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基于UPLC-Q-TOF-MS技术的渝东北地产“平术”化学分型研究 被引量:3
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作者 谭小燕 易东阳 《中药材》 CAS 北大核心 2019年第7期1560-1565,共6页
目的:利用UPLC-Q-TOF-MS技术结合主成分分析法研究确定"平术"化学分型并分析化学成分差异。方法:采用C18色谱柱(50 mm×2.1 mm,1.9μm);流动相为0.05%甲酸水溶液(A)-0.05%甲酸甲醇溶液(B),梯度洗脱;体积流量为0.4 mL/min... 目的:利用UPLC-Q-TOF-MS技术结合主成分分析法研究确定"平术"化学分型并分析化学成分差异。方法:采用C18色谱柱(50 mm×2.1 mm,1.9μm);流动相为0.05%甲酸水溶液(A)-0.05%甲酸甲醇溶液(B),梯度洗脱;体积流量为0.4 mL/min;柱温为30℃。采用H-ESI离子源,电喷雾正离子模式,QIMS采集方式,采集时间10.0 min,扫描范围m/z 100~1 500,扫描间隔0.9 s进行检测。使用Xcarlibur软件系统进行质谱信息数据处理,采用SIMCA软件进行主成分分析,判断"平术"化学分型和各样本变量差异,再通过二级碎片离子信息、化合物质谱数据库和相关文献数据对照,分析差异变量对应的化学成分。结果:将样本质谱信息利用主成分分析技术分析发现渝东北地产"平术"化学分型属茅苍术型,从这些样本中检出了39个化合物,共鉴定出了36个化合物,主要影响样本分型的化合物有10个。结论:渝东北地产"平术"化学分型属茅苍术型,与挥发油类化学成分分型属茅苍术型和"平术"植物形态分类属苍术的判定结果一致,为渝东北地产"平术"的品质评价和临床合理使用奠定了基础。 展开更多
关键词 苍术 平术 UPLC-Q-TOF-MS 主成分分析(PCA) 化学分型
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基于GC-MS结合模式识别研究渝东北地产平术化学分型 被引量:2
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作者 谭小燕 易东阳 《南京中医药大学学报》 CAS CSCD 北大核心 2018年第2期194-198,共5页
目的判断渝东北地产平术化学分型,为平术的临床合理使用及其品质评价提供科学依据。方法采用GC-MS技术测定不同产地平术和苍术药材10批样品,分析其质谱图,用SIMCA14.1软件和SPSS19.0软件进行模式识别分析,并通过MSSS质谱图库检索及标准... 目的判断渝东北地产平术化学分型,为平术的临床合理使用及其品质评价提供科学依据。方法采用GC-MS技术测定不同产地平术和苍术药材10批样品,分析其质谱图,用SIMCA14.1软件和SPSS19.0软件进行模式识别分析,并通过MSSS质谱图库检索及标准品对照对显著差异的特征化合物进行鉴定。结果渝东北地产平术化学分型属茅苍术型,与平术植物形态分类属苍术的结果吻合,并鉴定出了影响苍术化学生态分型的17个关键化合物。结论平术化学生态分型属茅苍术型,且品质与茅苍术接近。 展开更多
关键词 苍术 平术 化学分型 气相色谱-质谱 主成分分析 聚类分析
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转化生长因子β1、I型胶原在Borrmann Ⅳ型胃癌形成中的作用研究 被引量:1
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作者 孙琳 史炼钢 +2 位作者 王玉杰 徐皓 胡祥 《大连医科大学学报》 CAS 2006年第2期87-90,共4页
[目的]分析转化生长因子β1(TGF-β1)表达与胃癌肉眼形态的关系及其在Ⅰ型胶原(Colla-genⅠ)合成中的作用,初步探讨TGF-β1与Ⅳ型胃癌形成的关联。[方法]通过免疫组织化学染色SP方法,分析了109例胃癌患者原发灶中TGF-β1及CollagenⅠ的... [目的]分析转化生长因子β1(TGF-β1)表达与胃癌肉眼形态的关系及其在Ⅰ型胶原(Colla-genⅠ)合成中的作用,初步探讨TGF-β1与Ⅳ型胃癌形成的关联。[方法]通过免疫组织化学染色SP方法,分析了109例胃癌患者原发灶中TGF-β1及CollagenⅠ的表达。[结果]TGF-β1表达分级在Borrmann分型各型间有显著性差异(P<0.005),BorrmannⅣ型胃癌TGF-β1呈++^+++级表达的占96%,而在Ⅰ、Ⅱ、Ⅲ型中分别为38.46%、76.31%、81.82%;TGF-β1表达与CollagenⅠ表达有相关关系(P<0.005);CollagenⅠ表达在Borrmann分型各型间有显著性差异(P<0.001),Borrmann分型为Ⅰ、Ⅱ、Ⅲ、Ⅳ型的CollagenⅠ表达面积比分别为8.22±0.81、8.69±0.90、11.20±1.45、14.27±1.71。Ⅳ型与Ⅰ、Ⅱ、Ⅲ型之间均有显著性差异(P<0.001)。[结论]TGF-β1表达与CollagenⅠ表达有明显相关性,在以胃壁广泛纤维化为特点的BorrmannⅣ型胃癌形成过程中起促进作用。 展开更多
关键词 转化生长因子Β1 Ⅰ型胶原 胃肿瘤 免疫组织化学Borrmann分型
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Water quality changing trends of the Miyun Reservoir 被引量:6
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作者 王建平 程声通 贾海峰 《Journal of Southeast University(English Edition)》 EI CAS 2005年第2期215-219,共5页
In order to simulate changes in the water quality of the Miyun Reservoir dueto continuous descent of surface water level, a 3-D ecological hydrodynamic model was developedthrough coupling the water quality analysis si... In order to simulate changes in the water quality of the Miyun Reservoir dueto continuous descent of surface water level, a 3-D ecological hydrodynamic model was developedthrough coupling the water quality analysis simulation program (WASP) with the environmental fluiddynamics code (EFDC). The model was then calibrated and verified. Four scenarios (S1, S21, S22 andS23) were simulated using the model. Results show that the water quality of the Miyun Reservoirunder conditions of low surface water level is apparently affected by different amounts of inflowand different total phosphorus (TP) loadings. The chlorophyll-a concentration might exceed 10 μg/Lin many areas of the Miyun Reservoir (This limitative value is seen as a critical value ofeutrophication) when large loadings of TP enter due to the amount of inflow increasing. Results ofscenario S23 indicate that control of TP loadings can decrease chlorophyll-a concentrationeffectively, and the water quality of the Miyun Reservoir will improve or retain its status quo. 展开更多
关键词 water quality model hydrodynamic model scenario analysis changing trends
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A NEW BACCHARANE-TYPE TRITERPENOID ISOLATED FROM THE ROOTS OF SAUSSUREA LAPPA C.B.CLARKE 被引量:1
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作者 杨辉 谢金伦 孙汉董 《Acta Botanica Sinica》 CSCD 1997年第7期667-669,共3页
