scholarly journals Experimental Study on the Structural Features and Corrosion Characteristics of Dolomite and Limestone in the Karst Stone Mountainous Areas in Northern Guangxi

2021 ◽  
Author(s):  
Zhanfei Gu ◽  
Zhikui Liu
Keyword(s):  
Chemical Composition ◽  
Corrosion Test ◽  
Large Scale ◽  
Structural Features ◽  
Mountainous Areas ◽  
Chemical Corrosion ◽  
Vibration Load ◽  
Corrosion Rates ◽  
The North ◽  
Massive Structure

Abstract Taking dolomite and limestone in Guilin and Liuzhou regions in the north of Guangxi Province as research objects, this paper analyzed their mineral composition and chemical composition, and then carried out the chemical corrosion test, the corrosion test under the chemical-temperature actions, and the corrosion test under the action of vibration load, respectively. The results showed that: (i) the dolomite in northern Guangxi mainly has fine crystalline texture and massive structure with low content of acid insoluble matters, while limestone mainly has powder crystalline texture and massive structure with high content of acid insoluble matters, and the purity of both dolomite and limestone are very high; (ii) the difference of corrosion between dolomite and limestone mainly depends on the ratio of CaO/MgO in their chemical composition, and the content of silica and acid insoluble matters; (iii) the corrosion rates of the pure dolomite and the pure limestone are basically the same under the same external conditions; (iv) temperature and vibration load have relatively large influence on the corrosion rates of dolomite and limestone, and the corrosion rates of dolomite and limestone increase with the increase of temperature, but the influence of vibration load on the corrosion rate is more significant than temperature. This research can provide theoretical basis and technical support for large-scale engineering construction and prevention of karst geologic disasters in karst stone mountainous areas in the northern Guangxi. Keywords: dolomite and limestone; structural features; corrosion characteristics; northern Guangxi

scholarly journals GLASS FINDS FROM THE EARLY MEDIEVAL CEMETERIES IN THE MOUNTAINOUS AREAS OF THE NORTH CAUCASUS CENTRAL REGIONS: CHEMICAL COMPOSITION AND ORIGIN

2019 ◽  
Author(s):  
О.С. Румянцева ◽  
А.А. Кадиева ◽  
С.В. Демиденко ◽  
Д.А. Ханин ◽  
М.В. Червяковская ◽  
...  
Keyword(s):  
Roman Empire ◽  
Chemical Composition ◽  
Mountainous Areas ◽  
North Caucasus ◽  
Early Medieval ◽  
The North ◽  
Icp Ms ◽  
Central Regions ◽  
Plant Ash ◽  
Different Origin

В статье рассмотрен химический состав серии стеклянных изделий, происходящих из раннесредневековых могильников центральных районов Северного Кавказа (втор. пол. V VIII в.). Стекло проанализировано методами SEM EDS, EPMA, LA ICP MS. Стекло одного из украшений изготовлено на золе растений и происхождением связано с регионом к востоку от Евфрата (возможно, с сасанидским Ираном) остальные стекла содовые и происходят, вероятно, из Восточного и Юго Восточного Средиземноморья. По составу они находят соответствие среди групп, распространенных на территории Римской империи как в синхронное, так и в более раннее время (HIMT, группы Foy 3.2 Foy 4, Левантийская 1, римское зеленоголубое). Некоторые признаки химического состава позволяют говорить о случайном характере сырья, использовавшегося при изготовлении вставок, и/или о разном происхождении самих украшений со вставками. The paper explores the chemical composition of a series of glass items originating from the early medieval cemeteries discovered in the North Caucasus central regions (second half of the 5th 8th centuries). The glass was analyzed by SEM EDS, EPMA, LA ICP MS methods. The glass of one item was made of plant ash glass, originated from a region east of the Euphrates (possibly, Sasanian Iran) other items were made from soda glass and, most likely, came from the Eastern and Southeastern Mediterranean. Their composition is similar to the glass of the groups well known in the Roman Empire during the same period and earlier (HIMT, Foy 3.2 Foy 4, Roman bluegreen, Levantine I groups). Some aspects of the chemical composition suggest that the the accidental choice of the glass used in making inserts and/or about different origin of the items with inserts.

