|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Phase stability in high entropy alloys:Formation of solid-solution phase or amorphous phase | Sheng GUO C.T. LIU | 2011 | Progress in Natural Science:Materials International2011，21，6： | 91 |
| 2 | 固溶温度对激光立体成形GH4169高温合金组织和性能的影响(英文)显示文摘研究激光立体成形GH4169高温合金固溶处理后的组织,分析了固溶过程中合金元素的均匀化,并对材料显微硬度的变化做了讨论。结果表明,随固溶温度的升高,材料的晶界越来越清晰,经1000-1170°C固溶处理1h后材料发生再结晶,当固溶处理温度高于1100°C,有大量孪晶出现,晶粒相比沉积态显著细化,晶粒尺寸约200μm。合金元素的均匀化在1100°C保温1h后基本完成。显微硬度测试结果显示,材料的显微硬度值随固溶温度的升高而降低,在固溶温度低于1100°C时减小趋势较快,高于1100°C时减小趋势减缓。显微硬度的变化与材料中γ′和γ'相及δ相的形态和数量有关。1100°C是激光立体成形GH4169合金比较合适的固溶处理温度下限。 | 刘奋成 林鑫 赵卫卫 赵晓明 陈静 黄卫东 | 2010 | 稀有金属材料与工程2010，39，9： | 29 |
| 3 | AN ANALYTICAL SOLUTION TO LONGITUDINAL VIBRATION OF A PILE OF ARBITRARY SEGMENTS WITH VARIABLE MODULUS显示文摘The vibration problem of a pile of arbitrary segments with variable modulus under exciting force is established, in which the influence of the soil under pile toe and the surroundings is taken into account. With Laplace transforms, the transmit functions for velocity and displacement of pile are derived. Furthermore, in terms of the convolution theorem and inversed Laplace transform, an analytical solution for the time domain response of a pile subjected to a semi-sine impulse is developed,which is the theoretical basis of the sonic method in pile integrity testing. Based on the solution, the vibration properties of pile with sharp or continuous modulus are studied. The validity of this approach is verified through fidd dynamic tests on some engineering piles. It shows that the theoretical prediction and the response of the pile are in good agreement. | Wang Teng Wang Kuihua Xie Kanghe | 2001 | Acta Mechanica Solida Sinica2001，14，1： | 27 |
| 4 | 叶面喷施稀土对千年桐幼苗生长和生理的影响显示文摘The seedlings of Vernicia montana derived from seeds soaking with water (the first group)or 300 mg5L -1 mixed nitric_acid rare earth solution (the second group) were treated with various concentrations of mixed nitric_acid rare earth solution by foliage spraying. The results showed that the seedling heights sprayed with 100 和 1 000 mg·L -1 of the first group and with 50 和 100 mg·L -1 of the second group were significantly higher than the controls, and the diameter at ground level sprayed with 300 mg·L -1 of the second group was significantly greater than the control, being 26.92% more than the latter; except for spraying with 0 mg5L -1 and 700~1 500 mg5L -1 of the second group, the seedling dry weight above ground of others was 29.13%~73.91% greater than the control, whereas the seedling dry weight under ground of others was 20.78%~116.88% greater than the control; the contents of chlorophyll a and chlorophyll b for all spraying seedling were 91.67%~191.67% and 87.5%~306.25% greater than the control, respectively, and soluble proteins and soluble sugars were 16.00%~179.78% and 10.73%~105.65% greater than the control, respectively. Compared with the control, the activity of SOD tended to increase, whereas the contents of MDA decreased. These indicated that spraying leaves with optimum concentration of mixed nitric_acid rare earth solution could markedly promote the growth of seedlings and improve resistance ability of V. montana seedlings to bad environment. On the whole, the effects of spraying the leaves of seedling with 50~500 mg5L -1 mixed nitric_acid rare earth solution, which were derived from seeds soaking with 300 mg·L -1 mixed nitric_acid rare earth solution, were good. | 韦如萍 薛立 陈红跃 彭耀强 许松葵 | 2005 | 林业科学2005，41，2： | 28 |
| 5 | Barometric altimetry system as virtual constellation applied in CAPS显示文摘This work describes the barometric altimetry as virtual constellation applied to the Chinese Area Positioning System (CAPS), which uses the transponders of communication satellites to transfer navigation messages to users. Barometric altimetry depends on the relationship of air pressure varying with altitude in the Earth’s atmosphere. Once the air pressure at a location is measured the site altitude can be found. This method is able to enhance and improve the availability of three-dimensional positioning. The difficulty is that the relation between barometric pressure and altitude is variable in different areas and under various weather conditions. Hence, in order to obtain higher accuracy, we need to acquire the real-time air pressure corresponding to an altimetric region’s reference height. On the other hand, the altimetry method will be applied to satellite navigation system, but the greatest difficulty lies in how to get the real-time air pressure value at the reference height in the broad areas overlaid by satellite