地貌沉积学方法在活断层研究中的应用

地貌沉积学方法是研究活动断层运动规律的有效方法之一。综合大量已有研究成果,本文从活断层垂直运动、水平运动及垂直-水平组合性运动特征等方面对地貌沉积学原理在目前活断层研究工作中的应用及进展进行了综述;并探讨了今后地貌沉积学方法在活断层研究中需关注的一些关键技术。

沉积盆地古水深恢复方法与研究进展

古水深分析对古环境重建、盆地分析、层序地层学研究、古地貌恢复以及生、储、盖层条件的评价都有重要意义。古水深分析通常有古生物法、沉积学法、地球物理法、地球化学法及数字模拟法,各种方法优缺点并存,尽管某些方法在特定地质条件下存在优势,但在恢复同一环境的古水深时,不同方法还是存在其偏差;这些方法多以定性为主,许多方法易受自然条件限制,且对样品可靠性要求高,一定程度上限制了古水深研究。古水深恢复建议综合考虑地质背景、环境演化、研究地质体特征及地质资料情况等多种因素,多方法研究相互约束,以期更客观地再现古水深变化规律。

流动单元划分及其在地质中的应用

流动单元是侧向和垂向上连续的具有相同影响的流体流动特征参数的储层单元。流动单元的确定可以更加合理地划分储集层,预测储集层的分布及性质;提高储层岩石及流体物性参数模型的解释精度,更加准确地认识油藏;提高水淹层解释精度,确定剩余油的分布,选择加密调整及挖潜的对象,进而提高原油采收率;建立和确定更加符合生产动态的油藏模型和油藏特征参数,提高油藏数值模拟的精度。借鉴国内外油田开发经验,总结了流动单元划分的几种方法及其在地质中的应用。

Fabrication of titanium oxide films at low temperature from aqueous solution

Titanium oxide thin films were prepared on self-assembled monolayers-coated silicon substrate using layer-by-layer self-assembly method and chemical bath deposition from an aqueous solution. The effects of temperature on structural properties, thickness and morphologies of titanium oxide thin films were investigated. The results show that the absorption peak of peroxo complexes of titanium at 410 nm decreases gradually with increasing the temperature. The deposited films consisting of titanium oxide nanocrystals are believed to be fully amorphous by XRD. Titanium oxide thin films fabricated at 60 °C for 2 h are continuous, dense and homogeneous with a size in the range of 20-40 nm by SEM. The chemical compositions of deposited thin films were studied by EDS, and the mole ratio of O to Ti is 2.2：1.

Radiocarbon ages of different fractions of peat on coastal lowland of Bohai Bay: marine influence?

Peat in boreholes is the most important ^(14)C dating material used for constructing age framework. 20 bulk peat samples were collected from five boreholes, the ^(14)C ages of two fractions(organic sediment fraction and peat fraction) of the bulk peat samples were investigated by AMS-dating and which fraction is better to help construct an age framework for the boreholes were compared and discussed. The results indicated that the peat fraction give a good dating results sequence in the boreholes, compared with the corresponding organic sediment fraction. And the dating results of organic sediment fraction show 161-6 702 years older than corresponding peat fraction, which was caused by marine influence. Then, we suggest an experience formula as y =0.99 x-466.5 by the correlation analysis for correcting the marine influenced organic sediment ages within the conventional ages between 4 000 to 9 000 yrs BP, and more study should be carried out for the AMS ^(14)C dating of the bulk organic sediments.

Mesomechanical simulation of direct shear test on outwash deposits with granular discrete element method

The mechanical properties of outwash deposits which are taken as unconsolidated geo-materials with the characteristics of non-uniformity, heterogeneity and multiphase have attracted much attention in engineering. According to the results of laboratory direct shear test on the remolded samples, the soil particle parameters of numerical model based on in-situ particle size cumulative curves and 3D granular discrete element method were determined. Then, numerical experiments on different lithology, stone content and gradation composition were conducted. The results show that it is not a flat surface but a shear band that yields in the sample. The curve of particle velocity vs distance from the designed shear surface of test model that is taken as a datum plane in the vertical section of sample shows in "S" shape. The shear disturbance area is about twice the maximum diameter of stone blocks. The greater the stiffness of stone is, the rougher the shear surface is. The shear strength of outwash deposits is largely controlled by lithology and stone content, and the bite force between stone blocks is the root reason of larger friction angle. It is also shown that strain hardening and low shear dilatancy occur under high confining pressure as well as possibility of shear shrinkage. But it is easy to behave shear dilatation and strain softening under low confining pressure. The relationship between particle frictional coefficient and stone content presents an approximately quadratic parabola increase. The strain energy first increases and then drops with the increase of frictional energy. The cohesion increases with soil stiffness increasing but decreases with stone stiffness increasing. Numerical results are consistent with the laboratory test results of remolded samples, which indicate that this method can be a beneficial supplement to determine the parameters of engineering deposit bodies.

