Impact of typical environments in China’s western mountainous areas on the durability of railway concrete:a review

Purpose–This study aims to analyze the impact mechanism of typical environments in China’s western mountainous areas on the durability of railway concrete and propose measures to improve durability.Design/methodology/approach–With the continuous promotion of infrastructure construction,the focus of China’s railway construction has gradually shifted to the western region.The four typical environments of large temperature differences,strong winds and dryness,high cold and low air pressure unique to the western mountainous areas of China have adverse effects on the durability of typical railway structure concrete(bridges,ballastless tracks and tunnels).This study identified the characteristics of four typical environments in the western mountainous areas of China through on-site research.The impact mechanism of the four typical environments on the durability of concrete in different structural parts of railways has been explored through theoretical analysis and experimental research;Finally,a strategy for improving the durability of railway concrete suitable for the western mountainous areas of China was proposed.Findings–The daily temperature difference in the western mountainous areas of China is more than twice that of the plain region,which will lead to significant temperature deformation and stress in the multi-layered structure of railway ballastless tracks.It will result in cracking.The wind speed in the western plateau region is about 2.5 to 3 times that of the plain region,and the average annual rainfall is only 1/5 of that in the plain region.The drying effect on the surface of casting concrete will significantly accelerate its cracking process,leading to serious durability problems.The environmental temperature in the western mountainous areas of China is generally low,and there are more freeze-thaw cycles,which will increase the risk of freeze-thaw damage to railway concrete.The environmental air pressure in the western plateau region is only 60%of that in the plain region.The moisture inside the concrete is more likely to diffuse into the surrounding environment under the pressure difference,resulting in greater water loss and shrinkage deformation of the concrete in the plateau region.The above four issues will collectively lead to the rapid deterioration of concrete durability in the western plateau region.The corresponding durability improvement suggestions from theoretical research,new technology development and standard system was proposed in this paper.Originality/value–The research can provide the mechanism of durability degradation of railway concrete in the western mountainous areas of China and corresponding improvement strategies.

Food Hygiene and Safety Practices amongst Food Vendors in the Western Area, Sierra Leone

Food safety and hygiene practices require a multisectoral approach including food, water, sanitation, waste management, transport, education, trade, policies and programs that enable safe food preparation, storage and service. Unsafe food can cause illness keeping people from achieving their full potential and death. This was a descriptive study that uses a mixed method approach to derive insights into the characteristics of food vendors related to demography, knowledge, practices, infrastructure, compliance and recommendation for a policymaking framework. Using the Lemeshows’ sample size formula, 473 vendors from formal (restaurants) and informal (cookri-baffa/table top) sites were interviewed and observed. We found from discussions that respondents had a good understanding on how to keep food safe. However, observed practices were poor 93% handled food with their bare hands, 83% did not cover their hair, and 76% did not wear an apron whilst handling, preparing or serving food, 61% did not keep their finger nails clean or short and 57% did not wash their hand before preparing or serving food. Over half (51%) had access to a toilet but 32% reported their use required payment and emphasized their poor condition/inadequate management. Nearly half (47%) of the vending sites did not have a handwashing facility, with soap and water available. Only 7% reported having any authority oversight of food safety. Food safety and hygiene practices in most cookri shops and restaurants was ‘poor’ with very limited surveillance system in place by competent authorities for compliance of food operators. Hand washing, clean surroundings, and covered food were the most common and emphasized practices to mitigate the risks associated with unsafe food.

Poverty Alleviation through Employment Promotion in Extreme Poverty-stricken Areas in Western China: A Case Study of Targeted Poverty Alleviation through Employment Promotion in Awang Town,Dongchuan District

Poverty alleviation through employment promotion is to promote the poor households to get rid of poverty through promoting employment to increase income. It is the most effective and direct way out of poverty. Dongchuan District, located in the alpine valley area of northeastern Yunnan, is a typical extreme poverty-stricken county in China. Under its jurisdiction, Awang Town is a mountainous township with a wide area of poverty and an extreme poverty. The incidence of poverty in 2015 reached 35.39%. In recent years, through the implementation of various policies to combat poverty, combined with the advantages as a traditional "hometown of migrant labor", focusing on employment- promoting poverty alleviation work, Awang Town has made certain achievements in poverty alleviation work. By the end of 2018, the poverty rate in the town fell to 0.57%, marking a major victory in the town s fight against poverty. Through field investigations, this article summarizes the main practices of Awang Town to carry out employment-promoting targeted poverty alleviation, analyzes the poverty alleviation achievements and successful experience of the town s employment-promoting targeted poverty alleviation work and discusses the promotion and application of this model so as to provide reference Yunnan Province and other poverty-stricken areas to carry out employment-promoting poverty alleviation.

