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1.
● China has pledged ambitious carbon peak and neutrality goals for mitigating global climate change. ● Major challenges to achieve carbon neutrality in China are summarized. ● The new opportunities along the pathway of China’s carbon neutrality are discussed from four aspects. ● Five policy suggestions for China are provided. China is the largest developing economy and carbon dioxide emitter in the world, the carbon neutrality goal of which will have a profound influence on the mitigation pathway of global climate change. The transition towards a carbon-neutral society is integrated into the construction of ecological civilization in China, and brings profound implications for China’s socioeconomic development. Here, we not only summarize the major challenges in achieving carbon neutrality in China, but also identify the four potential new opportunities: namely, the acceleration of technology innovations, narrowing regional disparity by reshaping the value of resources, transforming the industrial structure, and co-benefits of pollution and carbon mitigation. Finally, we provide five policy suggestions and highlight the importance of balancing economic growth and carbon mitigation, and the joint efforts among the government, the enterprises, and the residents.  相似文献   
2.
Air inside poultry houses must be removed on a regular basis to prevent excess of heat, particles and noxious gases that can imperil animals. To cope with this issue, natural ventilation could be an effective method when assisted by accurate predictions. This study investigates air discharges caused by natural ventilation of a poultry house by means of a three-dimensional computational fluid dynamics (CFD) model. It solves the governing equations of momentum, heat and mass transport, radiative transfers and animal-generated heat. Wind directions of 0°, 36° and 56° (0° corresponds to a wind blowing perpendicular to the ridgeline) were investigated; the CFD model predictions achieved a RMSE of 1.2 °C and 0.6 g[H2O] kg?1 [dry air] for internal temperature and absolute humidity, respectively, when air blew with an angle of 36°. Air renewal rates (ARR) were 39.5 (±?1.9), 34.9 (±?2.2) and 33.6 (±?1.7) volumes of the building per hour, when air blew at 0°, 36° and 56°, respectively. Such ARR predictions served to know how the gases contained in air would likely spread downstream from the building in order to define regions of potentially high gas concentration that could endanger neighbouring habitable facilities.  相似文献   
3.
Species turnover patterns can be inconsistent due to differences in the dispersal ability of different growth forms. Here, species of trees, shrubs, herbs, and bryophytes in the Xiaoqinling National Nature Reserve in China were analyzed to determine patterns of species turnover along an elevation and spatial gradient. Variance partitioning was used to assess the relative contribution of topographic heterogeneity and dispersal limitation to species turnover. Our results suggest that the effect of dispersal limitation is more important than topographic heterogeneity on species turnover in temperate mountane ecosystems in the study area. Dispersal limitation has a greater effect on trees species turnover than on shrubs, herbs or bryophytes species turnover.  相似文献   
4.

Can Gio district is located in the coastal area of Ho Chi Minh City, southern Vietnam. Discharge of wastewater from Ho Chi Minh City and neighboring provinces to the rivers of Can Gio has led to concerns about the accumulation of trace metals (As, Cu, Cr, Ni, Pb, and Zn) in the coastal sediments. The main objective of this study was to assess the distribution of As, Cu, Cr, Ni, Pb, and Zn in surface and core sediments and to evaluate the contamination status in relation to local background values, as well as the potential release of these selected trace metals from sediments to the water environment. Sediment characteristization, including determination of fine fraction, pH, organic matter, and major elements (Al, Fe, Ca, K, Mg, and S), was carried out to investigate which parameters affect the trace metal enrichment. Fine fraction and Al contents were found to be the controlling proxies affecting the distribution of trace metals while other sediment characteristics did not show any clear influence on trace metals’ distribution. Although As concentrations in the sediments were much higher compared to its reference value in other areas, the enrichment factor based on local background values suggests minor contamination of this element as well as for Cr, Cu, and Pb. Risk assessment suggested a medium to very high risk of Mn, Zn, and Ni under acidification. Of importance is also that trace metals in sediments were not easily mobilized by organic complexation based on their low extractabilities by ammonium-EDTA extraction.

  相似文献   
5.
Understanding human behavior is vital to developing interventions that effectively lead to proenvironmental behavior change, whether the focus is at the individual or societal level. However, interventions in many fields have historically lacked robust forms of evaluation, which makes it hard to be confident that these conservation interventions have successfully helped protect the environment. We conducted a systematic review to assess how effective nonpecuniary and nonregulatory interventions have been in changing environmental behavior. We applied the Office of Health Assessment and Translation systematic review methodology. We started with more than 300,000 papers and reports returned by our search terms and after critical appraisal of quality identified 128 individual studies that merited inclusion in the review. We classified interventions by thematic area, type of intervention, the number of times audiences were exposed to interventions, and the length of time interventions ran. Most studies reported a positive effect (n = 96). The next most common outcome was no effect (n = 28). Few studies reported negative (n = 1) or mixed (n = 3) effects. Education, prompts, and feedback interventions resulted in positive behavior change. Combining multiple interventions was the most effective. Neither exposure duration nor frequency affected the likelihood of desired behavioral change. Comparatively few studies tested the effects of voluntary interventions on non-Western populations (n = 17) or measured actual ecological outcome behavior (n = 1). Similarly, few studies examined conservation devices (e.g., energy-efficient stoves) (n = 9) and demonstrations (e.g., modeling the desired behavior) (n = 5). There is a clear need to both improve the quality of the impact evaluation conducted and the reporting standards for intervention results.  相似文献   
6.
