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人LIGHT和HSV-TK-EGFP基因共转染的MSCs抗肿瘤免疫的体内研究
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作者 陈芬 江千秋 +1 位作者 焦兰 唐澍 《实用癌症杂志》 2024年第11期1744-1748,共5页
目的研究与单纯疱疹病毒的糖蛋白D竞争结合单纯疱疹病毒进入介导物(herpes virus entry mediator,HVEM)的淋巴毒素类似物(homologous to lymphotoxins,exhibits inducible expression,and competes with HSV glycoprotein D for HVEM,a ... 目的研究与单纯疱疹病毒的糖蛋白D竞争结合单纯疱疹病毒进入介导物(herpes virus entry mediator,HVEM)的淋巴毒素类似物(homologous to lymphotoxins,exhibits inducible expression,and competes with HSV glycoprotein D for HVEM,a receptor expressed by T lymphocytes,LIGHT)基因和单纯疱疹病毒胸苷激酶(herpes simplex virus thymidine kinase,HSV-TK)基因共转染的骨髓间充质干细胞(mesenchymal stem cells,MSCs)在体内的抗肿瘤免疫功能。方法将pIRES2-LIGHT基因和HSV-TK-EGFP基因共转染小鼠骨髓间充质干细胞(MSCs/LT组),以转染空载体和转染HSV-TK-EGFP基因的骨髓间充质干细胞作对照。流式细胞仪检测LIGHT分子和HSV-TK-EGFP分子在稳定转染的骨髓间充质干细胞上的表达。体内迁移实验观察MSCs/LT在小鼠体内迁移情况。观察更昔洛韦注射前后MSCs/LT对荷瘤小鼠体内肿瘤的治疗作用。ELISA法检测小鼠肿瘤组织中IFN-γ,IL-2和IL-10的水平。结果流式细胞仪检测发现,MSCs/LT能稳定高表达LIGHT分子。MSCs/LT有特异地向肿瘤组织趋化的特性。MSCs/LT和MSCs/T有较好的抑制肿瘤生长的能力,但在更昔洛韦诱导后,MSCs/LT的抗肿瘤效应下降甚至消失。同时,MSCs/LT可促使T细胞进入肿瘤组织,并促进T细胞分泌IL-2、IFN-γ,抑制IL-10分泌(P<0.05)。结论共转染人LIGHT和HSV-TK-EGFP基因的骨髓间充质干细胞能稳定高表达LIGHT分子,能特异性地向荷瘤小鼠体内肿瘤组织趋化并抑制肿瘤的生长,这种体内抗肿瘤功能可能与促进T淋巴细胞IL-2、IFN-γ等细胞因子的分泌,改善局部免疫抑制环境有关。 展开更多
关键词 抗肿瘤免疫 间充质干细胞 转染 light基因 HSV-TK-EGFP基因
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Correction Method of Light Hydrocarbons Losing and Heavy Hydrocarbon Handling for Residual Hydrocarbon (S_1) from Shale 被引量:7
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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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Energy and centrality dependence of light nuclei production in relativistic heavy-ion collisions 被引量:6
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作者 Li-Lin Zhu Bo Wang +1 位作者 Meng Wang Hua Zheng 《Nuclear Science and Techniques》 SCIE EI CAS CSCD 2022年第4期62-71,共10页
We study the energy and centrality dependence of deuteron and triton(helium-3)production in relativistic heavy-ion collisions at the BNL Relativistic Heavy Ion Collider(RHIC)and CERN Large Hadron Collider(LHC)using th... We study the energy and centrality dependence of deuteron and triton(helium-3)production in relativistic heavy-ion collisions at the BNL Relativistic Heavy Ion Collider(RHIC)and CERN Large Hadron Collider(LHC)using the Tsallis distribution,blast-wave(BW)model,and stationary Fokker-Planck(FP)solution.Our study shows that good agreement can be reached between the fitting results from the stationary FP solution and the experimental data for Au+Au collisions from the beam energy scan(BES)program of RHIC at√SNN=7.7,11.5,14.5,19.6,27,39,62.4,and 200 GeV and for Pb+Pb collisions at√SNN=2.76 TeV.The Tsallis distribution and BW model can reasonably describe the deuteron and triton(helium-3)trans verse momentum spectra obtained at RHIC and LHC.A more comprehensive comparison among the three methods suggests that the stationary FP solution is a sensible method,which is able to describe the energy dependence of the light nuclei yield ratio N_(t)N_(p)/N_(d)^(2) and provide a coherent description of deuteron and triton(helium-3)production for all centralities and various colliding energies at RHIC and LHC. 展开更多
关键词 light nucleiproduction heavy-ioncollisions Tsallis distribution Blast-wavemodel Fokker–Planck solution
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雷公藤多苷片对IgA肾病大鼠LIGHT-HVEM/LTβR通路的影响
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作者 王旭 方虹 +6 位作者 樊艳敏 季晗舒 宋珂 陈晨晨 卜继常 丁樱 宋纯东 《中国药理学通报》 CAS CSCD 北大核心 2024年第12期2277-2282,共6页
