期刊文献+
共找到268,447篇文章
< 1 2 250 >
每页显示 20 50 100
Influence of Fruit Tree Types and Arrangements on Yield, Quality and Economic Returns of Cotton of Intercropping System in Southern Xinjiang 被引量:2
1
作者 林涛 田立文 +3 位作者 郭仁松 汤秋香 崔建平 徐海江 《Agricultural Science & Technology》 CAS 2013年第9期1244-1248,1262,共6页
[Objective] The aim was to provide a theoretical basis for stable and highly effective intercropping arrangements and scientific management measures by selecting apple, pear, peach, apricot, walnut, jujube and other f... [Objective] The aim was to provide a theoretical basis for stable and highly effective intercropping arrangements and scientific management measures by selecting apple, pear, peach, apricot, walnut, jujube and other fruit trees to study their influence on yield, fiber quality and economic returns of intercropped cotton in southern Xinjiang. [Method] Based on major cropping pattern in production, randomized block design was adopted to explore growth indicators, canopy micrometeorological indicators, yield and fiber quality in key growth stage. [Result] Shading has a significant effect on cotton canopy micro-environment and canopy diameter is proportional to shading effect. According to comparisons of the same tree type, the change of canopy micro-environment was as follows: under canopyouter canopymiddle points and peachpearapplewalnutjujube for comparisons among different tree types. Canopy diameter is directly proportional to the number of tree branch and boll weight reductions and shading is the main cause of yield reduction. The canopy expansion is the major cause of decline of light intensity, temperature and humidity of cotton canopy. [Conclusion] Fruit trees, which will promote cotton yield,quality and canopy-environment, are as follows: jujube walnut apple pear peach trees. In practice, trees, which are small in canopy or well trimmed, are popular in production, such as jujube trees, to improve cotton yield and fiber quality. 展开更多
关键词 Intercropping of fruit trees and cottons Fruit tree type Intercropping arrangements COTTON INFLUENCE
下载PDF
Experimental Study on Vortex-Induced Vibration of Rough Risers with Coupling Interference Effect Under Side-by-Side Arrangement
2
作者 HU Ze-bo LIU Zhen +5 位作者 LI Peng GUO Hai-yan WANG Shu-bing REN Xiao-hui HOU Hao WANG Ye-shuo 《China Ocean Engineering》 SCIE EI CSCD 2024年第1期18-28,共11页
A vortex-induced vibration(VIV)experiment of rough risers with coupling interference effect under a side-by-side arrangement was carried out in a wave-current combined flume.The roughness of the riser was characterize... A vortex-induced vibration(VIV)experiment of rough risers with coupling interference effect under a side-by-side arrangement was carried out in a wave-current combined flume.The roughness of the riser was characterized by arranging different specifications of surface attachments on the surface of the riser.Rough risers with three different roughnesses were arranged side by side with smooth risers to explore the VIV response of the riser under the combined action of roughness and interference effect,and to reveal the coupling mechanism between roughness and interference effect.The experimental results show that,compared with that of a smooth riser,the VIV of a rough riser under the coupling interference effect has a wider"lock-in"region,and the displacement decreases more significantly at a high reduced velocity,which is more likely to excite higher-order modes and frequency responses.In addition,the displacement response and frequency response of the smooth riser are not significantly affected by wake interference from the rough riser,which is caused by the decrease of the wake region due to the delay of the boundary layer separation point of the rough riser. 展开更多
关键词 marine riser vortex-induced vibration side-by-side arrangement ROUGHNESS interference effect
下载PDF
Experimental Study on Vortex-Induced Vibration of Rough Risers Coupling with Interference Effect in Tandem Arrangement
3
作者 HU Ze-bo LIU Zhen +4 位作者 LI Peng GUO Hai-yan REN Xiao-hui HOU Hao HAO Lian-hong 《China Ocean Engineering》 SCIE EI CSCD 2024年第3期394-407,共14页