Impacts of formal credit on rural household income:Evidence from deprived areas in western China

Financial support is a crucial part of China's poverty alleviation effort.Thus,it is vital to understand how formal credit impacts income growth in rural households.In 2012,2015,and 2018,a survey was conducted to obtain a panel dataset of 592 rural households from 6 poverty-stricken counties in western China,including counties in Guizhou,Yunnan,and Shaanxi provinces.We use the data to examine the effect of formal credit on rural household income and the mechanism that underlies this effect.We find that formal credit can significantly increase rural households'income in deprived areas in western China.Furthermore,formal credit promotes the reallocation of household labor from the agricultural sector to the non-agricultural sector and changes rural households'decisions about investment-consumption behavior.These are the drivers of changes in the amount and structure of household income.Further analyses show that formal credit may widen income inequality among rural households in western China's deprived areas.The individual characteristics of rural households,such as different levels of material capital,human capital,and social capital,bring about differences in the effects of formal credit on income growth.This study emphasizes that the implementation of formal credit is an essential strategy for poverty alleviation in underdeveloped areas,but policymakers should not excessively interfere with the financial market.

Fluid Inclusions of Orogenic Gold Deposits in the Zhongchuan Area,Western Qinling and Their Geological Significance

Orogenically-derived gold deposits of the Zhongchuan area in the western Qinling are distributed in the exo-contact thermal metamorphic zone. The country rocks hosting the deposits are predominantly of Devonian age with low-grade metamorphism and strong deformation with the ore deposits directly controlled by multi-level tectonic systems. Three types of inclusions from these deposits have been recognized: CO2-H2O, CO2-rich, and aqueous. The ore-forming fluids were mainly CO2-NaCl-H2O type characterized by rich CO2, low salinity, high temperature and immiscibility. Incorporated with earlier isotopic data, the regional geological setting and features of diagenesis and metallogeny, it can be concluded that the ore-forming fluids were derived from deep magma and mixed with meteoric and metamorphic water. The deposits formed during an intra-continent collisional orogeny, and some of the materials derived from the deep might have been involved in the ore-forming process.

Fluid migration paths in the marine strata of typical structures in the western Hubei-eastern Chongqing area,China

The western Hubei-eastern Chongqing area is an important prospective zone for oil and gas exploration in the central Yangtze area. Three representative structures, the Xinchang structure, Longjuba gas-bearing structure and the Jiannan gas field, were selected to analyze biomarker parameters in marine strata and to examine various types of natural gas and hydrocarbon sources. Fluid inclusions; carbon, oxygen, and strontium isotopic characteristics; organic geochemical analysis and simulation of hydrocarbon generation and expulsion history of source rocks were used for tracing fluid migration paths in marine strata of the study area. The Carboniferous-Triassic reservoirs in three typical structures all experienced at least two stages of fluid accumulation. All marine strata above the early Permian were shown to have fluids originating in the Permian rocks, which differed from the late stage fluids. The fluids accumulated in the late Permian reservoirs of the Xinchang structure were Cambrian fluids, while those in the late Carboniferous reservoirs were sourced from a combination of Silurian and Cambrian fluids. A long-distance and large-scale cross-formational flow of fluids destroyed the preservation conditions of earlier accumulated hydrocarbons. A short-distance cross-formational accumulation of Silurian fluids was shown in the late Permian reservoirs of the Longjuba structure with favorable hydrocarbon preservation conditions. The fluid accumulation in the Carboniferous reservoirs of the Jiannan structure mainly originated from neighboring Silurian strata with a small amount from the Cambrian strata. As a result, the Jiannan structure was determined to have the best preservation conditions of the three. Comparative analysis of fluid migration paths in the three structures revealed that the zone with a weaker late tectonism and no superimposition and modification of the Upper and Lower Paleozoic fluids or the Upper Paleozoic zone with the fluid charging from the Lower Paleozoic in the western Hubei-easteru Chongqing area are important target areas for future exploration.