navigation. We propose an innovational method to solve this problem. It is to collect the real-time air pressures and temperatures of the 1860 known-altitude weather observatories over China and around via satellite communication and to carry out time extrapolation forecast uniformly. To reduce data quantity, we first partition the data and encode them and then broadcast these information via navigation message to CAPS users’ receivers. Upon the interpolations being done in receivers, the reference air pressure and temperature at the receiver’s nearby place is derived. Lastly, combing with the receiver-observed real air pressure and temperature, the site’s altitude can be determined. The work is presented in the following aspects: the calculation principle, formulae, data collection, encoding, prediction, interpolation method, navigation message transmission together with errors causes and analyses. The advantages and shortcomings of the technique are discussed at the end. | AI GuoXiang SHENG PeiXuan DU JinLin ZHENG YongGuang CAI XianDe WU HaiTao HU YongHui HUA Yu LI XiaoHui | 2009 | Science China(Physics,Mechanics & Astronomy)2009，52，3： | 22 |
| 6 | NEW METHOD OF SIMULATING CONCENTRATED DRAIN HOLES IN SEEPAGE CONTROL ANALYSIS显示文摘In this paper, based upon the basic solution of sink, the approximate solution of single drain hole in finite elements is derived by use of the superposition principle. Then, the theoretical solution is extended to the case of some drain holes in one finite element, and the method is used in seepage control analysis with quick convergence and high accuracy. On the other hand, if the positions of the drain holes are changed, only some control factors of drain holes are changed, but the finite element grid need not to be reformed. Therefore, the method is more suitable in optimal research of seepage control. | Zhan Mei li, Su Bao yu , Liu Jun yong, Shen Zhen zhong College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, P.R.China (Received Aug.1, 1998) | 1999 | Journal of Hydrodynamics1999，11，3： | 22 |
| 7 | EXISTENCE AND UNIQUENESS OF SMOOTH SOLUTION FOR SYSTEM OF FERROMAGNETIC CHAIN显示文摘In this paper, we are going to consider the initial value problem with periodic boundarycondition and the Cauchy problem associated with the system of ferromagnetic chain withthe Gilbert damping term Zt=-εZ×(Z×Zzz+Z×Zzz, (ε≥0).The existence of a unique smooth solution is established by using the technique of spatialdifference and crucial a priori estimates of higher-order derivatives in Sobolev spaces. | 周毓麟 郭柏灵 谭绍滨 | 1991 | Science China Mathematics1991，34，3： | 21 |
| 8 | 食道的有鳞的房间癌 - 先锋损害和早诊断显示文摘 Squamous cell carcinoma of the esophagus (SCCE) carries a poor prognosis due to late diagnosis.Early detection is highly desirable,since surgical and endoscopic resection offers the only possible cure for esophageal cancer.Population screening should be undertaken in high risk areas,and in low or moderate risk areas for people with risk factors (alcoholics,smokers,mate drinkers,history of head and neck cancer,achalasia and lye stricture of the esophagus).Esophageal balloon cytology is an easy and inexpensive sampling technique,but the current methods are insufficient for primary screening due to sampling errors.Conventional endoscopy with biopsy remains the standard procedure for the identification of pre-malignant and early malignant changes in esophageal mucosa and endoscopic detection.It may be enhanced by several techniques such as dye and optic chromoendoscopy,magnifying endoscopy,and optical-based spectroscopic and imaging modalities.Since more than 80% of SCCE deaths occur in developing countries,where expensive techniques such as narrow band imaging (NBI) and autofluorescence imaging are unavailable,the most cost-effective tool for targeting biopsies may be Lugol dye chromoendoscopy,since it is easy,accurate,inexpensive and available worldwide.In ideal conditions,or in developed countries,is it reasonable to think that optimal detection will require a combination of techniques,such as the combination of Lugol’s chromoendoscopy and NBI to identify esophageal areas that require further characterization by a high resolution technique.The efficacy and cost-effectiveness will determine whether these modalities will become part of standard endoscopy practice. | Antonio Barros Lopes Renato Borges Fagundes | 2012 | World Journal of Gastrointestinal Endoscopy2012，4，1： | 20 |
