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On Characterizations of Special Elements in Rings with Involution
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作者 Sanzhang XU Jianlong CHEN Dijana MOSIC 《数学年刊:B辑英文版》 SCIE CSCD 2019年第1期65-78,共14页
Let R be a ring with involution. It is well-known that an EP element in R is a core invertible element, but the question when a core invertible element is an EP element,the authors answer in this paper. Several new ch... Let R be a ring with involution. It is well-known that an EP element in R is a core invertible element, but the question when a core invertible element is an EP element,the authors answer in this paper. Several new characterizations of star-core, normal and Hermitian elements in R are also presented. 展开更多
关键词 Moore-Penrose INVERSE Core INVERSE EP ELEMENT Star-core ELEMENT Normal ELEMENT HERMITIAN ELEMENT
The smoothed finite element method (S-FEM):A framework for the design of numerical models for desired solutions
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作者 Gui-Rong Liu 《结构与土木工程前沿:英文版》 EI CSCD 2019年第2期456-477,共22页
The smoothed finite element method (S-FEM) was originated by G R Liu by combining some meshfree techniques with the well-established standard finite element method (FEM). It has a family of models carefully designed w... The smoothed finite element method (S-FEM) was originated by G R Liu by combining some meshfree techniques with the well-established standard finite element method (FEM). It has a family of models carefully designed with innovative types of smoothing domains. These models are found having a number of important and theoretically profound properties. This article first provides a concise and easy-to-follow presentation of key formulations used in the S-FEM. A number of important properties and unique features of S-FEM models are discussed in detail, including 1) theoretically proven softening effects;2) upper-bound solutions;3) accurate solutions and higher convergence rates;4) insensitivity to mesh distortion;5) Jacobian?free;6) volumetric-locking-free;and most importantly 7) working well with triangular and tetrahedral meshes that can be automatically generated. The S-FEM is thus ideal for automation in computations and adaptive analyses, and hence has profound impact on Al-assisted modeling and simulation. Most importantly, one can now purposely design an S-FEM model to obtain solutions with special properties as wish, meaning that S-FEM offers a framework for design numerical models with desired properties. This novel concept of numerical model demand may drastically change the landscape of modeling and simulation. Future directions of research are also provided. 展开更多
关键词 computational METHOD FINITE ELEMENT METHOD smoothed FINITE ELEMENT METHOD strain SMOOTHING technique SMOOTHING domain weakened weak form solid mechanics SOFTENING effect upper bound solution
Static analysis of corrugated panels using homogenization models and a cell-based smoothed mindlin plate element (CS-MIN3)
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作者 Nhan NGUYEN-MINH Nha TRAN-VAN +1 位作者 Thang BUI-XUAN Trung NGUYEN-THOI 《结构与土木工程前沿:英文版》 EI CSCD 2019年第2期251-272,共22页
