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Correction Method of Light Hydrocarbons Losing and Heavy Hydrocarbon Handling for Residual Hydrocarbon (S_1) from Shale 被引量:6
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作者 WANG Min TIAN Shansi +3 位作者 CHEN Guohui XUE Haitao HUANG Aihua WANG Wenguang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2014年第6期1792-1797,共6页
In China, hot researches on shale oil were raised by the important breakthrough of shale oil in America. Obviously, the first important issue is the actual shale oil resource potential of China, and the selection of t... In China, hot researches on shale oil were raised by the important breakthrough of shale oil in America. Obviously, the first important issue is the actual shale oil resource potential of China, and the selection of the key appraisement parameter is vital to the shale oil resource amount. Among the appraisement parameters, the oil content parameter(S1) is the key one, but the evaluation result is generally lower because of light hydrocarbon losing and heavy hydrocarbon handling. And the more important thing is that the light hydrocarbon with small molecular weight is more recoverable, and therefore its amount is important to the total shale oil yields. Based on pyrolysis experiments and the kinetic model of hydrocarbon generation, correction factors and a model of light hydrocarbon losing and heavy hydrocarbon handling were established. The results show that the correction factor of heavy hydrocarbon handling is 3.2, and that of light hydrocarbon losing is controlled by kerogen type, maturity and hydrocarbon generation environment(closed or open). 展开更多
关键词 oil content S1 shale oil light hydrocarbons losing heavy hydrocarbon handling
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Effects of Light and Heavy Rare Earths on Anti-Degradation of Nodular Cast Iron 被引量:4
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作者 王丽萍 郭二军 +2 位作者 陈洪彬 王敬泽 李大勇 《Journal of Rare Earths》 SCIE EI CAS CSCD 2006年第1期103-107,共5页
The effects of rare earths with different contents on anti-degradation of Y base heavy rare earths-magnesium and cerium base light rare earths-magnesium nodular cast iron were studied. Curves of the relationship betwe... The effects of rare earths with different contents on anti-degradation of Y base heavy rare earths-magnesium and cerium base light rare earths-magnesium nodular cast iron were studied. Curves of the relationship between the spheroidization grade of liguid iron treated by different nodulizers and holding time were obtained. The results show that the more the remains of the rare earth, the longer the anti-degradation time, the liquid iron was treated either by Y-Mg-Si or by Ce-Mg-Si nodulizer. When the rare earth remains are above certain quantity, the spheroidization grade starts to decline. When liquid iron treated by either Y-Mg-Si or Ce-Mg-Si nodulizer with proper remains of rare earths about 0.04% 0.06%(mass fraction), the anti-degradation is the best, and the remains of Mg being about 0.04% -0.07% (mass fraction). Rare earths-Mg nodulizer with moderate RE remains is better than that of Mg-Si nodulizer in anti-degradation property. However, Y-Mg-Si nodulizer with moderate remins of Re is better than Ce-Mg-Si nodulizer. Sometimes Ce-Mg- Si nodulizer can be used for the production of heavy section nodular cast iron. 展开更多
关键词 metal materials nodular cast iron anti-degradation Ce base light rare earths heavy rare earths
