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OPTIMAL INTERIOR PARTIAL REGULARITY FOR NONLINEAR ELLIPTIC SYSTEMS UNDER THE NATURAL GROWTH CONDITION:THE METHOD OF A-HARMONIC APPROXIMATION 被引量:11
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作者 陈淑红 谭忠 《Acta Mathematica Scientia》 SCIE CSCD 2007年第3期491-508,共18页
In this article, the authors consider the nonlinear elliptic systems under the natural growth condition. They use a new method introduced by Duzaar and Grotowski, for proving partial regularity for weak solutions, bas... In this article, the authors consider the nonlinear elliptic systems under the natural growth condition. They use a new method introduced by Duzaar and Grotowski, for proving partial regularity for weak solutions, based on a generalization of the technique of harmonic approximation. And directly establish the optimal Holder exponent for the derivative of a weak solution. 展开更多
关键词 Nonlinear elliptic systems the natural growth condition optimal partialregularity A-harmonic approximation technique
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Geological conditions of natural gas accumulation and new exploration areas in the Mesoproterozoic to Lower Paleozoic of Ordos Basin, NW China 被引量:6
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作者 DU Jinhu LI Xiangbo +6 位作者 BAO Hongping XU Wanglin WANG Yating HUANG Junping WANG Hongbo WANYAN Rong WANG Jing 《Petroleum Exploration and Development》 2019年第5期866-882,共17页
Based on field outcrop investigation,interpretation and analysis of drilling and seismic data,and consulting on a large number of previous research results,the characteristics of ancient marine hydrocarbon source rock... Based on field outcrop investigation,interpretation and analysis of drilling and seismic data,and consulting on a large number of previous research results,the characteristics of ancient marine hydrocarbon source rocks,favorable reservoir facies belts,hydrocarbon migration direction and reservoir-forming law in the Ordos Basin have been studied from the viewpoints of North China Craton breakup and Qilian-Qinling oceanic basin opening and closing.Four main results are obtained:(1)Controlled by deep-water shelf-rift,there are three suites of source rocks in the Ordos Basin and its periphery:Mesoproterozoic,Lower Cambrian and Middle-Upper Ordovician.(2)Controlled by littoral environment,paleo-uplift and platform margin,four types of reservoirs are developed in the area:Mesoproterozoic-Lower Cambrian littoral shallow sea quartz sandstone,Middle-Upper Cambrian–Ordovician weathering crust and dolomitized reservoir,and Ordovician L-shape platform margin reef and beach bodies.(3)Reservoir-forming assemblages vary greatly in the study area,with"upper generation and lower storage"as the main pattern in the platform,followed by"self-generation and self-storage".There are both"upper generation and lower storage"and"self-generation and self-storage"in the platform margin zone.In addition,in the case of communication between deep-large faults and the Changchengian system paleo-rift trough,there may also exist a"lower generation and upper reservoir"combination between the platform and the margin.(4)There are four new exploration fields including Qingyang paleo-uplift pre-Carboniferous weathering crust,L-shape platform margin zone in southwestern margin of the basin,Ordovician subsalt assemblage in central and eastern parts of the basin,and Mesoproterozoic–Cambrian.Among them,pre-Carboniferous weathering crust and L-shape platform margin facies zone are more realistic replacement areas,and Ordovician subsalt assemblage and the Proterozoic-Cambrian have certain potential and are worth exploring. 展开更多
关键词 natural gas exploration area hydrocarbon ACCUMULATION geological conditions MESOPROTEROZOIC NEOPROTEROZOIC Lower PALEOZOIC ORDOS Basin
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PARTIAL REGULARITY OF STATIONARY NAVIER-STOKES SYSTEMS UNDER NATURAL GROWTH CONDITION 被引量:1