Homogenization is a promising approach to capture the behavior of complex structures like corrugated panels. It enables us to replace high-cost shell models with stiffness-equivalent orthotropic plate alternatives. Ma... Homogenization is a promising approach to capture the behavior of complex structures like corrugated panels. It enables us to replace high-cost shell models with stiffness-equivalent orthotropic plate alternatives. Many homogenization models for corrugated panels of different shapes have been proposed. However, there is a lack of investigations for verifying their accuracy and reliability. In addition, in the recent trend of development of smoothed finite element methods, the cell-based smoothed three-node Mindlin plate element (CS-MIN3) based on the first-order shear deformation theory (FSDT) has been proposed and successfully applied to many analyses of plate and shell structures. Thus, this paper further extends the CS-MIN3 by integrating itself with homogenization models to give homogenization methods. In these methods, the equivalent extensional, bending, and transverse shear stiftriess components which constitute the equivalent orthotropic plate models are represented in explicit analytical expressions. Using the results of ANSYS and ABAQUS shell simulations as references, some numerical examples are conducted to verify the accuracy and reliability of the homogenization methods for static analyses of trapezoidally and sinusoidally corrugated panels. 展开更多
关键词 HOMOGENIZATION corrugated panel ASYMPTOTIC analysis smoothed finite ELEMENT method (S-FEM) cell-based smoothed three-node MINDLIN plate ELEMENT (CS-MIN3)
Solving Interface Problems of the Helmholtz Equation by Immersed Finite Element Methods 预览
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作者 Tao Lin Yanping Lin Qiao Zhuang 《应用数学与计算数学学报(英文)》 2019年第2期187-206,共20页
This article reports our explorations for solving interface problems of the Helmholtz equation by immersed finite elements (IFE) on interface independent meshes. Two IFE methods are investigated: the partially penaliz... This article reports our explorations for solving interface problems of the Helmholtz equation by immersed finite elements (IFE) on interface independent meshes. Two IFE methods are investigated: the partially penalized IFE (PPIFE) and discontinuous Galerkin IFE (DGIFE) methods. Optimal convergence rates are observed for these IFE methods once the mesh size is smaller than the optimal mesh size which is mainly dictated by the wave number. Numerical experiments also suggest that higher degree IFE methods are advantageous because of their larger optimal mesh size and higher convergence rates. 展开更多
关键词 HELMHOLTZ interface problems Immersed FINITE ELEMENT (IFE) METHODS HIGHER degree FINITE ELEMENT METHODS
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河套平原湖泊陈普海子沉积物粒度与元素分析 预览
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作者 汪敬忠 朱迟 +2 位作者 兰波 李霄 刘卓 《中国环境科学》 EI CAS CSCD 北大核心 2019年第1期358-365,共8页