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Relationship between light and heavy fractions of organic matter for several agricultural soils in China 被引量:1
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作者 YIN Yun-feng CAI Zu-cong LU Jia-long 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2005年第6期917-920,共4页
Although numerous studies about the nature and turnover of soil organic matter(SOM) in light and heavy fractions( LFOM and HFQM, respectively) have been made, little information is available in relation to the rel... Although numerous studies about the nature and turnover of soil organic matter(SOM) in light and heavy fractions( LFOM and HFQM, respectively) have been made, little information is available in relation to the relationship between LFQM and HFOM, and no attempts have been made to quantify a general relationship between LFQM and HFQM for agricultural soils under field condition. Qur hypothesis is there may be an inherent relationship between LFQM and HFQM for agricultural soils under certain unaltered management practices for a long period, to this end, we therefore studied typically soils taken from different parts in China by using a simple density fractionation procedure. The results indicated that LFQM was positively correlated with LFOM/HFOM ratio for three typical soils. This information will be of particular use not only in deepening our understanding of the dynamics of SQM fractions but also in evaluating the potential of agricultural soils to sequestrate C under different management practices in a long term. 展开更多
关键词 soil organic matter light fraction heavy fraction agricultural soils
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Manpower Systems Operating under Heavy and Light Tailed Inter-Exit Time Distributions
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作者 R. Sivasamy P. Tirupathi Rao K. Thaga 《Applied Mathematics》 2014年第2期285-291,共7页
This paper considers a Manpower system where “exits” of employed personnel produce some wastage or loss. This system monitors these wastages over the sequence of exit epochs {t0 = 0 and tk;k = 1, 2,…} that form a r... This paper considers a Manpower system where “exits” of employed personnel produce some wastage or loss. This system monitors these wastages over the sequence of exit epochs {t0 = 0 and tk;k = 1, 2,…} that form a recurrent process and admit recruitment when the cumulative loss of man hours crosses a threshold level Y, which is also called the breakdown level. It is assumed that the inter-exit times Tk = tk-1 - tk, k = 1, 2,… are independent and identically distributed random variables with a common cumulative distribution function (CDF) B(t) = P(Tk t) which has a tail 1 – B(t) behaving like t-v with 1 v as t → ∞. The amounts {Xk} of wastages incurred during these inter-exit times {Tk} are independent and identically distributed random variables with CDF P(Xk X) = G(x) and Y is distributed, independently of {Xk} and {tk}, as an exponentiated exponential law with CDF H(y) = P(Y y) = (1 - e-λy)n. The mean waiting time to break down of the system has been obtained assuming B(t) to be heavy tailed and as well as light tailed. For the exponential case of G(x), a comparative study has also been made between heavy tailed mean waiting time to break down and light tailed mean waiting time to break down values. The recruitment policy operating under the heavy tailed case is shown to be more economical in all types of manpower systems. 展开更多
关键词 Manpower System Recruitment Policy Inter-Exit TIME Wastage Waiting TIME to Breakdown heavy TAILED Inter-Exit TIME Distribution and light TAILED Distribution