Analysis on the Changes of Temperature and Heat Resources in Rural Area of Chaoyang in Western Liaoning

[Objective] The aim was to study the change characteristics of temperature and heat resources in rural area of Chaoyang in western Liaoning. [Method] Based on the data from rural meteorological station in Chaoyang in western Liaoning from 1966 to 2010, the change characteristics of temperature and heat resources in rural area in Chaoyang were analyzed by means of serial correlation and climate tendency method, so as to master its climate situation. [Result] The annual average value of daily average temperature, daily maximum temperature and daily minimum temperature in rural area of Chaoyang in western Liaoning from 1966 to 2010 showed fluctuation variation, and the annual average value of daily maximum temperature increased most obviously with the climatic tendency of 0.328 ℃/10 a and highest significant level, so it played an important role in temperature increase, next came daily average temperature (0.151 ℃/10 a), while there was no obvious decrease in daily minimum temperature. The average of daily maximum temperature in winter half year increased more obviously than that in summer half year, with the climatic tendency of 0.417 and 0.250 ℃/10 a, respectively; the trend of daily average temperature reached low significant level, and there was no obvious variation in daily minimum temperature. In addition, ≥10 ℃ accumulated temperature in rural area of Chaoyang in western Liaoning went up obviously, with the climatic tendency of 42.59 ℃·d/10 a, namely it increased by 192 ℃·d in recent 45 years. [Conclusion] The study could provide climatic reference for the adjustment of agriculture structure and varieties distribution.

Land Remediation Projects in Poverty-stricken Counties in Tibetan Areas Promoting Poverty Alleviation——A Case Study of Songpan County,Sichuan Province

Songpan County is a poverty-stricken county in the four provinces of China,one of the concentrated areas in China. This paper analyzes the effectiveness of land consolidation in Songpan County to promote poverty alleviation and development through specific cases. The results show that land remediation has improved agricultural production conditions,promoted agricultural efficiency,increased farmers' income,improved rural living conditions,promoted the development of urban and rural integration,improved the ecological environment,solved the problem that restricts the survival and development of poverty-stricken areas,enhanced the ability of farmers to develop themselves,raised the level of civilization in rural areas,and promoted poverty alleviation and development. The poverty alleviation and development has provided certain financial support for land remediation. It has promoted land remediation,and pointed out key directions for land remediation. It has an indirect promotion effect on land remediation.

Empirical Analysis of Factors Influencing Surplus Labor Transfer in Poverty-stricken Areas: A Case Study of Yimatu Town in Fuxin City

From the microscopic point of view,taking the surplus labor transfer in the Yimatu Town area as study object,we conduct survey of characteristics and transfer of rural surplus labor in Yimatu Town,through questionnaires and field interviews.Then we analyze the main factors influencing surplus labor transfer in rural areas from the personal characteristics of labor forces and family factor of labor forces.The results show that gender,age,educational level,farmland management days and other factors pertaining to the labor forces all affect the transfer of surplus labor, but the size and extent of the impact vary.In accordance with various influencing factors,we put forward recommendations for promoting the effective transfer of surplus labor in rural areas as follows:first,paying equal attention to macroscopic factors and microscopic factors influencing the transfer of surplus labor;second,focusing on the factors concerning the rural households and individual farmers,to find out the factors influencing the rational transfer;third,shifting the employment concept of surplus labor in rural areas;fourth,speeding up the construction of small towns and developing the secondary and tertiary industries.

GPR based RTM imaging technology for estimating rhizome diameters and application in the western China mining area

The rhizome functions are of great significance to the ecological protection of the western China mining area,whose ecological management can be provided with technical support via accurate calculations of the rhizome biomass.The rhizome diameter is an important index parameter of rhizome biomass.In this study,we propose an estimation of rhizome diameters based on ground penetrating radar(GPR)-based reverse time migration(RTM)imaging technology.First,the spatial distribution of shallow rhizomes is simulated using the finite difference time domain method.The simulation data are examined via RTM imaging and single-channel rhizome analysis to obtain the rhizome index parameters:Δh,the width of the maximum positive peak amplitude measured at an amplitude of zero,andΔH,the distance between the zero-amplitude position above the largest positive peak in the shallow region and the zero-amplitude position below the largest positive peak in the deeper region.The experiments of physical models verify the effectiveness of the two parameters(Δh andΔH).and indicate that the values ofΔh andΔH are independent of the rhizome burial depth;instead,they are only related to the diameter of the rhizome.For both the numerical simulations and the physical model experiment,the estimation errors ofΔh andΔH for the rhizome diameters can be constrained to less than 6%and 5%,respectively,which shows that the estimation of the rhizome diameters using GPR based RTM imaging technology is reasonable and effective and its high estimation accuracy meets the technical requirements.

