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| 1 | Prediction of permafrost distribution on the Qinghai-Tibet Plateau in the next 50 and 100 years显示文摘Intergovernmental Panel on Climate Change (IPCC) in 2001 reported that the Earth air temperature would rise by 1.4-5.8℃ and 2.5℃ on average by the year 2100. China re-gional climate model results also showed that the air temperature on the Qinghai-Tibet Plateau (QTP) would increase by 2.2-2.6℃ in the next 50 years. A numerical permafrost model was developed to predict the changes of permafrost distribution on the QTP over the next 50 and 100 years under the two climatic warming scenarios, i.e. 0.02℃/a, the lower value of IPCC’s estima-tion, and 0.052℃/a, the higher value predicted by Qin et al. Simulation results show that ( i ) in the case of 0.02℃/a air-temperature rise, permafrost area on the QTP will shrink about 8.8% in the next 50 years, and high temperature permafrost with mean annual ground temperature (MAGT) higher than ?0.11℃ may turn into seasonal frozen soils. In the next 100 years, perma-frost with MAGT higher than ?0.5℃ will disappear and the permafrost area will shrink up to 13.4%. (ii) In the case of 0.052℃/a air-temperature rise, permafrost area on the QTP will reduce about 13.5% after 50 years. More remarkable degradation will take place after 100 years, and permafrost area will reduce about 46%. Permafrost with MAGT higher than ?2℃ will turn into seasonal frozen soils and even unfrozen soils. | NAN Zhuotong LI Shuxun CHENG Guodong | 2005 | Science China Earth Sciences2005，48，6： | 40 |
| 2 | B-Theory of Runge-Kutta methods for stiff Volterra functional differential equations显示文摘B-stability and B-convergence theories of Runge-Kutta methods for nonlinear stiff Volterra func-tional differential equations (VFDEs) are established which provide unified theoretical foundation for the studyof Runge-Kutta methods when applied to nonlinear stiff initial value problems (IVPs) in ordinary differentialequations (ODEs), delay differential equations (DDEs), integro-differential equations (IDEs) and VFDEs ofother type which appear in practice. | 李寿佛 | 2003 | Science China Mathematics2003，46，5： | 18 |
| 3 | Estimation methods of eco-environmental water requirements: Case study显示文摘Supplying water to the ecological environment with certain quantity and quality is significant for the protection of diversity and the realization of sustainable development. The conception and connotation of eco-environmental water requirements, including the definition of the conception, the composition and characteristics of eco-environmental water requirements, are evaluated in this paper. The classification and estimation methods of eco-environmental water requirements are then proposed. On the basis of the study on the Huang-Huai-Hai Area, the present water use, the minimum and suitable water requirement are estimated and the cor-responding water shortage is also calculated. According to the interrelated programs, the eco-environmental water requirements in the coming years (2010, 2030, 2050) are estimated. The result indicates that the minimum and suitable eco-environmental water requirements fluc-tuate with the differences of function setting and the referential standard of water resources, and so as the water shortage. Moreover, the study indicates that the minimum eco-environmental water requirement of the study area ranges from 2.84×1010m3 to 1.02×1011m3, the suitable water requirement ranges from 6.45×1010m3 to 1.78×1011m3, the water shortage ranges from 9.1×109m3 to 2.16×1010m3 under the minimum water requirement, and it is from 3.07×1010m3 to 7.53×1010m3 under the suitable water requirement. According to the different values of the water shortage, the water priority can be allocated. The ranges of the eco-environmental water re-quirements in the three coming years (2010, 2030, 2050) are 4.49×1010m3?1.73×1011m3, 5.99×10m3?2.09×1011m3, and 7.44×1010m3?2.52×1011m3, respectively. | YANG Zhifeng1,2, CUI Baoshan1 & LIU Jingling 1. School of Environment, Beijing Normal University, Beijing 100875, China 2. State Key Joint Laboratory of Environmental Simulation and Pollution Control, Beijing 100875, China | 2005 | Science China Earth Sciences2005，48，8： | 7 |