A new baccharane-type triterpene, 3-acetoxy-9(11)-baccharene(1),as well as a known compound, a-amyrin(2), has been isolated from the ether extract of the roots of Saussurea lappa C. B. Clarke. The structure of the new... A new baccharane-type triterpene, 3-acetoxy-9(11)-baccharene(1),as well as a known compound, a-amyrin(2), has been isolated from the ether extract of the roots of Saussurea lappa C. B. Clarke. The structure of the new compound was identified by spectrum analysis. 展开更多
关键词 Scussurea lappa COMPOSITAE Baccharane-type triterpenoid 3β-acetoxy-9(11)-bac-charene
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Eremophilane Sesquiterpenoids from Coleus xanthanthus
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作者 梅双喜 张宏杰 +5 位作者 姜北 李朝明 吕扬 龚宁波 郑启泰 孙汉董 《Acta Botanica Sinica》 CSCD 2001年第8期868-870,共3页
A new eremophilane sesquiterpenoid, along with two known ones, was isolated from the ethyl acetate soluble fraction of the aerial part of Coleus xanthanthus C. Y. Wu et Y. C. Huang. Their structures were elucidate... A new eremophilane sesquiterpenoid, along with two known ones, was isolated from the ethyl acetate soluble fraction of the aerial part of Coleus xanthanthus C. Y. Wu et Y. C. Huang. Their structures were elucidated as 4,5,11_trimethyl_8,9_seco_1(10),7(11)_eremophiladien_8,12_olid_9_oic acid (1), 2,9_dioxoeuryopsin (2) and 9_oxoeuryopsin (3) by spectral methods. The 1H_NMR and 13 C NMR data of compounds 1, 2 and 3 were unambiguously assigned on the basis of two_dimensional NMR spectroscopy. 展开更多
关键词 Coleus xanthanthus eremophilane sesquiterpenoids 4 5 11_trimethyl_8 9_seco_1(10) 7(11)_eremophiladien_8 12_olid_9_oic acid 2 9_dioxoeuryopsin 9_oxoeuryopsin
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Behavior of phenol adsorption on thermal modified activated carbon 被引量:12
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作者 Dengfeng Zhang Peili Huo Wei Liu 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2016年第4期446-452,共7页
Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon (AC) samples after thermal modification were prepared by using muffle furnace. The phen... Adsorption process is acknowledged as an effective option for phenolic wastewater treatment. In this work, the activated carbon (AC) samples after thermal modification were prepared by using muffle furnace. The phenol ad- sorption kinetics and equilibrium measurements were carried out under static conditions at temperature ranging from 25 to 55 ~C. The test results show that the thermal modification can enhance phenol adsorption on AC samples. The porous structure and surface chemistry analyses indicate that the decay in pore morphology and decrease of total oxygen-containing functional groups are found for the thermal modified AC samples. Thus, it can be further inferred that the decrease of total oxygen-containing functional groups on the modified AC sam- ples is the main reason for the enhanced phenol adsorption capacity. For both the raw sample and the optimum modified AC sample at 900 ~C, the pseudo-second order kinetics and Langmuir models are found to fit the exper- imental data very well. The maximum phenol adsorption capacity of the optimum modified AC sample can reach 144,93 mg.g ~ which is higher than that of the raw sample, i.e. 119.53 mg.g 1. Adsorption thermodynamics analysis confirms that the phenol adsorption on the optimum modified AC sample is an exothermic process and mainly via physical adsorption. 展开更多
关键词 AdsorbentsActivated carbonPhenolAdsorptionThermal modificationOxygen-containing functional groups
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Quantitative analysis of globularization and modeling of TC17 alloy with basketweave microstructure 被引量:2
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作者 Hao-yu PANG Jiao LUO +3 位作者 Zhi-gang ZHANG Wen-chao HAN Keng-feng XU Miao-quan LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第3期850-867,共18页
