低品位铁矿资源开发经济分析模型与应用研究

随着铁矿资源选冶技术水平的提升,在国内消费不断扩张及市场价格不断高涨的情况下,使得低品位铁矿资源开发利用的时机日益成熟。通过引入经济品位概念,从量上界定了低品位铁矿资源的具体范畴;以盈亏平衡为基点,导出了计算低品位矿产资源开发利用临界品位的经济分析模型。在广泛收集相关参数及预计未来铁精矿价格走势的基础上,通过计算,从促进低品位铁矿资源开发利用角度考虑,认为我国低品位铁矿资源开发利用的临界品位定在17％是比较合理的。建议对铁品位在17％及以下的低品位铁矿资源开发实施优惠的激励政策;对铁品位在17％-23％的铁矿资源开发,在目前的经济技术条件下可以不需要政策优惠,但要注重政策引导.     

油页岩原位裂解用注热管柱数值传热模拟与试验研究

油页岩作为一种非常规油气资源,有望成为石油的替代品。油页岩原位裂解技术对环境污染小,生成的油页岩油油品好,具有良好的开发前景。在原位裂解过程中,减少注热过程中的热量损失具有十分重要的意义,因此本文将对保温注热管柱的传热特性进行数值模拟和试验研究。通过传热学计算分析,保温注热管柱设计为外径?32mm的钢管,外层缠绕共计24mm的纳米保温材料。数值分析表明氮气流量越大,注热管柱出口温度达到稳定的时间越短,稳定温度也越高;当管柱氮气入口温度为500℃时,管柱出口温度在一定注气时间后均可达到400℃以上。在农安油页岩原位裂解先导试验工程中对注热管柱进行野外试验,管柱达到注热保温效果,井底温度达到设计温度,最终成功获得油页岩油。     

MOVEMENT OF GRADED SEDIMENT WITH DIFFERENT SIZE RANGES

1　ＩＮＴＲＯＤＵＣＴＩＯＮ　Ｎｕｍｅｒｏｕｓｓｅｄｉｍｅｎｔｔｒａｎｓｐｏｒｔｅｑｕａｔｉｏｎｓｈａｖｅｂｅｅｎｐｒｏｐｏｓｅｄｉｎｔｈｅｐａｓｔｆｅｗｄｅｃａｄｅｓ.Ｔｈｅａｐｐｌｉｃａｂｉｌｉｔｙｏｆｅａｃｈｏｆｔｈｅｓｅｄｉｍｅｎｔｔｒａｎｓｐ...     

细颗粒泥沙动水絮凝的机理分析

本文首先阐述由环形水槽试验所得出的细颗粒泥沙动水絮凝的若干规律。然后进行絮凝体形成和破碎的机理分析。从而得出产生动水絮凝的充分、必要条件:一是泥沙和电介质的物理、化学性质;二是絮凝体的抗剪能力大于所受到的剪切力,由此引出动水絮凝临界流速的概念。     

STABILITY ANALYSIS OF RIVERBANK SUBJECT TO SEEPAGE

The stability of riverbanks subject to seepage is studied experimentally and theoretically in this paper. By including seepage in a 3-dimensional theoretical analysis, the study first shows how the critical slope or angle of repose of a cohesionless material is related to the ratio of the hydraulic gradient of seepage to its critical value under the fluidization condition. The critical stable slope is shown to be related to not only the hydraulic gradient but also the seepage direction. Measured laboratory data reasonably fit well with the theoretical relationship for the case of injection and suction. The data reveal that the slope is reduced with injection and increased with suction, respectively. Additionally, the study identifies the seepage direction which results in a minimum critical stable slope for a certain hydraulic gradient of seepage.     