| 9 | A CLASS OF SINGULARLY PERTURBED GENERALIZED BOUNDARY VALUE PROBLEMS FOR QUASI-LINEAR ELLIPTIC EQUATION OF HIGHER ORDER显示文摘The singularly perturbed generalized boundary value problems for the quasi_linear elliptic equation of higher order are considered. Under suitable conditions,the existence, uniqueness and asymptotic behavior of the generalized solution for the Dirichlet problems are studied. | MO Jia-qi(莫嘉琪) OUYANG Cheng(欧阳成) | 2001 | Applied Mathematics and Mechanics(English Edition)2001，22，3： | 19 |
| 10 | Bowel cleansing before colonoscopy:Balancing efficacy,safety,cost and patient tolerance显示文摘Effective colorectal cancer screening relies on reliable colonoscopy findings which are themselves dependent on adequate bowel cleansing. Research has consistently demonstrated that inadequate bowel preparation adversely affects the adenoma detection rate and leads gastroenterologists to recommend earlier follow up than is consistent with published guidelines. Poor preparation affects as many as 30% of colonoscopies and contributes to an increased cost of colonoscopies. Patient tolerability is strongly affected by the preparation chosen and manner in which it is administered. Poor tolerability is,in turn,associated with lower quality bowel preparations. Recently,several new developments in both agents being used for bowel preparation and in the timing of administration have brought endoscopists closer to achieving the goal of effective,reliable,safe,and tolerable regimens. Historically,large volume preparations given in a single dose were administered to patients in order to achieve adequate bowel cleansing. These were poorly tolerated,and the unpleasant taste of and significant side effects produced by these large volume regimens contributed significantly to patients' inability to reliably complete the preparation and to a reluctance to repeat the procedure. Smaller volumes,including preparations that are administered as tablets to be consumed with water,given as split doses have significantly improved both the patient experience and efficacy,and an appreciation of the importance of the preparation to colonoscopy interval have produced additional cleansing. | Nicole M Harrison Michael C Hjelkrem | 2016 | World Journal of Gastrointestinal Endoscopy2016，8，1： | 19 |
| 11 | EXISTENCE AND GLOBAL ATTRACTIVITY OF POSITIVE PERIODIC SOLUTION OF A LOGISTIC GROWTH SYSTEM WITH FEEDBACK CONTROL AND DEVIATING ARGUMENTS显示文摘In this paper, we study the existence and global attractivity of positive peri- odic solutions of a Logistic growth system with feedback control and deviating arguments. A sufficient condition is derived for the existence of a unique peri- odic solution with strictly positive components which is globally asymptotically stable by using the method of coincidence degree and Liapunov functional. Some new results are obtained. The known results are improved and generalized. | 杨帆 蒋达清 | 2001 | Annals of Differential Equations2001，17，4： | 17 |
| 12 | Exponential stability and periodic solutions of delayed cellular neural networks显示文摘A set of criteria are presented for the global exponential stability and the existence of periodic solutions of delayed cellular neural networks (DCNNs) by constructing suitable Lyapunov function-als, introducing many parameters qij* , rij* , qij, rij∈ R and wi>0 (i, j = 1, 2, …, n) and combining them with the elementary inequality 2ab≤a2 + b2 technique. These criteria have important significance in the design and applications of globally stable DCNNs and periodic oscillatory DCNNs. In addition, the results in literature are extended and improved. Two examples are given to illustrate the theory. | 曹进德 | 2000 | Science China(Technological Sciences)2000，43，3： | 17 |
| 13 | Data envelopment analysis显示文摘This review introduces the history and present status of data envelopment analysis (DEA) research, particularly the evaluation process. And extensions of some DEA models are also described. It is pointed out thatmathematics, economics and management science are themain forces in the DEA development, optimization provides the fundamental method for the DEA research, and the wide range of applications enforces the rapid development ofDEA. | WEI Quanling Institute of Operations Research and Mathematical Economics, Renmin University of China, Beijing 100872, China | 2001 | Chinese Science Bulletin2001，46，16： | 16 |
| 14 | 烧结温度对Ti/IrO_2-Ta_2O_5纳米氧化物阳极微观结构和电催化性能的影响(英文)显示文摘采用Pechini法制备Ti/IrO2-Ta2O5纳米氧化物阳极,通过SEM、EDX、XRD、极化曲线、循环伏安、电化学阻抗谱及强化电解寿命试验等测试手段,研究了烧结温度对Ti/IrO2-Ta2O5阳极微观结构和电催化性能的影响。结果表明,阳极涂层成分分布均匀,IrO2晶粒偏析不明显;Ta在铱钽固溶体中的固溶度随烧结温度升高而增大,涂层晶粒逐渐细化。随着烧结温度的升高,阳极析氧电催化活性降低,电化学活性表面积减小;500℃下所得Ti/IrO2-Ta2O5阳极表现出最高的强化电解寿命。 | 辛永磊 许立坤 王均涛 李相波 | 2010 | 稀有金属材料与工程2010，39，11： | 16 |