The globularization behavior and mechanism of TC17 alloy with basketweave microstructure were investigated, and the models of dynamic and static globularization kinetics were established. The quantitative and metallog... The globularization behavior and mechanism of TC17 alloy with basketweave microstructure were investigated, and the models of dynamic and static globularization kinetics were established. The quantitative and metallographic results show that the globularization of α phase is sensitive to the parameters of deformation and heat treatment. By EBSD analysis, the formation and evolution mechanisms of intra-α boundaries are related to discontinuous dynamic recrystallization and continuous dynamic recrystallization, which can form α grains with high and low misorientations between neighbour grains after the heat treatment, respectively. Based on the globularization behavior and mechanism, two modified JMAK models are developed to predict the dynamic and static globularization kinetics, and the mean absolute relative errors(MARE) of 10.67% and 13.80% indicate the accuracy of the dynamic and static globularization kinetics models. The results of this work can provide guidance for controlling microstructure of titanium alloy. 展开更多
关键词 TC17 alloy basketweave microstructure globularization quantitative analysis kinetics model
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Calculation of Environmental Capacity of Petroleum Hydrocarbon in Jiaozhou Bay 被引量:1
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作者 李克强 王修林 +4 位作者 邓宁宁 石晓勇 祝陈坚 韩秀荣 胡海燕 《Marine Science Bulletin》 CAS 2004年第1期53-59,共7页
The method has been established to calculate the environmental capacity (ECO), surplus environment capacity (SECO) of water with respect to marine petroleum hydrocarbons associated with oil (PHAOs) and the self-purifi... The method has been established to calculate the environmental capacity (ECO), surplus environment capacity (SECO) of water with respect to marine petroleum hydrocarbons associated with oil (PHAOs) and the self-purification capacity (SPCO) of main self-purification process to PHAOs in the Jiaozhou Bay, China, according to the dynamic model for distribution of marine PHAOs among multiphase environments. The variation of concentration of PHAOs in the Jiaozhou Bay is well simulated by the dynamic model. Based on the model, the ECo, SECo of water with respect to PHAOs in the Jiaozhou Bay were calculated during the last 10 years under the first-class and second-class quality standard requirement, according to SPCO of main self-purification process to PHAOs. The results show that about 200 tons of PHAOs could be discharged into the Jiaozhou Bay for maintaining the first class seawater quality standard, and about 600 tons of PHAOs for the second class seawater quality standard later. 展开更多
关键词 petroleum-hydrocarbon Jiaozhou Bay environmental capacity self-purification capacity kinetic model
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π-Conjugated Unit-Dependent Optical Properties of Linear Conjugated Oligomers
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作者 Ning Sui Lu Zou +7 位作者 Yun-fei Song Qiu-lin Zhong Ying-hui Wang Xiao-gang Wei Zeng-bin Wang Yu-guang Ma Yan-qiang Yang Han-zhuang Zhang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第3期315-320,共6页
The optical properties of three linear conjugated oligomers (F-P, F-P-F, and P-F-P-F-P), where phenothiazine (P) and fluorene (F) groups arrange alternately, are investigated. With the enhancement of the π-conj... The optical properties of three linear conjugated oligomers (F-P, F-P-F, and P-F-P-F-P), where phenothiazine (P) and fluorene (F) groups arrange alternately, are investigated. With the enhancement of the π-conjugated system, their absorption and emission bands both gradually red shift, and their two-photon properties are also improved. Meanwhile, their fluorescence dynamic traces are analyzed with continuous rate distribution model, exhibiting that their decay rates gradually accelerate and the rate distribution width become narrower. The quantum chemical calculation offers their molecular structures and transition mechanism, showing that the enhancement of π-conjugated system should be responsible for tile improvement of two-photon properties. 展开更多
关键词 OLIGOMER Z-SCAN Fluorescence dynamics
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La_(1-x)Ca_xMn_(1-y)Al_yO_3 perovskites as efficient catalysts for two-step thermochemical water splitting in conjunction with exceptional hydrogen yields 被引量:3