土壤质量决定着农产品的质量和农业生产的可持续发展,然而土壤退化成为农业生产的重要限制因素之一,施用土壤调理剂有利于减缓土壤退化的速度。该研究配制土壤调理剂,即蚯蚓粪:草菇渣:蛭石=6:3:1、钼酸钠50 g·kg-1、硼酸13.3 g·kg-1,并设5个不同的处理CK、QY-T1、QY-T2、QY-T3、QY-T4,研究该调理剂对土壤理化性质和肥力的影响作用,分析其对茄子硼、钼和生长状况的促进作用。结果表明,该调理剂能提高土壤温度,5 cm、09:00的土壤温度QY-T4较高,但10 cm、14:00的土壤温度QY-T3最高;土壤容重随着施用量的增大而显著降低至1.50 g·cm-3以下,土壤pH值从CK的4.93提高到QY-T4的5.57、微生物量碳分别比CK高29.9%、36.1%、47.6%和52.2%,有机质分别比CK高10.8%、11.7%、12.5%和7.0%,QY-T2、QY-T3、QY-T4土壤有效硼达到0.35、0.36、0.42mg·kg-1,QY-T1、QY-T2的有效钼分别为0.107、0.140mg·kg-1,随着调理剂的增多而增多,但QY-T3、QY-T4分别为0.101、0.092 mg·kg-1反而随着调理剂的增多而下降,茄子硼、钼含量都随着调理剂的增加而增大,且显著高于对照(P<0.01);总产量比CK分别提高了29%、36%、190%和66%,总个数分别增加了25%、28%、155%和66%,59 d株高和叶片面积分别比CK增高了23%、1.4%、23%、16%和6.8%、11%、9.3%、7.4%,而叶片数量,所有的处理差异不显著,因此推荐该土壤调理剂用量与QY-T3相同,为1.5×104kg·hm-2。该研究可为土壤调理剂修复土壤退化的应用提供依据。  相似文献   
7.
The annual relative mass of storage organs cycle of Bufo gargarizans in southwestern China was studied from December 2005 to November 2006. We described how those organs changed in response to extreme temperatures. Energy reservation dropped to the lowest levels after dormancy for both sexes, and then increased for period of 4.25 month. However, the mass of these organs dropped again rapidly until August (liver) and September (fat bodies) due to the constraint from extreme high temperature occurred during the summer, and then non-significantly increased before hibernation. For ovaries, varied with a different profile to those of liver and fat bodies have a resting period of four months. In addition, the toads’ ovaries kept growing when the mass of liver and fat bodies declining accordingly during hibernation. Therefore, ovarian mass increased during the hibernation and non-hibernation period.  相似文献   
8.
对2014—2016年齐齐哈尔市PM_(2.5)与PM_(10)质量浓度的时间变化特征进行简要分析,并探究PM_(2.5)/PM_(10)以及PM_(2.5)与PM_(10)的相关性。结果表明:2014—2016年齐齐哈尔的PM_(2.5)与PM_(10)的年均质量浓度分别为36.7、62.9μg/m~3,且呈逐渐下降趋势;冬季的PM_(2.5)与PM_(10)浓度最高,秋季次之,春季与夏季相对较低;2014—2016年PM_(2.5)与PM_(10)质量浓度月变化趋势基本相同,整体呈现2—6月逐渐下降,9—11月逐渐上升的规律;PM_(2.5)与PM_(10)质量浓度的日变化均呈双峰现象;对PM_(2.5)与PM_(10)进行线性拟合,相关系数为0.896 3。同时,残差分析也说明两者拟合情况良好,四季相关系数为r_(秋季)(0.982 2)r_(冬季)(0.964 4)r_(夏季)(0.943 9)r_(春季)(0.829 6);2014—2016年PM_(2.5)/PM_(10)平均值为55.27%,大气颗粒物PM_(2.5)的贡献率高达一半以上。  相似文献   
9.
10.
通过在玻璃绝缘子上配置不同的 RTV 涂层方式,模拟涂覆了 RTV 涂层的绝缘子表面各种憎水性分布情况,进行短时污秽耐受试验和人工污秽闪络试验,研究 RTV 涂层表面憎水性分布不均对其防污闪性能的影响。研究结果表明:当涂覆有 RTV 涂料的绝缘子表面憎水性分布不均时,其污闪电压严重下降。绝缘子下表面涂层的憎水性对绝缘子防污闪能力影响尤为显著。  相似文献   
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