目的 基于炎症相关通路探讨雷公藤多苷片对IgA肾病大鼠肾脏的作用机制。方法 雄性SPF级SD大鼠,随机分为空白组、造模组。造模组采用联合“牛血清白蛋白+四氯化碳+脂多糖”建立IgA肾病大鼠模型。造模成功的大鼠随机分为模型组、泼尼松组... 目的 基于炎症相关通路探讨雷公藤多苷片对IgA肾病大鼠肾脏的作用机制。方法 雄性SPF级SD大鼠,随机分为空白组、造模组。造模组采用联合“牛血清白蛋白+四氯化碳+脂多糖”建立IgA肾病大鼠模型。造模成功的大鼠随机分为模型组、泼尼松组、雷公藤多苷片组,于第13周开始治疗组灌胃给药,给药4周后留取大鼠24 h尿液、血液、肾组织并检测尿红细胞数、24 h-UTP、BUN、Scr;ELISA检测血清IL-1β、TNF-α水平;HE染色观察各组大鼠肾组织病理学变化;Western blot及RT-PCR检测大鼠肾组织LIGHT、HVEM、LTβR蛋白及其mRNA的表达。结果 雷公藤多苷片明显降低IgA肾病大鼠尿红细胞数、24 h-UTP、BUN、Scr水平,改善肾组织病理,降低血清炎症因子IL-1β、TNF-α水平,降低肾组织中LIGHT、HVEM、LTβR蛋白及其mRNA表达水平。结论 雷公藤多苷片可能通过下调LIGHT-HVEM/LTβR信号通路,抑制免疫反应,减少炎症因子释放,从而减轻炎症反应,降低尿红细胞及尿蛋白,改善肾脏病理损伤,保护肾功能。 展开更多
关键词 雷公藤多苷片 IGA肾病 light-HVEM/LTβR 炎症 免疫反应 保护
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Study on Diagnosis Weather Process and Flight Impact of Heavy Snowfall in Northeast China “11/2021” 被引量:2
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作者 Xiaohui Zhang Hengrui Tao Ying Zheng 《Journal of Geoscience and Environment Protection》 2022年第5期170-183,共14页
Based on ERA5 reanalysis data, the characteristics of weather situation, water vapor condition, dynamic uplift condition, energy condition, ice accumulation environment and flight effect of aircraft in the heavy snowf... Based on ERA5 reanalysis data, the characteristics of weather situation, water vapor condition, dynamic uplift condition, energy condition, ice accumulation environment and flight effect of aircraft in the heavy snowfall process in northeast China from November 5 to 12, 2021 are analyzed. The results show that the heavy snowfall process in Northeast China is caused by the combination of Northeast China Cold Vortex, trough, low level frontal cyclone and cold front. Through the analysis of the physical field, it is found that the sufficient water vapor transport is from the south and the southeast, the convergence rising in the lower layer, divergence “pumping” in the upper layer, air flow rising in the vertical plane and a large amount of convection effective potential energy are all contributing to the heavy snowfall. The impact of heavy snowfall on flight mainly includes low visibility and ice accumulation. Water vapor flux, water vapor flux divergence, vertical velocity, potential temperature and convective effective potential energy can all be used as the judging indexes of heavy snowfall forecast. 展开更多
关键词 heavy Snow Weather Situation Water Vapor Energy Aircraft Icing
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Assessment of heavy metals in sediment in a heavily polluted urban river in the Chaohu Basin, China 被引量:3
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作者 邵世光 薛联青 +4 位作者 刘成 商景阁 王兆德 何翔 范成新 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2016年第3期526-538,共13页
The Nanfei River (Anhui Province, China) is a severely polluted urban river that flows into Chaohu Lake. In the present study, sediments were collected from the river and analyzed for their heavy metal contents. Mul... The Nanfei River (Anhui Province, China) is a severely polluted urban river that flows into Chaohu Lake. In the present study, sediments were collected from the river and analyzed for their heavy metal contents. Multivariate statistics and the fuzzy comprehensive assessment method were used to determine the sources of pollution, the current pollution status, and spatial and temporal variations in heavy metal pollution in sediments. The concentrations of arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), mercury (Hg), nickel (Ni), lead (Pb), and zinc (Zn) in sediments ranged from 5.67-113, 0.08-40.2, 41.6-524, 15.5-460, 0.03-4.84, 13.5-180, 18.8-250, and 47.9-1 996 mg/kg, and the average concentrations of each metal were 1.7, 38.7, 1.8, 5.5, l 8.8, 1.3, 2.5, and 11.1 times greater than the background values, respectively. Multivariate statistical analysis demonstrated that Hg, Cu, Cr, Cd, and Ni may have originated from industrial activities, whereas As and Pb came from agricultural activities. The fuzzy comprehensive assessment method, based on the fuzzy mathematics theory, was used to obtain a detailed assessment of the sediment quality in the Nanfei River watershed. The results indicated that the pollution was moderate in the downstream tributaries of the Nianbu and Dianbu Rivers, but was severe in the main channel of the Nanfei River and in the upstream tributaries of the Sill and Banqiao Rivers. Therefore, sediments in the Nanfei River watershed are heavily polluted and urgent measures should be taken to remedy the status. 展开更多