| 15 | POSITIVE SOLUTIONS OF FOURTH-ORDER TWO-POINT BOUNDARY VALUE PROBLEMS显示文摘We study the existence of positive solutions of the equation f(x, y(x),y'(x)) =0 with either y(0)= y(1) =y'(0) = y'(1) =0 or y(0) = y’(1)=y'(0) = y'(1) = 0. We show the existence of at least one positive solution if f is either superlinear of sublinear by a simple application of a fixed point theorem In cones. | 马如云 | 1999 | Annals of Differential Equations1999，15，3： | 16 |
| 16 | Determining the Optimal Solution Set for Linear Fractional Programming显示文摘The structure of the optimal solution set is derived for linear fractional programming with the representation theorem of polyhedral sets. Based on an adaptation of the convex simplex method credited to Gilmore and Gomory, we give the uniqueness condition of optimal solution and the computational procedures to find all optimal solutions if the uniqueness condition is not satisfied. Finally, an illustrative example is also given. | Xue Shengjia Management College, Jinan University,Guangzhou 510632, P.R. China | 2002 | Journal of Systems Engineering and Electronics2002，13，3： | 15 |
| 17 | An analytical solution to contaminant transport through composite liners with geomembrane defects显示文摘To investigate the performance of landfill composite liner system,a one-dimensional model was developed for solute transport through composite liners containing geomembrane defects.An analytical solution to the model was obtained by the method of Laplace transformation.The results obtained by the presented solution agree well with those obtained by the numerical method.Results show that leachate head and construction quality of geomembrane(GM) have significant influences on the performance of the composite liners for heavy metal ions.The breakthrough time of lead decreases from 50 a to 19 a when the leachate head increases from 0.3 m to 10 m.It is also indicated that the contaminant mass flux of volatile organic compounds(VOCs) induced by leakage can not be neglected in case of poor construction quality of the landfill barrier system.It is shown that diffusion coefficient and partition coefficient of GM have great influences on solute transport through composite liners for VOCs.The breakthrough time of heavy metal ions will be greatly overestimated if the effects of diffusion and adsorption of clay and geosynthetic clay liner(GCL) are neglected.The composite liner consisting of a geomembrane and a GCL provides a poor barrier for VOCs.The presented analytical solution is relatively simple to apply and can be used for preliminary design of composite liners,evaluating experimental results,and verifying more complex numerical models. | XIE HaiJian1,2,CHEN YunMin1 & LOU ZhangHua1,2 1MOE Key Laboratory of Soft Soils and Geoenvironmental Engineering,Zhejiang University,Hangzhou 310058,China 2Institute of Hydrology and Water Resources Engineering,Zhejiang University,Hangzhou 310058,China | 2010 | Science China(Technological Sciences)2010，53，5： | 15 |
| 18 | Invariant sets and solutions to the generalized thin film equation显示文摘The invariant sets and the solutions of the 1+2-dimensional generalized thin film equation are discussed. It is shown that there exists a class of solutions to the equations, which are invariant with respect to the set E0 = {u : ux = vxF(u), uy = vyF(u)}, where v is a smooth function of variables x, y and F is a smooth function of u. This extends the results of Galaktionov (2001) and for the l+l-dimensional nonlinear evolution equations. | Chang-zheng QU & Chun-rong ZHU Center for Nonlinear Studies, Northwest University, Xi’an 710069, China Department of Mathematics, Northwest University, Xi’an 710069, China Department of Mathematics, Anhui Normal University, Wuhu 241000, China | 2007 | Science China Mathematics2007，50，6： | 15 |
| 19 | Existence and global attractivity of a positive periodic solution of a class of delay differential equation显示文摘The existence and the global attractivity of a positive periodic solution of the delay differential equation y·(t)=y(t)F[t, y(t-τ 1(t)),...,y(t-τ n(t))] are studied by using some techniques of the Mawhin coincidence degree theory and the constructing suitable Liapunov functionals. When these results are applied to some special delay bio-mathematics models, some new results are obtained, and many known results are improved. | 李永昆 | 1998 | Science China Mathematics1998，41，3： | 15 |
| 20 | 国外隧道施工测量技术的现状和发展显示文摘在隧道施工中,将提高工效的宗旨贯穿于从初始开挖到最后的竣工验收,是每个施工企业所追求的目标,隧道工程的成功与否与隧道断面开挖的准确程度有着极大的关系。通过介绍瑞士尤特利(Uetliberg)隧道在施工测量中应用TMS Solution隧道测量系统的详细内容和方法,对国内的建设和监理单位对隧道综合测量技术的认识和了解有一定意义。 | 肖书安 | 2007 | 隧道建设2007，27，1： | 14 |
您所在的机构暂未开通此部分的功能，请联系管理员