Increase in thermoelectric power factor of carbon-nanotube films after addition of polystyrene

We report the enhancement of the thermoelectric power factors of single-walled carbon-nanotube (SWCNT) films caused by the addition of polystyrene to the films as a binder. The Seebeck coefficient of the SWCNT films was increased by addition of polystyrene. On the other hand, the electrical conductivity gradually decreased with increasing amount of polystyrene. The power factor was maximum for a polystyrene concentration of 20 wt%; it was approximately 1.7 times higher than that of a pure SWCNT film. These results indicate that polystyrene is a superior binder polymer for synthesizing CNT/polymer thermoelectric composites.     

Analysis of tunnel displacement accuracy with total station

The remote distance measurement (RDM) method requires only common total stations and not special post-processing software. Moreover, this method is easy to operate and highly accurate results can be obtained. Therefore, RDM is used in the displacement monitoring of tunnel engineering. This study presents the calculation formulas for the crown settlement and wall convergence of tunnel as measured by RDM with total station. The mean error formulas are derived based on error propagation laws. When tunnel displacements measured by using total station with the m_s not more than 2 mm + 2D ppm (D is the measurement distance) and m_α not more than 1″, the horizontal distance between the rear viewpoint and the monitoring section is in the range of 50–150 m, the horizontal distance between the total station and the monitoring section ranges from 40 m to 60 m, and the total station is near the tunnel centerline, the measurement accuracy can reach 1 mm.     

The freeze-thaw cycles-time analogy method for forecasting long-term frozen soil strength

To determine the stability of a frozen soil structure, the soil’s long-term shear strength must first be determined. Freeze-thaw cycling is a weathering process in soil (i.e., a process of energy input and output). In cold climates, the freeze-thaw cycle (FTC) has a great influence on long-term strength and stability of soil, which are important considerations for frozen soil engineering. This paper offers a brief introduction to the spherical template indenter and introduces the FTC-time analogy method for forecasting long-term strength of frozen soil. Using the number of cycle repetitions (numbers of freeze-thaw cycles) and the cycle duration (minutes), we calculate the long-term strength of the curve family and their normalized curves, which allows us to predict the long-term frozen soil deformation and strength. Because of the soil transformation that occurs due to the number of repetitions and the duration of FTCs, the results of earlier research can be compared. The FTC-time analogy method can be used to solve problems of forecasting long-term frozen soil strength, as well as for research concerning frozen soil engineering.     

Field investigation and numerical simulation of the seismic triggering mechanism of the Tahman landslide in eastern Pamir,Northwest China

Bulletin of Engineering Geology and the Environment - Landslides are one of the most common geological hazards in many parts of the world, which have brought catastrophic consequences to mankind....     

Exploration of CoSi-based alloys promising for thermoelectricity

The cobalt silicide CoSi seems a suitable material for thermoelectricity: it is inexpensive and non-toxic, but its thermal conductivity is large. Forming CoSi-based alloys by replacing part of Co or Si with a heteroatom M can change electronic properties and improve thermoelectric performances. The insertion energy of different CoSi-based alloys containing abundant, inexpensive and non-toxic elements was estimated by using DFT calculations. Several alloys were synthesized using arc-melting or powder reaction and then characterized using X-Rays powder Diffraction (XRD) and Electron Micro Probe Analysis (EMPA) to determine the limit of solubility of these heteroatoms within CoSi. DFT predictions of solubility limit were in qualitative agreement with experimental results. Vibrational and thermoelectric properties were measured for alloys containing highly soluble elements (Mn and Cr) but also poorly soluble ones (Ti and V). These new CoSi-based alloys, studied for the first time for thermoelectric applications, do not exhibit a notable improvement of the performances.     

草原石林：东北亚早白垩世花岗岩伸展穹隆和岩浆成矿爆发的地质遗迹及其形成过程

东北亚地区至少发育9个大型草原石林,属花岗岩石林的一种,是东北亚早白垩世巨量伸展和第四系冰川、风化作用的共同产物,主要特点是发育密集的近水平节理。本文通过整理岩浆岩专题填图和构造研究发现,这些石林的主体是早白垩世东北亚地区巨量伸展过程中形成众多的不对称花岗岩穹隆或同减薄岩体,岩体边部发育韧性剪切带,核部发布近水平岩浆流动面理,伸展和岩浆多期侵位导致与成矿密切相关的岩浆热液大量上涌,岩体抬升至地表,沿岩浆面理发育密集的近水平节理和部分垂直节理,后期沿这些构造面理发生的物理风化和化学作用(包括风蚀、冰川以及盐风化等)造就了千奇百怪的形态。草原石林是花岗岩地貌中的“另类”,不仅具有指示东北亚地区花岗岩形成时代(早白垩世)的特点,也是寻找晚中生代中国北方大规模成矿的良好标志体,而且风化形成的千姿百态的景色极具观赏价值,可以作为整个蒙古草原地区和大兴安岭南段地区特色的地学科普和生态旅游资源。     