| 4 | A comparative study of spatial interpolation methods fordetermining fishery resources density in the Yellow Sea显示文摘Spatial interpolation is a common tool used in the study of fishery ecology, especially for the construction of ecosystem models. To develop an appropriate interpolation method of determining fishery resources density in the Yellow Sea, we tested four frequently used methods, including inverse distance weighted interpolation(IDW), global polynomial interpolation(GPI), local polynomial interpolation(LPI) and ordinary kriging(OK).A cross-validation diagnostic was used to analyze the efficacy of interpolation, and a visual examination was conducted to evaluate the spatial performance of the different methods. The results showed that the original data were not normally distributed. A log transformation was then used to make the data fit a normal distribution. During four survey periods, an exponential model was shown to be the best semivariogram model in August and October 2014, while data from January and May 2015 exhibited the pure nugget effect.Using a paired-samples t test, no significant differences(P>0.05) between predicted and observed data were found in all four of the interpolation methods during the four survey periods. Results of the cross-validation diagnostic demonstrated that OK performed the best in August 2014, while IDW performed better during the other three survey periods. The GPI and LPI methods had relatively poor interpolation results compared to IDW and OK. With respect to the spatial distribution, OK was balanced and was not as disconnected as IDW nor as overly smooth as GPI and LPI, although OK still produced a few 'bull's-eye' patterns in some areas.However, the degree of autocorrelation sometimes limits the application of OK. Thus, OK is highly recommended if data are spatially autocorrelated. With respect to feasibility and accuracy, we recommend IDW to be used as a routine interpolation method. IDW is more accurate than GPI and LPI and has a combination of desirable properties, such as easy accessibility and rapid processing. | CHEN Yunlong SHAN Xiujuan JIN Xianshi YANG Tao DAI Fangqun YANG Dingtian | 2016 | Acta Oceanologica Sinica2016，35，12： | 7 |
| 5 | Efficient parallel multivalue hybrid methods for stiff differential equations显示文摘A class of efficient parallel multivalue hybrid methods for stiff differential equations are presented,which are all extremely stable at infinity, A-stable for orders 1-3 and A(α)-stable for orders 4-8. Eachmethod of the class can be performed parallelly using two processors with each processor having almost thesame computational amount per integration step as a backward differentiation formula (BDF) of the same orderwith the same stepsize performed in serial, whereas the former has not only much better stability propertiesbut also a computational accuracy higher than the corresponding BDF. Theoretical analysis and numericalexperiments show that the methods constructed in this paper are superior in many respects not only to BDFsbut also to some other commonly used methods. | 李寿佛 | 2002 | Science China Mathematics2002，45，10： | 6 |
| 6 | FAST SOLUTION FOR LARGE SCALE LINEAR ALGEBRAIC EQUATIONS IN FINITE ELEMENT ANALYSIS显示文摘The computational efficiency of numerical solution of linear algebraic equations in finite elements can be improved in tow wqys. One is to decrease the fill-in numbers, which are new non-ze-ro numbers in the matrix of global stiffness generated during the process of elimination.The other is to reduce the computational operation of multiplying a real number by zero.Based on the fact that the order of elimination can determine how many fill-in numbers should be generated, we present a new method for optimization of numbering nodes. This method is quite different from bandwidth optimization. Fill-in numbers can be decreased in a large scale by the use of this method. The bi-factorization method is adoted to avoid multiplying real numbers by zero.For large scale finite element analysis, the method presented in this paper is more efficient than the traditional LDLT method. | Qi Zhaohui Liu Yuqi Hu Ping | 2001 | Acta Mechanica Solida Sinica2001，14，1： | 3 |
| 7 | Extraction and physicochemical characteristics of a red pigment produced by marine bacterium strain S - 9801显示文摘-- A red pigment that has better biological properties is produced by marine bacterium strain S- 9801. The extraction methods, physicochemical and toxicity of the pigment have been studied.Dissolubility of pigment in the five organic solvent has been tested, and ethanol is optimally chosen for extraction. Physicochemical characteristics of this pigment was stable. The absorbance of the pigment solution was no losing when put under natural light for 10 days or treated by UV for 30 minutes, color of the pigment unchanged after 100 ℃ hythere for 1 h or 80 ℃ xerother for 2 h. The median lethal dose (LD50) of the rat by celiac injection was 670.04 mg/kg and minimum lethal dose of oral was greater than 2 000 mg/kg. | Tian Li He Peiqing Liu Chenlin Bian Ji Miao Jinlai | 2002 | Acta Oceanologica Sinica2002，21，3： | 2 |