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作者 Lianhua HE Zhong TAN 《Acta Mathematica Scientia》 SCIE CSCD 2019年第1期94-110,共17页
In this article, we consider the partial regularity of stationary Navier-Stokes system under the natural growth condition. Applying the method of A-harmonic approximation,we obtain some results about the partial regul... In this article, we consider the partial regularity of stationary Navier-Stokes system under the natural growth condition. Applying the method of A-harmonic approximation,we obtain some results about the partial regularity and establish the optimal Holder exponent for the derivative of a weak solution on its regular set. 展开更多
关键词 PARTIAL REGULARITY Navier-Stoke systems natural growth condition A-harmonic APPROXIMATION
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Natural Resource Conditions and Economic Development in the Uttaranchal Himalaya,India 被引量:1
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作者 Vishwambhar Prasad Sati 《Journal of Mountain Science》 SCIE CSCD 2005年第4期336-350,共15页
Uttaranchal is bestowed with numerous rivers, huge forest resources ranging from tropical to temperate, tourists' places, pilgrimages and feasible climatic conditions for growing fruits, vegetables, food grains, live... Uttaranchal is bestowed with numerous rivers, huge forest resources ranging from tropical to temperate, tourists' places, pilgrimages and feasible climatic conditions for growing fruits, vegetables, food grains, livestock rearing, tea garden practices, etc. The economic development, on the other hand, could not take place partly due to lack of modern technology with innovation in agricultural system and also unwillingness of the people towards using it. Furthermore, due to its harsh climatic conditions, rigorous terrain and distinct identity, as a part of Uttar Pradesh state, the development could not take place and today the state is believed to be one of the poorer states. Infrastructurally, this region is lagged behind due to its inaccessibility. The ideal geographical and agrarian conditions might be used evenly for the developmental processes. Ecologically, the whole region is socio-economic activities, fragile. The diverse harsh traditional beliefs and hard working potentials further change the entire scenario of the state. Only the need of the hours is to frame and implementation of the rational policies and planning for sustainable development of the state. What had appeared during the past, pertaining to the economic development, needs radical changes in policies, planning and beliefs. This paper aims to evaluate the present conditions of resources as a form of natural vegetation, agricultural crops, horticultural farming, herbs, tea garden practices, livestock rearing, hydropower projects and economic development of the Uttaranchal Himalaya. 展开更多
关键词 Climatic condition livestock rearing tea economic development natural resource agricultural system infrastructure socio-economic condition
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Potential of Natural Killer Cell Enriched Conditioned Media for Skin Care and Anti-Aging 被引量:1
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作者 Dong Soo Kim Dong Ju Kim +2 位作者 Hyun Pyo Kim Sung Hwan Hwang Jung Hwa Kang 《Journal of Cosmetics, Dermatological Sciences and Applications》 2021年第2期123-139,共17页
Natural killer (NK) cell is a type of immune cell and is known to be particularly responsible for innate immunity such as anti-cancer immunity, defense mechanisms against infections, and secretion of various cytokines... Natural killer (NK) cell is a type of immune cell and is known to be particularly responsible for innate immunity such as anti-cancer immunity, defense mechanisms against infections, and secretion of various cytokines and chemokines for increasing recruitment of other immune cells. In this study, we investigated the potentials of NK-enriched lymphocytes (NKEL) conditioned media (CM) on skin care for cosmeceutical compositions. Various cytokines of NKEL CM can improve wound healing through epithelial-mesenchymal transition (EMT) by increasing KLKs (kallikreins) and reduce metalloproteinase (MMP)-1 and MMP-2 to inhibit wrinkle formation. Our results suggest that NKEL CM which has various cytokines promotes up-regulation of cell migration and KLKs and down-regulation of MMP-1 and MMP-2 by stimulating HaCaT keratinocytes migration. Therefore, NKEL CM can be used as a cosmetic composition that can play a role in skin regeneration and anti-aging. 展开更多