通过对河套地区不同类型沉积物进行粒度和元素分析,根据区域陈普海子沉积岩芯的年代和环境代用指标结果,借助于判别分析技术,结合历史文献资料,揭示区域近300a来两个典型时段的环境变化.结果表明,约1850a受黄河河道变迁引起的洪水活动影... 通过对河套地区不同类型沉积物进行粒度和元素分析,根据区域陈普海子沉积岩芯的年代和环境代用指标结果,借助于判别分析技术,结合历史文献资料,揭示区域近300a来两个典型时段的环境变化.结果表明,约1850a受黄河河道变迁引起的洪水活动影响,陈普海子岩芯55~50cm(CP1)沉积物表现为灰黄色黏土层,其粒度参数、分布曲线与黄河岸边缓流沉积物相似,两者的中值粒径和众数数值分别为3.8,7.7μm和4.4,5.0μm,元素及其比值K/Ti、Al/Ti和K/Sr(数值分别为7.1、21.5、102.7和6.2、20.7、87.8)的得分散点分布在判别得分散点图的同一区域,与其它类型沉积物的分布区域明显分离,元素比值K/Ti、Al/Ti和K/Sr可作为湖泊沉积指示洪水活动的环境代用指标;自1995年以来,由于区域人类活动,沙荒土地大规模开垦,致使风沙活动增强,岩芯15cm以上(CP2)沉积物粒度参数、分布曲线与风积物相似,两者的中值粒径和众数数值分别为20.1,19.6μm和41.6,45.7μm,元素的得分散点分布在判别得分散点图的同一区域,研究结果与文献记录具有较好的一致性. 展开更多
关键词 河套平原 沉积物 粒度 元素 判别分析 环境变化
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Design of packing cup interference fit value of hypercompressors for low density polyethylene production
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作者 Da LEI Xuehong LI +1 位作者 Yun LI Xiwen REN 《能源前沿:英文版》 CSCD 2019年第1期107-113,共7页
The hypercompressor is one of the core facilities in low density polyethylene production,with a discharge pressure of approximately 300 MPa.A packing cup is the basic unit of cylinder packing,assembled by the interfer... The hypercompressor is one of the core facilities in low density polyethylene production,with a discharge pressure of approximately 300 MPa.A packing cup is the basic unit of cylinder packing,assembled by the interference fit between an inner cup and an outer cup.Because the shrink-fitting prestresses the packing cup,serious design is needed to gain a favorable stress state,for example,a tri-axial compressive stress state.The traditional method of designing the interference fit value for packing cups depends on the shrink-fit theory for thickwalled cylinder subject to internal and external pressure.According to the traditional method,critical points are at the inner radii of the inner and external cup.In this study,the finite element method(FEM)has been implementcd to determine a more accurate stress level of packing cups.Different critical points have been found at the edge of lapped sealing surfaces between two adjacent packing cups.The maximum Von Mises equivalent stress in a packing cup increases after a decline with the rise of the interference fit value.The maximum equivalent stress initially occurs at the bore of the inner cup,then at the edge of lapped mating surfaces,and finally at the bore of the outer cup,as the interference radius increases.The traditional method neglects the influence of axial preloading on the interference mating pressure.As a result,it predicts a lower equivalent stress at the bore of the external cup.A higher interference fit value accepted by the traditional method may not be feasible as it might already make packing cups yield at the edge of mating surfaces or the bore of the external cup.Along with fatigue analysis,the feasible range of interference fit value has been modified by utilizing FEM.The modified range tends to be narrower and safer than the one derived from the traditional method,after getting rid of shrink-fit values that could result in yielding in a real packing cup. 展开更多
关键词 INTERFERENCE FIT VALUE PACKING CUP hypercompressor finite element method(FEM)
知识窗 预览
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《制造技术与机床》 北大核心 2019年第6期40-40,51,59,92,106,125,128,134,139,144,153,159,175,188,193,202共16页