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作者 Lulu Wang Mohammad Al‐Mamun +3 位作者 Porun Liu Yun Wang Hua Gui Yang Huijun Zhao 《Chinese Journal of Catalysis》 EI CSCD 北大核心 2017年第6期1079-1086,共8页
Solar‐driven thermochemical water splitting represents one efficient route to the generation of H2as a clean and renewable fuel.Due to their outstanding catalytic abilities and promising solar fuel production capacit... Solar‐driven thermochemical water splitting represents one efficient route to the generation of H2as a clean and renewable fuel.Due to their outstanding catalytic abilities and promising solar fuel production capacities,perovskite‐type redox catalysts have attracted significant attention in this regard.In the present study,the perovskite series La1‐xCaxMn1‐yAlyO3(x,y=0.2,0.4,0.6,or0.8)was fabricated using a modified Pechini method and comprehensively investigated to determine the applicability of these materials to solar H2production via two‐step thermochemical water splitting.The thermochemical redox behaviors of these perovskites were optimized by doping at either the A(Ca)or B(Al)sites over a broad range of substitution values,from0.2to0.8.Through this doping,a highly efficient perovskite(La0.6Ca0.4Mn0.6Al0.4O3)was developed,which yielded a remarkable H2production rate of429μmol/g during two‐step thermochemical H2O splitting,going between1400and1000°C.Moreover,the performance of the optimized perovskite was found to be eight times higher than that of the benchmark catalyst CeO2under the same experimental conditions.Furthermore,these perovskites also showed impressive catalytic stability during two‐step thermochemical cycling tests.These newly developed La1‐xCaxMn1‐yAlyO3redox catalysts appear to have great potential for future practical applications in thermochemical solar fuel production. 展开更多
关键词 Two‐step thermochemical route Water splitting Solar fuel Perovskite‐type redox catalyst Hydrogen production
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Fatigue behaviour of welded joints assembled by longitudinal corrugated plates 被引量:2
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作者 王志宇 王清远 +1 位作者 刘永杰 孙美 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第7期2752-2760,共9页
Fatigue is usually the cause for the cracks identified at bridge elements in service. With an increase in the introduction of corrugated steel web girders in recent highway bridge construction, the understanding of th... Fatigue is usually the cause for the cracks identified at bridge elements in service. With an increase in the introduction of corrugated steel web girders in recent highway bridge construction, the understanding of the fatigue behaviour of welded details in such structures becomes an important issue for the design. The typical welded details were represented as welded joints assembled by longitudinal corrugated plates. All the experiments were performed under fatigue loading using a servo-control testing machine. The test results from the failure mode observation with the aid of infrared thermo-graph technology show that the failure manner of these welded joints is comparable to that of the corrugated steel web beams reported previously. It is indicated from the stiffness degradation analysis that the welded joints with larger corrugation angle have higher stiffness and greater stiffness degradation in the notable stiffness degradation range. It is shown from the test S-N relations based on the free regression and forced regression analyses that there is a good linear dependence between lg(N) and lg(ΔS). It is also demonstrated that the proposed fracture mechanics analytical model is able to give a prediction slightly lower but on the safe side for the mean stresses at 2 million cycles of the test welded joints. 展开更多
关键词 corrugated web fatigue behaviour S-N relation stiffness degradation fracture mechanics
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Effect of Nutrient Type on Chemical Composition and Dry Matter Partitioning of Cassava (Manihot esculenta Crantz)
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作者 V. D. Taffouo E. Tsoata +3 位作者 M. Kenne R. J. Priso T. Fonkou A. Akoa 《Journal of Agricultural Science and Technology》 2010年第4期96-102,共7页