Coupling interaction between biodiversity and aquatic habitat area in Western Route Project vicinity

The Western Route of the South-to-North Water Transfer Project will divert water from the upper Yangtze River and its tributaries, the Dadu River and Yalong River, to the upper Yellow River. The project may ease the water shortage in the Yellow River Basin. However, it may also have some effects on the ecosystem in the upper Yangtze River Basin. Benthic invertebrates play an important role in the river ecosystem, particularly in the circulation of materials and nutrition. Benthic invertebrates are widely used to quickly assess river ecosystems because of their rapid response to changes in the water environment. The diversity of benthic invertebrates is closely associated with the aquatic habitat area. This study examined this interaction by sampling the benthic invertebrates in an expanding area. The conclusions are that the diversity of benthic invertebrates begins to decrease when the aquatic habitat area is reduced to 45% of the original area, and decreases dramatically when the aquatic habitat area is reduced to 10% of the original area. The aquatic habitat area should be kept at more than 45% of the original area in order to maintain the significant diversity of benthic invertebrates.

Satisfaction of Village Doctors with the Township and Village Health Services Integration Policy in the Western Minority-inhabited Areas of China

Township and Village Health Services Integration Management（TVHSIM） is an essential form of China＇s two-tiered health service integration plan at the township and village level. Its main purpose, also one of the target goals in China＇s new healthcare reform, is to gradually integrate rural health services and appropriately allocate rural health resources. This study aims to assess the village doctors＇ satisfaction with the TVHSIM and provide scientific base to further improve TVHSIM. A cross-sectional study was carried out in which 162 village doctors from Qinghai, Inner Mongolia and Xinjiang in western China were interviewed. Descriptive analysis, independent t-test, one-way ANOVA, Spearman rank correlation and multiple linear regression were used to analyze the difference and relevance between village doctors＇ personal characteristics and their satisfaction with TVHSIM and six subscales. Village doctors with different years of practice, social insurance status and essential medical knowledge level showed statistically significant differences in their satisfaction levels（all P〈0.05）. Age（P〈0.05） and years of practice（P〈0.01） were negatively correlated with Drug and Medical Device Management and Financing Management. Essential medical knowledge level（P〈0.05） was negatively correlated with Operations Management as well. However, social insurance status（P〈0.05） was positively correlated with Human Resources Management and Drug and Medical Device management. Gender, age and years of practice respectively had significant influence on village doctors＇ satisfaction with TVHSIM（P〈0.01）. In conclusion, in order to further promote TVHSIM policy in rural China, a well-rounded social insurance model for village doctors is urgently needed. In addition, the development of TVHSIM is regionally imbalanced. Efficient and effective measures aiming at rationalizing gender and age structure and enhancing essential medical training should be carefully considered.

Rural vulnerability,migration,and relocation in mountain areas of Western China:An overview of key issues and policy interventions

Western China features a vast area of mountains and high plateaus where millions of people,including diverse ethnic minority groups,have inhabited for generations.Geographically located in the mountainous,remote,and isolated regions,rural communities are prone to natural hazards and thus become vulnerable to impoverishment.To reduce rural vulnerability,many people residing in mountainous villages opted to out-migrate from their original villages and hometowns while some took in-situ adaptation measures.A host of government-sponsored resettlement programs have been carried out to help rural villagers seek alternative livelihoods elsewhere over the past four decades.To achieve a sustainable future for rural communities in mountainous areas of western China,more effective policies and measures need to be developed and enforced.

Characteristics of change of the SST in the tropical western Pa-cific and the tropical Indian Ocean and its response to thechange of the Antarctic ice area

In this paper, by using ocean surface temperature data(COADS), the study is made of the characteristics of the monthly and annual changes of the SST in the tropical western Pacific and Indian Oceans, which have important influences on the climate change of the whole globe and the relation between ENSO(El Nio Southern Oscillation) and the Antarctic ice area is also discussed. The result indicates that in the tropical western Pacific and the Indian Oceans the change of Sea Surface Temperture(SST) is conspicuous both monthly and annaully, and shows different change tendency between them. This result may be due to different relation in the vibration period of SST between the two Oceans. The better corresponding relationship is obvious in the annual change of SST in the tropical Indian Ocean with the occurrence El Nio and La Nia. The change of the SST in the tropical western Pacific and the tropical Indian Oceans has a close relation to the Antarctic ice area, especially to the ice areas in the eastern south Pole and Ross Sea, and its notable correlative relationship appears in 16 months when the SST of the tropical western Pacific and the Indian Oceans lag back the Antarctic ice area.

Identification of the Concealed Structures in the Beiya Area of Western Yunnan

The interpretation of regional gravity and magnetic data, especially the extracted information about concealed targets and structures, provide important evidence for geological structure research, oil-gas resource assessment, mineral potential forecast and prospective area delineation. Several interpretation methods have been proposed to determine structural boundary, including vertical derivative, horizontal first-order derivative, total horizontal derivative, total gradient modulus, tilt derivative, and theta graph, and each have their advantages and disadvantages. This study used the tilt derivate method to obtain bouguer gravity anomalies in the Beya area, as shown in Fig. 1a.