Characterizing incipient motion of low fines content soils with varying compositions,water contents,and relative densities

Laboratory flume experiments were conducted to quantify the effects of the soil characteristics on the critical shear stress of low fines content soil samples collected from the Montauk shores in New York. The collected soils were reconstituted at five different fines contents, ranging between 0 and 20%. These soil mixtures were composed of two initial water contents, dry of optimum and optimum moistures, and two relative densities, one moderate dense and the other dense. The strength indices of...     

考虑水压效应的基坑边坡稳定性计算分析

地下水的存在给工程带来了巨大的隐患。如何研究分析地下水对工程的作用是地质工程界的一个重点和难点。本文基于地下水的破坏效应,分析研究了地下水引起的接触面积的变化,并推导了饱水情况下平面滑动的临界角变化公式。A* 越小,即越小,发生失稳破坏的临界角就越小。而地下水p的增加有助于A* 的减小,造成了在水压作用下土体更容易发生失稳破坏。     

“Turn your brand into a destination”: toponymic commodification and the branding of place in Dubai and Winnipeg

ABSTRACT

The selling of naming rights to corporate sponsors has led urban policymakers to increasingly view the identities of public places as rent-generating assets to fund urban infrastructure. Yet few scholars have critically analyzed this emerging global trend of toponymic commodification and the seeking of “naming rent.” Through a combination of archival research, on-site field observations, and semi-structured interviews, this study examines how the practice of toponymic commodification is transforming the cultural landscapes of contemporary cities by considering two naming rights programs: Dubai’s Metro Naming Rights Initiative and the Sponsor Winnipeg Program. In each case, we explore the implications of commodifying public place names as well as the conflicting perceptions of such sponsorship programs. In doing so, the present study illustrates how the selling of naming rights is reshaping the built environment into a space of symbolic/economic capital transformations as brands become destinations and public places are reconceived as marketing opportunities.     

Naming rights,place branding,and the tumultuous cultural landscapes of neoliberal urbanism

ABSTRACT

In recent decades, urban policymakers have increasingly embraced the selling of naming rights as a means of generating revenue to construct and maintain urban infrastructure. This practice of “toponymic commodification” first emerged with the commercialization of professional sports during the second half of the 20th century and has become an integral part of the policy toolkit of neoliberal urbanism more generally. As a result, the naming of everything from sports arenas to public transit stations has come to be viewed as a sponsorship opportunity, yet such naming rights initiatives have not gone uncontested. This special issue examines the political economy of urban place naming through a series of case studies that consider how the commodification of naming rights is transforming the cultural landscapes of contemporary cities. In this introductory article, we provide an overview of the geographies of toponymic commodification as an emerging research focus within the field of critical urban toponymies and propose several theoretical approaches that can enhance our understanding of the commodification of naming rights as an urban spatial practice. We then discuss the main contributions in this special issue and conclude by exploring potential directions for future research on the geographies of urban toponymic commodification.     

锂辉石:巨型花岗伟晶岩锂-铯-钽矿床中关键含锂矿物SCIEI北大核心CSCD

寻找传统化石燃料的替代能源已成为全球性议题。受动力电池消费的拉动,锂资源需求急剧上升,伟晶岩型锂矿勘查热度持续攀升。虽然众多伟晶岩型锂矿地质特征尚不清晰,已有证据表明锂辉石是大多数大型-巨型伟晶岩型锂矿床的主要含锂矿物。与许多近直立的伟晶岩脉群不同,世界范围内大多数太古代伟晶岩矿脉往往呈近水平或缓倾斜在角闪岩相围岩中产出,它们往往具有复杂的三维形态并发育明显的矿物和地球化学分带。这些太古代伟晶岩脉通常形成于挤压或压剪构造体制下同变质环境中,成岩期最小主应力(σ;)近竖直。因此,伟晶岩常常侵位于近水平的构造局部引张区而形成复杂的几何学形态。压性的构造环境为富锂熔体多次脉动式注入和富含挥发分熔体垂向结晶分异提供了充足的时间;锂辉石在中高温压条件下结晶成为缓倾富锂带中最为常见的含锂矿物。