宁夏红寺堡盆地隐伏古隆起成因机制及其对区域沙漠化的影响

目前对于青藏高原东北缘活动构造研究多集中于活动断裂带的活动性,而对夹持于其间的沉积盆地构造格架及活动性研究甚少。以夹持于烟筒山断裂与牛首山—罗山断裂之间的宁夏红寺堡盆地为研究对象,采用重力资料重处理解译、音频大地电磁测深(AMT)和地震勘探相结合,揭示红寺堡盆地隐伏构造特征,并进一步采用盆山一体化思路分析隐伏构造的成因机制及其对区域沙漠化的控制作用。结果表明:青藏高原在中新世末发生强烈的NE向推挤、扩展和隆升,红寺堡盆地由坳陷盆地转变为挠曲盆地; 在青藏高原NE向扩展的影响下,烟筒山断裂发生强烈的逆冲作用,古生代—中生代基底逆冲于古近系—新近系之上,受构造变形影响的最新地层为中新统彰恩堡组; 红寺堡盆地内的隐伏古隆起呈NW—SE向,与烟筒山构造带具有相同的构造动力学背景,受青藏高原NE向扩展影响形成于中新世末,并且至今仍具有活动性; 隐伏古隆起周缘断裂的活动破坏了地表稳定性、蓄水能力和地表植被,导致区域沙漠化呈现有规律的NW—SE向带状展布。该研究成果对于宁夏红寺堡盆地区域稳定性评价及沙漠化的综合治理具有现实指导意义。     

Multi-wheat-model ensemble responses to interannual climate variability

We compare 27 wheat models' yield responses to interannual climate variability, analyzed at locations in Argentina, Australia, India, and The Netherlands as part of the Agricultural Model Intercomparison and Improvement Project (AgMIP) Wheat Pilot. Each model simulated 1981–2010 grain yield, and we evaluate results against the interannual variability of growing season temperature, precipitation, and solar radiation. The amount of information used for calibration has only a minor effect on most models' climate response, and even small multi-model ensembles prove beneficial. Wheat model clusters reveal common characteristics of yield response to climate; however models rarely share the same cluster at all four sites indicating substantial independence. Only a weak relationship (R² ≤ 0.24) was found between the models' sensitivities to interannual temperature variability and their response to long-term warming, suggesting that additional processes differentiate climate change impacts from observed climate variability analogs and motivating continuing analysis and model development efforts.     

Heavy metal ions retention by bi-functionalized lignin: Synthesis,applications, and adsorption mechanisms

Bi-functionalized lignin with amino and sulfonic groups (ASL) was synthesized via Mannich reaction and sulfomethylation. It was systematically characterized by FT-IR, element analysis, surface charge and XPS. Effects of initial pH, contact time and initial metal ion concentration on the adsorption of Cu(II) and Pb(II) onto ALS were studied. Results indicated that the biosorbent showed excellent performance for metals even from low pH solutions. The adsorption kinetics and isotherms could be described well with Pseudo-second-order and D–R model, respectively. Further investigation of the metal-loaded ASL by FT-IR and XPS elucidated the amino and sulfonic groups reacted with metals in different way.     

塔北哈拉哈塘地区奥陶系碳酸盐岩岩溶层组特征与溶蚀强度分析

塔北哈拉哈塘地区奥陶系多个层位均发育岩溶缝洞型储层。对钻井岩心系统采样测试分析,总结了哈拉哈塘地区不同地层的岩石类型及其纵向组合发育特征。不同类型碳酸盐岩溶蚀试验研究发现,泥质含量及Mg O含量对岩石可溶性具有影响,溶蚀强度为纯颗粒石灰岩白云质灰岩白云岩泥灰岩。以此为基础进行层组划分,将奥陶系碳酸盐岩划分为2类3型5个亚型:一间房组及鹰一、二段为灰岩连续型层组,属强岩溶层组;良一段,鹰三、四段为灰岩夹云岩亚型,岩溶强度属中等;其余各层组溶蚀性较弱。实际钻井结果及地震剖面"串珠"发育情况统计认为,该区岩溶层组类型控制了缝洞型储层的发育。