利用光薄片测试镜媒反射率

显微光度测定法现已广泛地应用于煤岩和沉积岩的分散有机物质的研究.尤其在所分析的物质微少,其他方法又难以使用的情况下,镜煤反射率的测定却能快速而准确地提供出所需数据.所以说,在沉积岩的有机物质研究方面,显微光度测定法较化学分析方法具有一定的优点.

高稳定度光泵浦腔内倍频488nm半导体薄片激光器

设计了一种性能稳定、结构紧凑的光泵浦腔内倍频488 nm半导体薄片激光器。为获得光束质量好、输出性能稳定的488 nm激光器,利用808 nm LD从顶面垂直泵浦半导体增益介质芯片获得976 nm基频光,通过在腔内置入Ⅰ类相位匹配的LBO晶体进行倍频获得488 nm激光输出。半导体增益介质芯片具有13量子阱和808 nm/976 nm双反射带反射镜,其双面键合金刚石散热片。在泵浦功率为9.2 W时,获得111 m W 488 nm激光输出,光谱线宽为1.3 nm,光-光效率为1.2%,光束质量Mx2、My2分别为1.03和1.02,连续工作3 h激光输出功率不稳定度为0.6%。

实物地质资料分类定级管理方法研究

实物地质资料是指地质工作过程中形成的岩芯、标本、光薄片、副样等资料,具有重要的重复利用价值。但因其数量多、体积大、重量大等特点,在资料保管方面存在较大困难,资料的重复利用价值也没能得到较好发挥。"分类定级"的管理思路是解决实物地质资料保管难题,提高实物地质资料利用水平的有效途径,通过"分类定级",对实物地质资料进行筛选,划分为国家级、省级和基层级实物地质资料,分别采用不同的管理模式进行管理,可改变以往不加以区分的粗放式的管理模式,使有限的库房资源保管最为重要、珍贵的实物地质资料,切实提高资料的保管水平和重复利用效率。

陨石样品制作工艺及处理技巧

陨石是在太阳系早期历史的过程中形成的,可提供太阳系组成的物理和化学信息,这些信息代表了太阳系形成时的时空条件,因此陨石具有巨大的科研价值。陨石收集入库后首先要对其进行精确的基础分类工作,制作陨石样品进行光薄片是必不可少的。一方面陨石样品非常珍贵,要求制作标准的0.03mm的光薄片,在样品不被破坏和浪费的要求下进行光片制作存在相当大的难度,而地球岩石样品只需进行光片或者薄片的制作;另一方面绝大多数陨石中含有金属,由于金属的应力及其导热等特性,在薄片的制作过程中,容易产生金属脱落,样品损坏等情况,所以大部分岩石磨片室都处理不好陨石样品。笔者参与了500块的陨石样品光薄片制作,根据陨石光薄片制作的经验描述陨石样品处理的基本流程,及其在制作过程中常出现的问题和处理技巧,从而提高国内陨石样品的处理方法与技术。

4500P显微镜Leicamw软件在鞍山式铁矿工艺粒度测量中的应用

铁矿的工艺粒度粗细对铁矿选矿作业过程中的破碎、磨矿至关重要,本文总结了鞍山式铁矿工艺粒度测量方法,并以图表方式准确反映了铁矿工艺粒度分布特征,为指导破碎、磨矿作业提供详实资料,具有实际意义和经济意义。

Relationship Between Leaf Structure and Aloin Content in Six Species of Aloe L.

The leaf structure, content and the storage location of aloin in the leaves of six species of Aloe L. were studied by means of semi-thin section, high performance liquid chromatography (HPLC) and fluorescent microscope. Results showed that all leaves consisted of epidermis, chlorenchyma, aquiferous tissue and vascular bundles. The leaves had the xeromorphic characteristics, including thickened epidermal cell wall, thickened cuticle, sunken stomata and well-developed aquiferous tissue. With the exception of thus, there were remarkable differences in leaf structure among the six species. The chlorenchyma cells were similar to palisade tissues in Aloe arborescens Mill. and A. mutabilis Pillans, but isodiametric in A. vera L., A. vera L. var. chinensis Berg., A. saponaria Hawer and A. greenii Bali. A. arborescens, A. mutabilis, A. very and A. vera var. chinensis included large parenchymatous cells at the vascular bundles, whereas no such cells were observed at the vascular bundles of A. saponaria and A. greenii. In A. arborescens, A. mutabilis and A. vera, the aquiferous tissue sheaths were present and composed of a layer of small parenchymatous cells without chloroplasts around the aquiferous tissue. While there were no aquiferous tissue sheaths in A. vera var. chinensis, A. saponaria and A. greenii. The HPLC revealed that the content of aloin was high in A. arborescens, low in A. vera, and very low in A. saponaria among the six species. The fluorescent microscopy showed that the yellow-green globule only appeared in the large parenchymatous cells of vascular bundles, vascular bundle sheath and aquiferous tissue sheath, but not in the chlorenchyma and aquiferous tissue. Consequently, the large parenchymatous cells of vascular bundles, vascular bundle sheath and aquiferous tissue sheath were the storage location of aloin. They were positively correlated with the content of aloin.