声学部件(acoustic element)超声波加工机床的重要部件。由换能器、振幅扩大棒和工具组成。它的作用是把高频电能转变为机械能,使工具作一定频率和一定振幅的电高频连续振动,促使液体中的磨粒不断冲击工件,并使液直体产生空化作用,以达... 声学部件(acoustic element)超声波加工机床的重要部件。由换能器、振幅扩大棒和工具组成。它的作用是把高频电能转变为机械能,使工具作一定频率和一定振幅的电高频连续振动,促使液体中的磨粒不断冲击工件,并使液直体产生空化作用,以达到加工的目的。声频钻削(sonic drilling)用连接在-个声频机电转换器上,并以声频往复振动的工具来推动磨料浆液以钻削工件或使其成形的加工方法。 展开更多
关键词 ELEMENT 知识 加工机床 连续振动 空化作用 加工方法 磨料浆液 超声波
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职工安全文化研究 预览
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作者 安红昌 《工业安全与环保》 2019年第7期54-56,共3页
为了揭示事故和伤害的深层次原因,从安全文化的定义出发,区分了安全文化的主体,认为职工安全文化是企业安全文化建设中不可或缺的部分。从大量的事故和伤害案例以及研究文献出发,提出职工安全文化的"三维八度433"模型,包括本... 为了揭示事故和伤害的深层次原因,从安全文化的定义出发,区分了安全文化的主体,认为职工安全文化是企业安全文化建设中不可或缺的部分。从大量的事故和伤害案例以及研究文献出发,提出职工安全文化的"三维八度433"模型,包括本体维(生命安全、健康安全)、社会维(生活安全、工作安全)、文化维(安全意识、安全责任、安全行为、安全形象),并对要素进行了深入解析,阐明了要素之间的相互关系,为职工安全文化建设和评估奠定了理论和实践基础。通过内蒙古锡林郭勒盟"2·23"重大事故案例分析,表明职工安全文化建设是预防事故的关键。 展开更多
关键词 职工 安全文化 模型 要素 案例分析
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基于无机元素的花椒产地溯源和品种聚类分析 预览
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作者 吴振 李红 +5 位作者 杨勇 谭红军 詹永 贾凤霞 李孝彬 王福强 《食品科学》 EI CAS CSCD 北大核心 2019年第16期213-219,共7页
采用电感耦合等离子体原子发射光谱法,对红花椒(陕西韩城、四川汉源、四川茂汶、甘肃武都)和青花椒(云南昭通、贵州关岭、四川金阳、四川汉源、重庆江津)9大主产地的80个样品中21个无机元素含量进行测定。采用主成分分析(principal comp... 采用电感耦合等离子体原子发射光谱法,对红花椒(陕西韩城、四川汉源、四川茂汶、甘肃武都)和青花椒(云南昭通、贵州关岭、四川金阳、四川汉源、重庆江津)9大主产地的80个样品中21个无机元素含量进行测定。采用主成分分析(principal component analysis,PCA)和偏最小二乘判别分析(partial least squaresdiscriminationanalysis,PLS-DA)对红花椒和青花椒中无机元素进行综合评价,PCA和PLS-DA将80个花椒聚为9组,PLS-DA分类效果更佳,并能将红花椒和青花椒有效区分,从元素组成角度揭示了红花椒和青花椒的亲缘关系和地域分布特征。研究证明多元素分析结合PLS-DA可作为一种花椒品种和产地识别的有效工具,对于产地溯源和品种鉴定具有重要意义。 展开更多
关键词 红花椒 青花椒 元素 偏最小二乘判别分析 品种 产地
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威斯金属“单元13”——世界最大的单一废罐再生系统 预览
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《轻金属》 北大核心 2019年第3期61-62,共2页
美国阿拉巴马州(AL)穆斯克尔·肖尔斯镇(Muscle Shoals)的威斯合金公司(Wise Alloys,LLC)新建的废旧罐再生系统于2012年3月3日正式投产,将这条生产线命名为“单元13”(Element 13),是全世界最大的废旧铝罐单一处理熔炼生产系统。
关键词 再生系统 世界 ELEMENT 废罐 金属 阿拉巴马州 WISE 生产系统
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红外光谱结合X射线荧光光谱分析多种塑料袋组份的研究 预览
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作者 姜红 鞠晨阳 +2 位作者 张冰钰 满吉 任继伟 《化学研究与应用》 CAS CSCD 北大核心 2019年第3期391-396,共6页
为建立一种简便快捷、准确可靠的检验塑料袋样品的分析方法,利用傅立叶红外光谱仪(FTIR)结合能量色散型X射线荧光光谱仪(XRF),对43个不同品牌、不同规格的塑料袋样品进行测定。结果表明,依据样品的有机成分和样品中所含元素的种类及含... 为建立一种简便快捷、准确可靠的检验塑料袋样品的分析方法,利用傅立叶红外光谱仪(FTIR)结合能量色散型X射线荧光光谱仪(XRF),对43个不同品牌、不同规格的塑料袋样品进行测定。结果表明,依据样品的有机成分和样品中所含元素的种类及含量的不同,可以对样品进行区分,同时,利用SPSS聚类分析Ward法作为类间距离,对塑料袋样品进行分类,效果较好。并且该方法操作简便快速、结果准确可靠、样品无需特殊的前处理,且属于无损检验,该方法可以用于公安机关实际办案。 展开更多
关键词 塑料袋 傅立叶红外光谱法 X射线荧光光谱法 元素
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Alleviation of Calcium on Toxicity of Cadmium to Rice Seedlings by Inhibiting Cadmium Accumulation and Relieving Oxidative Damage 预览
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作者 Tang Qi Zhang Shuo +2 位作者 Li Hua-xin Zhang Chang-bo Liu Zhong-qi 《东北农业大学学报:英文版》 CAS 2019年第2期33-40,共8页