The objective of our study was to determine the effects of four types of fertilisers enrichments (manure potassic (K), phosphatic (P), phosphatic and potassic (PK) and nitrogenized, phosphated and potassic (NP... The objective of our study was to determine the effects of four types of fertilisers enrichments (manure potassic (K), phosphatic (P), phosphatic and potassic (PK) and nitrogenized, phosphated and potassic (NPK)) on chemical composition and dry matter in cassava (Manihot esculenta) organs (clone 1171) during harvest period. The pots experiment was laid out in randomised complete bloc design with five treatments and four replications. Water, nitrogen, potassium, phosphorus, sodium, total proteins and total lipids contents of the leaves, shoots and tubers were determined. After 9 months growing period, results showed that fertilizer types enriched with K, PK and NPK significantly increased the organic compounds contents of the leaves (P〈0.05). Furthermore, fertilizers with high phosphorus content significantly increased the lipid contents of the leaves (25%). Fertilizers enriched with NPK positively influenced the biomass partitioning in Manihot esculenta. Application of fertilizers enriched with NPK led to higher levels of total proteins in the leaves and tubers (70 mg g DM^-1 and 30 mg g DM^-1 respectively) compared to control (17 mg g DM^-1 and 9 mg g DM^-1 respectively). These results help to demonstrate the value of these fertilizers enrichment to improve the chemical composition and dry matter partitioning of cassava. 展开更多
关键词 CASSAVA nutrient type chemical composition partitioning dry weight
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Dynamic Alignment of D2 Enhanced by Two Few-cycle Pulses
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作者 Zeng-qiang Yang Zhi-rong Guo +1 位作者 Bao-xiang Yin Mao-zhu Sun 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2008年第5期421-426,共6页
Dynamic alignment of D2 induced by two few-cycle pulses was investigated by solving the time-dependent Schr6dinger equation numerically based on a rigid rotor model. The results show that alignment of D2 can be enhanc... Dynamic alignment of D2 induced by two few-cycle pulses was investigated by solving the time-dependent Schr6dinger equation numerically based on a rigid rotor model. The results show that alignment of D2 can be enhanced by two few-cycle pulses compared with the level achievable by a single few-cycle pulse as long as the time delay between two pulses is chosen properly, and the pulse duration of two lasers plays an important role in the aligning process of D2 molecules. 展开更多
关键词 Dynamic alignment Few-cycle pulses Pulse duration
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Energetic and Exergetic Analysis of Organic Rankine Cycle Powered by Hot Geothermal Water
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作者 Fathi Latrash Mohammed A. Al-Weshahi +1 位作者 Basim M.A Makhdoum Brian Agnew 《Journal of Energy and Power Engineering》 2014年第7期1217-1231,共15页
The paper presents an investigation of energy and exergy analysis of an existing ORC (organic rankine cycle) unit powered by hot geothermal water. The validated model of this unit was used to examine 25 refrigerants... The paper presents an investigation of energy and exergy analysis of an existing ORC (organic rankine cycle) unit powered by hot geothermal water. The validated model of this unit was used to examine 25 refrigerants belonging to different chemical compositions. The study revealed that R141b and R123 produced the best net power, energy efficiency, and exergy efficiency, whereas R125 was the lowest. Hydrofluorocarbons (except R143a), hydrocarbons, and inorganic reflected attractive energy and exergy efficiencies. All investigated mixtures gained low performance compared with other studied candidates. The R245ca was the best among the hydrofluorocarbons studied refrigerants, and R501 was the best among the mixture refrigerants. Furthermore, within the ORC system, the evaporator was found to have the highest exergy destruction and the refrigerant pump was the lowest. 展开更多
关键词 Organic Rankine cycle EXERGY ENERGY refrigerants.