Realization Path for Inclusive Finance to Support Rural Revitalization in Poverty-stricken Areas

Based on the quarterly economic,social and financial development data of 39 poverty-stricken counties in Henan Province during 2016-2018,this paper utilized the entropy-based TOPSIS method to objectively measure the rural revitalization index,and then built the quantile regression model to study the effects of various elements of inclusive finance on different stages of rural revitalization.Research results show that industrial development,agricultural modernization,targeted poverty alleviation,endogenous demand,and rural governance are the main points of inclusive finance in poverty-stricken areas to support rural revitalization;the rural revitalization index indicates that compared with the Dabie Mountain area and the non-contiguous poverty-stricken areas,the rural revitalization of the Qinba Mountain area is slower;for inclusive finance supporting rural revitalization,it is necessary to bring into play the role of monetary policy tools in re-lending,functions of credit in supporting industrial development,and role of insurance in risk protection;furthermore,inclusive finance solves problems such as the diminishing marginal effect of physical machinery investment in rural revitalization support,financial support for the coordinated development of small farmers and new agricultural business entities,financial support for the development of the entire industry chain,and the"siphon effect"of capital.

Variation of Air-Sea Heat Fluxes over the Western Pacific Warm Pool Area and Its Relationship with the South China Sea Summer Monsoon Onset

Based on oceanic and atmospheric parameters retrieved by satellite remote sensing using a neural network method, air-sea heat fluxes over the western Pacific warm pool area were calculated with the advanced the advanced Coupled Ocean-Atmosphere Response Experiment 3.0 (COARE3.0) bulk algorithm method. Then, the average annual and interannual characteristics of these fluxes were analyzed. The rela- tionship between the fluxes and the South China Sea (SCS) summer monsoon onset is highlighted. The results indicate that these fluxes have clear temporal and spatial characteristics. The sensible heat flux is at its maximum in the Kuroshio area, while the latent heat flux is at its maximum in the North Equatorial Current and Kuroshio area. The distribution of average annual air-sea heat fluxes shows that both sensible and latent heat fluxes are maximized in winter and minimized in summer. The air-sea heat fluxes have obvious interannual variations. Correlation analysis indicates a close lag-correlation between air-sea heat fluxes in the western Pacific warm pool area and at the SCS summer monsoon onset. The lagcorrelation can therefore predict the SCS summer monsoon onset, providing a reference for the study of precipitation related to the monsoon.

Implement PPET Strategy and Develop Ecotourism of Minority Areas in Western China——Take Xinlong County of Ganzi Tibetan Autonomous Prefecture in Sichuan Province as An Example

To help the poor and to develop tourism are two mportant problems in poverty-stricken areas. However, they were isolated for years.The PPET strategy was put forward in this paper based on PPT.The feasibility and the realistic meaning of the strategy in developing the ecotourism, overcoming poverty, and achieving prosperity of minority areas inwestern China are analyzed bytaking Xinlong county of Ganzi Tibetan Autonomous Prefecture in Sichuan Province as an example.

A Study on Forest Species Diversity and Its Ecological Service Function in the Plateau Area of Western Sichuan

This paper presents a study on species diversity and its ecological service function in the plateau area in western Sichuan. The results show that species diversity in the plantations on the cutover land has a tendency to increase and that its ecological service function is to be improved with stand age growing. The species diversity in forest communities is also gradually increased on different succession stage till reaching a climax level. But the species diversity in the climax community is slightly decreased before it reaches a relatively constant status. Ecological service function of diversity is gradually strengthened with the progress of succession. In addition, species diversity in a stand in a similar site and at a same age differs among forest types. Species diversity index within a coniferous and broad-leaved mixed forest is larger than that within a coniferous forest. Meanwhile, species diversity enriches as the tree density increases.

Structural Styles of Fronts of Thrust-Detachment Faults in Petroleum-bearing Areas of Western China

The front of a thrust-detachment fault may have various styles such as decoupling, fold, forethrust and backthrust ones because of differences in magnitude, direction and time of the forces exerted on the fault and the inhomogeneity of rock mechanical properties. They have different characteristics and are usually associated with gravity structure, inverse structure and diapir structure. These structures exist together in the same thrust-detachment fault and can influence, compensate for and convert into each other. They provide important grounds not only for the study of the dynamic state, propagation mode, evolutionary process and formation mechanism but also for the analysis of the petroleum generation, migration, accumulation and preservation and arrangement of drill holes in foreland basins.