西坞口矿区锡(钨)多金属矿床矿石矿物特征

通过偏光显微镜下矿石矿物、脉石矿物的光、薄片研究,结合野外地质、钻孔岩芯取样等方法,对西坞口矿区矿物锡(钨)矿床矿石矿物特征进行了分析,并划分了硅化、角岩化、云英岩化、白云母化4个蚀变带。根据矿物共生组合、矿物共生次序、交代关系、变质程度,查明了矿体主要赋存在云英岩化及白云母化带。研究表明:该矿床属于典型的岩浆期后气成热液矿床,即高温气成热液黄玉石英脉型钨锡矿床,同时又伴生有铜、钼、铋、铍等多金属矿床,成矿形式为高温石英脉型钨矿、钨锡矿和云英岩化花岗斑岩锡矿系列组合型矿床。

2D mesoporous ultrathin Cd0.5Zn0.5S nanosheet:Fabrication mechanism and application potential for photocatalytic H2 evolution

Two-dimensional mesoporous ultrathin Cd0.5Zn0.5S nanosheets with a thickness of~1.5 nm were fabricated using a multistep chemical transformation strategy involving inorganic–organic hybrid ZnS-ethylenediamine(denoted as ZnS(en)0.5)as a hard template.Inorganic–organic hybrid ZnS(en)0.5,Cd0.5Zn0.5S(en)x,and Cd0.5Zn0.5S nanosheets were sequentially fabricated,and their transformation processes were analyzed in detail.The fabricated Cd0.5Zn0.5S nanosheets exhibited high photocatalytic hydrogen evolution reaction activity in the presence of a sacrificial agent.The Cd0.5Zn0.5S nanosheets exhibited remarkably high H2 production activity of~1395μmol∙h^−1∙g^−1 in pure water with no co-catalyst,which is the highest value reported thus far for bare photocatalysts,to the best of our knowledge.The high activity of these nanosheets is attributed to their distinct nanostructure(e.g.,short transfer distance of photoinduced charge carriers,large number of unsaturated surface atoms,and large surface area).Moreover,ternary NiCo2S4 nanoparticles were employed to facilitate the charge separation and enhance the surface kinetics of H2 evolution.The H2 production rate reached~62.2 and~2436μmol∙h^−1∙g^−1 in triethanolamine and pure water,respectively,over the NiCo2S4/Cd0.5Zn0.5S heterojunctions.The result indicated that the Schottky junction was critical to the enhanced activity.The proposed method can be used for fabricating other highly efficient CdZnS-based photocatalysts for solar-energy conversion or other applications.

Analysis of the application of the laser equipment in the production line of the amorphous silicon film solar cells

The laser equipment is one of the key equipment in the production line of the solar energy. In this article, the author de-scribes the application of the laser equipment in the production line of the amorphous silicon film solar cells, and points out that the stable and exactitude is the key direction of the future development of the laser scribing equipment.

能谱仪PPA分析方法的实验研究:以山西大同新生代玄武岩样品为例

以山西大同新生代玄武岩样品为例,利用Quanta 200扫描电镜、GENESIS能谱仪对能谱仪PPA分析方法进行了实验研究,该方法为粒度和物相自动分析方法.笔者首次把能谱仪PPA分析方法应用到地质学领域的岩石光薄片研究中,快速得出了一系列不同物相的形态学数据及化学成分分析结果:物相种类、每一种物相的颗粒数、每一个颗粒的平均直径、面积、周长、圆度、长宽比及化学成分等,并得出了不同物相在该视域所占的面积百分比及每种物相颗粒的平均直径,克服了传统光薄片粒度分析方法的所有缺点,为矿物学、岩石学及矿床学研究提供了一套非常有意义的数据.

Chemical vapor deposition growth of monolayer MoSe2 nanosheets

The synthesis of two-dimensional （2D） layered materials with controllable thickness is of considerable interest for diverse applications. Here we report the first chemical vapor deposition growth of single- and few-layer MoSe2 nanosheets. By using Se and MoO3 as the chemical vapor supply, we demonstrate that highly crystalline MoSe2 can be directly grown on the 300 nm SiO2/Si substrates to form optically distinguishable single- and multi-layer nanosheets, typically in triangular shaped domains with edge lengths around 30 btm, which can merge into continuous thin films upon further growth. Micro-Raman spectroscopy and imaging was used to probe the thickness-dependent vibrational properties. Photoluminescence spectroscopy demonstrates that MoSe2 monolayers exhibit strong near band edge emission at 1.55 eV, while bilayers or multi-layers exhibit much weaker emission, indicating of the transition to a direct band gap semiconductor as the thickness is reduced to a monolayer.

