Agricultural Structure in Western China by Comparing with before and after CFFG Based on Shift-share Method

Abstract

Based on shift-share method, this article employs regional share, structural shift and competitive shift to analyze the structural benefit and competitive position of agricultural structure in western China by comparing with agriculture, foresting, stockbreeding and fishing before and after Conversion of Farmland to Forest and Grassland (CFFG). Then authors draw following conclusion: while CFFG program has been put in practice, the agricultural structure in western China has some typical characteristics, such as growth faster, structural predominance obvious and more competitive. But the contributiveness from the competition is not too much yet, and the structural benefit of forest estate and stockbreeding are restrained.     

渤黄海上空气溶胶遥感探测与分析

气溶胶的来源及变化分析对于研究气候变化和海洋环境污染都有重要意义.遥感技术能实时提供大尺度气溶胶时空变化信息,这对于估算入海通量有重要参考价值.本文利用MODIS资料,通过查算表拟合等方法对渤黄海上空的气溶胶光学厚度和Angstrom指数,进行了估算.整个空间分布结果基本合理,和台站测试结果也比较类似.研究表明遥感方法较好地展现了气溶胶光学厚度和Angstrom指数的空间变化特征,可为进一步分析气溶胶输移路径及建立人海通量估算模型等研究提供参考.     

泥浆护壁钻孔灌注桩安全施工技术

分析了泥浆护壁钻孔灌注桩施工中的安全隐患及原因,提出相应的对策.     

Occurrence and distribution of micro- and mesoplastics in the high-latitude nature reserve,northern China

• The first study on micro(meso)plastics (MMPs) in the Liaohe River Reserve is reported. • Diverse MMP were detected in surface water and sediment at all 32 sites. • The abundance of MMPs decreased in the course of the river. • The MMPs abundance in water is significant association with the county population. Microplastics pollution has received growing attention worldwide in recent years. However, data on microplastics in the freshwater environment are still limited, especially in high-latitude nature reserves in Northern China. The first study on microplastic pollution in the Liaohe River Reserve in Northern China is reported here, and mesoplastics were also incorporated. Surface water and sediment samples were collected from 32 sites along the nature reserve. The abundance, type, shape, color, and size of micro- and mesoplastics were measured using density extraction, optical microscopy, and FTIR spectroscopy. The data showed that diverse micro- and mesoplastics were found widespread in the 32 sites, and the average abundance of these plastics was 0.11±0.04 10⁻² items/L in surface water and 62.29±54.30 items/kg in sediment. Moreover, 70% and 66% were smaller than 2000 μm in surface water and sediment, respectively. Fiber accounted for 91.86% in surface water and 43.48% in sediment, indicating that the major source of micro- and mesoplastics in the Liaohe River Reserve may be domestic sewage and aquaculture. A total of 16 and 27 polymers were identified in surface water and sediment, respectively, and mostly consisted of rayon, polyester, polystyrene, and poly(ethylene terephthalate). Moreover, both the risk index and the pollution load index demonstrated a low risk of micro- and mesoplastics in surface water and sediment in the Liaohe River Reserve.     

Measuring environmental efficiency and technology inequality of China’s power sector: methodological comparisons among data envelopment analysis,free disposable hull,and super free disposable hull models

Environmental Science and Pollution Research - China’s power sector has received great research attention because of its large energy consumption and CO2 emissions. This study assesses the...     

Association of individual green space exposure with the incidence of asthma and allergic rhinitis: a systematic review and meta-analysis