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Selective Separation of Light and Heavy Rare Earth Elements from the Pregnant Leach Solution of Apatite Ore with D2EHPA
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作者 Ariuntuya Battsengel Altansukh Batnasan +1 位作者 Kazutoshi Haga Atsushi Shibayama 《Journal of Minerals and Materials Characterization and Engineering》 2018年第5期517-530,共14页
Different separation techniques such as solvent extraction, ion exchange, and precipitation are often used for recovery of rare earth elements (REEs) from pregnant leach solutions obtained from acid leaching. Solvent ... Different separation techniques such as solvent extraction, ion exchange, and precipitation are often used for recovery of rare earth elements (REEs) from pregnant leach solutions obtained from acid leaching. Solvent extraction is generally accepted as the most appropriate commercial technology for separating REEs due to the need to be able to handle larger volumes of diluted pregnant solutions. This study focused on the development of selective separation of light and heavy REEs from the pregnant leach solution obtained from leaching of apatite ore in 1 M sulfuric acid (H2SO4) using solvent extraction. Three different commercial organophosphorus extractants (di-(2-ethylhexyl) phosphoric acid (D2EHPA), 2-ethylhexyl phosphonic acid mono-2-ethylhexyl ester (PC88A) and tributyl phosphate (TBP)), and the influences of experimental parameters such as extractant concentration, organic/aqueous phase ratio, diluent type, pH, extraction time and stripping agent concentration were examined. Results showed that light REEs (LREEs) and heavy REEs (HREEs) in the pregnant leach solution were selectively separated with D2EHPA via a two-stage extraction process. In the first-stage of solvent extraction, >90% of (0.05 g/L) HREEs was extracted with 1.8 M D2EHPA in kerosene while the vast majority (>95%) of LREEs was remained in raffinate. In the second-stage, >93% (1.01 g/L) of LREEs was extracted from the raffinate with 1.8 M D2EHPA dissolved in kerosene at pH 1.6. HREEs (>95%) and LREEs (>90%) loaded with D2EHPA after the first and second-stage of extraction were stripped by 4 M H2SO4 and 1 M H2SO4 solutions, respectively. Distribution of middle rare earth elements (MREEs) was discussed through the extraction processes in this study. 展开更多
关键词 light RARE EARTH ELEMENTS heavy RARE EARTH ELEMENTS Solvent Extraction Di-(2-ethylhexyl) Phosphoric Acid Stripping
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Azimuthally Anisotropic Emission of Unstable Light Nuclei in Heavy Ion Collisions at Intermediate Energy
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作者 He Zhiyong Jin Genming +6 位作者 Li Zuyu Duan Limin Dai GuangXi Zhang Baoguo Wu Heyu Wen .Wanxin Qi Yujin and Luo Qingzheng 《IMP & HIRFL Annual Report》 1995年第0期16-17,共2页
Azimuthally Anisotropic Emission of Unstable Light Nuclei in Heavy Ion Collisions at Intermediate EnergyAzim... Azimuthally Anisotropic Emission of Unstable Light Nuclei in Heavy Ion Collisions at Intermediate EnergyAzimuthallyAnisotropi... 展开更多
关键词 INTERMEDIATE Azimuthally COLLISIONS EMISSION Energy heavy ANISOTROPIC Ion light NUCLEI
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Optical anisotropy and the direction of polarization of exciton emissions in a semiconductor quantum dot:Effect of heavy-and light-hole mixing