Optical contrast determination of the thickness of SiO_2 film on Si substrate partially covered by two-dimensional crystal flakes

SiO_2/Si substrate has been widely used to support two-dimensional （2-D） crystal flakes grown by chemical vapor deposition or prepared by micromechanical cleavage. The visibility of 2-D flakes is very sensitive to the thickness of the SiO_2 layer （hsiO_2）, which can not be determined precisely after the deposit of 2-D flakes. Here, we demonstrated a simple, fast and nondestructive tech- nique to precisely determine hsiO_2 of SiO_2 films on Si substrate only by optical contrast measurement with a typical micro-Raman confocal system. Because of its small lateral resolution down to the micrometer scale, this tech- nique can be used to access hsiO_2 on SiO_2/Si substrate that has been partially covered by 2-D crystal flakes, and then further determine the layer number of the 2-D crystal flakes. This technique can be extended to other dielectric multilayer substrates and the layer-number determination of 2-D crystal flakes on those substrates.

High thermal conductivity of suspended few-layer hexagonal boron nitride sheets

The thermal conduction of suspended few-layer hexagonal boron nitride （h-BN） sheets was experimentally investigated using a noncontact micro-Raman spectroscopy method. The first-order temperature coefficients for monolayer （1L）, bilayer （2L） and nine-layer （9L） h-BN sheets were measured to be -（3.41 ± 0.12）× 10-2, -（3.15 ± 0.14） × 10-2 and -（3.78 ±0.16）× 10-2 cm-1.K-1, respectively. The room-temperature thermal conductivity of few-layer h-BN sheets was found to be in the range from 227 to 280 W.m-1-K-1, which is comparable to that of bulk h-BN, indicating their potential use as important components to solve heat dissipation problems in thermal management configurations.

SnO_2 nanosheet as a photoanode interfacial layer for dyesensitized solar cells

SnO2 nanosheet films about 200 nm in thickness are successfully fabricated on fluorine-doped tin oxide （FTO） glass by a facile solution-grown approach. The prepared SnO2 nanosheet film is appfied as an interfacial layer between the nanocrystalline TiO2 film and the FTO substrate in dye-sensitized solar cells （DSCs）. Experimental results show that the introduction of a SnO2 nanosheet film not only suppresses the electron back-transport reaction at the electrolyte/FTO interface but also provides an efficient electron transition channel along the SnO2 nanosheets, and as a result, increasing the open circuit voltage and short current density, and finally improving the conversion efficiency for the DSCs from 3.89% to 4.62%.

BiOCl/ultrathin polyaniline core/shell nanosheets with a sensitization mechanism for efficient visible-light-driven photocatalysis

Photocatalytic technology holds great promise in renewable energy and environmental protection.Herein,we report the synthesis of a class of polyaniline-sensitized BiOCI core/shell nanosheets with visible-light photocatalytic activity by a one-step oxidative polymerization method and show how the hybrid nanosheet boosts the photocatalytic activity and stability for degradation of Rhodamine B (RhB).In this unique structure,the ultrathin polyaniline (PANI)as a shell with the thickness of about 1-2nm,can widen the response of the catalyst to visible light to boost photocatalysis and the BiOCI core can promote the separation of photogenerated carriers from the PANI.We demonstrate that the optimized BiOCl/ PANI core/shell photocatalyst shows nearly three times higher photocatalytic activity for the degradation of RhB than pure BLOC1and also shows high stability.This work provides a new strategy for the design of a highly efficient hybrid photo- catalyst driven by visible light.

The influence of two-dimensional organic adlayer thickness on the ultralow frequency Raman spectra of transition metal dichalcogenide nanosheets

Recently, it has been reported that physisorbed adsorbates can be trapped between the bottom surface of twodimensional(2D) materials and supported substrate to form2 D confined films. However, the influence of such 2D confined adsorbates on the properties of 2D materials is rarely explored. Herein, we combined atomic force microscopy(AFM), Kelvin probe force microscopy(KPFM) and Raman spectroscopy especially the ultralow frequency(ULF) Raman spectroscopy to explore the influence of 2D confined organic adlayer thickness on the ULF breathing modes of few-layer MoS2 and WSe2nanosheets. As the thickness of organic adlayers increased, red shift, coexistence of blue and red shifts as well as blue shift of ULF breathing mode was observed. KPFM measurement confirmed the enhanced n-doping and p-doping behaviors of organic adlayers as their thickness increased,respectively. Our results will provide new insights into the interaction between 2D confined adsorbates and bottom surface of 2D nanosheets, which could be useful for modulating properties of 2D materials.

Fast and reliable identification of atomically thin layers of TaSe2 crystals

Deposition of clean and defect-free atomically thin two-dimensional crystalline flakes on surfaces by mechanical exfoliation of layered bulk materials has proven to be a powerful technique, but it requires a fast, reliable and non-destructive way to identify the atomically thin flakes among a crowd of thick flakes. In this work, we provide general guidelines to identify ultrathin flakes of TaSe2 by means of optical microscopy and Raman spectroscopy. Additionally, we determine the optimal substrates to facilitate the optical identification of atomically thin TaSe2 crystals. Experimental realization and isolation of ultrathin layers of TaSe2 enables future studies on the role of the dimensionality in interesting phenomena such as superconductivity and charge density waves.