| 8 | ON THE BREAKDOWNS OF THE GALERKIN AND LEAST-SQUARES METHODS显示文摘The Galerkin and least-squares methods are two classes of the most popular Krylov subspace methOds for solving large linear systems of equations. Unfortunately, both the methods may suffer from serious breakdowns of the same type: In a breakdown situation the Galerkin method is unable to calculate an approximate solution, while the least-squares method, although does not really break down, is unsucessful in reducing the norm of its residual. In this paper we first establish a unified theorem which gives a relationship between breakdowns in the two methods. We further illustrate theoretically and experimentally that if the coefficient matrix of a lienar system is of high defectiveness with the associated eigenvalues less than 1, then the restarted Galerkin and least-squares methods will be in great risks of complete breakdowns. It appears that our findings may help to understand phenomena observed practically and to derive treatments for breakdowns of this type. | Zhong Baojiang(钟宝江) | 2002 | Numerical Mathematics A Journal of Chinese Universities(English Series)2002，11，2： | 2 |
| 9 | Monotone projected gradient methods for large-scale box-constrained quadratic programming显示文摘Inspired by the success of the projected Barzilai-Borwein (PBB) method for largescale box-constrained quadratic programming, we propose and analyze the monotone projected gradient methods in this paper. We show by experiments and analyses that for the new methods,it is generally a bad option to compute steplengths based on the negative gradients. Thus in our algorithms, some continuous or discontinuous projected gradients are used instead to compute the steplengths. Numerical experiments on a wide variety of test problems are presented, indicating that the new methods usually outperform the PBB method. | ZHOU Bin, GAO Li & DAI Yuhong School of Mathematical Sciences and LMAM, Peking University, Beijing 100871, China State Key Laboratory of Scientific and Engineering Computing, Institute of Computational Mathematics and Scientific/Engineering Computing, Academy of Mathematics and Systems Science, Chinese Academy of Sciences, Beijing 100080, China | 2006 | Science China Mathematics2006，49，5： | 2 |
| 10 | Maximum Likelihood Estimation of the Identification Parameters and Its Correction显示文摘By taking the subsequence out of the input-output sequence of a system polluted by white noise, anindependent observation sequence and its probability density are obtained and then a maximum likelihood estimation of theidentification parameters is given. In order to decrease the asymptotic error, a corrector of maximum likelihood (CML)estimation with its recursive algorithm is given. It has been proved that the corrector has smaller asymptotic error thanthe least square methods. A simulation example shows that the corrector of maximum likelihood estimation is of higherapproximating precision to the true parameters than the least square methods. | An Kai, Ma Jiaguang & Fu Chengyu Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu 610041, P. R. China | 2002 | Journal of Systems Engineering and Electronics2002，13，4： | 2 |
| 11 | ON A LINEAR EQUATIONS METHOD OF NONLINEAR POLYNOMIAL EQUATIONS-SOLVING显示文摘A method for solving nonlinear polynomial equations is given which avoids theappearance of redundant factors as in the previous characteristic set method developed bythe present author. The new method seems thus to be of much higher efficiency than theprevious one. It has the further advantage that numerical data may be inserted at willeither at the outset or during the procedure so far removal of factors by divisions may beavoided. | WU Wenjun Wu Wen-tsun Institute of Systems Science, Academia Sinica, Beijing 100080, China | 1993 | Systems Science and Mathematical Sciences1993，6，1： | 2 |
| 12 | Present state,basic theories,methods and progresses of investigation and assessment on marine hazardous geology in China显示文摘The achievement progresses of investigation and studies on marine hazardous geology are summarized and presentsd in the late 20 century in China.The importance,research value and present-day studies of marine hazardous geology,a newly developing branch of geoscience, are well expatiated. Several often confused concepts and theories are explained and redefined here. The comment on the means of investigations,assessment of marine hazardous geology,as well as its evolution,innovation,existing questions and future tasks are also introduced and presented.The concepts of 'hazard geology','geohazard','map of marine hazard geology','integrated evaluaton on seafloor stablity'are respectively discussed,including their definition,research objects,methods and contents. The types and classification of marine hazardous geology,principles and methods of marine hazardous geology map compilation,the assessment methods and models of marine hazardous geology environment and seafloor stability and so on are also discussed. | Li Peiying1, Li Ping1, Liu Lejun1, Du Jun1, Zhang Xiaolong1, Wang Shengji2 1. First Institute of Oceanography,State Oceanic Administration,Qingdao 266061,China 2. Institute of Marine Geology,Ministry of Land and Natural Resources,Qingdao 266071,China | 2003 | Acta Oceanologica Sinica2003，22，4： | 1 |