关键词 natural Killer Cell NKEL Skin Care Wound Healing ANTI-AGING KLKs MMPS EMT conditioned Media
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REGULARITY FOR NONLINEAR ELLIPTIC SYSTEMS WITH DINI COEFFICIENTS UNDER NATURAL GROWTH CONDITION FOR THE CASE:1
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作者 邱亚林 《Acta Mathematica Scientia》 SCIE CSCD 2012年第5期1937-1958,共22页
In this article,we consider interior regularity for weak solutions to nonlinear elliptic systems of divergence type with Dini continuous coefficients under natural growth condition for the case 1〈m〈 2.All estimates ... In this article,we consider interior regularity for weak solutions to nonlinear elliptic systems of divergence type with Dini continuous coefficients under natural growth condition for the case 1〈m〈 2.All estimates in the case of m≥2 is no longer suitable,and we can’t obtain the Caccioppoli’s second inequality by using these techniques developed in the case of m≥2.But the Caccioppoli’s second inequality is the key to use A-harmonic approximation method.Thus,we adopt another technique introduced by Acerbi and Fcsco to overcome the difficulty and we also overcome those difficulties due to Dini condition.And then we apply the A-harmonic approximation method to prove partial regularity of weak solutions. 展开更多
关键词 nonlinear elliptic systems natural growth condition partial regularity Aharmonic approximation technique
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Bifurcation for a Type of Quasilinear Elliptic Equations On R" under the Natural Growth Conditions
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作者 Wu Ganchang 《佛山科学技术学院学报(社会科学版)》 1993年第2期1-16,共16页
The article proved the existence of H<sup>1</sup> (R) ∩ L<sup>∞</sup> (R<sup>n</sup>) at the bifurcation λ= 0 by discussing the following nonlinear eigenvalue:—D-(ij)(a<... The article proved the existence of H<sup>1</sup> (R) ∩ L<sup>∞</sup> (R<sup>n</sup>) at the bifurcation λ= 0 by discussing the following nonlinear eigenvalue:—D-(ij)(a<sub>ij</sub>(x,u)D<sub>j</sub>u) +1/2a<sub>iju</sub>(x,u)D<sub>i</sub>uD<sub>j</sub>u — q(x)|u|<sup>σ</sup>u = λu0≠u∈H<sup>1</sup>(R<sup>n</sup>) ,0【σ【 4/n,n≥3,x∈ R<sup>n</sup>Meanwhile the article studied the conditions of q(x) under which λ=0 was a bifurcation point for the nonlinear eigenvalue . Here a<sub>ij</sub> are not required to be bounded as u varies. 展开更多
关键词 BIFURCATION QUASILINEAR ELLIPTIC EQUATIONS natural GROWTH conditions
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ON THE EIGENVALUE PROBLEM FOR ELLIPTIC SYSTEMS WITH STRONGLY EIGEN-EXPONENT UNDER NATURAL GROWTH CONDITIONS
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作者 徐海祥 《Acta Mathematica Scientia》 SCIE CSCD 1993年第2期188-194,共7页
Let Ω be a bounded domain with smooth boundary Ω in R~n. We consider the following eigenvalue problem for systems of elliptic equations under the natural growth conditions
关键词 ON THE EIGENVALUE PROBLEM FOR ELLIPTIC SYSTEMS WITH STRONGLY EIGEN-EXPONENT UNDER natural GROWTH conditionS
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EXISTENCE OF NONTRIVIAL SOLUTION OF QUASILINEAR ELLIPTIC EIGENVALUE PROBLEM ON R^n WITH NATURAL GROWTH CONDITIONS
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作者 严树森 李工宝 《Acta Mathematica Scientia》 SCIE CSCD 1990年第2期121-134,共14页
In this paper, we get the existence result of the nontrivial weak solution (λ, u) of the following eigenvalue problem with natural growth conditions.
