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411.
Payments for ecosystem services (PES) are one kind of important tool for environmental protection, and have been widely studied by international scholars and conservationists. Based various definitions of PES from recent articles, we have outlined four principles for PES: parity, measurability, additionality and conditionality, and then have used these principles to develop a formula to calculate a standard for PES. Finding a way to use PES to achieve a win-win relationship between economic growth and environmental protection in the Beijing-Tianjin-Hebei Region (BTHR) is a key task for Chinese government. Synergetic development of BTHR has become a national strategy, like The Belt and Road Initiative. This article employed the formula we developed to calculate the net horizontal PES amounts that each provincial government within BTHR should pay. Our findings show that Beijing should have paid 10.44×109 Yuan (0.4% of Beijing’s GRP) and Tianjin 16.56×109 Yuan (0.93% of Tianjin’s GRP) to Hebei in 2016. 相似文献
412.
为研究东海区厚壳贻贝(Mytilus coruscus)遗传多样性,以厚壳贻贝F mtDNA D-loop为标记,对浙江省舟山嵊山岛、宁波渔山岛、温州南麂岛、福建省宁德湾和莆田南日岛五个海区的厚壳贻贝群体进行了遗传分析。结果表明,厚壳贻贝各群体的遗传多样性差异不明显,在5个群体中,宁德群体的遗传多样性相对最丰富;将5个群体作为一个整体时,呈现出较高的单倍型多样性和较低的核苷酸多样性。对厚壳贻贝5个群体间的遗传分化系数(Fst)和基因流(Nm)进行检测,结果显示群体间Fst值都很低,但Nm值都很高(Nm绝对值1),表明5个群体间存在丰富的基因交流。但宁德群体与浙江沿海的3个群体(嵊山、渔山、温州)的Fst值相对较高,且差异显著(P0.5),表明宁德群体与这3个群体间出现遗传分化。本研究旨在为海洋经济贝类资源的保护管理提供理论依据。 相似文献
413.
渤海夏季环流的高分辨率海浪-潮汐-环流耦合模式研究 总被引:2,自引:0,他引:2
The Bohai Sea is a shallow semi-enclosed inner sea with an average depth of 18 m and is located at the west of the northern Yellow Sea. The climatological circulation pattern in summer of the Bohai Sea is studied by using a wave-tide-circulation coupled model. The simulated temperature and the circulation agree with the observation well. The result shows that the circulation pattern of the Bohai Sea is jointly influenced by the tidal residual current, wind and baroclinic current. There exists an obvious density current along the temperature front from the west part of the Liaodong Bay to the offshore area of the Huanghe Estuary. In the Liaodong Bay there exists a clockwise gyre in the area north to the 40°N. While in the area south to the 40°N the circulation shows a two-gyre structure, the flow from the offshore area of the Huanghe Estuary to the Liaodong Bay splits into two branches in the area between 39°N and 40°N. The west branch turns into north-west and forms an anti-clockwise gyre with the south-westward density current off the west of the Liaodong Bay. The east branch turns to the east and forms a clockwise gyre with the flow along the east coast of the Liaodong Bay. The forming mechanism of the circulation is also discussed in this paper. 相似文献
414.
The B/Ca ratio of planktonic foraminifer shells has been used as a proxy for reconstructing past ocean carbonate chemistry. However, recent studies have revealed significant uncertainties associated with this proxy, such as whether seawater temperature or [ CO_3~(2-)] is the dominant control on the partition coefficient(K_D) of planktonic foraminiferal B/Ca. To address these uncertainties and thus improve our understanding of the planktonic foraminiferal B/Ca proxy, we analysed B/Ca ratios in the tests of Neogloboquadrina dutertrei(300–355 μm) and Pulleniatina obliquiloculata(355–400 μm) in surface sediment samples from the tropical western Pacific and South China Sea. The relationship between these B/Ca ratios and bottom water calcite saturation states(Δ[ CO_3~(2-)]) is weak, thus suggesting only a small dissolution effect on the B/Ca of the two species. The correlation coefficients(R~2) between the B/Ca ratios of N. dutertrei and P. obliquiloculata and environmental parameters(e.g., temperature, salinity, phosphate, DIC and ALK) in the tropical western Pacific and South China Sea are not high enough to justify using B/Ca ratios as a palaeoenvironmental proxy in the study areas. The significant correlation between K_D values of N. dutertrei and P. obliquiloculata and carbonate system parameters(e.g.,[ CO_3~(2-)], DIC, ALK, pH and [ HCO_3~-]) in the study area reflect chemical links between the K_D denominator and these variables. Based on our surface sediment calibration, an empirical relationship between the K_D of N.dutertrei and temperature is proposed in the tropical western Pacific. We also generated a record of B/Ca ratios in N. dutertrei(300–355 μm) from Core MD06-3052 in the tropical western Pacific over the past 24 ka to evaluate the application of the revised B/Ca proxy method. Based on the reconstructed empirical relationship for B/Ca and subsurface seawater ALK, we estimated subsurface seawater carbonate system parameters in the tropical western Pacific since 24 ka. In general, the estimated subsurface seawater pH and [ CO_3~(2-)] show an increase with time, and the record of subsurface seawater pCO_2 shows a decrease with time, in the tropical western Pacific over the past 24 ka. The consistent trends in subsurface seawater pCO_2 and opal flux during deglaciation may imply that the reported increase in subsurface water pCO_2 in the study area was promoted by enhanced upwelling in the Southern Ocean. 相似文献
415.
