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241.
In this study, we applied chemical geothermometers to the estimation of formation temperatures of chlorites from various types of hydrothermally altered rocks in the Toyoha geothermal field, using core samples from six drill holes (TH-2 to TH-7) together with wasted ore samples from Toyoha vein-type ore deposit. Based on the preliminary examination of mineral assemblages by X-ray powder diffraction and optical microscopy, hydrothermal alteration observed through the drill holes was classified into four types of alteration zones: propylitic, mixed-layer minerals, kaolin minerals, and ore mineralized zones. The mineral assemblage of the ore mineralized zone observed through TH-2, TH-4, and TH-6 is similar to those of Toyoha ore veins reported previously. The Fe3+/ΣFe ratios of chlorites were determined by X-ray photoelectron spectroscopy (XPS), in addition to the usual microprobe analyses. The ratios ranged from 0.20–0.26 for chlorites from the propylitic alteration zone and from 0.13 to 0.17 for those from the ore mineralized zone associated with sulfide minerals. After correcting the Fe3+ contents in the octahedral sites of chlorite structures, we obtained acceptable temperatures of the chlorite formation by application of geothermometers, for instance, a similar range of 150–300°C for chlorites from either the propylitic zone or the ore mineralized zone developed through TH-2, TH-4, and TH-6. Chlorites from the ore mineralized zone proximal to the Toyoha deposit are characterized by high Fe and Mn contents compared to the propylitic chlorites, which is similar to the Toyoha vein-filling chlorites; the formation temperatures were close to both the homogenization temperatures of fluid inclusions and the present subsurface temperatures measured through drill holes. Chlorites from the Toyoha ore veins, however, gave slightly higher formation temperatures (180–350°C) than those of chlorites from the ore mineralized zone in the drill cores. This suggests that several types of hydrothermal alteration occurred at different stages in the Toyoha geothermal field and the composition of product chlorite was controlled not only by the temperature but also the composition of fluid related to the formation. Reliable estimation of temperature for the chlorite formation provides basic information on evaluating correctly other physicochemical conditions prevalent at the formation.  相似文献   
242.
食物生产系统的碳排放占人类活动碳排放总量的 30%, 碳汇渔业是一种重要的面向人类社会高质量食物蛋白质供给 的低碳发展路径。本文基于常见的 11 种养殖贝类的固碳系数和蛋白质含量特性研究,系统评估了我国2019 年养殖牡蛎 、蛤 类、扇贝、贻贝和蚶类等在养殖周期内碳捕集特性以及对低碳发展的贡献。研究表明: (1) 11 种养殖贝类之间贝壳和软体 组织含碳量的差异并不明显,但干重比和出肉率差异显著。因此,贝类固碳量核算不能忽视种类差异。 (2)所选 11 种贝类 软体组织皆属于高蛋白食品,虾夷扇贝软体组织 (干重) 的蛋白质含量最高。针对单位质量贝类养殖,长牡蛎的碳封存贡献 度最大,而华贵栉孔扇贝提供的蛋白质最多,两者都是碳汇渔业的优势种。(3) 据估算,我国2019 年海水养殖贝类中牡蛎、蛤 类 、扇贝和蚶类总共吸收固定了约 117.98 万吨 C02,提供了 40.65 万吨蛋白质 。这些蛋白质相比于牛肉源蛋白质可减少 4 048.74 万吨 C02 当量的排放量。由于贝类固碳强度大,探索低碳可持续的贝类养殖是绿色渔业经济的重要引擎, 也是建立可持续高质量“蓝色粮仓”和生物固碳的重要路径, 将在我国低碳产业发展中发挥重要作用。  相似文献   
243.
为探究长牡蛎在繁殖期间的糖原含量与类胰岛素基因(cgMIP123cgMIP4cgMILP7cgILP)和相关转录调控因子(cgPdx)相对表达量的相关性,自2020年5月至2020年10月采集了山东胶南养殖海区的长牡蛎,测定了血糖含量、糖原含量、条件指数、类胰岛素基因相对表达量及环境因子(酸度、温度、盐度)等数据,采用多元统计方法对数据进行分析。logistic回归分析结果显示,长牡蛎配子排放前后血糖含量和内脏团糖原含量具有显著差异。构建的回归模型可以通过血糖含量和内脏团糖原含量准确判断配子是否已经排放,区分度C-index为0.903,Hosmer-Lemeshow拟合优度检验χ2值为9.06,P>0.05,验证结果显示该模型可靠。多元线性回归分析结果显示:条件指数与cgMIP123和cgMIP4基因的相对表达量具有相关性,R2为0.91,P值为0.0076,极显著相关;内脏团和唇瓣组织的糖原含量与ILPscgPdx相对表达量具有一定的相关性,其中cgMILP7的相对表达量与内脏团和唇瓣组织的糖原含量呈负相关,cgPdx相对表达量与唇瓣组织的糖原含量呈负相关,cgMIP4cgILP的相对表达量与糖原含量呈正相关。  相似文献   
244.
徐琳琳  周彬  虞虎  张鹏飞 《地理研究》2023,42(2):422-439
重大节事活动对旅游地形象的影响具有时序动态特征,分析其内在机理有利于促进目的地营销和竞争力提升。本文采用Python数据挖掘技术和自然语言处理技术(NLP),爬取国内知名旅游门户网站的旅游评论,从“认知-情感-整体”3个维度构建分析框架,探究2022年冬奥会申办期、筹备期、预热举办期的张家口城市旅游地形象的时序变化特征,解析特殊时期冬奥会对城市旅游地形象的潜在影响和作用机制。结果表明:(1)张家口市的城市旅游地形象构成要素日趋多元化,冬奥会的作用效果由弱变强。张家口市的冰雪旅游形象关键度不断提升,经历了由模糊向具象转变的细化过程,情感形象产生积极变化;(2)冬奥会对张家口城市旅游地形象产生了渐进式影响效应,通过旅游体验的建构作用、投射形象的引致作用和品牌感知的晕轮作用发挥效果。冬奥会推动张家口市的产品业态创新、基础设施升级及服务水平提升,通过改善游客体验对城市旅游地形象产生积极影响。研究结果对东道主城市的旅游营销和规划具有一定指导意义。  相似文献   
245.