关键词 fuzzy comprehensive assessment (FCA) heavy metal pollution changing process distribution characteristics Nanfei River SEDIMENT
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基于改进GWO-LightGBM的磨煤机故障预警方法研究 被引量:2
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作者 陈思勤 周浩豪 茅大钧 《自动化仪表》 CAS 2024年第2期106-110,115,共6页
为提高燃煤电厂磨煤机运维效率、降低运维成本,对磨煤机故障预警进行了研究。创新性地提出一种基于改进灰狼优化(GWO)算法的轻量级梯度提升机(LightGBM)故障预警方法。通过建立LightGBM轴承温度预测模型获取磨煤机轴承温度阈值,并引入改... 为提高燃煤电厂磨煤机运维效率、降低运维成本,对磨煤机故障预警进行了研究。创新性地提出一种基于改进灰狼优化(GWO)算法的轻量级梯度提升机(LightGBM)故障预警方法。通过建立LightGBM轴承温度预测模型获取磨煤机轴承温度阈值,并引入改进GWO算法优化模型超参数,以提高算法效率和性能。试验结果表明,改进GWO-LightGBM算法相比支持向量机(SVM)等传统算法具有更高的精度和更优的泛化能力。通过实际故障案例证明,该方法能够提前2 h对磨煤机进行早期故障预警。该方法对燃煤电厂磨煤机安全运维具有指导意义。 展开更多
关键词 燃煤电厂 磨煤机 故障预警 改进灰狼优化算法 轻量级梯度提升机 滑动窗口法 Halton
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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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基于CEEMDAN-VMD-TCN-lightGBM模型的水质预测研究
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作者 项新建 张颖超 +3 位作者 许宏辉 厉阳 王世乾 郑永平 《中国农村水利水电》 北大核心 2024年第3期86-95,共10页
针对目前水质预测模型中因为数据本身的复杂性、在信号处理过程中存在的噪声干扰以及分解深度不够导致单一分解难以全面捕捉信号非线性特征的问题,提出了一种基于二次分解的水质预测模型。该模型采用完全自适应噪声集合经验模态分解(CEE... 针对目前水质预测模型中因为数据本身的复杂性、在信号处理过程中存在的噪声干扰以及分解深度不够导致单一分解难以全面捕捉信号非线性特征的问题,提出了一种基于二次分解的水质预测模型。该模型采用完全自适应噪声集合经验模态分解(CEEMDAN)对原始数据进行分解,再利用变分模态分解(VMD)对熵值最高的模态分量进行二次分解,最终将处理后的时间序列输入到TCN-lightGBM多特征预测模型中。同时,采用麻雀算法(SSA)对预测模型进行优化。以山东省玉符河水质为例,本模型的均方根误差(RMSE)是0.1053,平均绝对误差(MAE)是0.0815,决定系数(R2)是0.9471,与GRU、LSTM、LightGBM、TCN等当下较为流行的模型的预测指标进行比较。结果显示,在R2上本模型提升了53.04%、70.41%、66.07%、65.20%等,在RMSE上减少了62.76%、65.50%、64.93%、64.80%等,在MAE上降低了62.76%、66.24%、63.80%、65.24%等。由此可知,基于CEEMDAN-VMD-TCN-lightGBM的模型具有更好的预测性能、泛化能力和捕捉信号非线性特征的能力。 展开更多
关键词 二次分解 TCN lightGBM 多特征预测 水质预测 麻雀算法
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A Heavy Metal Analysis Device Based on Light-addressable Potentiometric Sensor
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作者 Hong Men Jianguo Wang +1 位作者 Jing Gao Ping Wang 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2006年第A03期230-231,共2页
<正>A full automatic device to detect heavy metal Hg,Fe,Cr elements based on thin-film sensitive materials prepared on surface of light-addressable potentiometric sensors (LAPS) by means of pulsed laser depositi... <正>A full automatic device to detect heavy metal Hg,Fe,Cr elements based on thin-film sensitive materials prepared on surface of light-addressable potentiometric sensors (LAPS) by means of pulsed laser deposition PLD) technique is developed. High-purity chemical compound AgI:Ag_2S:HgI synthesized were used as target of PLD,thin film sensitive to Hg~ (2+) ion was prepared on the surface of LAPS.All-solide-state chalcogenide glass ion-selective electrodes ISE) ,Fe-ISE and Cr-ISE,were also used as targets of PLD,and thin-film sensors on different LAPS sensitive to Fe~ (3+) and Cr~ (6+) ions were prepared.The heavy metal analysis device with characteristics of collect sample in-site,real-time determination,communication and multifunction software were designed.Hardware design of the device mainly includes control and measurement aspects.The detected limits of Hg,Fe,Cr ions are 3.44×10~ (-7) mol/L,6.31×10~ (-6) mol/L and 2.09×10~ (-7) mol/L,respectively. 展开更多