Accumulation characteristics and antioxidant enzyme activities in rice seedlings from a high-cadmium(Cd)-accumulating cultivar Tyou705(705)and low-Cd-accumulating cultivar Xiangzao 24(X24)were studied,based on hydropo... Accumulation characteristics and antioxidant enzyme activities in rice seedlings from a high-cadmium(Cd)-accumulating cultivar Tyou705(705)and low-Cd-accumulating cultivar Xiangzao 24(X24)were studied,based on hydroponic experiment.Three levels of calcium(Ca)(0,1.0 and 2.0 mmol?L-1)and two levels of Cd(0 and 2.7μmol·L^-1)were designed in this study.Experimental results showed that the tolerance of rice seedlings to Cd stress was significantly improved by adding 1.0 or 2.0 mmol·L^-1 Ca.Comparing with Cd control,adding 1.0 mmol·L^-1 Ca made the seedling biomass of 705 and X24 increased by 68.9%and 116.2%,respectively.Addition of 2.0 mmol·L^-1 Ca was more effective than that of 1.0 mmol·L^-1 Ca in promoting rice biomass,root tip number,total root length,and total root surface area.After addition of 2.0 mmol·L^-1 Ca and Cd contents in roots and shoots of 705 decreased by 23.5%and 35.2%,Cd in roots and shoots of X24 decreased by 22.2%and 18.7%,respectively.Addition of Ca significantly promoted the accumulation of Mg,K and Zn in shoots and roots of X24 under Cd stress environment and eliminated the inhibitory effect of Cd on the uptake of these elements.Both 1.0 and 2.0 mmol·L^-1 Ca significantly decreased the activities of superoxide dismutase(SOD)and peroxidase(POD)in rice seedlings under Cd stress.These results indicated that 1.0-2.0 mmol·L^-1 Ca could significantly reduce Cd content in rice roots and shoots,promote the uptake and accumulation of essential elements and alleviate the oxidative damage caused by Cd stress in rice seedlings. 展开更多
关键词 rice CADMIUM CALCIUM essential element OXIDATIVE DAMAGE
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Plastic Effect on the Sliding Inception Bet ween a Cylinder and a Rigid Flat
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作者 S.Zhang J.Huan +2 位作者 H.Song X.Liu Y.G.Wei 《固体力学学报:英文版》 SCIE EI CSCD 2019年第1期1-16,共16页
The effec ts of mat erial plasticity and local slip on the sliding inception of asperity are studied in the present work.Firstly,a semi-analytical solution is derived under the full-stick condition to analyze the effe... The effec ts of mat erial plasticity and local slip on the sliding inception of asperity are studied in the present work.Firstly,a semi-analytical solution is derived under the full-stick condition to analyze the effect of material plasticity on sliding friction.Then,a friction model with contact stiffness criterion is proposed to study the cases from partial-slip condition to full-stick condition.Finite element simulations with the provided model are used to present the friction map.The friction coefficient of full-s tick interface converges at a st able value,approxima tely 0.3.Plasticity saturation appears as the normalized contact interference u*is larger than 3.A transition mechanism from slip-dominated to yield-dominated takes place in the sliding process.The simulation results are compared with the semi-analytical solution. 展开更多
关键词 Mat erial YIELDING Local SLIP Contact STIFFNESS criterion Finite element simulation
The enhanced element enrichment in the supercritical states of granite-pegmatite systems
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作者 Rainer Thomas Paul Davidson Karen Appel 《中国地球化学学报:英文版》 EI CAS CSCD 2019年第3期335-349,共15页
