辽宁西部上侏罗统义县组研究新认识

根据丰富的，最新的野外地质资料，对辽宁西部锦州和义县地区晚侏罗世义县组的岩石地层划分和对比中的重要问题进行了补充和修正。以《国际地层指南》的多重地层划分观点为基础，建立了一套完整的义县组岩石岩层单位。根据最新的原始鸟类以及昆虫，鱼，爬行类等生物化石研究结果，认为义县组的形成时期限于晚侏罗世晚期。     

基于岩样细观图像深度学习的岩性自动分类方法

在现阶段的岩土工程中,通常采用人工识别的方法来判别岩样种类,不仅耗时长、专业性强,还易受主观因素影响,准确率不理想。随着计算机技术的发展,机器学习逐渐被应用于岩性的自动识别,开启了岩样分类的新路径。本文以重庆市主城区4种典型岩样（泥岩、砂质泥岩、泥质砂岩和砂岩）的细观图像为研究对象,基于Inception V3卷积网络模型和迁移学习算法,建立了岩样细观图像深度学习模型,并完成了训练学习。结果显示：模型在训练1 000次后,训练集中的分类准确率达到92.77%,验证集中的分类准确率为76.31%。其中,验证集中的砂岩识别准确率为97.28%,泥岩识别准确率为81.85%,泥质砂岩识别准确率为72.59%,砂质泥岩识别准确率为72.35%。与现有的机器学习方法相比,本识别模型不仅可以自动识别岩性极为相近的岩样,而且具有较好的识别准确率、鲁棒性和泛化能力。     

湘赣浙紫色土的类型与分布特点

湘赣浙紫色土主要分布在沅江、湘江、赣江、信江、衢江流域几个NE或NNE向平行排列的紫色丘陵盆地内,出露上白垩统一下第三系红色碎屑岩,可见中丘中谷、低丘宽谷和缓丘带坝三类地形,分布不同风化程度的成土风化壳和紫色土类型。三省酸性紫色土和中性紫色土比例较大,达73％,比四川盆地多38—39％。     

The toxic effects of copper on larvae of the barnacle species Chthamalus challengeri

With the increased use of copper(Cu)-based antifouling(AF) paints,copper has become a potential threat to marine organisms. Experiments were performed to investigate the effects of copper on larvae of the barnacle Chthamalus challengeri. These experiments attempted to identify a more sensitive index to monitor copper pollution in marine environments. The 24 h LC5 0 ranged from 156.07 μg/L(nauplius II) to 817.15 μg/L(cypris) and the no observed effect concentration(NOEC) ranged from 81.75 μg/L(nauplius II) to 571.04 μg/L(cypris). The cypris settlement rate declined significantly when copper concentrations ≥135 μg/L. No cypris was found in the copper concentration of 60 and 75 μg/L treatment groups stressed for 22 d. Nauplius II moulting was not affected by exposure to copper for 24 h; however,when extended to 48 h,the percent moulted in 75 μg/L treatment group was declined to 37.12%,which was significant lower( P 0.05) than that in the control group. The phototaxis of nauplius II decreased significantly when copper concentrations ≥45 μg/L. Despite an initial significant increase at copper concentrations of 30 μg/L,ammonia excretion rate decreased when copper concentrations ≥60 μg/L. These results suggested that:(1) nauplius II could not develop to the cypris when the copper concentration ≥60 μg/L;(2) cypris settlement is more susceptible to copper than cypris mortality rate;(3) nauplius II is the most sensitive larval stage;(4) nauplius II ammonia excretion rate is the most sensitive index to copper and might be as the indicator for copper pollution monitoring.     

An Improved Method for Calculating Paleoheat Flow from Vitrinite Reflectance Profiles

lNTRODUCTIONIt is wel1 established that the vitrinite reflectance (R<, ) de-pends on the temperature history that a basin has undergone.In general, Ro is a function of maximum paleotemperature andeffective heating time. Thus, the paleotemperature of sedi-ments and the value of vitrinite ref1ectance are controlled by theflow of heat Q(t) into the basin and by the thermal parametersof the sediments. Therefore, in principle, it is possible to cal-culate the thermal vitrinite reflectance of …     

HBV相关肝病患者外周血NK细胞PD-1、Tim-3表达及意义

目的 了解HBV相关肝病患者外周血NK细胞表面PD-1、Tim-3的表达情况,探讨PD-1和Tim-3的表达与血清HBV-DNA载量的相关情况。方法 选择HBV感染相关肝病患者74例,其中CHB患者30例,LC患者24例,HCC患者20例,健康对照18例。应用流式细胞术检测NK细胞表面PD-1、Tim-3表达,荧光定量PCR检测HBV-DNA量,ELISA法检测细胞因子分泌水平。统计各组患者PD-1和Tim-3的表达率,比较各组差异,分析其与病情的相关性。结果 CHB、LC、HCC组外周血NK细胞表面PD-1和Tim-3的表达率分别为34.46%±7.31%、59.09%±12.35%、61.49%±15.26%和19.18%±6.05%、28.64%±11.20%、31.24%±11.85%,均高于对照组（P<0.01）,LC组和HCC组明显高于CHB组（P<0.01）,LC组和HCC组比较无统计学差异。在CHB组,PD-1的表达率与HBV-DNA呈负相关关系（R=-0.437,P=0.033）。CHB、LC、HCC各组血清中细胞因子TNF-α和IFN-γ水平分别为0.66±0.63、0.75±0.66、0.85±0.71和1.76±0.88、1.83±1.23、1.60±0.53,均低于健康对照组（P<0.01）。结论 HBV相关肝病患者NK细胞表面PD-1、Tim-3表达均增加,且与病情严重程度有关,增加表达的PD-1与血清HBV-DNA载量存在负相关性,HBV肝病各组血清TNF-α、IFN-γ分泌减少。     