关键词 analysis chemistry SENSOR heavy metal LAPS PLD
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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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语料库工具与英语词汇教学之light Vs.heavy
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作者 杨行 《科技信息》 2011年第16期170-171,共2页
本文旨在利用语料库工具来深入对比light和heavy这对词的搭配,限于两词在意义上相反时的情况。根据剑桥在线词典http://dictio-nary.cambridge.org/dictionary/,我们找到两词表达相反意义的义项。
关键词 light 语料库 英语词汇 工具 教学 在线词典
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Public health importance of light intensity physical activity 被引量:1
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作者 Robert Ross Ian Janssen Mark S.Tremblay 《Journal of Sport and Health Science》 SCIE CAS CSCD 2024年第5期674-675,共2页
1.Light intensity physical activity(PA)benefits health PA guidelines worldwide recommend that adults accumulate 150 min of moderate intensity or 75 min of vigorous intensity PA(moderate-to-vigorous PA(MVPA))weekly to ... 1.Light intensity physical activity(PA)benefits health PA guidelines worldwide recommend that adults accumulate 150 min of moderate intensity or 75 min of vigorous intensity PA(moderate-to-vigorous PA(MVPA))weekly to achieve health benefits.1-3 Absent from these guidelines are recommendations for light intensity PA(LPA,e.g.,walking at a leisurely pace of 3 km/h or less,equivalent to 1.5-2.9 metabolic equivalents). 展开更多
关键词 INTENSITY light BENEFITS
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THE SPATIOTEMPORAL CHARACTERISTICS OF LIGHT RAIN DAYS AND LOW CLOUD COVER UNDER HEAVY POLLUTION OVER SOUTH CHINA
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作者 符传博 丹利 +1 位作者 陈红 何鑫 《Journal of Tropical Meteorology》 SCIE 2017年第2期229-236,共8页
By using the data set of light rain days and low cloud cover at 51 stations in South China(SC), and the method of linear regression and correlative analysis, we analyze the spatiotemporal characteristics of the light ... By using the data set of light rain days and low cloud cover at 51 stations in South China(SC), and the method of linear regression and correlative analysis, we analyze the spatiotemporal characteristics of the light rain days and low cloud cover including annual variation and long-term seasonal change. The results are as follows:(1) The trends of light rain days and low cloud cover over SC are opposite(light rain days tended to decrease and low cloud cover tended to increase in the past 46 years). The value distributed in east is higher than that in west, and coastal area higher than inland area.(2) The regression coefficients of light rain days and low cloud cover during 1960-2005 are4.88 d/10 years and 1.14%/10 years respectively, which had all passed the 0.001 significance level.(3) Variations of light rain days are relatively small in spring and summer, but their contributions are larger for annual value than that of autumn and winter.(4) There are two regions with large values of aerosol optical depth(AOD), which distribute in central and southern Guangxi and Pearl River Delta(PRD) of Guangdong, and the value of AOD in PRD is up to 0.7.The aerosol index distributed in coastal area is higher than in the inland area, which is similar to the light rain days and low cloud cover over SC. Aerosol indexes in SC kept increasing with fluctuation during the past 27 years. The GDP of the three provinces in SC increased obviously during the past 28 years, especially in Guangdong, which exhibited that there is simultaneous correlation between light rain days with the variables of low cloud cover and release of aerosols over SC during 1960 to 2005. 展开更多
关键词 light rain days low cloud cover AOD Aerosol index South China