Preparation of N-Doped TiO_2-Loaded Halloysite Nanotubes and Its Photocatalytic Activity under Solar-Light Irradiation

The N-doped TiO2-loaded halloysite nanotubes(N-Ti O2/HNTs) nanocomposites were prepared by using chemical vapor deposition method which was realized in autoclave. The photocatalytic activity of nanocomposites was evaluated by virtue of the decomposition of formaldehyde gas under solar-light irradiation. The XRD patterns verified that the anatase structured TiO2 was deposited on HNTs. The TEM images showed that the surface of HNTs was covered with nanosized TiO2 with a particle size of ca. 20 nm. The UV-vis spectra indicated that the N-Ti O2/HNTs presented a significant absorption band in the visible region between 400 nm and 600 nm. Under solar-light irradiation, the highest degradation rate of formaldehyde gas attained 90% after 100 min of solar-light irradiation. The combination of the photocatalytic property of TiO2 and the unique structure of halloysite would assert a promising perspective in degradation of organic pollutants.

Composite Ni-Nanodiamond Coating Deposited by Electroless Method

The work in this study is focused on investigation of composite nickel coatings. The coatings were deposited on ductile cast iron samples of different composition by electroless method EFTTOM NICKEL with addition of strengthening nanodiamond particles （2-4 nm）, The samples were prepared by casting and austempering. The microstructure, microhardness and wear resistance of the coatings were investigated. The thickness of the coatings was also determined （8-10μm）. Metallographic analyses, SEM （scanning electron microscopic） investigation, microhardness measurements by knoop method, wear resistance tests were carried out. The coatings with and without heat treatment at 290℃, 6 h were tested. Duplication of microhardness value and improvement of the coating＇s properties of heat treated coatings were observed.

Seismic sedimentology of conglomeratic sandbodies in lower third member of Shahejie Formation (Palaeogene) in Shengtuo area, East China

The sand-conglomerate fans are the major depositional systems in the lower third member of Shahejie Formation in Shengtuo area, which formed in the deep lacustrine environment characterized by steep slope gradient, near sources and intensive tectonic activity. This work was focused on the sedimentary feature of the glutenite segment to conduct the seismic sedimentology research. The near-shore subaqueous fans and its relative gravity channel and slump turbidite fan depositions were identified according to observation and description of cores combining with the numerous data of seismic and logging. Then, the depositional model was built depending on the analysis of palaeogeomorphology. The seismic attributes which are related to the hydrocarbon but relative independent were chosen to conduct the analysis, the reservoir area of the glutenite segment was found performing a distribution where the amplitude value is relatively higher, and finally the RMS amplitude attribute was chosen to conduct the attribute predicting. At the same time, the horizontal distribution of the sedimentary facies was analyzed qualitatively. At last, the sparse spike inversion method was used to conduct the acoustic impedance inversion, and the inversion result can distinguish glutenite reservoir which is greater than 5 m. This method quantitatively characterizes the distribution area of the favorable reservoir sand.

Application of geophysical-geochemical method in verification of stream sediment anomaly in Baoxinggou area of Heilongjiang

Baoxinggou area is located in northern Daxing'anling. In this area,comprehensive use of geophysical and geochemical exploration methods plays an important role in the prospecting,and has yielded some application results so far. Based on the 1 /100 000 stream sediment anomaly survey,the methods of 1 /20 000 soil geochemical measurement,trenching engineering on the earth's surface and 1 /10 000 IP intermediate gradient survey were all used to verify and decompose drainage anomalies,as well as to find and locate ore bodies. In this way,an effective,economical and quick prospecting method was concluded,which focuses on the middle and lower mountain forest swamp landscape in the northern part of Daxing'anling,and provides reference for the prospecting in the area.

An Electrochemically Assisted Mechanically Controllable Break Junction Approach for Single Molecule Junction Conductance Measurements

We report an electrochemically assisted mechanically controllable break junction （EC-MCBJ） approach to investigating single molecule conductance. Electrode pairs connected with a gold nanobridge were fabricated by electrochemical deposition and then mounted on a homebuilt MCBJ platform. A large number of Au- molecule-Au junctions were produced sequentially by repeated breaking and reconnecting of the gold nanobridge. In order to measure their single molecule conductance, statistical conductance histograms were generated for benzene-l,4-dithiol （BDT） and 4,4＇-bipyridine （BPY）. The values extracted from these histograms were found to be in the same range as values previously reported in the literature. Our method is distinct from the ones used to acquire these previously reported literature values, however, in that it is faster, simpler, more cost-effective, and changing the electrode material is more convenient.

