First and Second Ionization Potentials, Reactions, and Surface Collisions of C60 and Related Clusters

1990 ◽  
Vol 206 ◽  
Author(s):  
Stephen W. McElvany ◽  
Mark M. Ross ◽  
John H. Callahan

The physical and chemical properties of large carbon clusters, Cn(n>40), have been studied extensively over the past six years. The spherical nature of these clusters has been debated and inferred from both experimental and theoretical studies until the recent isolation and subsequent spectroscopic identification of bulk C60 and C70. Although the n=60 and 70 cluster ions are anomalously abundant (“magic numbers”) in the mass spectra and are proposed to be highly symmetric species, the other “magic number” clusters have yet to be isolated.

Nanoscale ◽  
2020 ◽  
Vol 12 (43) ◽  
pp. 21971-21987
Author(s):  
Qicheng Zhang ◽  
Wenchao Peng ◽  
Yang Li ◽  
Fengbao Zhang ◽  
Xiaobin Fan

Over the past several decades, nanomaterials have been extensively studied owing to having a series of unique physical and chemical properties that exceed those of conventional bulk materials.


2018 ◽  
Vol 9 (15) ◽  
pp. 3623-3637 ◽  
Author(s):  
Xiubing Huang ◽  
Guixia Zhao ◽  
Ge Wang ◽  
John T. S. Irvine

Perovskite-type metal oxides have been widely investigated and applied in various fields in the past several decades due to their extraordinary variability of compositions and structures with targeted physical and chemical properties (e.g., redox behaviour, oxygen mobility, electronic and ionic conductivity).


2012 ◽  
Vol 479-481 ◽  
pp. 2028-2032
Author(s):  
Zhi Yong Pan ◽  
Sheng Yin Song ◽  
Wen Hong Liu ◽  
Xin Li Han ◽  
Jun Han ◽  
...  

Dropout may be happen to round thread connection by main reasons of design and process of product, material’s property, make-up torque or make-up position, field operation problems etc.. Casing’s property has get a high improvement with the development over the past decade in China. But the number of connection dropout accident didn’t declined obviously. These lead to great economy loss and safety hazard had taken place. Research on a round thread connection pullout case was carried out combining relative theorys with tests. Macroscopic analysis and dimension measurement and material’s physical and chemical properties were checked for casings and couplings. Thread inspection and full-scale tests were done for casing simples that are same lot with dropout. Comprehensive analysis was carried out on these results. The results showed that dropout failure was ascribe to two main causes. One is make-up location cann’t reach standard location at field end, and the other is incorrect holding position on coupling in the course of making up.


Nanoscale ◽  
2021 ◽  
Author(s):  
Bowen Li ◽  
Jiazhong Geng ◽  
Haoqiang Ai ◽  
youchao Kong ◽  
Haoyun Bai ◽  
...  

Two-dimensional (2D) materials have attracted increasing interest in the past decades due to their unique physical and chemical properties for diverse applications. In this work, we present a first-principle design...


2011 ◽  
Vol 35 (4) ◽  
pp. 1069-1080 ◽  
Author(s):  
Fábio Henrique Alves Bispo ◽  
Alexandre Christofaro Silva ◽  
Pablo Vidal Torrado

In the upper Jequitinhonha valley, state of Minas Gerais, Brazi, there are large plane areas known as "chapadas", which are separated by areas dissected by tributaries of the Jequitinhonha and Araçuaí rivers. These dissected areas have a surface drainage system with tree, shrub, and grass vegetation, more commonly known as "veredas", i.e., palm swamps. The main purpose of this study was to characterize soil physical, chemical and morphological properties of a representative toposequence in the watershed of the Vereda Lagoa do Leandro, a swamp near Minas Novas, MG, on "chapadas", the highlands of the Alto Jequitinhonha region Different soil types are observed in the landscape: at the top - Typic Haplustox (LVA), in the middle slope - Xanthic Haplustox (LA), at the footslope - Xanthic Haplustox, gray color, here called "Gray Haplustox" ("LAC") and, at the bottom of the palm swamp - Typic Albaquult (GXbd). These soils were first morphologically described; samples of disturbed and undisturbed soils were collected from all horizons and subhorizons, to evaluate their essential physical and chemical properties, by means of standard determination of Fe, Al, Mn, Ti and Si oxides after sulfuric extraction. The contents of Fe, Al and Mn, extracted with dithionite-citrate-bicarbonate and oxalate treatments, were also determined. In the well-drained soils of the slope positions, the typical morphological, physical and chemical properties of Oxisols were found. The GXbd sample, from the bottom of the palm swamp, is grayish and has high texture gradient (B/A) and massive structure. The reduction of the proportion of crystalline iron compounds and the low crystallinity along the slope confirmed the loss of iron during pedogenesis, which is reflected in the current soil color. The Si and Al contents were lowest in the "LAC" soil. There was a decrease of the Fe2O3/TiO2 ratio downhill, indicating progressive drainage restriction along the toposequence. The genesis and all physical and chemical properties of the soils at the footslope and the bottom of the palm swamp of the "chapadas" of the Alto Jequitinhonha region are strongly influenced by the occurrence of ground water on the surface or near the surface all year long, at present and/or in the past. Total concentrations of iron oxides, Fe d and Fe o in soils of the toposequence studied are related to the past and/or present soil colors and drainage conditions.


KALPATARU ◽  
2015 ◽  
Vol 24 (1) ◽  
pp. 47
Author(s):  
M. Fadlan S.