In order to study the response law of vortex-induced vibration(VIV)of marine risers under the combined action of roughness and interference effects,and to reveal the coupling mechanism of roughness and interference ef... In order to study the response law of vortex-induced vibration(VIV)of marine risers under the combined action of roughness and interference effects,and to reveal the coupling mechanism of roughness and interference effects on the riser,a VIV experiment of rough risers in tandem arrangement was conducted in a wave−current combined flume.The experiment characterized the risers’roughness by arranging different specifications of attachments on the surface of the risers.Three rough risers with different roughness and smooth risers were arranged in tandem arrangement,with the rough risers arranged downstream.The experimental results indicate that the suppression of the attachments on the downstream risers’vibration are more significant both in the CF and IL directions as the reduced velocity increases.For the downstream riser,the amplitude response of rough riser is more significantly weakened compared with the smooth one at high reduced velocity.For the upstream risers,changes in the roughness and spacing ratio have an impact on their‘lock-in’region.When the roughness of downstream risers is relatively large(0.1300)and the spacing between risers is small(S/D=4.0),the reduced velocity range of‘lock-in’region in the CF direction of upstream risers is obviously expanded,and the displacement in the‘lock-in’region is severer. 展开更多
关键词 marine riser vortex-induced vibration tandem arrangement ROUGHNESS interference effect
下载PDF
Interaction Mechanisms between Natural Debris Flow and Rigid Barrier Deflectors:A New Perspective for Rational Design and Optimal Arrangement
4
作者 Yu Huang Beilei Liu +1 位作者 Dianlei Feng Hao Shi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第5期1679-1699,共21页
Rigid barrier deflectors can effectively prevent overspilling landslides,and can satisfy disaster prevention requirements.However,the mechanisms of interaction between natural granular flow and rigid barrier deflector... Rigid barrier deflectors can effectively prevent overspilling landslides,and can satisfy disaster prevention requirements.However,the mechanisms of interaction between natural granular flow and rigid barrier deflectors require further investigation.To date,few studies have investigated the impact of deflectors on controlling viscous debris flows for geological disaster prevention.To investigate the effect of rigid barrier deflectors on impact mechanisms,a numerical model using the smoothed particle hydrodynamics(SPH)method with the Herschel–Bulkley model is proposed to simulate the interaction between natural viscous flow and single/dual barriers with and without deflectors.This model was validated using laboratory flume test data from the literature.Then,the model was used to investigate the influence of the deflector angle and multi-barrier arrangements.The optimal configuration of multi-barriers was analyzed with consideration to the barrier height and distance between the barriers,because these metrics have a significant impact on the viscous flow pile-up,run-up,and overflow mechanisms.The investigation considered the energy dissipation process,retention efficiency,and dead-zone formation.Compared with bare barriers with similar geometric characteristics and spatial distribution,rigid barriers with deflectors exhibit superior effectiveness in preventing the overflow and overspilling of viscous debris flow.Recommendations for the rational design of deflectors and the optimal arrangement of multi-barriers are provided to mitigate geological disasters. 展开更多
关键词 Rigid barrier deflectors deflector angle single-barrier dual-barrier arrangements viscous debris flow over-spilling delta-plus-SPH
下载PDF
Molecular diagnostic approaches in detecting rearranged during transfection oncogene mutations in multiple endocrine neoplasia type 2
5
作者 Sambasivam Gopinath Velmurugan Ramaiyan 《World Journal of Clinical Cases》 SCIE 2024年第31期6436-6440,共5页
Different types of neuroendocrine cancer,including medullary thyroid cancer(MTC)and thyroid C-cell hyperplasia,are part of multiple endocrine neoplasia type 2(MEN2).A proto-oncogene mutation of the rearranged during t... Different types of neuroendocrine cancer,including medullary thyroid cancer(MTC)and thyroid C-cell hyperplasia,are part of multiple endocrine neoplasia type 2(MEN2).A proto-oncogene mutation of the rearranged during transfection(RET)gene changes the way that receptor tyrosine kinases work.Multiple endocrine neoplasia,a pathological condition,involves these kinases.When the RET protooncogene changes,it can cause endocrine adenomas and hyperplasia to happen at the same time or one after the other.Pheochromocytoma,medullary thyroid carcinoma,and hyperparathyroidism,alone or in combination,are present in MEN2A patients.Some patients may also have skin lichen amyloidosis or Hirschsprung's disease.Patients with MEN2A often present with MTC.MTC is aggressive and has the worst prognosis,as most patients exhibit lymph node metastasis.MTC is one of the important causes of death in patients with MEN2A.RET mutation analysis aids in identifying MEN2A symptoms and monitoring levels of calcium,thyroid hormones,calcitonin,normetanephrine,fractionated metanephrines,and parathyroid hormone.The earlier diagnosis of MTC significantly improves survival and prompts better management of MEN2A.In this editorial,we will discuss the significance of molecular diagnostic approaches in detecting RET oncogene mutations in MEN2A. 展开更多