In this paper, we show that supercritical fluids have a greater significance in the generation of pegmatites,and for ore-forming processes related to granites than is usually assumed. We show that the supercritical me... In this paper, we show that supercritical fluids have a greater significance in the generation of pegmatites,and for ore-forming processes related to granites than is usually assumed. We show that the supercritical melt or fluid is a silicate phase in which volatiles;principally H2O are completely miscible in all proportions at magmatic temperatures and pressures. This phase evolves from felsic melts and changes into hydrothermal fluids, and its unique properties are particularly important in sequestering and concentrating low abundance elements, such as metals. In our past research, we have focused on processes observed at upper crustal levels, however extensive work by us and other researchers have demonstrated that supercritical melt/fluids should be abundant in melting zones at deep-crustal levels too. We propose that these fluids may provide a connecting link between lower and upper crustal magmas,and a highly efficient transport mechanism for usually melt incompatible elements. In this paper, we explore the unique features of this fluid which allow the partitioning of variouselements and compounds, potentially up to extreme levels,and may explain various features both of mineralization and the magmas that produced them. 展开更多
关键词 GRANITES PEGMATITES SUPERCRITICAL state Extreme ELEMENT ENRICHMENT
Finite element analysis of the effect of interlayer on interfacial stress transfer in layered graphene nanocomposites
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作者 C.C. Roach Y.C. Lu 《材料科学技术学报:英文版》 SCIE EI CAS CSCD 2019年第6期1147-1152,共6页
Understanding the roles of interlayers in reinforcement efficiencies by layered graphene is very important in order to produce strong and light graphene based nanocomposites. The present paper uses the finite element ... Understanding the roles of interlayers in reinforcement efficiencies by layered graphene is very important in order to produce strong and light graphene based nanocomposites. The present paper uses the finite element method to evaluate the interfacial strain transfers and reinforcement efficiencies in layered graphene-polymer composites. Results indicate that the presence of compliant interlayers in layered graphene plays significant roles in the transfers of strain/stress from matrix to graphene and subsequently the reinforcement effectiveness of layered graphene. In general, the magnitude of shear strain transferred onto the rigid graphene decreases as the thickness of the interlayer increases. This trend becomes insignificant as the graphene becomes sufficiently large(s>25,000). The shear strain at the interface of graphene-matrix is also greatly influenced by the interlayer modulus. A stiffer interlayer would result in a higher shear strain transferred on the graphene. The performance of the interlayers is further affected by the property of the composite and the architecture of the layered graphene stack. If a composite contains more graphene phase, the efficiency of reinforcement by a layered graphene becomes improved. If a graphene stack contains more interlayers, the effectiveness of reinforcement at the edges of the graphene becomes negatively affected. 展开更多