Abstrak. Tembikar merupakan salah satu sisa benda budaya yang paling sering ditemukan dalam penelitian arkeologi, yang terbuat dari tanah liat yang dibakar. Analisis teknologi laboratoris tembikar dari situs-situs di DAS Bengawan Solo Bojonegoro, bertujuan untuk memperoleh hasil yang akurat tentang sifat fisik dan sifat kimia. Melalui kajian analisis teknologi laboratoris dapat digambarkan kualitas tembikar yang dibuat oleh para pengrajin pada masa lampau. Berdasarkan hasil analisis teknologi laboratoris tembikar dari situs-situs DAS Bengawan Solo, Bojonegoro mempunyai kualitas sedang hingga kualitas baik. Tembikar-tembikar tersebut termasuk dalam kategori peralatan sehari-hari yang berfungsi untuk menampung air, mengolah makanan dan untuk penyajian makanan serta minuman. Tingkat pembakarannya mencapai 600°-800° Celcius, dan warna tembikar didominasi warna gelap (dark colors) dibanding dengan warna terang (light colors). Adanya perbedaan prosentase dari setiap unsur kimia pada tembikar tersebut, tidak terlepas dari daya tahan mineral terhadap pelapukan.Abstract. Pottery, which is made of fired clay, is the most frequently found cultural remains during archaeological researches. Technological Laboratory Analysis on pottery from sites along the Bengawan Solo (Solo River) in Bojonegoro aims at obtaining accurate results about the nature of the physical and chemical properties. Through the technological laboratory analysis can be described the quality of pottery made by craftsmen in the past. Based on the results of the analysis, pottery from the sites along the Bengawan Solo, Bojonegoro Regency, have moderate up to good qualities. The pottery belongs to a category of daily equipment that serves to store water, cook food and to serve food and drink. The rate of heat during firing was up to 600°-800° Celsius, and the color of pottery is predominantly dark colors (black colors) with only a few light colors (bright colors). The difference in the percentage of each chemical element in the pottery is due to the durability of the minerals to weathering.


1997 ◽  
Vol 17 (2) ◽  
pp. 109-122 ◽  
Author(s):  
Christian Lüder ◽  
Dimitris Prekas ◽  
Michalis Velegrakis

We have studied the stability and the structure of doped noble gas cluster ions of the type M+Xn, (M=In, Al, Na, X=Ar, Kr, Xe) by systematically changing the composition M/X and observing changes in the magic number patterns appearing in the mass spectra. When the metal ion radius is comparable to the radius of the noble gas atom, the mass spectra show the familar icosahedral magic numbers n+ 1=13,19,23,26,29,32, 46, 55,... In constrast, for metal ions with radii significantly smaller than the noble gas atoms, we observe a new series of magic numbers n + 9, 11, 17, 21,24, 26,... This series converts into the icosahedral one for larger clusters. Using a simple hard sphere packing model, we show that this new series of magic numbers is consistent with a cluster growth sequence which is based on a capped square antiprism (CSA) geometrical structure of the clusters.


2006 ◽  
Vol 45 ◽  
pp. 1260-1267 ◽  
Author(s):  
Michael Scheffler ◽  
Franziska Scheffler

Zeolites find various applications in heterogeneous catalysis, microreactor techniques, sorption techniques, ion exchange and more recently in heat pump applications. In common processes zeolites are used as shaped bodies with a size in the millimeter range. Novel processes made it necessary to apply zeolites as coating on inert or reactive bulk or porous substrate materials. In the past fifteen years various methods for zeolite coatings have been developed and adapted to the specific requirements with respect to the process they are to be used and to the specific physical and chemical properties of the support material.


2021 ◽  
Vol 22 (1) ◽  
pp. 399
Author(s):  
Yale Yue ◽  
Xiao Zhao

Photothermal therapy (PTT) mediated by nanomaterial has become an attractive tumor treatment method due to its obvious advantages. Among various nanomaterials, melanin-like nanoparticles with nature biocompatibility and photothermal conversion properties have attracted more and more attention. Melanin is a natural biological macromolecule widely distributed in the body and displays many fascinating physicochemical properties such as excellent biocompatibility and prominent photothermal conversion ability. Due to the similar properties, Melanin-like nanoparticles have been extensively studied and become promising candidates for clinical application. In this review, we give a comprehensive introduction to the recent advancements of melanin-like nanoparticles in the field of photothermal therapy in the past decade. In this review, the synthesis pathway, internal mechanism and basic physical and chemical properties of melanin-like nanomaterials are systematically classified and evaluated. It also summarizes the application of melanin-like nanoparticles in bioimaging and tumor photothermal therapy (PTT)in detail and discussed the challenges they faced in clinical translation rationally. Overall, melanin-like nanoparticles still have significant room for development in the field of biomedicine and are expected to applied in clinical PTT in the future.


2020 ◽  
Vol 12 (1) ◽  
Author(s):  
Youning Gong ◽  
Zhitao Lin ◽  
Yue-Xing Chen ◽  
Qasim Khan ◽  
Cong Wang ◽  
...  

AbstractIn recent years, emerging two-dimensional (2D) platinum diselenide (PtSe2) has quickly attracted the attention of the research community due to its novel physical and chemical properties. For the past few years, increasing research achievements on 2D PtSe2 have been reported toward the fundamental science and various potential applications of PtSe2. In this review, the properties and structure characteristics of 2D PtSe2 are discussed at first. Then, the recent advances in synthesis of PtSe2 as well as their applications are reviewed. At last, potential perspectives in exploring the application of 2D PtSe2 are reviewed.


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