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Effects of thinning on the understory light environment of different stands and the photosynthetic performance and growth of the reforestation species Phoebe bournei 被引量:2
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作者 Shicheng Su Nianqing Jin Xiaoli Wei 《Journal of Forestry Research》 SCIE EI CAS CSCD 2024年第1期12-28,共17页
Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in... Light levels determine regeneration in stands and a key concern is how to regulate the light environment of different stand types to the requirements of the understory.In this study,we selected three stands typical in south China(a Cryptomeria japonica plantation,a Quercus acutissima plantation,and a mixed stand of both)and three thinning intensities to determine the best understory light environ-ment for 3-year-old Phoebe bournei seedlings.The canopy structure,understory light environment,and photosynthe-sis and growth indicators were assessed following thin-ning.Thinning improved canopy structure and understory light availability of each stand;species composition was the reason for differences in the understory light environ-ment.Under the same thinning intensity,the mixed stand had the greatest light radiation and most balanced spectral composition.P.bournei photosynthesis and growth were closely related to the light environment;all three stands required heavy thinning to create an effective and sustained understory light environment.In a suitable understory light environment,the efficiency of light interception,absorption,and use by seedlings was enhanced,resulting in a higher carbon assimilation the main limiting factor was stomatal conductance.As a shade-avoidance signal,red/far-red radia-tion is a critical factor driving changes in photosynthesis and growth of P.bournei seedlings,and a reduction increased light absorption and use capacity and height:diameter ratios.The growth advantage transformed from diameter to height,enabling seedlings to access more light.Our findings suggest that the regeneration of shade-tolerant species such as P.bournei could be enhanced if a targeted approach to thinning based on stand type was adopted. 展开更多
关键词 THINNING Understory light environment Phoebe bournei Photosynthetic performance Growth performance
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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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Impacts of Future Changes in Heavy Precipitation and Extreme Drought on the Economy over South China and Indochina 被引量:1
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作者 Bin TANG Wenting HU +4 位作者 Anmin DUAN Yimin LIU Wen BAO Yue XIN Xianyi YANG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2024年第6期1184-1200,I0022-I0034,共30页
Heavy precipitation and extreme drought have caused severe economic losses over South China and Indochina(INCSC)in recent decades.Given the areas with large gross domestic product(GDP)in the INCSC region are distribut... Heavy precipitation and extreme drought have caused severe economic losses over South China and Indochina(INCSC)in recent decades.Given the areas with large gross domestic product(GDP)in the INCSC region are distributed along the coastline and greatly affected by global warming,understanding the possible economic impacts induced by future changes in the maximum consecutive 5-day precipitation(RX5day)and the maximum consecutive dry days(CDD)is critical for adaptation planning in this region.Based on the latest data released by phase 6 of the Coupled Model Intercomparison Project(CMIP6),future projections of precipitation extremes with bias correction and their impacts on GDP over the INCSC region under the fossil-fueled development Shared Socioeconomic Pathway(SSP5-8.5)are