The Structure and Evolution of Extratropical Cyclones, Fronts, Jet Streams, and the Tropopause in the GEOS General Circulation Model

2001 ◽  
Vol 82 (9) ◽  
pp. 1853-1868 ◽  
Author(s):  
A. L. Conaty ◽  
J. C. Jusem ◽  
L. Takacs ◽  
D. Keyser ◽  
R. Atlas
Keyword(s):  
General Circulation Model ◽  
General Circulation ◽  
Large Scale ◽  
North Atlantic Ocean ◽  
Potential Temperature ◽  
Circulation Model ◽  
Structural Features ◽  
Extratropical Cyclones ◽  
Jet Streams ◽  
The North

The realism of extratropical cyclones, fronts, jet streams, and the tropopause in the Goddard Earth Observing System (GEOS) general circulation model (GCM), implemented in assimilation and simulation modes, is evaluated from climatological and case-study perspectives using the GEOS-1 reanalysis climatology and applicable conceptual models as benchmarks for comparison. The latitude-longitude grid spacing of the datasets derived from the GEOS GCM ranges from 2° × 2.5° to 0.5° × 0.5°. Frontal systems in the higher-resolution datasets are characterized by horizontal potential temperature gradients that are narrower in scale and larger in magnitude than their lower-resolution counterparts, and various structural features in the Shapiro–Keyser cyclone model are replicated with reasonable fidelity at 1° × 1° resolution. The remainder of the evaluation focuses on a 3-month Northern Hemisphere winter simulation of the GEOS GCM at 1° × 1° resolution. The simulation realistically reproduces various large-scale circulation features related to the North Pacific and Atlantic jet streams when compared with the GEOS-1 reanalysis climatology, and conforms closely to a conceptualization of the zonally averaged troposphere and stratosphere proposed originally by Napier Shaw and revised by Hoskins. An extratropical cyclone that developed over the North Atlantic Ocean in the simulation features surface and tropopause evolutions corresponding to the Norwegian cyclone model and to the LC2 life cycle proposed by Thorncroft et al., respectively. These evolutions are related to the position of the developing cyclone with respect to upper-level jets identified in the time-mean and instantaneous flow fields. This article concludes with the enumeration of several research opportunities that may be addressed through the use of state-of-the-art GCMs possessing sufficient resolution to represent mesoscale phenomena and processes explicitly.

Why Has There Been No People’s Power Rebellion in North Korea?

2018 ◽  
pp. 1-34
Author(s):  
Andrew Jackson
Keyword(s):  
Rural Areas ◽  
North Korea ◽  
Large Scale ◽  
Political Elite ◽  
Information Control ◽  
Al Jazeera ◽  
The North ◽  
New Information ◽  
Effective System ◽  
The Right

One scenario put forward by researchers, political commentators and journalists for the collapse of North Korea has been a People’s Power (or popular) rebellion. This paper analyses why no popular rebellion has occurred in the DPRK under Kim Jong Un. It challenges the assumption that popular rebellion would happen because of widespread anger caused by a greater awareness of superior economic conditions outside the DPRK. Using Jack Goldstone’s theoretical expla-nations for the outbreak of popular rebellion, and comparisons with the 1989 Romanian and 2010–11 Tunisian transitions, this paper argues that marketi-zation has led to a loosening of state ideological control and to an influx of infor-mation about conditions in the outside world. However, unlike the Tunisian transitions—in which a new information context shaped by social media, the Al-Jazeera network and an experience of protest helped create a sense of pan-Arab solidarity amongst Tunisians resisting their government—there has been no similar ideology unifying North Koreans against their regime. There is evidence of discontent in market unrest in the DPRK, although protests between 2011 and the present have mostly been in defense of the right of people to support themselves through private trade. North Koreans believe this right has been guaranteed, or at least tacitly condoned, by the Kim Jong Un government. There has not been any large-scale explosion of popular anger because the state has not attempted to crush market activities outright under Kim Jong Un. There are other reasons why no popular rebellion has occurred in the North. Unlike Tunisia, the DPRK lacks a dissident political elite capable of leading an opposition movement, and unlike Romania, the DPRK authorities have shown some flexibility in their anti-dissent strategies, taking a more tolerant approach to protests against economic issues. Reduced levels of violence during periods of unrest and an effective system of information control may have helped restrict the expansion of unrest beyond rural areas.