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Preliminary Developments of Miniplate-Type Fuel of U-2.5Zr-7.5Nb Alloy Dispersed and Cladded in Zircaloy
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作者 Natalia Mattar Cantagalli Kelly Cristina Martins Faeda Rafael Witter Dias Pais Ana Maria Matildes dos Santos Wilmar Barbosa Ferraz 《Journal of Energy and Power Engineering》 2014年第8期1409-1414,共6页
Nuclear fuel based on uranium metal alloys is utilized in research and test reactors. For the purpose of the reduction of fuel enrichment, high densities of uranium-235 in this kind of fuel are needed. This can be ach... Nuclear fuel based on uranium metal alloys is utilized in research and test reactors. For the purpose of the reduction of fuel enrichment, high densities of uranium-235 in this kind of fuel are needed. This can be achieved when uranium alloys are used containing elements such as Zr, Mo and Nb. The construction of fuel element with high-uranium density requires materials with low cross sections for neutron absorption, stability under irradiation and absence of the chemical interactions between the fuel and cladding elements. In case of U-Zr-Nb alloys, Zry (zircaloy) cladding is a better option due to the fact that they have a higher chemical compatibility when compared with the use of aluminum alloys. This study aims to develop plate type nuclear fuel using the U-2.5Zr-7.5Nb alloy dispersed in Zry. Powders of this uranium based alloy and Zry were obtained by hydriding-dehydriding process. These powders were homogenized, compacted in pellet that was sandwiched in plates and frame of Zry. This assembly was hot rolled forming the dispersion fuel miniplate. 展开更多
关键词 Nuclear fuel plate U-Zr-Nb alloy Zry
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Chemical Fractionation and Sorption of Phosphorus in Greek Inceptisols
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作者 M. Bastounopoulou D. Gasparatos C. Haidouti I. Massas 《Journal of Agricultural Science and Technology(A)》 2011年第1X期33-38,共6页
Phosphorus fractionation and sorption, both separately and jointly, were studied in two cultivated Inceptisols in Northern Greece. Hedley's extraction was used to separate soil phosphorus (P) into inorganic Pi (ge... Phosphorus fractionation and sorption, both separately and jointly, were studied in two cultivated Inceptisols in Northern Greece. Hedley's extraction was used to separate soil phosphorus (P) into inorganic Pi (geochemical) and organic Po (biological) fractions. Direct extractable P by Olsen (Olsen-P), by Mehlich llI (M3-P) and by ammonium oxalate (Pox) was also determined. Phosphorus sorption was carried out with 1:10 soil/solution ratio and sorption parameters were derived from the Langmuir model to the experimental data. Most of the total P occurred in inorganic P forms (74% of Pt), while organic P comprised only 26% of the Pt. Among the various inorganic P forms relatively large amount of residual P (111 mg kg^-1) was observed, while occluded P in calcium phosphate minerals (d.HCI-Pi) and in Fe, Al-oxides (c.HCI-Pi) existed in equal amounts (83.1 and 83.7 mg kg^-1 respectively). The phosphorus sorption parameters showed positive relationships with clay content, cation exchange capacity and the sum of exchangeable calcium plus magnesium. Overall, this study indicated that Ca and Mg compounds strongly influence the P chemistry in moderately weathered soils, with relatively high concentration of primary P minerals. 展开更多
关键词 Phosphorus fractionation SORPTION langmuir equation INCEPTISOLS
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Modeling the Effects of Nutrient Dynamics and Surface Circulation on the Productivity of Hooghly Estuary
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作者 Saswati Dcb Arun Chakraborty 《Journal of Shipping and Ocean Engineering》 2012年第5期255-262,共8页
River estuarine environment plays a key role in the cycling of biological and chemical parameters and a significant region for the transaction of freshwater and seawater. In the present study, a first attempt has been... River estuarine environment plays a key role in the cycling of biological and chemical parameters and a significant region for the transaction of freshwater and seawater. In the present study, a first attempt has been made towards the development of a coupled three-dimensional hydrodynamic circulation model with four compartment (nitrate, phytoplankton, zooplankton and detritus) biogeochemical model in the Hooghly estuary (21 °36′-22° 16′1 and 87°42'-88°15′E) to simulate the varying effect of plankton biomass with the heavy input of anthropogenic litter from industrial effluents of Haldia port which is effecting the chemical and biological processes that control the plankton dynamics in the estuary. In-situ observational data for physico-chemical and biological parameters are collected from Calcutta University during 2010 are assimilated using multiscale OA (objective analysis) for different seasons and incorporated in ROMS (Regional Ocean Modeling System) to develop a high resolution (0.5 km x 0.5 kin) biogeochemical model. Recent analysis on physico-chemical parameters of the estuary is done as it is one of the largest estuaries in India and is the habitat for vast biodiversity. Influence of high nitrate (above 34 μg/L) and phosphate (5.22 μg/L) is predominant whereas DO (dissolved oxygen) is low (4.07 mg/L) in the Haldi River mouth which is sliding the productivity (less than 1 mg/L) and also affects water quality. 展开更多
关键词 Biogeochemical model Hooghly estuary OA PRODUCTIVITY ROMS.