The association between allergic respiratory diseases, such as asthma and allergic rhinitis (AR), and green space (GS) remains controversial. Our study aimed to summarize and synthesize the association between individual GS exposure and the incidence of asthma/AR. We systematically summarized the qualitative relationship between GS exposure and asthma and AR. The pooled odds ratio (OR) with 95% confidence intervals (CIs) was used to estimate the effect of the Normalized Difference Vegetation Index (NDVI) on asthma and AR. A total of 21 studies were included for systematic review, and 8 of them underwent meta-analysis. In the meta-analysis of current asthma, the 0?<?radius?≤?100 m group, 100?<?radius?≤?300 m group, and 500?<?radius?≤?1000 m group presented weak negative associations between the NDVI and current asthma. For ever asthma, slight positive associations existed in the 0?<?radius?≤?100 m group and 300?<?radius?≤?500 m group. In addition, the NDVI might slightly reduce the risk of AR in radius of 100 m and 500 m. Our findings suggest that the effects of GS exposure on asthma and AR were not significant. Differences in GS measurements, disease diagnoses and adjusted confounders across studies may have an impact on the results. Subsequent studies should consider potential confounding factors and use more accurate GS exposure measurements to better understand the impact of GS exposure on respiratory disease in the population.

     

Review on heterogeneous oxidation and adsorption for arsenic removal from drinking water

The long term exposure of arsenic via drinking water has resulted in wide occurrence of arsenisim globally, and the oxidation of the non-ionic arsenite (As(III)) to negatively-charged arsenate (As(V)) is of crucial importance for the promising removal of arsenic. The chemical oxidants of ozone, chlorine, chlorine dioxide, and potassium permanganate may achieve this goal; however, their application in developing countries is sometimes restricted by the complicate operation and high cost. This review paper focuses on the heterogeneous oxidation of As(III) by solid oxidants such as manganese oxide, and the adsorption of As(V) accordingly. Manganese oxide may be prepared by both chemical and biological methods to achieve good oxidation performance towards As(III). Additionally, manganese oxide may be combined with other metal oxides, e.g., iron oxide, to improve the adsorption capability towards As(V). Furthermore, manganese oxide may be coated onto porous materials of metal organic frameworks to develop novel adsorbents for arsenic removal. To achieve the application in engineering works, the adsorbents granulation may be achieved by drying and calcination, agglomeration, and the active components may also be in situ coated onto the porous materials to maintain the oxidation and adsorption activities as much as possible. The novel adsorbents with heterogeneous oxidation and adsorption capability may be carefully designed for the removal of arsenic in household purifiers, community-level decentralized small systems, and the large-scale drinking water treatment plants (DWTPs). This review provides insight into the fundamental studies on novel adsorbents, the development of innovative technologies, and the demonstration engineering works involved in the heterogeneous oxidation and adsorption, and may be practically valuable for the arsenic pollution control globally.     

Pre-oxidation enhanced cyanobacteria removal in drinking water treatment: A review

Cyanobacterial bloom has many adverse effects on source water quality and drinking water production. The traditional water treatment process can hardly achieve satisfactory removal of algae cells. This review examines the impact of pre-oxidation on the removal of cyanobacteria by solid-liquid separation processes. It was reported that the introduction of chemical oxidants such as chlorine, potassium permanganate, and ozone in algae-laden water pretreatment could improve algae removal by the subsequent solid-liquid separation processes. However, over dosed oxidants can result in more serious water quality risks due to significant algae cell lysis and undesirable intracellular organic matter release. It was suggested that moderate pre-oxidation may enhance the removal of cyanobacteria without damaging algae cells. In this article, effects of moderate pretreatment on the solid-liquid separation processes (sedimentation, dissolved air flotation, and membrane filtration) are reviewed.     

Polybrominated diphenyl ethers in South China maternal and fetal blood and breast milk

Twenty-one-paired human fetal and maternal serum and 27 breast milk samples at South China were analyzed for concentrations of polybrominated diphenyl ethers (PBDEs). Seven PBDE congeners (BDE-28, -47, -99, -100, -153, -154, and -183) were quantified using gas chromatography/mass spectrometry (GC/MS). This is the first report to present the residue levels of PBDEs in human samples of China. The concentrations of total PBDEs ranged from 1.5 to 17 ng/g in the samples and were within the range reported in European samples for a similar population, but lower than human tissue levels in North America. BDE-47 and -153 were the dominant PBDE congeners in all samples and accounted for 60% of the total PBDEs. Further research is needed to determine the exposure route of PBDEs and their health effects.