Information And Map-Made Control With The Functions Of Business Analytics For Urban Management

2019 ◽  
pp. 72-78
Keyword(s):  
Large Scale ◽  
Information Support ◽  
Urban Management ◽  
Business Analytics ◽  
Administrative District ◽  
The North ◽  
Model Of Management ◽  
Complex Development ◽  
Coordination System ◽  
Key Aspects

The key aspects of the process of designing and developing an information and cartographic control tool with business analytics functions for the municipal level of urban management are considered. The review of functionality of the developed tool is given. Examples of its use for the analysis and monitoring of implementation of the program of complex development of territories are given. The importance of application of information support of management and coordination at all levels of management as an integral part of the basic model of management and coordination system of large-scale urban projects of dispersed construction is proved. Information and map-made tool with business intelligence functions was used and was highly appreciated in the preparation of information-analytical and presentation materials of the North-Eastern Administrative District of Moscow. Its use made it possible to significantly optimize the list of activities of the program of integrated development of territories, their priority and timing.

THE POVERTY REDUCTION SOLUTIONS FOR ETHNIC MINORITIES IN THE NORTH EASTERN BORDER AREA USING THE MARKET ACCESS

2018 ◽  
Author(s):  
Phi Hung Cuong ◽  
Vu Van Anh
Keyword(s):  
Ethnic Minorities ◽  
Poverty Reduction ◽  
Market Access ◽  
Poverty Rate ◽  
Living Standards ◽  
Mountainous Areas ◽  
Important Indicator ◽  
The North ◽  
North Eastern ◽  
Eastern Border

Income is an important indicator for assessing the level of economy development as well as identifying and assessing living standards. The population in Northeast border is poor, facilities are outdated, people’s life is difficult, but it hold great potentials for economic development. However, the region’s biggest challenge today is low living standards and high poverty rate. Differences in income and living standards across regions and strata tend to increase the gap. The sustainability of the trend of income increase and improvement of living standards of the population is not stable. As a result, the development of mountainous areas is dependent on poverty reduction solutions for ethnic minorities through the increase of incomes and improvement of market connectivity for ethnic minorities in mountainous areas.

Accelerated Discovery of High-Refractive-Index Polyimides via First-Principles Molecular Modeling, Virtual High-Throughput Screening, and Data Mining

2019 ◽  
Author(s):  
Mohammad Atif Faiz Afzal ◽  
Mojtaba Haghighatlari ◽  
Sai Prasad Ganesh ◽  
Chong Cheng ◽  
Johannes Hachmann
Keyword(s):  
Data Mining ◽  
Refractive Index ◽  
High Throughput ◽  
First Principles ◽  
High Throughput Screening ◽  
Large Scale ◽  
Computational Study ◽  
High Refractive Index ◽  
Structural Features ◽  
Learning Program

<div>We present a high-throughput computational study to identify novel polyimides (PIs) with exceptional refractive index (RI) values for use as optic or optoelectronic materials. Our study utilizes an RI prediction protocol based on a combination of first-principles and data modeling developed in previous work, which we employ on a large-scale PI candidate library generated with the ChemLG code. We deploy the virtual screening software ChemHTPS to automate the assessment of this extensive pool of PI structures in order to determine the performance potential of each candidate. This rapid and efficient approach yields a number of highly promising leads compounds. Using the data mining and machine learning program package ChemML, we analyze the top candidates with respect to prevalent structural features and feature combinations that distinguish them from less promising ones. In particular, we explore the utility of various strategies that introduce highly polarizable moieties into the PI backbone to increase its RI yield. The derived insights provide a foundation for rational and targeted design that goes beyond traditional trial-and-error searches.</div>