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作者 Ranber Singh Rajiv Kumar Vikramjeet Singh 《Chinese Physics B》 SCIE EI CAS CSCD 2017年第8期400-406,共7页
The dependence of the directions of polarization of exciton emissions, fine structure splittings (FSS), and polarization anisotropy on the light- and heavy-hole (LH-HH) mixing in semiconductor quantum dots (QDs)... The dependence of the directions of polarization of exciton emissions, fine structure splittings (FSS), and polarization anisotropy on the light- and heavy-hole (LH-HH) mixing in semiconductor quantum dots (QDs) is investigated using a mesoscopic model. In general, all QDs have a four-fold exciton ground state. Two exciton states have directions of polarization in the growth-plane, while the other two are along the growth direction of the QD. The LH-HH mixing does affect the FSS and polarization anisotropy of bright exciton states in the growth-plane in the low symmetry QDs (e.g., C2v, CS, C1 ), while it has no effect on the FSS and polarization anisotropy in high symmetry QDs (e.g., C3V, D2d). When the hole ground state is pure HH or LH, the bright exciton states in the growth-plane are normal to each other. The LH-HH mixing affects the relative intensities and directions of bright exciton states in the growth-plane of the QD. The polarization anisotropy of exciton emissions in the growth-plane of the QD is independent of the phase angle of LH-HH mixing but strongly depends on the magnitude of LH-HH mixing in low symmetry QDs. 展开更多
关键词 light-heavy hole mixing EXCITONS quantum dots
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Theoretical and Experimental Study on The Speed-up of Freight Train with Mixed Marshaling of Light and Heavy Vehicle
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作者 Xing ZHANG Li LI +2 位作者 Dabin CUI Yaodong FU Haiyang GUO 《Mechanical Engineering Science》 2021年第1期12-18,共7页
To study the influence of the speed-up of a freight train with mixed marshaling of light and heavy vehicles on the dynamic behavior,a dynamic model of the freight train was established based on the modular method of c... To study the influence of the speed-up of a freight train with mixed marshaling of light and heavy vehicles on the dynamic behavior,a dynamic model of the freight train was established based on the modular method of cyclic variables,and the dynamic behavior of the freight train was simulated and analyzed under different marshaling patterns,speeds and line conditions.On-site speed-up test with different marshaling freight trains was carried out,and the stability and ride-index of the train before and after the speed-up were compared and analyzed.The feasibility of increasing the speed of freight trains with mixed marshaling of light and heavy cars was demonstrated theoretically and experimentally.The results show that the theory is in good agreement with the test,which can effectively reflect the dynamic behavior of the vehicle.The dynamic behavior of the freight train in the study meets the requirements of increasing speed to 90 km/h.This paper provides a theoretical basis and method for railway freight transportation and the speed-up of freight vehicles. 展开更多
关键词 Mixed marshaling of light and heavy vehicle Freight train Dynamic behavior
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基于强降水时序特征的TSVGG-Light暴雨灾情指数预测模型构建及风险灾情一致性分布验证
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作者 刘付永在 冯明亮 +1 位作者 黄允哲 田霖 《气象水文海洋仪器》 2024年第2期41-45,共5页