Photoluminescence and surface photovoltage properties of Zn Se nanoribbons

ZnSe nanoribbons were synthesized with chemical vapor deposition route. The excitation power-dependent photol and surface photovoltage （SPV） techniques were used to study the optoelectronic properties of the as-grown ZnSe nanoribbons. Three deep defect （DD）-related emission bands, respectively, centered at 623 nm （DD1）, 563 nm （DD2） and 525 nm （DD3）, emerge orderly with increasing the excitation power, which is attributed to the saturation of the DD states from deeper to shallower level. The SPV spectrum and the corresponding phase spectrum show that DD1 mainly acts as recombination center, while DD2 and DD3 can act as both the recombination center and electron traps. The influence of the trapping electrons on the SPV response dynamic was studied with transient SPV.

Acoustic estimation of suspended sediment concentration

In this paper, the acoustic estimation of suspended sediment concentration is discussed and two estimation methods of suspended sediment concentration are presented. The first method is curve fitting method, in which, according to the acoustic backscattering theory we assume that the fit-ting factor K1 (r) between the concentration M(r) obtained by acoustic observation and the concentra-tion M0(r) obtained by sampling water is a high order power function of distance r. Using least-square algorithm, we can determine the coefficients of the high order power function by minimizing the differ-ence between M(r) and M0(r) in the whole water profile. To the absorption coefficient of sound due to the suspension in water we do not give constraint in the first method. The second method is recur-sive fitting method, in which we take M0(r) as the conditions of initialization and decision and give ra-tional constraints to some parameters. The recursive process is stable. We analyzed the two methods with a lot of experimental data. The analytical results show that the estimate error of the first method is less than that of the second method and the latter can not only estimate the concentration of suspended sediment but also give the absorption coefficient of sound. Good results have been obtained with the two methods.

Fast growth of graphene on SiO2/Si substrates by atmospheric pressure chemical vapor deposition with floating metal catalysts

Graphene on dielectric substrates is essential for its electronic applications. Graphene is typically synthesized on the surface of metal and then transferred to an appropriate substrate for fabricating device applications. This post growth transfer process is detrimental to the quality and performance of the as-grown graphene. Therefore, direct growth of graphene films on dielectric substrates without any transfer process is highly desirable. However, fast growth of graphene on dielectric substrates remains challenging. Here, we demonstrate a transfer-free chemical vapor deposition (CVD) method to directly grow graphene films on dielectric substrates at fast growth rate using Cu as floating catalyst. A large area (centimeter level) graphene can be grown within 15 min using this CVD method, which is increased by 500 times compared to other direct CVD growth on dielectric substrate in the literatures. This research presents a significant progress in transfer-free growth of graphene and graphene device applications.

Three-dimensional lithiophilic Cu@Sn nanocones for dendrite-free lithium metal anodes

The uneven deposition of lithium(Li) on current collectors causes serious dendrite growth and volume expansion. Commercial foamed copper(Cu) current collectors are unsuitable for Li anodes because of their large volume and mass and lithiophobic nature. Herein, a three-dimensional(3 D) copper@tin(Cu@Sn) nanocone current collector with small volume, light weight, and lithiophilic nature was prepared by a simple electrodeposition method. The synergy of the nanoconical structure and lithiophilic Sn promotes the even deposition of Li and effectively inhibits the formation of Li dendrites. The resultant half batteries exhibit high Coulombic efficiency of 97.6% after 100 cycles at 1 mA cm^(-2), and the symmetrical Li battery demonstrates a prolonged lifespan of over 600 h at 1 mA cm^(-2). The full battery based on organic liquid electrolyte with LiFePO_(4) also exhibits a long lifespan of 550 cycles with high capacity retention of 95.1% at 1 C.Moreover, 3 D Cu@Sn nanocone-based solid-state batteries exhibit excellent electrochemical performance and show no decay after 500 cycles at 1 C. Our work provides a strategy for fabricating 3 D current collectors for high-energy-density Li metal batteries.

The growth and properties of an m-plane InN epilayer on LiAlO_2 (100) by metal-organic chemical vapor deposition

The m-plane InN （1 100） epilayers have been grown on a LiAlO2 （1 0 0） substrate by a two-step growth method using a met- al-organic chemical vapor deposition （MOCVD） system. The low temperature InN buffer layer （LT-InN） is introduced to overcome the drawbacks of thermal instability of LiAlO2 （LAO） and to relieve the strains due to a large thermal mismatch be- tween LAO and InN. Then the high temperature m-plane InN （1 1 00） epilayers （HT-InN） were grown. The results of X-ray diffraction （XRD） suggest that the m-plane InN （1 1 00） epilayer is a single crystal. The X-ray rocking curves （co scans） （XRC） and atomic force microscopy （AFM） indicate that the m-plane InN （1 1 00） epilayer has anisotropic crystallographic properties. The PL studies of the materials reveal a remarkable energy band gap structure around 0.70 eV at 15 K.