Structural features and strength behavior of TRIP/TWIP steels

2020 ◽  
pp. 5-18
Author(s):  
D. V. Prosvirnin ◽  
◽  
M. S. Larionov ◽  
S. V. Pivovarchik ◽  
A. G. Kolmakov ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Composition ◽  
Thermomechanical Processing ◽  
Maximum Load ◽  
Structural Features ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Structural And Functional Properties ◽  
Twip Steels ◽  
The Creation

A review of the literature data on the structural features of TRIP / TWIP steels, their relationship with mechanical properties and the relationship of strength parameters under static and cyclic loading was carried out. It is shown that the level of mechanical properties of such steels is determined by the chemical composition and processing technology (thermal and thermomechanical processing, hot and cold pressure treatment), aimed at achieving a favorable phase composition. At the atomic level, the most important factor is stacking fault energy, the level of which will be decisive in the formation of austenite twins and / or the formation of strain martensite. By selecting the chemical composition, it is possible to set the stacking fault energy corresponding to the necessary mechanical characteristics. In the case of cyclic loads, an important role is played by the strain rate and the maximum load during testing. So at high loading rates and a load approaching the yield strength under tension, the intensity of the twinning processes and the formation of martensite increases. It is shown that one of the relevant ways to further increase of the structural and functional properties of TRIP and TWIP steels is the creation of composite materials on their basis. At present, surface modification and coating, especially by ion-vacuum methods, can be considered the most promising direction for the creation of such composites.

SPRING RAPE CULTIVATION TECHNOLOGY FOR THE GREEN CONVEYOR CROP ROTATION IN THE MOUNTAINOUS AREAS OF THE NORTH CAUCASUS

2019 ◽  
Vol 14 (6) ◽  
pp. 884-892
Author(s):  
Anna Shalygina ◽  
◽  
Taisiya Batsazova ◽  
Larisa Ikoeva ◽  
Albina Tedeeva ◽  
...  
Keyword(s):  
Crop Rotation ◽  
Mountainous Areas ◽  
North Caucasus ◽  
The North ◽  
Cultivation Technology ◽  
Spring Rape

DESIGN AND IMPLEMENTATION OF THE OCEANOGRAPHIC MODELING AND OBSERVATION NETWORK (REMO) FOR PHYSICAL OCEANOGRAPHY STUDIES AND OCEAN FORECASTING

2014 ◽  
Vol 31 (2) ◽  
Author(s):  
Jose Antonio Moreira Lima
Keyword(s):  
Atlantic Ocean ◽  
Large Scale ◽  
North Pacific Ocean ◽  
Integrated Approach ◽  
Sea Surface ◽  
Global Ocean ◽  
Height Anomaly ◽  
The North ◽  
Observation Network ◽  
Ocean Forecasting

This paper is concerned with the planning, implementation and some results of the Oceanographic Modeling and Observation Network, named REMO, for Brazilian regional waters. Ocean forecasting has been an important scientific issue over the last decade due to studies related to climate change as well as applications related to short-range oceanic forecasts. The South Atlantic Ocean has a deficit of oceanographic measurements when compared to other ocean basins such as the North Atlantic Ocean and the North Pacific Ocean. It is a challenge to design an ocean forecasting system for a region with poor observational coverage of in-situ data. Fortunately, most ocean forecasting systems heavily rely on the assimilation of surface fields such as sea surface height anomaly (SSHA) or sea surface temperature (SST), acquired by environmental satellites, that can accurately provide information that constrain major surface current systems and their mesoscale activity. An integrated approach is proposed here in which the large scale circulation in the Atlantic Ocean is modeled in a first step, and gradually nested into higher resolution regional models that are able to resolve important processes such as the Brazil Current and associated mesoscale variability, continental shelf waves, local and remote wind forcing, and others. This article presents the overall strategy to develop the models using a network of Brazilian institutions and their related expertise along with international collaboration. This work has some similarity with goals of the international project Global Ocean Data Assimilation Experiment OceanView (GODAE OceanView).

Sign in / Sign up

Export Citation Format

Share Document