关键词 EXISTENCE OF NONTRIVIAL SOLUTION OF QUASILINEAR ELLIPTIC EIGENVALUE PROBLEM ON R~n WITH natural GROWTH conditionS
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Fourth-Order Compact Formulation for the Resolution of Heat Transfer in Natural Convection of Water-Cu Nanofluid in a Square Cavity with a Sinusoidal Boundary Thermal Condition
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作者 Mostafa Zaydan Naoufal Yadil +2 位作者 Zoubair Boulahia Abderrahim Wakif Rachid Sehaqui 《World Journal of Nano Science and Engineering》 2016年第2期70-89,共20页
In the present work, we numerically study the laminar natural convection of a nanofluid confined in a square cavity. The vertical walls are assumed to be insulated, non-conducting, and impermeable to mass transfer. Th... In the present work, we numerically study the laminar natural convection of a nanofluid confined in a square cavity. The vertical walls are assumed to be insulated, non-conducting, and impermeable to mass transfer. The horizontal walls are differentially heated, and the low is maintained at hot condition (sinusoidal) when the high one is cold. The objective of this work is to develop a new height accurate method for solving heat transfer equations. The new method is a Fourth Order Compact (F.O.C). This work aims to show the interest of the method and understand the effect of the presence of nanofluids in closed square systems on the natural convection mechanism. The numerical simulations are performed for Prandtl number ( ), the Rayleigh numbers varying between  and for different volume fractions varies between 0% and 10% for the nanofluid (water + Cu). 展开更多
关键词 NANOFLUID Heat Transfer natural Convection Fourth-Order Compact (F.O.C) Formulation Numerical Performance Sinusoidal Boundary Thermal condition
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Natural conditions and cropping regionalization of rice area in China
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作者 Wu Xianzhang.CNRRI.Hangzhou310006,China.Li Liu,Jiangsu Acad of Agri Sei Nanjing210014 ,China.and Li Luping.CNRRI.Hangzhou310006,China 《Chinese Rice Research Newsletter》 1994年第3期8-9,共2页
The formation of rice distribution is based on certain natural ecological conditions and social economic environments. In China, rice cropping is distributed in a vast area extending across 5 tempera ture belts, the n... The formation of rice distribution is based on certain natural ecological conditions and social economic environments. In China, rice cropping is distributed in a vast area extending across 5 tempera ture belts, the northernmost of rice growing area in the world being in China. Distribution of rice cropping is characterized by a gradual decrease from south to north, from large and concentrated regions in Southeast to small and separated areas in Northwest. Natural conditions in rice regions differ in China with a varied topography, high in the west and low in the east. Rice fields in the west are mostly distributed on flatlands on plains, valleys among mountains, tablelands in river valleys, yellow-soil plains and basins in low valleys, alluvial plains, plains in river valleys, while those in the east are mainly distributed on alluvial plains, hilly areas among low mountains, coastal plains, along rivers and lakes and in basins among mountains. 展开更多
关键词 In natural conditions and cropping regionalization of rice area in China area
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Detecting the presence of natural forests using airborne laser scanning data
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作者 Marie-Claude Jutras-Perreault Terje Gobakken +1 位作者 Erik Næsset Hans OleØrka 《Forest Ecosystems》 SCIE CSCD 2023年第6期668-680,共13页
Centuries of forest exploitation have caused significant loss of natural forests in Europe,leading to a decline in populations for many species.To prevent further loss in biodiversity,the Norwegian government has set ... Centuries of forest exploitation have caused significant loss of natural forests in Europe,leading to a decline in populations for many species.To prevent further loss in biodiversity,the Norwegian government has set a target of protecting 10%of the forested area.However,recent data from the National Forest Inventory(NFI)reveals that less than 2%of Norway's forested area consists of natural forests.To identify forests with high conservation value,we used vertical and horizontal variables derived from airborne laser scanning(ALS)data,along with NFI plot measurements.Our study aimed to predict the presence of natural forests across three counties in southeastern Norway,using three different definitions:pristine,near-natural,and semi-natural forests.Natural forests are scarce,and their underrepresentation in field reference data can compromise the accuracy of the predictions.To address this,we assessed the potential gain of including additional field data specifically targeting natural forests to achieve a better balance in the dataset.Additionally,we examined the impact of stratifying the data by dominant tree species on the performance of the models.Our results revealed that semi-natural forests were the most accurately predicted,followed by near-natural and pristine forests,with Matthews correlation coefficient values of 0.32,0.24,and 0.17,respectively.Including additional field data did not improve the predictions.However,stratification by species improved the accuracy of predictions for near-natural and semi-natural forests,while reducing accuracy for pristine forests.The use of horizontal variables did not improve the predictions.Our study demonstrates the potential of ALS data in identifying forests with high conservation value.It provides a basis for further research on the use of ALS data for the detection and conservation of natural forests,offering valuable insights to guide future forest preservation efforts. 展开更多