文章针对强降水灾情预测问题,提出了一种基于强降水时序特征的TSVGG-Light暴雨灾情指数预测模型。该模型利用气象观测数据中的降水时序特征作为输入,对数据进行特征提取和建模,预测出未来一段时间内的强降水灾情指数。为了验证模型的有... 文章针对强降水灾情预测问题,提出了一种基于强降水时序特征的TSVGG-Light暴雨灾情指数预测模型。该模型利用气象观测数据中的降水时序特征作为输入,对数据进行特征提取和建模,预测出未来一段时间内的强降水灾情指数。为了验证模型的有效性,文中还进行了风险灾情一致性分布验证。实验结果表明,TSVGG-Light模型在强降水灾情预测上具有较高的准确性和稳定性,并且模型预测结果与实际灾情分布具有较好的一致性。TSVGG-Light模型可以成为预测和评估强降水灾情的有效工具。 展开更多
关键词 强降水时序特征 TSVGG-light 暴雨灾情指数预测模型 风险灾情一致性
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Conventional tillage improves the storage of soil organic carbon in heavy fractions in the Loess Plateau, China 被引量:1
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作者 HAN Huige LI Xudong +5 位作者 NIU Decao Sharon J HALL GUO Ding WAN Changgui Jennifer K LEARNED FU Hua 《Journal of Arid Land》 SCIE CSCD 2015年第5期636-643,共8页
Soil labile organic carbon (C) plays an important role in improving soil quality. The relatively stable fractions of soil organic C (SOC) represent the bulk of SOC, and are also the primary determinant of the long... Soil labile organic carbon (C) plays an important role in improving soil quality. The relatively stable fractions of soil organic C (SOC) represent the bulk of SOC, and are also the primary determinant of the long-term C balance of terrestrial ecosystems. Different land use types can influence the distribution patterns of different SOC fractions. However, the underlying mechanisms are not well understood. In the present study, different fractions of SOC were determined in two land use types: a grazed grassland (established on previously cultivated cropland 25 years ago, GG) and a long-term cultivated millet cropland (MC). The results showed that C concentration and C storage of light fractions (LF) and heavy fractions (HF) presented different patterns along the soil profiles in the two sites. More plant residues in GG resulted in 91.9% higher LF storage at the 0-10 cm soil depth, further contributed to 21.9% higher SOC storage at this soil depth; SOC storage at 20-60 cm soil depth in MC was 98.8% higher than that in GG, which could be mainly attributed to the HF storage 104.5% higher than in GG. This might be caused by the long-term application of organic manure, as well as the protection from plough pan and silt- and clay-sized particles. The study indicated that different soil management practices in this region can greatly influence the variations of different SOC fractions, while the conventional tillage can greatly improve the storage of SOC by in- creasing heavy fractions. 展开更多
关键词 land use soil organic carbon heavy fraction organic carbon light fraction organic carbon particle size distribution
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Production of light nuclei and hypernuclei at High Intensity Accelerator Facility energy region 被引量:4
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作者 Peng Liu Jin-Hui Chen +1 位作者 Yu-Gang Ma Song Zhang 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第4期84-90,共7页
Heavy-ion collisions are powerful tools for studying hypernuclear physics.We develop a dynamical coalescence model coupled with an ART model(version1.0) to study the production rates of light nuclear clusters and hype... Heavy-ion collisions are powerful tools for studying hypernuclear physics.We develop a dynamical coalescence model coupled with an ART model(version1.0) to study the production rates of light nuclear clusters and hypernuclei in heavy-ion reactions,for instance,the deuteron(d),triton(t),helium(~3He),and hypertriton(_A^3H)in minimum bias(0-80%centrality)~6Li+^(12)C reactions at beam energy of 3.5A GeV.The penalty factor for light clusters is extracted from the yields,and the distributions of 0 angle of particles,which provide direct suggesetions about the location of particle detectors in the near future facility-High Intensity heavy-ion Accelerator Facility(HIAF) are investigated.Our calculation demonstrates that HIAF is suitable for studying hypernuclear physics. 展开更多