Water use efficiency (WUE) is an important variable to explore coupled relationships in carbon and water cycles. In this study, we first compared the spatial variations of annual gross primary productivity (GPP) and evapotranspiration (ET) using four GPP and ET products. Second, we selected the products closest to the flux towers data to estimate WUE. Finally, we quantitatively analyzed the impact of climate change and soil water content on WUE. The results showed that: (1) Four GPP and ET products provided good performance, with GOSIF-GPP and FLDAS-ET exhibiting a higher correlation and the smallest errors with the flux tower data. (2) The spatial pattern of WUE is consistent with that of GPP and ET, gradually decreasing from the northeast to the southwest. Higher WUE values appeared in the northeast forest ecosystem, and lower WUE values occurred in the western Gobi Desert, with a value of 0.28 gC m?2 mm?1. The GPP and ET products showed an increasing trend, while WUE showed a decreasing trend (55.15%) from 2001 to 2020. (3) The spatial relationship between WUE and driving factors reveal the variations in WUE of Inner Mongolia are mainly affected by soil moisture between 0 and 10 cm (SM0-10cm), vapor pressure deficit (VPD), and precipitation, respectively. (4) In arid regions, VPD and precipitation exhibit a major influence on WUE. An increase in VPD and precipitation has a negative and positive effect on WUE, with threshold values of approximately 0.36 kPa and 426 mm, respectively. (5) In humid regions, SM0-10cm, VPD, SM10-40cm, and SM40-100cm exert a significant impact on WUE, especially SM0-10cm, and weakens with increasing soil depths, these differences may be related to physiological structure and living characteristics of vegetation types in different climate regimes. Our results emphasize the importance of VPD and soil moisture in regional variability in WUE.  相似文献   
246.
Assessing and managing the spatial variability of hydropedological properties are important in environmental,agricultural,and geological sciences.The spatial variability of soil apparent electrical conductivity(ECa) measured by electromagnetic induction(EMI) techniques has been widely used to infer the spatial variability of hydrological and pedological properties.In this study,temporal stability analysis was conducted for measuring repeatedly soil ECa in an agricultural landscape in 2008.Such temporal stability was statistically compared with the soil moisture,terrain indices(slope,topographic wetness index(TWI),and profile curvature),and soil properties(particle size distribution,depth to bedrock,Mn mottle content,and soil type).Locations with great and temporally unstable soil ECa were also associated with great and unstable soil moisture,respectively.Soil ECa were greater and more unstable in the areas with great TWI(TWI 〉 8),gentle and concave slope(slope 〈 3%; profile curvature 〉 0.2).Soil ECa exponentially increased with depth to bedrock,and soil profile silt and Mn mottle contents(R2= 0.57),quadratically(R2 = 0.47),and linearly(R 2 = 0.47),respectively.Soil ECa was greater and more unstable in Gleysol and Nitosol soils,which were distributed in areas with low elevation(〈 380 m),thick soil solum(〉 3 m),and fluctuated water table(shallow in winter and spring but deep in summer and fall).In contrast,Acrisol,Luvisol,and Cambisol soils,which are distributed in the upper slope areas,had lower and more stable soil ECa.Through these observations,we concluded that the temporal stability of soil ECa can be used to interpret the spatial and temporal variability of these hydropedological properties.  相似文献   
247.
基于气泡群平衡方程(BPBE),提出一种用于更系统表征舰船气泡尾流变化特征的数值模型。模型的创新处在于既能反映气体传质因素的影响,又考虑了尾流中实际存在的气泡聚并现象,且具有简单易行,运算效率高的特点。分析结果表明:聚并在近尾流区作用强烈,传质在远程尾流区作用明显;聚并对BND的分布变化影响不大,对气含量的发展变化则发挥着主要作用;尺寸为70~80 um的气泡BND最大,尺寸为200 um的气泡气含量最大。  相似文献   
248.
张浩 《海洋地质前沿》2014,(2):46-49,55
上海地区(及其他软土地区)以静探触探作为岩土工程勘察的主要原位测试手段,积累了大量的工程数据,其结果稳定可靠,重现性好,具客观性。采用上海地区静探液化判别方法,对收集的大量资料进行统计分析,以期通过静探Ps值快速、简单地作出地基土是否液化的初步判断,有效指导勘察设计工作。  相似文献   
249.
250.
Factors of shale gas accumulation can be divided into the external and internal factors, according to accumulation mechanism and characteristics of shale gas. The internal factors mainly refer to parameters of organic geochemistry, mineral components and physical parameters. Six factors were presented in this study, i. e. organic matter, maturity, quartz, carbonate, clay mineral and pore. The external factors mainly refer to geologic environment of shale gas reservoir, including four factors: temperature, pressure, depth and thickness. Based on the experiment results of 26 samples of drilling cores from Wuling fold belt in Lower Paleozoic Silurian of the Upper Yangtze Basin, combined with the integrated analysis of geology, logging and test, the correlation of the gas content of shale gas to the above-mentioned ten factors was concluded. Six important evaluation indicators were preliminarily established in the gas-bearing core area of marine shale in the Upper Yangtze Basin.  相似文献   
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