关键词 natural forest ALS naturalNESS Vertical variables Horizontal variables BIODIVERSITY Forest condition Ecosystem services
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Assessing the Effect of Farmers' Supplementation Strategy on Feed Intake and Liveweight of Goats Grazing Natural Range and Crop Fields of Zamfara Reserve in Semi-Arid Nigeria
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作者 Bello S. Malami Pierre Hiernaux +1 位作者 Hussaini M. Tukur Joerg Steinbach 《Journal of Agricultural Science and Technology(A)》 2012年第5期628-635,共8页
This on-farm study was conducted in Zamfara reserve of north western Nigeria between July, 2002 and June, 2003 to assess feed intake and liveweight of 12 indigenous Red Sokoto castrated bucks, separated into two group... This on-farm study was conducted in Zamfara reserve of north western Nigeria between July, 2002 and June, 2003 to assess feed intake and liveweight of 12 indigenous Red Sokoto castrated bucks, separated into two groups of six, supplemented and nonsupplemented respectively. The nonsupplemented group grazed natural pasture and crop stubble of crop fields, whereas the supplemented group grazed natural pasture, crop stubbles and received concentrate supplementation. Concentrate supplement (wheat offal) was fed at 1% of the metabolic weight of the animals which corresponds to the mean of the farmers offer. The total faecal collection method and grab samples of feed were used to estimate total intake of dry matter (DM), organic matter (OM), crude protein (CP) and metabolizable energy (ME). Liveweight of the animal was recorded at five weekly intervals. Results of the study indicated that nutrients intake of supplemented animals were generally higher than those of the nonsupplemented group, but not significantly different (P 〉 0.05). However, it was observed that supplementation significantly (P 〈 0.05) affected the liveweight of the supplemented bucks during early dry season in December, During this period feed became more available to the grazing animals from crop residues. It was therefore concluded that supplementation with wheat offal at 1% metabolic weight may not be enough to counteract weight loss of grazing goats during the other periods of dry season in this environment. 展开更多
关键词 Supplementation goats LIVEWEIGHT natural range cropfields semi-arid.
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Dynamic stiffness method for free vibration of an axially moving beam with generalized boundary conditions 被引量:3
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作者 Hu DING Minhui ZHU Liqun CHEN 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2019年第7期911-924,共14页
Axially moving beams are often discussed with several classic boundary conditions, such as simply-supported ends, fixed ends, and free ends. Here, axially moving beams with generalized boundary conditions are discusse... Axially moving beams are often discussed with several classic boundary conditions, such as simply-supported ends, fixed ends, and free ends. Here, axially moving beams with generalized boundary conditions are discussed for the first time. The beam is supported by torsional springs and vertical springs at both ends. By modifying the stiffness of the springs, generalized boundaries can replace those classical boundaries. Dynamic stiffness matrices are, respectively, established for axially moving Timoshenko beams and Euler-Bernoulli (EB) beams with generalized boundaries. In order to verify the applicability of the EB model, the natural frequencies of the axially moving Timoshenko beam and EB beam are compared. Furthermore, the effects of constrained spring stiffness on the vibration frequencies of the axially moving beam are studied. Interestingly, it can be found that the critical speed of the axially moving beam does not change with the vertical spring stiffness. In addition, both the moving speed and elastic boundaries make the Timoshenko beam theory more needed. The validity of the dynamic stiffness method is demonstrated by using numerical simulation. 展开更多
关键词 AXIALLY moving BEAM natural frequency TIMOSHENKO BEAM model DYNAMIC stiffness matrix generalized boundary condition
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Modelling and development of recycled water conditioning of copper-molybdenum ores processing 被引量:1
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作者 Irina Pestriak Valery Morozov Erdenetuya Otchir 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2019年第2期313-317,共5页