关键词 heavy-ION accelerator FACILITY HYPERON HYPERNUCLEI COALESCENCE light NUCLEI
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Heavy Industry Share Increase Is Causing Higher Energy Consumptioni 被引量:1
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作者 齐志新 陈文颖 吴宗鑫 《China Economist》 2007年第4期37-46,共10页
The"11th Five-Year"plan sets the objective of reducing energy consumption per unit of GDP by 20% in five years.Readjusting industrial structure is one of the possible means to reach this goal.As for energy c... The"11th Five-Year"plan sets the objective of reducing energy consumption per unit of GDP by 20% in five years.Readjusting industrial structure is one of the possible means to reach this goal.As for energy consumption reduction through industrial readjustment,however,present research only explores the effects of industry structural change in the six sectors such as agriculture,industry,construction,transportation and commerce,yet without considering the ramifications of sub-sector two-digit code industry structure.In this paper,we have calculated the effects of structural change in light- heavy industries on energy consumption and energy intensity from 1993 to 2005 using the factor decomposition method.As a result,we found for each percentage point gain in favour of heavy industry in the light-heavy industry mix,China’s energy consumption increases by nearly 9 million metric tons of coal equivalent.However the overall effects of structural change in light-heavy industry are less than those of sub-sector intensity factors on industrial energy intensity and energy consumption per unit of GDP.The heavy industry share gain has over recent years exerted a significant impact on industrial energy intensity.For example,78% of the abnormal increase in industrial energy intensity in 2003 could be attributed to this factor.Finally,an analytical framework for energy intensity based on this study is presented. 展开更多
关键词 light-heavy industry structure ENERGY CONSUMPTION ENERGY intensity
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基于四桥臂智能软开关的柔性互联配电台区三相不平衡与轻重载综合调控策略
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作者 李天麟 郭祺 +4 位作者 王鑫 冀浩然 涂春鸣 侯玉超 李俊豪 《电网技术》 EI CSCD 北大核心 2024年第10期4358-4366,I0125,共10页
随着分布式能源与随机负荷的大量接入,配电台区三相负荷不平衡与变压器轻重载运行问题日益突出,这将威胁台区安全可靠运行。然而,既有关于互联台区的研究鲜有兼顾三相不平衡与轻重载运行问题的综合治理。对此,该文提出一种基于四桥臂智... 随着分布式能源与随机负荷的大量接入,配电台区三相负荷不平衡与变压器轻重载运行问题日益突出,这将威胁台区安全可靠运行。然而,既有关于互联台区的研究鲜有兼顾三相不平衡与轻重载运行问题的综合治理。对此,该文提出一种基于四桥臂智能软开关(four-leg soft open point,F-SOP)的柔性互联配电台区三相不平衡与轻重载综合调控策略。首先,分析了F-SOP和变压器的综合损耗特性,结果表明不平衡度和负载率均会影响设备运行效率;其次,建立三相不平衡与轻重载综合调控策略模型,设立变压器输出功率不平衡度与负载率的指标约束,以系统综合损耗最小为优化目标求解F-SOP最优调控指令。接着,针对F-SOP拓扑架构及其功率调控的需求,提出一种改进对等控制方法,进一步提高F-SOP稳定性能与动态性能,确保综合调控策略的实现。最后,通过算例分析与仿真实验验证了所提综合调控策略的有效性和可行性。 展开更多
关键词 柔性互联配电台区 智能软开关 三相不平衡 轻重载 综合调控
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填闲作物还田方式对烟田土壤轻重组有机碳的影响
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作者 宋艳丹 韩会阁 +6 位作者 王孟孟 徐文正 李建华 刘巧真 阎海涛 王典 吴照辉 《山西农业科学》 2024年第3期60-67,共8页