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Integrated Process for Production of Surfactin(III)Modeling of Adsorption Column
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作者 Ludovic Montastruc 刘涛 +2 位作者 Iordan Nikov Pascal Floquet Serge Domenech 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2011年第3期357-364,共8页
The study is focused on modeling of separation process and optimization.An adsorption separation process is simulated.The surfactin production process by Bacillus subtilis ATCC 21332 followed by surfactin adsorption i... The study is focused on modeling of separation process and optimization.An adsorption separation process is simulated.The surfactin production process by Bacillus subtilis ATCC 21332 followed by surfactin adsorption in a fixed-bed column packed with commercial active carbon is studied in laboratory.The adsorption column achieves high surfactin recovery(94%)by up-flow methanol elution at 25°C.The adsorption column is simulated with a complex one-dimensional plug flow dispersion model coupled with nonlinear adsorption equilibrium,based on the assumption that the adsorption of surfactin is monomolecular layer and no micelle is formed.The molecular diffusion coefficient of surfactin in water solution with electric neutrality is estimated to be 0.428×10 -5 cm 2 ·s -1 by molecular dynamics simulation.The model developed can describe the complex interplay of adsorption kinetics,fluid dynamics,and mass-transfer phenomena based on the assumption of no radial temperature and concentration gradients,and is of adequate precision.The work involved in this paper is valuable for the optimization of the production process of surfactin. 展开更多
关键词 SURFACTANT ADSORPTION mathematical modelling KINETICS integrated process
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Determining soil redistribution in Dian Lake catchment by combined use of caesium-137 and selected chemical properties
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作者 Zhang Mingli Yang Hao Xu Congan Wang Yihong 《Ecological Economy》 2009年第1期91-100,共10页
Recent development in the use of the environmental radionuclide caesium-137 for documenting rates and soil redistribution on the cultivated or uncultivated land and estimating rates of sediment deposition on represent... Recent development in the use of the environmental radionuclide caesium-137 for documenting rates and soil redistribution on the cultivated or uncultivated land and estimating rates of sediment deposition on represents an important advance that overcomes many of the limitations of the conventional techniques commonly applied in such investigations. A study on soil redistribution (including soil erosion and deposition) was carried out in the Dian Lake catchment, Yunnan Province, using ^137Cs and selected chemical properties. The average soil erosion rate was 1,280.2 t km^2 yr^-1. Soil erosion rate occurring on different parts of the slope was significantly different on different parts of the slope, increasing.from the top. the bottom to the middle slope. The average soil erosion rate is also different with the land use type and that of the cultivated land (1, 672. 8 t km^-2 yr^-1) is higher than oJ the uncultivated land (1.161.2t km^-2 yr^-1 ). The result shows that landform, slope gradient and land use type are key factors that influence the size of soil erosion. In addition, we also find the SOC and TN contents and amount of the soil erosion to be correlated in the soil. With the soil erosion occurring, there are land degradation and the local eco-environmental problems, such as water eutrophication in Dian Lake. 展开更多
关键词 ^137 - Cs SOC TN soil redistribution Dian Lake catchment
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