Current use of enrichment and processing technologies of ores requires the introduction of closed circuits of water treatment. A decrease in technological properties is caused by accumulations of ion-molecular compone... Current use of enrichment and processing technologies of ores requires the introduction of closed circuits of water treatment. A decrease in technological properties is caused by accumulations of ion-molecular components in the circulating water. The objective of the simulation is to determine the maximum allowable concentrations of ions and molecules as well as the choice of conditions for deposition or adsorption.First of all, our examinations decrease the concentration of copper ions and fatty acids in the circulating water. By pre-mixing water with the highest concentration of these ions, a reduction of copper ion and fatty acid concentrations in the recycled water occurs. The results do not only ensure the achievement of the maximum permitted concentration(MPC) of copper and iron, significantly reducing the amount of oxidized copper, they also make it possible to use the united sewage as current water for the flotation process. Mixing and adding filtrate of tailings, discharges of urban wastewater treatment and effluent of ash pit of thermal power stations(TPS) to recycled water causes an increase in the capacity of the enrichment plant by 15–17%. 展开更多
关键词 TAILINGS recycling WATER CLOSED cycle Urban waste WATER conditionING FLOTATION of ORE natural WATER
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Forecasting changes of hydrological and hydrochemical conditions in the Aral Sea 被引量:1
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作者 Vakhob Rafikov Mamadjanova Gulnora 《Geodesy and Geodynamics》 2014年第3期55-58,共4页
The increase of irretrievable river water withdrawals and regulation of river flow has a negative effect on the natural regime of the Aral Sea. The Ainu Darya River and the Syr Darya River Basins are the largest irrig... The increase of irretrievable river water withdrawals and regulation of river flow has a negative effect on the natural regime of the Aral Sea. The Ainu Darya River and the Syr Darya River Basins are the largest irrigated farming areas. Their favorable soil and climatic conditions ensure guaranteed yields of various crops on irrigated lands. Since 1961, for the drastic increase of irretrievable river water withdrawal, mainly for irrigation, the inflow of fiver water into the Aral Sea has started to decrease significantly, accordingly the sea's hydrological and hydrochemical regimes disrupted dramatically. The sea level has continued to drop as evaporation exceeds inflow. This negatively transforms the natural environment and worsens socio-economic conditions in Priaralie as a whole, especially in the lower reaches of Amu Darya and Syr Darya, where natural conditions are largely determined by the sea's impact. At present, this causes desertification of the nonirrigated zone in the deltas, spreading to new areas as the Aral Sea dries out. 展开更多
关键词 Aral Sea hydrological condition hydrochemical condition fiver water withdrawal natural environment
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VIV analysis of pipelines under complex span conditions 被引量:1
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作者 James WANG F.Steven WANG Paul JUKES 《Journal of Marine Science and Application》 2009年第2期105-109,共5页
Spans occur when a pipeline is laid on a rough undulating seabed or when upheaval buckling occurs due to constrained thermal expansion. This not only results in static and dynamic loads on the flowline at span section... Spans occur when a pipeline is laid on a rough undulating seabed or when upheaval buckling occurs due to constrained thermal expansion. This not only results in static and dynamic loads on the flowline at span sections,but also generates vortex induced vibration (VIV),which can lead to fatigue issues. The phenomenon,if not predicted and controlled properly,will negatively affect pipeline integrity,leading to expensive remediation and intervention work. Span analysis can be complicated by:long span lengths,a large number of spans caused by a rough seabed,and multi-span interactions. In addition,the complexity can be more onerous and challenging when soil uncertainty,concrete degradation and unknown residual lay tension are considered in the analysis. This paper describes the latest developments and a'state-of-the-art' finite element analysis program that has been developed to simulate the span response of a flowline under complex boundary and loading conditions. Both VIV and direct wave loading are captured in the analysis and the results are sequentially used for the ultimate limit state (ULS) check and fatigue life calculation. 展开更多
关键词 boundary condition (BC) fatigue limit state (FLS) force model (FM) kilometer post (KP) mode shape natural frequency response model (RM) vortex-induced vibration (VIV) ultimate limit state (ULS) unit stress
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Have some landscapes in the eastern Canadian boreal forest moved beyond their natural range of variability?