investigated.Results indicate that RX5day will intensify robustly throughout the INCSC region,while CDD will lengthen in most regions under global warming.The changes in climate consistently dominate the effect on GDP over the INCSC region,rather than the change of GDP.If only considering the effect of climate change on GDP,the changes in precipitation extremes bring a larger impact on the economy in the future to the provinces of Hunan,Jiangxi,Fujian,Guangdong,and Hainan in South China,as well as the Malay Peninsula and southern Cambodia in Indochina.Thus,timely regional adaptation strategies are urgent for these regions.Moreover,from the sub-regional average viewpoint,over two thirds of CMIP6 models agree that maintaining a lower global warming level will reduce the economic impacts from heavy precipitation over the INCSC region. 展开更多
关键词 CMIP6 heavy precipitation extreme drought South China INDOCHINA economic impact
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Spatio-Temporal Characteristics of Heavy Precipitation Forecasts from ECMWF in Eastern China 被引量:1
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作者 徐同 谭燕 顾问 《Journal of Tropical Meteorology》 SCIE 2024年第1期29-41,共13页
This study examines the spatio-temporal characteristics of heavy precipitation forecasts in eastern China from the European Centre for Medium-Range Weather Forecasts(ECMWF) using the time-domain version of the Method ... This study examines the spatio-temporal characteristics of heavy precipitation forecasts in eastern China from the European Centre for Medium-Range Weather Forecasts(ECMWF) using the time-domain version of the Method for Object-based Diagnostic Evaluation(MODE-TD). A total of 23 heavy rainfall cases occurring between 2018 and 2021 are selected for analysis. Using Typhoon “Rumbia” as a case study, the paper illustrates how the MODE-TD method assesses the overall simulation capability of models for the life history of precipitation systems. The results of multiple tests with different parameter configurations reveal that the model underestimates the number of objects’ forecasted precipitation tracks, particularly at smaller radii. Additionally, the analysis based on centroid offset and area ratio tests for different classified precipitation objects indicates that the model performs better in predicting large-area, fast-moving, and longlifespan precipitation objects. Conversely, it tends to have less accurate predictions for small-area, slow-moving, and shortlifespan precipitation objects. In terms of temporal characteristics, the model overestimates the forecasted movement speed for precipitation objects with small-area, slow movement, or both long and short lifespans while underestimating it for precipitation with fast movement. In terms of temporal characteristics, the model tends to overestimate the forecasted movement speed for precipitation objects with small-area, slow movement, or both long and short lifespans while underestimating it for precipitation with fast movement. Overall, the model provides more accurate predictions for the duration and dissipation of precipitation objects with large-area or long-lifespan(such as typhoon precipitation) while having large prediction errors for precipitation objects with small-area or short-lifespan. Furthermore, the model’s simulation results regarding the generation of precipitation objects show that it performs relatively well in simulating the generation of large-area and fast-moving precipitation objects. However, there are significant differences in the forecasted generation of small-area and slow-moving precipitation objects after 9 hours. 展开更多
关键词 MODE-TD ECMWF heavy precipitation Eastern China
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