| 13 | Convergence of one-leg methods for singular perturbation problems with delays显示文摘This paper is concerned with the error behaviour of one-leg methods applied to some classes of one-parameter multiple stiff singularly perturbed problems with delays. We obtain convergence results of A-stable one-leg methods with linear interpolation procedure. Numerical experiments further confirm our theoretical analysis. | 甘四清 孙耿 | 2002 | Science China Mathematics2002，45，3： | 1 |
| 14 | Convergence analysis for general linear methods applied to stiff delay differential equations显示文摘For Runge-Kutta methods applied to stiff delay differential equations (DDEs), the concept of D-convergence was proposed, which is an extension to that of B-convergence in ordinary differential equations (ODEs). In this paper, D-convergence of general linear methods is discussed and the previous related results are improved. Some order results to determine D-convergence of the methods are obtained. | ZHANG Chengjian(Department of Mathematics, Huazhong University of Science and Technology, Wuhan 430074, China) | 2002 | Progress in Natural Science:Materials International2002，12，6： | 1 |
| 15 | Effect of Planting Date, Spacing and Seeding Methods on Disease Development and Yield Components of Rice (Oryza sativa L.) in Southeastern Nigeria显示文摘To investigate the effect of planting date, spacing and seeding methods on disease development and yield components ofrice, a factorial experiment in randomized complete block design (RCBD) with four replications was conducted during 2011 plantingseason at Izzi Local Government Area (LGA) of Ebonyi State, Nigeria. This experiment was carried out with four levels of plantingdates (early June, late June, early July and late July), three levels of spacing (15, 20 and 25 cm) and two levels of seeding method(direct seeding and seedling transplanting). The studied traits included plant height (PH), number of tillers (NT), leaf area (LA), rootlength (RL), panicle length (PL), 1,000 seed weight (SW), disease incidence and severity. The result showed that all the factors hadsignificant effect on the parameters measured. Sowing in early July had the highest LA of 65.38 cm^2, PH of 122.00 cm, RL of 29.04cm and TN of 10.54, and the second largest PL of 25.08 cm and SW of 25.12 g. Also sowing in early July had the highest diseaseseverity of 3.21, followed by 3.14 which occurred in late July, while the least 2.17 occurred in early June. The direct seeding methodhad the highest disease incidence of 70.83%, followed by plant spacing of 15 cm × 15 cm which had the disease incidence of 69.72%,while sowing in early June had the least disease incidence of 57.50%. In conclusion, planting of rice in Southeastern Nigeria shouldbe done in early July, as the yield components were significantly better than in other dates though with the highest disease severity. | Christian Chukwunenye Iwuagwu Charles Ikechukwu Umechuruba Andrew Chukwuma Nwogbaga | 2017 | Journal of Agricultural Science and Technology(B)2017，7，2： | 1 |
| 16 | Confirming Ground Geophysical Survey for Mineralization in Al Bayda Area,Yemen显示文摘The Jabal Mabal-prospect of Al Bayda area is covered by meta-volcano sedimentary rocks. The importance of the study area comes from previous studies, which proved that the area has mineralization zones at the periphery of Jabal Al-Mabal. These mineralized zones lie along northwest-southeast shear zones, which occur inside the meta-volcanic rocks. The previous studies concluded that the mineralization was mostly associated with sulphides, especially at the reduction zones. These sulphides give a good response to electrical or electromagnetic techniques. The present study uses electrically induced polarization and Genie electromagnetic surveys to explore the extension of the mineralization zones at the subsurface.The self-potential (SP) technique shows numerous of mineralized zones. Most of these zones are distributed in the southern area along the contact between the quartz and gabbro. The induced polarization (IP) method has been applied on the selected profiles to delineate the subsurface contact between calcite, gabbro and quartz in Al-Jarra Valley and to calculate the shape and depth of the mineralization zones in the subsurface along these profiles. The Genie electromagnetic survey, which has been applied on selected profiles, delineated some weak mineralization occurrences corresponding to the shear zones. The integration of the results obtained using these three techniques, in addition to the different ground geophysical methods previously used, makes it possible to determine the most appropriate zones for development of exploration at the area of investigation. | Faisal S. Al-Huzaim | 2003 | Global Geology2003，8，2： | 0 |
