溶蚀量远远小于地上样品的溶蚀量; ( 3)从华北到西北存在一个碳酸盐岩样品由溶蚀变为沉淀的地带;同理,从我国北方碳酸盐岩样品土下溶蚀量小于地上溶蚀量到南方土下溶蚀量大于地上溶蚀量区域变化过程中,又存在土下与地上溶蚀量接近的地带,这两个地带是控制我国现代岩溶作用机制的重要分界线,对岩溶地貌的发育与演化研究具有重要意义。   相似文献   

11.
因一字形钎头破岩效率低和几何形状结构缺陷等问题,瑞典从70年代中期就用锥体连接的十字和球齿钎头取代了一字形犴头。现在,我们建议用更具优势的复合片齿钎头逐步更新一字形钎头,新系列钎头寿命为一字,球齿钎头寿命的2-4倍,而价格仅比同直径一字,球齿钎头高1/5-1/3。  相似文献   

12.
郑文琛 《矿物学报》1989,9(2):165-168
用晶体场理论研究了方镁石中Cr~(3+)离子的零场劈裂D随单轴压力的变化,发现杂质离子附近的局部压缩率的确不同于基质晶体的压缩率,即由于Cr~(3+)离子附近有阳离子空位出现,空位附近的氧离子将更易于向空位压缩,造成局部压缩率不同于基质晶体压缩率。  相似文献   

13.
逆断层地裂缝在黄土中破裂扩展的数值模拟   总被引:1,自引:0,他引:1  
隐伏地裂缝在黄土中的扩展机理,其影响的范围、程度等问题,都是城市工作者所广泛关注和亟待解决的重要问题。为了研究黄土中逆断层地裂缝的扩展机理和扩展特征,参照正断层大型物理模型试验,利用数值模拟的方法,建立了三维数值分析模型,进行了黄土中逆断层的扩展机理研究。研究表明,隐伏逆断层地裂缝活动时,在地裂缝的上端,土体单元受到拉、压、剪的共同作用,裂缝很快被贯通,因而在其上端形成了破裂区,但向两侧的扩展有限;地裂缝的下盘在地裂缝活动时,受到的影响较小,即逆断层主要影响地裂缝的上盘,而对下盘影响甚微;同时,逆断层的影响范围和深度都明显小于正断层。由此可见,逆断层地裂缝活动特征明显区别于正断层,在黄土中的扩展有其独特之处。   相似文献   

14.
文章通过成矿物质来源、成矿作用与岩浆岩及构造的关系、成矿阶段的划分等方面的研究,认定卧龙泉金矿为多阶段、多成因、多来源的中-低温热液矿床.进而确定了卧龙泉金矿床的成矿模式.  相似文献   

15.
张友良  谭飞  张礼仁  施明明 《岩土力学》2016,37(11):3309-3316
讨论了亿万单元有限元模型的可扩展并行计算方法。从软件和硬件两个方面提出了前处理、并行计算方法、程序算法、后处理实现等核心问题的解决方案。采用网格加密方法生成一亿单元的有限元模型,利用对偶原始有限元撕裂内联法(FETI-DP)求解系统方程。基于图论理论建立了子区域间的通讯拓扑关系,实现了子区域间点对点通讯,避免速度慢、通信量大的全局通讯。在自主开发程序基础上,增加相应模块,采用面向对象编程技术和MPI消息传递库开发程序。对一个一亿多单元的工程实例运用5 000核并行计算,得到了超线性加速比。计算结果在专用图形工作站上进行后处理,显示和交互操作速度良好。研究在两方面实现了突破:一是将模型规模提高到了一亿多单元;二是同时调用了5 000个计算核来并行运算,并得到了很高效率。高分辨率有限元并行模拟研究成果可为岩土工程中结构特别复杂、计算区域特别大、地质情况复杂等模拟提供很好的技术方法和实现手段。  相似文献   