为了提高多年连作烟田的土壤肥力,改善土壤生态环境,在烤烟冬闲期种植油菜、冬牧70、光叶紫花苕等3种作物,同时以冬季空闲不种植任何作物为对照,采取2种方式(掩青和收割)进行处理,通过测定不同处理不同土层的土壤轻、重组有机碳含量、... 为了提高多年连作烟田的土壤肥力,改善土壤生态环境,在烤烟冬闲期种植油菜、冬牧70、光叶紫花苕等3种作物,同时以冬季空闲不种植任何作物为对照,采取2种方式(掩青和收割)进行处理,通过测定不同处理不同土层的土壤轻、重组有机碳含量、比例及储量,探讨填闲作物收割和掩青处理对烟田土壤轻重组有机碳的影响。结果表明,不同填闲作物和不同还田方式下土壤总有机碳、重组有机碳、轻组有机碳含量均随着土壤深度的增加而降低。与对照相比,填闲作物掩青处理能够显著增加土壤总有机碳、重组有机碳、轻组有机碳含量,尤其是冬牧70在20~40 cm土层增加比较显著,分别增加了22.3%、21.98%、27.78%;填闲作物收割处理会降低土壤轻组有机碳比例和土壤轻组有机碳储量,而掩青处理则会增加土壤轻组有机碳比例和轻组有机碳储量,其中冬牧70掩青在0~20 cm土层增加比较明显,分别增加了18.14%、40.03%。填闲作物掩青处理增加了烟田土壤的含水量和持水量、降低了土壤容重以及增加土壤轻重组有机碳储量。综合来看,冬牧70掩青处理效果最好,能显著增加土壤总有机碳和轻重组有机碳含量,油菜次之。 展开更多
关键词 填闲作物 烟田 掩青 收割 轻组有机碳 重组有机碳
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土壤-超积累植物体系中稀土元素的空间富集-分异特征与富集机理
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作者 何柳青 王园园 +1 位作者 朱润良 朱建喜 《地球化学》 CAS CSCD 北大核心 2024年第1期87-101,共15页
离子吸附型稀土矿是我国南方特色的优质稀土资源,但由于落后的采矿方式和无节制的开采,大量稀土元素(稀土元素+Y,简称稀土元素)被带入环境中,导致稀土矿区周边出现许多环境污染和植被退化问题。乌毛蕨是一种对稀土元素具有较强耐受性和... 离子吸附型稀土矿是我国南方特色的优质稀土资源,但由于落后的采矿方式和无节制的开采,大量稀土元素(稀土元素+Y,简称稀土元素)被带入环境中,导致稀土矿区周边出现许多环境污染和植被退化问题。乌毛蕨是一种对稀土元素具有较强耐受性和超强富集能力的蕨类超积累植物,能被用于稀土污染土壤或尾矿的生态修复。本研究以离子吸附型矿区表生土壤上生长的稀土超积累植物乌毛蕨及其根际土为研究对象,通过化学消解和ICP-MS方法测定根际土、根表、根部、叶柄、叶片中稀土元素的含量,分析土壤–植物体系中稀土元素的空间分布、富集与分异特征;采用顺序提取法测定土壤中不同化学形态的稀土元素含量,同时利用微区X射线荧光光谱(μ-XRF)与扫描电镜能谱分析技术(SEM-EDS),阐明乌毛蕨对稀土元素的吸收与富集机理。化学测试结果表明,乌毛蕨对稀土元素有较强的富集和地上转运能力,富集系数(BF)和转移系数(TF)分别为2.61和2.85;植物器官富集能力顺序为:叶片(1750μg/g)>根部(512μg/g)>叶柄(56.5μg/g);植株整体稀土元素配分模式具有与根际土相似的富轻土元素和Ce负异常特征,不同的是,植株整体Eu无异常(根际土δEu=0.51);根际土壤中富集离子交换态的轻稀土离子(34%~64%,(La/Yb)N=2.36),与根系表面呈轻微富轻稀土元素((La/Yb)N=1.29)的现象暗示根际大部分轻稀土元素能以离子形式被根系吸收,重稀土元素与有机配体络合而被吸附在根系表面;稀土元素在向上迁移过程中,(La/Yb)N值下降(叶柄=27.63,叶片=17.17),揭示木质部伤流液的重稀土元素可能比轻稀土元素更容易向上迁移;μ-XRF与SEM-EDS结果显示,乌毛蕨地上部的超富集器官(叶片)将稀土元素主要储存在叶缘的表皮层细胞,且能将大部分非生理需要的稀土元素有效区室化。上述认识揭示了在离子吸附型稀土矿区表生环境中,稀土元素从土壤向植物体内迁移并在地上部富集与分异的过程、规律和主要原因,为今后利用稀土超积累植物实现植物采矿或稀土尾矿生态修复提供科学认知基础。 展开更多
关键词 离子吸附型稀土矿 超积累植物 乌毛蕨 富集 轻、重稀土分异 地上部
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不同形态河谷沉积物中稀土元素的粒径分布特征
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作者 尚月婷 张加琼 白茹茹 《土壤学报》 CAS CSCD 北大核心 2024年第3期746-756,共11页
稀土元素(REE)作为一种重要的土壤侵蚀示踪元素,明确其含量随土壤颗粒粒径的变化特征,对准确量化土壤侵蚀速率具有重要意义。本研究基于Samonova等采样测定的不同粒径范围(<1、1~10、10~50、50~250和250~1 000μm)土壤/沉积物颗粒中... 稀土元素(REE)作为一种重要的土壤侵蚀示踪元素,明确其含量随土壤颗粒粒径的变化特征,对准确量化土壤侵蚀速率具有重要意义。本研究基于Samonova等采样测定的不同粒径范围(<1、1~10、10~50、50~250和250~1 000μm)土壤/沉积物颗粒中的REE含量,分析了俄罗斯普罗特瓦河左岸河谷形态(“U”和“V”形谷)、地貌部位(坡面、沟坡/沟壁、沟道底部和洪积扇)、侵蚀(坡面、沟坡/沟壁)和沉积(沟道底部和洪积扇)环境对土壤/沉积物REE含量、富集系数等的影响。结果表明:(1)“U”和“V”形谷四类地貌下,轻稀土(LREE)、重稀土(HREE)和总稀土(ΣREE)含量均随颗粒粒径变粗呈降低趋势。在相同地貌部位,“U”形谷细颗粒(<50μm)中LREE、HREE和ΣREE含量较“V”形谷分别低14.6%~24.7%、10.0%~33.5%和14.2%~21.1%。(2)无论河谷形态和地貌部位,LREE和HREE均明显富集在细颗粒中,尤其是“V”形谷,LREE和HREE主要富集在<10μm的颗粒中。(3)对比侵蚀和沉积区,“U”和“V”形谷沉积区细颗粒中LREE和HREE的富集程度均显著(P<0.05)大于侵蚀区。可见,无论河谷形态、地貌部位和侵蚀沉积区,REE均主要富集在细颗粒中;但河谷形态和侵蚀、沉积对REE含量的粒径分布有重要影响。 展开更多
关键词 侵蚀区域 沉积区域 地貌部位 轻稀土元素 重稀土元素 富集
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典型立式轻工业建筑结构抗震性能实例研究
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作者 吴斌 杨悦 +3 位作者 姚仰平 王凇晗 姜雪薇 许立言 《北京航空航天大学学报》 EI CAS CSCD 北大核心 2024年第4期1240-1250,共11页
立式轻工业建筑结构存在大跨度、高空重载及竖向质量分布不均匀等特点,为研究该结构形式的振动响应特征,以某典型立式轻工业生产车间为背景,建立了精细化三维非线性计算模型,通过有限元仿真技术对该结构形式开展抗震性能研究。结果表明... 立式轻工业建筑结构存在大跨度、高空重载及竖向质量分布不均匀等特点,为研究该结构形式的振动响应特征,以某典型立式轻工业生产车间为背景,建立了精细化三维非线性计算模型,通过有限元仿真技术对该结构形式开展抗震性能研究。结果表明:通过合理设计,立式轻工业建筑结构能满足结构抗震设计要求,结构损伤呈由外及里的发展过程,塑性铰分布规律表现为高层多,低层少,重载层多,非重载层少的特点,在抗震设计过程中,应将重载楼层视为薄弱层予以加固,对外侧抗风柱应设置水平及垂直支撑,以延缓内部承载构件的损伤破坏,提高结构的整体抗震性能。此外,当结构存在大质量比可变荷载时,应该考虑其质量变化对结构动力特性的影响;当设备质量占比较小时,可忽略设备与结构之间的相互作用,抗震分析时可采用设备-结构固结模型进行简化计算。 展开更多
关键词 立式轻工业建筑 大跨度 高空重载 抗震性能 时程分析
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基于48V轻混重型汽车技术发展与趋势
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作者 周鹏 王皓 +3 位作者 李慧东 谢磊磊 牛子孺 普玉春 《昆明冶金高等专科学校学报》 CAS 2024年第4期59-63,共5页