| 17 | Clinical Value of Molecular Biological Methods in Respiratory Tuberculosis in Children显示文摘The pattern of clinical forms of respiratory tuberculosis in children shows a preponderance of intrathoracic lymph node tuberculosis (89.4%) that is characterized by a complicated process in every third child under present-day conditions. Positive result of PCR closely correlates with the severity and extent of the specific process in children. Real-time PCR (RT-PCR) was ascertain to exhibit the highest sensitivity in detecting Mycobacterium tuberculosis DNA in children with primary generalized tuberculosis (62.5%) and in those with a disseminated specific process (55.6%), which was much higher than conventional bacteriological study of diagnostic materials. By taking into account the findings, the RT-PCR detection of M. tuberculosis was considered as a substantial criterion for evaluating the magnitude of specific changes and the degree of tuberculosis infection activity in children. | Ulia Ovchinnikova Anna Starshinova Irina Dovgalyuk Natalia Kornev Viacheslav Zhuravlev | 2014 | Journal of Health Science2014，2，5： | 0 |
| 18 | Variational Analysis of Toda Systems(To Ham with admiration and gratitude)显示文摘The author surveys some recent progress on the Toda system on a twodimensional surface Σ, arising in models from self-dual non-abelian Chern-Simons vortices,as well as in differential geometry. In particular, its variational structure is analysed, and the role of the topological join of the barycentric sets of Σ is shown. | andrea malchiodi | 2017 | Chinese Annals of Mathematics,Series B2017，38，2： | 0 |
| 19 | A PREDICTOR-CORRECTOR INTERIOR-POINT ALGORITHM FOR CONVEX QUADRATIC PROGRAMMING显示文摘The simplified Newton method, at the expense of fast convergence, reduces the work required by Newton method by reusing the initial Jacobian matrix. The composite Newton method attempts to balance the trade-off between expense and fast convergence by composing one Newton step with one simplified Newton step. Recently, Mehrotra suggested a predictor-corrector variant of primal-dual interior point method for linear programming. It is currently the interiorpoint method of the choice for linear programming. In this work we propose a predictor-corrector interior-point algorithm for convex quadratic programming. It is proved that the algorithm is equivalent to a level-1 perturbed composite Newton method. Computations in the algorithm do not require that the initial primal and dual points be feasible. Numerical experiments are made. | Liang Ximing(梁昔明) Qian Jixin(钱积新) | 2002 | Numerical Mathematics A Journal of Chinese Universities(English Series)2002，11，1： | 0 |
| 20 | Ensembles vs. information theory: supporting science underuncertainty显示文摘Multi-model ensembles are one of the most common ways to deal with epistemic uncertainty in hydrology. This is a problem because there is no known way to sample models such that the resulting ensemble admits a measure that has any systematic (i.e., asymptotic, bounded, or consistent) relationship with uncertainty. Multi-model ensembles are effectively sensitivity analyses and cannot - even partially - quantify uncertainty. One consequence of this is that multi-model approaches cannot support a consistent scientific method - in particular, multi-model approaches yield unbounded errors in inference. In contrast, information theory supports a coherent hypoth-esis test that is robust to (i.e., bounded under) arbitrary epistemic uncertainty. This paper may be understood as advocating a procedure for hypothesis testing that does not require quantifying uncertainty, but is coherent and reliable (i.e., bounded) in the presence of arbitrary (unknown and unknowable) uncertainty. We conclude by offering some suggestions about how this proposed philosophy of science suggests new ways to conceptualize and construct simulation models of complex, dynamical systems. | Grey S.NEARING Hoshin V.GUPTA | 2018 | Frontiers of Earth Science2018，12，4： | 0 |
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