16.
次网格积雪参数化在祁连山区斑状积雪带模拟中的应用   总被引:2,自引:0,他引:2  
运用中尺度大气模式MM5,积雪参数化分别采用简单的积雪参数化方案以及考虑次网格积雪分布和雪密度变化的复杂积雪参数化方案,对黑河流域上游祁连站附近气温和降水进行模拟,与祁连站的观测值对比,检验积雪参数化方案中次网格积雪分布和雪密度变化在该地区气温和降水模拟中的作用.结果表明:简单积雪方案对网格积雪的非0即1描述在斑状积雪带是不合理的,尤其在黑河流域海拔3 300 m以下积雪多为斑状或片状,网格内积雪非均匀性的处理是非常必要的;通过耦合简单和复杂积雪方案的大气模式对气温模拟和观测值比较发现,新方案模拟的气温比旧方案模拟值更接近观测值,在气温低于0℃时改进尤其明显,说明使用复杂积雪/融雪方案可改进斑状积雪带气温的模拟.耦合复杂积雪方案的大气模式模拟的降水与观测值绝对误差低于耦合简单积雪方案模拟结果,复杂积雪方案的模拟结果降水错报率为使用简单积雪方案结果的一半,证明了耦合复杂积雪方案可以提高大气模式对该地区春季降水模拟的准确性.与积雪面积变化相对应,耦合复杂积雪方案模拟出了融雪产流量,而使用简单积雪方案则没有模拟出来.综上所述,耦合考虑次网格积雪分布和雪密度变化的复杂积雪参数化方案比耦合“非0即1”积雪方案可以更准确地模拟祁连山区冬、春季气温和降水.  相似文献   

17.
塔里木多旋回盆地复合构造样式初步分析   总被引:10,自引:10,他引:10  
塔里木盆地多旋回的演化历史导致了多期次的复合构造变形作用。不同方式的构造运动导致了不同方式的复合,不同等级和不同规模的变形叠加导致了不同级次的复合构造。根据造成复合构造的应力场变化的特征,结合具体实例将塔里木盆地复合构造划分为8种主要类型:继承性挤压、继承性走滑、挤压--走滑、走滑--挤压、拉张--挤压、挤压--拉张、挤压--重力和重力--挤压复合构造。复合构造为油气运移提供了新的运移动力场及高效输导体系。构造复合一方面可能会加大早期构造的幅度并使其更为复杂,另一方面会导致各种圈闭更为复杂的平面组合与纵向叠置方式。构造复合对早期已聚集的油气存在一定的破坏作用,同时,由多油源、多期生烃、多通道、多圈闭类型和多成藏期组成的成藏条件也在复合构造中形成了以塔河--轮南特大型油气田为代表的复式油气聚集带。  相似文献   

18.
Since the attainment of democracy in 1994 one of the major concerns of the South African government has been to address the social and economic injustices that characterised the apartheid regime. With tourism on the rise in South Africa and international arrivals growing at a rate almost triple the global rate, the tourism industry has been identified as one of the important industries to drive the transformation agenda. This study sought to assess the employment situation in Cape Town’s lodging sector, identify the existing types of jobs and skills requirements of the sector, determine career aspirations of and skills development needs for lodging sector employees as well as asses the state of transformation. Study findings showed that the lodging sector is labour intensive, requires low academic skill, and offers low paying employment following the findings that about a quarter of the respondents indicated that their jobs didn’t require any formal qualification, the average working day was 9.2 h and 52% earned below R3,500 a month. The study showed significant differences in income based on race. White employees earned significantly more than their black and coloured counterparts. However, white employees working as general labour were also significantly more qualified than their black and coloured counterparts. There was a significant positive relationship between income and length of service for white employees, but the same wasn’t true for black and coloured employees. There was a significant negative relationship between length of service and academic qualifications for black employees implying that black people’s length of service for one employer decreases as they become more academically qualified. Also significant was skills development opportunities based on gender. Significantly more females than males had attended on-the-job training programs.  相似文献   

19.
Social practice theories provide a unique platform for understanding how everyday practices become globalised through migration, spreading from one place to another, replacing local, often more sustainable, variations. Set in the context of the spreading of resource-intensive practices such as multiple daily showers, we explore the movement and migration of domestic practices, acknowledging that they are constantly shifting from one relatively stable form to another. Drawing on the phenomenon of human migration where, for various reasons, people move from one country to another, we argue that migrants ‘carry’ practices which can ‘travel’ between and across cultures, generations and living arrangements. People who migrate from one place to another are exposed to a greater range of practices than other more sedentary populations. On encountering new practices in the destination country, we propose the practices carried by migrants are subject to various forms of integration, disintegration and transferral across generations. Borrowing the idea of muscle memory from the biophysical sciences, we introduce ‘practice memory’ to explain how some practices thought to be ‘dead’ can be resurrected with relative ease. We also suggest that practice memory may explain how some practices can be performed in new contexts despite a person never having performed them before. We conclude by reflecting on how understanding these migratory processes, and the role of practice memory within them, offer new insights into how practices move and migrate from one time–space to another.  相似文献   

20.
文章通过成矿物质来源、成矿作用与岩浆岩及构造的关系、成矿阶段的划分等方面的研究,认定卧龙泉金矿为多阶段、多成因、多来源的中-低温热液矿床。进而确定了卧龙泉金矿床的成矿模式。  相似文献   

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