416.
采用香港11个GPS测站的观测资料进行1 h、2 h、3 h和4h静态PPP解算,获得4组PPP坐标序列,利用调和分析求取11个测站处8个主要分潮的负荷位移参数(振幅和相位),将其与海潮模型计算的负荷位移参数进行对比,并比较分析PPP反演值与海潮模型值改正海潮负荷信号的效果。结果表明,垂直和水平方向上,不同PPP结果反演8个分潮的负荷位移分别具有约5 mm和7 mm的差异;PPP反演8个分潮垂向负荷位移优于全球海潮模型,但水平方向上的反演效果稍弱。 相似文献
417.
418.
Examining the Relationship Between Spatial Configurations of Urban Impervious Surfaces and Land Surface Temperature 总被引:1,自引:0,他引:1
The urban heat island(UHI) effect has significant effects on the quality of life and public health. Numerous studies have addressed the relationship between UHI and the increase in urban impervious surface area(ISA), but few of them have considered the impact of the spatial configuration of ISA on UHI. Land surface temperature(LST) may be affected not only by urban land cover, but also by neighboring land cover. The aim of this research was to investigate the effects of the abundance and spatial association of ISAs on LST. Taking Harbin City, China as an example, the impact of ISA spatial association on LST measurements was examined. The abundance of ISAs and the LST measurements were derived from Landsat Thematic Mapper(TM) imagery of 2000 and 2010, and the spatial association patterns of ISAs were calculated using the local Moran’s I index. The impacts of ISA abundance and spatial association on LST were examined using correlation analysis. The results suggested that LST has significant positive associations with both ISA abundance and the Moran’s I index of ISAs, indicating that both the abundance and spatial clustering of ISAs contribute to elevated values of LST. It was also found that LST is positively associated with clustering of high-ISA-percentage areas(i.e.,>50%) and negatively associated with clustering of low-ISA-percentage areas(i.e.,<25%). The results suggest that, in addition to the abundance of ISAs,their spatial association has a significant effect on UHIs. 相似文献
419.
为探讨形态性状对体质量的影响,指导毛蚶的选育,以毛蚶天津群体为研究对象,测量壳长、壳宽、壳高、体质量,并进行统计分析。结果表明,壳宽是体质量的主要影响因子,其与体质量的相关系数为0.953,直接作用为0.505,间接作用为0.448,壳长、壳高间接作用分别为0.483、0.480,综合决定系数为0.706 6。毛蚶体质量多元回归方程为Y=-40.8+0.438X1+1.124X2+0.469X3,R2=0.924;以壳宽为自变量,体质量回归方程为:Y=5.443×10-3X22.519,R2=0.937。 相似文献
420.
通过溶胶-凝胶法,以CNTS-TiO2为前驱物制备了Li+掺杂CNTS-TiO2的纳米复合光催化剂(以下均称为Li+/CNTS-TiO2),采用X射线衍射(XRD)、扫描电镜(SEM)等测试手段对光催化剂进行表征,结果表明制得的催化剂为纳米材料且在TiO2的基础上增大了比表面积。利用掺杂量为3%的Li+掺杂CNTS-TiO2复合光催化剂(以下均称为3%Li+/CNTS-TiO2)光催化降解海洋柴油污染,在可见光条件下考察了Li+掺杂量、煅烧温度、光催化剂投加量、柴油初始质量浓度、光催化反应时间、H2O2质量浓度等条件对光催化实验的影响。进行正交实验,确定最优化工艺条件为:Li+掺杂量为3%,光催化剂的煅烧温度为600 ℃,3%Li+/CNTS-TiO2的投加量为0.1 g/L,降解柴油初始质量浓度为0.4 g/L,光催化反应时间为3 h,H2O2质量浓度为0.6 g/L,降解率可以达到95%以上。同时对此光催化剂进行应用试验,试验结果表明光催化剂去除效果优异,去除率可达91.87%。 相似文献