Some statistic characteristics of “Underground Hot vortex” in China during 1980–1993 (I)

Using ground temperature data from meteorological stations as well as earthquake, ground tilt and precipitation data, the spatial-temporal distribution of “Underground Hot Vortex” (UHV) in China was analyzed in detail. The results show that concerning an “Underground Hot Vortex” cell, its life-span is 3–8 seasons, 1.5 years on average; the mean horizontal scale is 600 km and its characteristic velocity is about 400 km/a; UHV is likely to appear in some areas where the crustal movement is intense and the absolute value of vertical deformation rate is relatively high; its activity could hardly be detected in the area where the crust is stable and the vertical deformation is weak; most of “Underground Hot Vortex Groups” originate from the edge of Indian Plate, then migrate eastwards with a leaping-frog style. 5–10 years are needed for their arrival in the eastern border of China. Their horizontal migrating velocity is 200–500 km/a which is nearly equal to the characteristic velocity of a single UHV. Project sponsored by the National Climbing Project and Key Project of the Chinese Academy of Sciences.     

A kinetic model for thermally induced hydrogen and carbon isotope fractionation of individual n-alkanes in crude oil

A quantitative kinetic model has been proposed to simulate the large D and ¹³C isotope enrichments observed in individual n-alkanes (C₁₃-C₂₁) during artificial thermal maturation of a North Sea crude oil under anhydrous, closed-system conditions. Under our experimental conditions, average n-alkane δ¹³C values increase by ∼4‰ and δD values increase by ∼50‰ at an equivalent vitrinite reflectance value of 1.5%. While the observed ¹³C-enrichment shows no significant dependence on hydrocarbon chain length, thermally induced D-enrichment increases with increasing n-alkane carbon number. This differential fractionation effect is speculated to be due to the combined effect of the greater extent of thermal cracking of higher molecular weight, n-alkanes compared to lower molecular weight homologues, and the generation of isotopically lighter, lower molecular weight compounds. This carbon-number-linked hydrogen isotopic fractionation behavior could form the basis of a new maturity indicator to quantitatively assess the extent of oil cracking in petroleum reservoirs. Quantum mechanical calculations of the average change in enthalpy (ΔΔH^‡) and entropy (ΔΔS^‡) as a result of isotopic substitution in n-alkanes undergoing homolytic cleavage of C-C bonds lead to predictions of isotopic fractionation that agree quite well with our experimental results. For n-C₂₀ (n-icosane), the changes in enthalpy are calculated to be ∼1340 J mol^-1 (320 cal mol^-1) and 230 J mol^-1 (55 cal mol^-1) for D-H and ¹³C-¹²C, respectively. Because the enthalpy term associated with hydrogen isotope fractionation is approximately six times greater than that for carbon, variations in δD values for individual long-chain hydrocarbons provide a highly sensitive measure of the extent of thermal alteration experienced by the oil. Extrapolation of the kinetic model to typical geological heating conditions predicts significant enrichment in ¹³C and D for n-icosane at equivalent vitrinite reflectance values corresponding to the onset of thermal cracking of normal alkanes. The experimental and theoretical results of this study have significant implications for the use of compound-specific hydrogen isotope data in petroleum geochemical and paleoclimatological studies. However, there are many other geochemical processes that will significantly affect observed hydrogen isotopic compositions (e.g., biodegradation, water washing, isotopic exchange with water and minerals) that must also be taken into consideration.     

Thermodynamic Calculation of Solubility of Na2SO4/K2SO4 in Hydrothermal Fluids

Sulfate fluids are common fluids in nature, and their salinity studies can provide important information for the evolution of ore-forming fluids, migration and enrichment of ore-forming elements, and the classification of deposit types. Considerable research has been carried out to investigate the solubility of Na₂SO₄ and K₂SO₄ in hydrothermal fluids, however most of the literature reported experimental data were under saturated vapor pressure or the water supercritical region. A few data have been reported for the low temperature hydrothermal mineralization region. Thermodynamic model is a useful method to study the properties of hydrothermal geofluids, especially for mineral solubility. Pitzer interaction model is one of the most widely used model to calculate the thermodynamic properties of hydrothermal fluids, but few work have ever been carried out to calculate the solubility of sulfate at high temperature and pressure. With Pitzer specific interaction model, using the literature reported density data of Na₂SO₄ and K₂SO₄ solutions at high temperature and pressure, the pressure effect on Pitzer activity coefficient of sulfate and the standard partial molar volume change during sulfate dissolution process were evaluated and related parameters were obtained. The standard partial molar volumes of Na₂SO₄ and K₂SO₄ calculated with these parameters agreed well with those reported in the literature. Combined with the relevant parameters in the literature under saturated vapor pressure, a thermodynamic model for Na₂SO₄ and K₂SO₄ solubility calculation with temperature up to 250 ℃ and pressure up to 40 MPa was developed. The model gave very good agreement with the experimental solubility data. With this model, Na₂SO₄ and K₂SO₄ solubility was calculated at high temperature and pressure. The calculation results showed that pressure had a positive effect on both the average activity coefficient and solubility product of Na₂SO₄ and K₂SO₄, but the solubility of Na₂SO₄ and K₂SO₄ decreased with pressure due to the larger change of the average activity coefficient with pressure. And as the temperature increased, the degree of such reduction became larger. The results herein can provide instructions for the compositional analysis of sulfate fluid inclusions.