关键词 INTERLAYER LAYERED graphene NANOCOMPOSITES INTERFACIAL stress transfer FINITE element method
INTERIOR ESTIMATES OF SEMIDISCRETE FINITE ELEMENT METHODS FOR PARABOLIC PROBLEMS WITH DISTRIBUTIONAL DATA
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作者 Li Guo Hengguang Li Yang Yang 《计算数学:英文版》 SCIE CSCD 2019年第4期458-474,共17页
Let Ω CR^d,1≤d≤3, be a bounded d-polytope. Consider the parabolic equation on Q with the Dirac delta function on the right hand side. We study the well-posedness, regularity, and the interior error estimate of semi... Let Ω CR^d,1≤d≤3, be a bounded d-polytope. Consider the parabolic equation on Q with the Dirac delta function on the right hand side. We study the well-posedness, regularity, and the interior error estimate of semidiscrete finite element approximations of the equation. In particular, we derive that the interior error is bounded by the best local approximation error, the negative norms of the error, and the negative norms of the time derivative of the error. This result implies different convergence rates for the numerical solution in different interior regions, especially when the region is close to the singular point. Numerical test results are reported to support the theoretical prediction. 展开更多
关键词 Parabolic problems Dist ributional DATA Finite element met hods INTERIOR ESTIMATES WELL-POSEDNESS SINGULARITY
黔中喀斯特区典型土地利用类型的土壤亲合性元素特征
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作者 喻阳华 杨丹丽 钟欣平 《地球与环境》 CAS CSCD 北大核心 2019年第4期429-435,共7页
为阐明黔中喀斯特区不同土地利用类型的土壤亲合性元素特征,揭示土地利用对矿质元素的影响效应,促进农业可持续发展,本研究以玉米(Zea mays)、柚木(Tectona)、火龙果(Hylocereus undulatus)、花椒(Zanthoxylum bugeanum)、金银花(Lonice... 为阐明黔中喀斯特区不同土地利用类型的土壤亲合性元素特征,揭示土地利用对矿质元素的影响效应,促进农业可持续发展,本研究以玉米(Zea mays)、柚木(Tectona)、火龙果(Hylocereus undulatus)、花椒(Zanthoxylum bugeanum)、金银花(Lonicera japonica)、核桃(Juglans regia)6种典型土地利用类型土壤为对象,测定土壤Fe、Ca、Cu等23种矿质元素含量,探讨不同亲合性元素的变化特征,分析元素间的互作效应.结果表明:(1)黔中喀斯特区各亲合性元素在不同土地利用类型之间的变化规律存在差异,玉米地土壤亲铁、亲铜元素含量较丰富,金银花群落土壤亲铜、亲气元素含量较高,核桃林土壤利于亲气、亲石元素积累,花椒林土壤亲石元素含量较高;(2)不同元素间的关联程度不同,Mn、Ca、Al与其他元素的关系较密切.黔中石漠化区可通过补充土壤铁、硫元素,改善通气性等措施调控矿质元素含量. 展开更多
关键词 土地利用类型 土壤 元素 亲合性 黔中喀斯特区
NUMERICAL ANALYSIS OF ELLIPTIC HEMIVARIATIONAL INEQUALITIES FOR SEMIPERMEABLE MEDIA
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作者 Weimin Han Ziping Huang +1 位作者 Cheng Wang Wei Xu 《计算数学:英文版》 SCIE CSCD 2019年第4期506-523,共18页
In this paper, we consider elliptic hemivariational inequalities arising in applications in semipermeable media. In its general form, the model includes both interior and boundary semipermeability terms. Detailed stud... In this paper, we consider elliptic hemivariational inequalities arising in applications in semipermeable media. In its general form, the model includes both interior and boundary semipermeability terms. Detailed study is given on the hemivariational inequality in the case of isotropic and homogeneous semipermeable media. Solution existence and uniqueness of the problem are explored. Convergence of the Galerkin