关键词 Multiple endocrine neoplasia type 2 Medullary thyroid cancer PHEOCHROMOCYTOMA THYROIDECTOMY Rearranged during transfection
下载PDF
Coupling Characteristics and Control of Dual Mechanical Port Machine with Spoke Type Permanent Magnet Arrangement
6
作者 ZHUANG Xingming SONG Qiang +2 位作者 WEN Xuhui ZHAO Feng FAN Tao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2014年第6期1186-1202,共17页
Dual mechanical port machine(DMPM), as a novel electromechanical energy conversion device, has attracted widespread attention. DMPM with spoke type permanent magnet arrangements(STPM-DMPM), which is one of several... Dual mechanical port machine(DMPM), as a novel electromechanical energy conversion device, has attracted widespread attention. DMPM with spoke type permanent magnet arrangements(STPM-DMPM), which is one of several types of DMPM, has been of interest recently. The unique coupling characteristics of STPM-DMPM are beneficial to improving system performance, but these same characteristics increase the difficulties of control. Now there has been little research about the control of STPM-DMPM, and this has hindered its practical application. Based on a mathematical model of STPM-DMPM, the coupling characteristics and the merits and demerits of such devices are analyzed as applied to a hybrid system. The control strategies for improving the disadvantages and for utilizing the advantage of coupling are researched. In order to weaken the interaction effect of torque outputs in the inner motor and the outer motor that results from coupling in STPM-DMPM, a decoupling control method based on equivalent current control is proposed, and independent torque control for the inner motor and outer motor is achieved. In order to solve address the problem of adequately utilization of coupling, minimizing the overall copper loss of the inner motor and the outer motor of STPM-DMPM is taken as the optimization objective for optimal control, and the purpose of utilizing the coupling adequately and reasonably is achieved. The verification tests of the proposed decoupling control and optimal control strategies are carried out on a prototype STPM-DMPM, and the experimental results show that the interaction effect of torque outputs in the inner motor and the outer motor can be markedly weakened through use of the control method. The overall copper loss of the inner motor and the outer motor can be markedly reduced through use of the optimal control method, while the power output remains unchanged. A breakthrough in the control problem of STPM-DMPM is accomplished by combining the control methods. Good performance in the control of STPM-DMPM will enhance its practicality, particularly as applied to hybrid systems. 展开更多
关键词 dual mechanical port machine spoke type permanent magnet arrangement coupling characteristics decoupling control optimal control
下载PDF
The Application of Piano in Chinese Pop Music Arrangements
7
作者 Linchuan Li 《Journal of Contemporary Educational Research》 2024年第8期101-106,共6页
By exploring the application of piano in Chinese pop music arrangements,this article aims to enhance the understanding of the position of piano in pop music and provide useful insights and references for the future de... By exploring the application of piano in Chinese pop music arrangements,this article aims to enhance the understanding of the position of piano in pop music and provide useful insights and references for the future development of Chinese pop music.Starting from the unique position of piano in Chinese pop music arrangements,the article analyses in detail the specific applications of piano in Chinese pop music arrangements.The analysis finds that the piano has been deeply integrated into the bloodline of Chinese popular music and become an indispensable part.From simple melodic embellishments to complex arrangement ideas,the piano has injected endless vitality and vigor into popular music with its unique timbre and expressive power. 展开更多
关键词 PIANO China Pop music arrangement
下载PDF
Genetic Diversity of Intragenomic Rearrangement of Porcine Circovirus Type 2 in vitro and in vivo 被引量:1
8