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作者 Pierre Grondin Sylvie Gauthier +3 位作者 Veronique Poirier Patrice Tardif Yan Boucher Yves Bergeron 《Forest Ecosystems》 SCIE CSCD 2018年第4期412-428,共17页
Background: In the contxt of ecosystem management, the present study aims to compare the natural and the present-day forested landscapes of a large territory in Quebec(Canada). Using contemporary and long-term fire cy... Background: In the contxt of ecosystem management, the present study aims to compare the natural and the present-day forested landscapes of a large territory in Quebec(Canada). Using contemporary and long-term fire cycles, each natural forst landscape is defined according to the variability of its structure and composition, and compared to the present-day landscape. This analysis was conducted to address the question of whether human activities have moved these ecosystems outside the range of natural landscape variability.Methods: The study encompassed a forested area of 175 000 km2 divided into 14 landscapes. Using a framework that integrates fire cycles, age structure and forest dynamics, we characterized the forest composition and age structures that resulted from three historical fire cycles(110,140, and 180 years) representative of the boreal forest of eastern Canada. The modeled natural landscapes were compared with present-day landscapes in regard to the proportion of old-growth forests(landscape level) and the proportion of late-successional forest stands(landscape level and potential vegetation type).Results: Four landscapes(39%) remain within their natural range of variability. In contrast, nine landscapes(54%)show a large gap between natural and present-day landscapes. These nine are located in the southern portion of the study area, and are mainly associated with Abies-Betula vegetation where human activities have contributed to a strong increase in the proportion of Populus tremuloides stands(early-successional stages) and a decrease of oldgrowth forest stands(more than 100 years old). A single landscape(7%), substantially changed from its potential natural state, is a candidate for adaptive-based management.Conclusion: Comparison of corresponding natural(reference conditions) and present-day landscapes showed that ten landscapes reflecting an important shift in forest composition and age structure could be considered beyond the range of their natural variability. The description of a landscape's natural variability at the scale of several millennia can be considered a moving benchmark that can be re-evaluated in the context of climate change.Focusing on regional landscape characteristics and long-term natural variability of vegetation and forest age structure represents a step forward in methodology for defining reference conditions and following shifts in landscape over time. 展开更多
关键词 Ecosystem management Reference conditions natural variability RESILIENCE Fire cycle Age structure Forest dynamics Potential vegetation type Landscape ecology Theoretical natural landscape Present-day landscape
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Forecasting Methods of Agrometeorological Conditions in the Northern Zone of the Republic of Kazakhstan
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作者 Bakytkan Dauletbakov Lyazzat Seidakhmetovna Sultangaliyeva Zhadra Dnimova 《Agricultural Sciences》 2018年第9期1205-1214,共10页
This work presents the forecast of quality indicators of wheat from weather conditions in the Northern zone of the Republic of Kazakhstan, obtained on the basis of the correlation of protein and gluten content of grai... This work presents the forecast of quality indicators of wheat from weather conditions in the Northern zone of the Republic of Kazakhstan, obtained on the basis of the correlation of protein and gluten content of grain with an average monthly air temperature and precipitation. The equation obtained by the authors allows estimating the quality of grain with the monthly advance, which is important in the organization of harvesting of grain crops. 展开更多
关键词 natural and CLIMATIC conditions AGRICULTURAL METEOROLOGICAL Changes GRAIN YIELD Regression Analysis Forecasting
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Standardization of Robot Instruction Elements Based on Conditional Random Fields and Word Embeddin
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作者 Hengsheng Wang Zhengang Zhang +1 位作者 Jin Ren Tong Liu 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2019年第5期32-40,共9页
Natural language processing has got great progress recently. Controlling robots with spoken natural language has become expectable. With the reliability problem of this kind of control in mind a confirmation process o... Natural language processing has got great progress recently. Controlling robots with spoken natural language has become expectable. With the reliability problem of this kind of control in mind a confirmation process of natural language instruction should be included before carried out by the robot autonomously and the prototype dialog system was designed thus the standardization problem was raised for the natural and understandable language interaction. In the application background of remotely navigating a mobile robot inside a building with Chinese natural spoken language considering that as an important navigation element in instructions a place name can be expressed with different lexical terms in spoken language this paper proposes a model for substituting different alternatives of a place name with a standard one (called standardization). First a CRF (Conditional Random Fields) model is trained to label the term required be standardized then a trained word embedding model is to represent lexical terms as digital vectors. In the vector space similarity of lexical terms is defined and used to find out the most similar one to the term picked out to be standardized. Experiments show that the method proposed works well and the dialog system responses to confirm the instructions are natural and understandable. 展开更多
关键词 WORD embedding conditional Random Fields ( CRFs ) STANDARDIZATION interaction Chinese natural Spoken LANGUAGE (CNSL) natural LANGUAGE Processing (NLP) human-robot
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