method is shown under the basic solution regularity available from the existence result. An optimal order error estimate is derived for the linear finite element solution under suitable solution regularity assumptions. The results can be readily extended to the study of more general hemivariational inequalities for non-isotropic and heterogeneous semipermeable media with interior semipermeability and/or boundary semiperrneability. Numerical examples are presented to show the performance of the finite element approximations;in particular, the theoretically predicted optimal first order convergence in H' norm of the linear element solutions is clearly observed. 展开更多
关键词 Hemivariational INEQUALITY INTERIOR semipermeability Boundary semipermeability Finite element method ERROR ESTIMATE
ICP-MS法同时测定小牛血去蛋白提取物注射液中14种元素的含量 预览
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作者 邵天舒 周长明 +1 位作者 余立 郭雷 《中国药房》 CAS 北大核心 2019年第14期1902-1908,共7页
目的:建立同时测定小牛血去蛋白提取物注射液中14种元素含量的方法。方法:采用电感耦合等离子体质谱法。射频功率为1350W,载气(氩气)流量为1.1L/min,碰撞气(氦气)流量为4.5L/min,积分时间为1.5s,等离子体气流量为18L/min,采样深度为65mm... 目的:建立同时测定小牛血去蛋白提取物注射液中14种元素含量的方法。方法:采用电感耦合等离子体质谱法。射频功率为1350W,载气(氩气)流量为1.1L/min,碰撞气(氦气)流量为4.5L/min,积分时间为1.5s,等离子体气流量为18L/min,采样深度为65mm,进样蠕动泵转速为24.0r/min,数据采样模式为跳峰模式,重复次数为3次。结果:镉、铅、砷、汞、钴、钒、镍、铊、银、钼、铜、铬、钡、铝的检测质量浓度线性范围分别为0.05~50 μg/L(r=0.999 7)、0.05~50 μg/L(r=0.999 7)、0.05~50 μg/L(r=0.999 8)、0.05~50 μg/L(r=0.999 5)、0.05~50 μg/L(r=0.999 5)、0.05~50 μg/L(r=0.999 8)、0.05~50 μg/L(r=0.999 6)、0.05~50 μg/L(r=0.999 5)、0.05~50 μg/L(r=0.999 5)、0.05~50 μg/L(r=0.999 8)、0.05~50 μg/L(r=0.999 6)、0.05~50 μg/L(r=0.999 6)、0.05~50 μg/L(r=0.999 7)、0.5~70 μg/L(r=0.999 8);定量限分别为0.003 1、0.008 9、0.016 0、0.025 0、0.002 1、0.006 9、0.038 1、0.002 1、0.005 5、0.002 0、0.023 1、0.005 0、0.002 0、0.324 9 μg/L;检测限分别为0.000 9、0.002 7、0.004 8、0.007 5、0.000 6、0.002 1、0.011 4、0.0006、0.0165、0.0006、0.0069、0.0015、0.0006、0.0975μg/L;精密度、稳定性、重复性试验的RSD均小于8%;加样回收率分别为87.4%~94.3%(RSD=2.6%,n=9)、110.3%~118.2%(RSD=1.8%,n=9)、89.8%~99.7%(RSD=3.1%,n=9)、77.7%~84.4%(RSD=2.5%,n=9)、105.6%~113.4%(RSD=2.3%,n=9)、106.7%~116.5%(RSD=2.7%,n=9)、89.1%~104.5%(RSD=4.5%,n=9)、105.6%~118.6%(RSD=3.6%,n=9)、77.8%~88.0%(RSD=4.0%,n=9)、106.7%~116.1%(RSD=2.8%,n=9)、88.5%~97.1%(RSD=3.1%,n=9)、80.5%~88.6%(RSD=2.9%,n=9)、85.2%~99.4%(RSD=4.2%,n=9)、97.6%~109.3%(RSD=3.2%,n=9)。结论:该方法操作简便、准确,精密度、稳定性、重复性均较好,可用于同时测定小牛血去蛋白提取物注射液中14种元素的含量。 展开更多
关键词 小牛血去蛋白提取物注射液 元素 电感耦合等离子体质谱法 含量测定
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世界主要产地碧玉的地球化学特征、成矿来源及成矿过程 预览
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作者 于海燕 杨晓文 《桂林理工大学学报》 CAS 北大核心 2019年第2期311-320,共10页
对世界不同产地的碧玉(14块样品)的主量元素、微量元素及稀土元素进行了测试,研究分析了碧玉的地球化学特征、成矿来源及成矿过程。结果显示,不同产地的碧玉主要矿物为透闪石阳起石,过渡性金属元素Ti、 V、 Mn、 Cr、 Ni含量较高,其平... 对世界不同产地的碧玉(14块样品)的主量元素、微量元素及稀土元素进行了测试,研究分析了碧玉的地球化学特征、成矿来源及成矿过程。结果显示,不同产地的碧玉主要矿物为透闪石阳起石,过渡性金属元素Ti、 V、 Mn、 Cr、 Ni含量较高,其平均值分别为415.85×10 -6 、 284.30×10 -6 、 1 495.26×10 -6 、 665.68×10 -6 、 388.81×10 -6;微量元素蛛网图基本相似,表现为大离子亲石元素略微富集,高场强元素轻微亏损;稀土元素均为右倾的轻稀土富集的分配模式,(La/Yb) N为4.57~20.26 ,δEu为0.65~1.22,δCe为1.04~1.59。碧玉样品的稀土元素分配模式、微量元素蛛网图、过渡性金属元素分配模式与辉长岩相似,说明了相似的起源。碧玉成矿分为3个成矿阶段:超镁铁岩蚀变—辉长岩蚀变—蛇纹石蚀变。碧玉样品晶体化学性质及特征元素分析结果表明:成矿温度越低,氧逸度越低,碧玉质地越细腻。 展开更多
关键词 碧玉 元素 成矿来源 成矿过程
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