针对当前化石燃料短缺,全球环境恶化,对国家及各科研机构的应对策略进行了分析。通过介绍研究48 V轻混动力技术与控制策略,提出了48 V轻混动力源混动机理和能量管理策略,阐述各主机厂对48 V轻混系统的应用发展与趋势,得出该48 V轻混动... 针对当前化石燃料短缺,全球环境恶化,对国家及各科研机构的应对策略进行了分析。通过介绍研究48 V轻混动力技术与控制策略,提出了48 V轻混动力源混动机理和能量管理策略,阐述各主机厂对48 V轻混系统的应用发展与趋势,得出该48 V轻混动力技术的可行性。最后,分析了国家层面的GDP碳排放量总体规划,进行总结,提出展望。 展开更多
关键词 48 V轻混系统 政策导向与发展趋势 重型车辆 控制策略
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旋挤钻法在软土及砂土地层施工灌注桩的研究
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作者 朱正余 陶涛 +4 位作者 陈珣 王玉波 顾乡 常聚友 侯龙 《铁道工程学报》 EI CSCD 北大核心 2024年第4期54-59,共6页
研究目的:采用常规旋挖钻法在地下水丰富的黏土地层和软土及砂土地层施工的灌注桩,部分灌注桩因坍孔出现扩径和缩径,扩径浪费混凝土,缩径使灌注桩不合格,由此提出把旋挖钻法改进为旋挤钻法,达到灌注桩轻微扩径不缩径不浪费混凝土的完整... 研究目的:采用常规旋挖钻法在地下水丰富的黏土地层和软土及砂土地层施工的灌注桩,部分灌注桩因坍孔出现扩径和缩径,扩径浪费混凝土,缩径使灌注桩不合格,由此提出把旋挖钻法改进为旋挤钻法,达到灌注桩轻微扩径不缩径不浪费混凝土的完整合格桩,本文对其展开研究。研究结论:(1)把旋挖钻法钻斗的慢速重钻改进为旋挤钻法钻斗的快速轻钻可行,可减小振动,挤密孔壁土,预防孔壁坍孔;(2)旋挤钻法成孔对于地表浅部极易坍孔地层用长护筒护壁,且护筒长度要大于极易坍孔地层厚度,对于易坍孔和不易坍孔地层用比重1.25和1.15等指标的泥浆护壁,且泥浆护壁是以垂直式的可控泥浆和离心力水平式的扰动土混合泥浆共同作用于护壁,迫使孔内部分扰动土与泥浆粘黏旋挤进入孔壁内,孔壁得到加固稳定不坍孔;(3)采用旋挤钻法在地下水丰富的黏土地层和软土及砂土地层施工的灌注桩,灌注混凝土充盈系数为1.02~1.03和1.04~1.05,均达到轻微扩径不缩径不浪费混凝土的完整合格桩;且成孔效率高,可减少污染、节约成本;(4)本研究成果可为铁路、公路等领域提高混凝土灌注桩施工质量提供参考。 展开更多
关键词 旋挖钻法 旋挤钻法 慢速重钻 快速轻钻 护壁 质量
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Congophilic fibrils in the glomeruli with polyclonal immunoglobulin gamma staining-another cause for diagnostic overlap:A case report
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作者 Maria Bernadette Che-Ying Chow Lucas Bushrow +3 位作者 Irmeen Siddiqui April Chiu Mirza Hamirani Anjali A Satoskar 《World Journal of Clinical Cases》 SCIE 2024年第17期3200-3205,共6页
BACKGROUND Glomerulopathy with fibrillary deposits is not uncommon in routine nephropathology practice,with amyloidosis and fibrillary glomerulonephritis being the two most frequently encountered entities.Renal amyloi... BACKGROUND Glomerulopathy with fibrillary deposits is not uncommon in routine nephropathology practice,with amyloidosis and fibrillary glomerulonephritis being the two most frequently encountered entities.Renal amyloid heavy and light chain(AHL)is relatively uncommon and its biopsy diagnosis is usually limited to cases that show strong equivalent staining for a single immunoglobulin(Ig)heavy chain and a single light chain,further supported by mass spectrometry(MS)and serum studies for monoclonal protein.But polyclonal light chain staining can pose a challenge.CASE SUMMARY Herein we present a challenging case of renal AHL with polyclonal and polytypic Ig gamma(IgG)staining pattern by immunofluorescence.The patient is a 62-yearold Caucasian male who presented to an outside institution with a serum creatinine of up to 8.1 mg/dL and nephrotic range proteinuria.Despite the finding of a polyclonal and polytypic staining pattern on immunofluorescence,ultrastructural study of the renal biopsy demonstrated the presence of fibrils with a mean diameter of 10 nm.Congo red was positive while DNAJB9 was negative.MS suggested a diagnosis of amyloid AHL type with IgG and lambda,but kappa light chains were also present supporting the immunofluorescence staining results.Serum immunofixation studies demonstrated IgG lambda monoclonal spike.The patient was started on chemotherapy.The chronic renal injury however was quite advanced and he ended up needing dialysis shortly after.CONCLUSION Tissue diagnosis of AHL amyloid can be tricky.Thorough confirmation using other available diagnostic techniques is recommended in such cases. 展开更多
关键词 heavy and light chain amyloid Fibrillary glomerulonephritis DNAJB9 Serum immunofixation Protein electrophoresis Mass spectrometry Congo red Case report
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