作者 Libin WEN Fengzhi WANG +5 位作者 Bin LI Yang YU Zhengyu YU Aihua MAO Jianping XIE Kong-wang HE 《Agricultural Science & Technology》 CAS 2013年第12期1719-1722,共4页
We characterized the genome sequences of defective-interfering(DI) particle DNA of porcine circovirus type 2(PCV2) by sequencing and bioinformatics analyses. DI particles were both generated by serial passage of PCV2 ... We characterized the genome sequences of defective-interfering(DI) particle DNA of porcine circovirus type 2(PCV2) by sequencing and bioinformatics analyses. DI particles were both generated by serial passage of PCV2 in PK15 cells and obtained from sera of pigs with postweaning multisystemic wasting syndrome(PMWS). These subviral isolates ranged from 358 nt to 1 125 nt genomes. Investigating the complexity and diversity of PCV2 DI in vivo and in vitro can help elucidating the evolutionary history of PCV2. 展开更多
关键词 Porcine circovirus type 2 Rearrangement In vivo In vitro
下载PDF
Interleukin 1βreceptor and synaptic dysfunction in recurrent brain infection with Herpes simplex virus type-1
9
作者 Roberto Piacentini Claudio Grassi 《Neural Regeneration Research》 SCIE CAS 2025年第2期416-423,共8页
Several experimental evidence suggests a link between brain Herpes simplex virus type-1 infection and the occurrence of Alzheimer’s disease.However,the molecular mechanisms underlying this association are not complet... Several experimental evidence suggests a link between brain Herpes simplex virus type-1 infection and the occurrence of Alzheimer’s disease.However,the molecular mechanisms underlying this association are not completely understood.Among the molecular mediators of synaptic and cognitive dysfunction occurring after Herpes simplex virus type-1 infection and reactivation in the brain neuroinflammatory cytokines seem to occupy a central role.Here,we specifically reviewed literature reports dealing with the impact of neuroinflammation on synaptic dysfunction observed after recurrent Herpes simplex virus type-1 reactivation in the brain,highlighting the role of interleukins and,in particular,interleukin 1βas a possible target against Herpes simplex virus type-1-induced neuronal dysfunctions. 展开更多
关键词 herpes simplex virus type 1 interleukin MICROGLIA NEUROINFLAMMATION synaptic dysfunction
下载PDF
Understanding the link between type 2 diabetes mellitus and Parkinson's disease:role of brain insulin resistance
10
作者 Theodora Ntetsika Sergiu-Bogdan Catrina Ioanna Markaki 《Neural Regeneration Research》 SCIE CAS 2025年第11期3113-3123,共11页
Type 2 diabetes mellitus and Parkinson's disease are chronic diseases linked to a growing pandemic that affects older adults and causes significant socio-economic burden.Epidemiological data supporting a close rel... Type 2 diabetes mellitus and Parkinson's disease are chronic diseases linked to a growing pandemic that affects older adults and causes significant socio-economic burden.Epidemiological data supporting a close relationship between these two aging-related diseases have resulted in the investigation of shared pathophysiological molecular mechanisms.Impaired insulin signaling in the brain has gained increasing attention during the last decade and has been suggested to contribute to the development of Parkinson's disease through the dysregulation of several pathological processes.The contribution of type 2 diabetes mellitus and insulin resistance in neurodegeneration in Parkinson's disease,with emphasis on brain insulin resistance,is extensively discussed in this article and new therapeutic strategies targeting this pathological link are presented and reviewed. 展开更多
关键词 brain insulin resistance brain insulin signaling diabetes type 2 GLP-1 receptor agonists GLP-1 signaling insulin resistance insulin signaling NEURODEGENERATION Parkinson's disease targeted therapy
下载PDF
Drosophila models used to simulate human ATP1A1 gene mutations that cause Charcot-Marie-Tooth type 2 disease and refractory seizures
11
作者 Yao Yuan Lingqi Yu +8 位作者 Xudong Zhuang Dongjing Wen Jin He Jingmei Hong Jiayu Xie Shengan Ling Xiaoyue Du Wenfeng Chen Xinrui Wang 《Neural Regeneration Research》 SCIE CAS 2025年第1期265-276,共12页
Certain amino acids changes in the human Na^(+)/K^(+)-ATPase pump,ATPase Na^(+)/K^(+)transporting subunit alpha 1(ATP1A1),cause Charcot-Marie-Tooth disease type 2(CMT2)disease and refractory seizures.To develop in viv... Certain amino acids changes in the human Na^(+)/K^(+)-ATPase pump,ATPase Na^(+)/K^(+)transporting subunit alpha 1(ATP1A1),cause Charcot-Marie-Tooth disease type 2(CMT2)disease and refractory seizures.To develop in vivo models to study the role of Na^(+)/K^(+)-ATPase in these diseases,we modified the Drosophila gene homolog,Atpα,to mimic the human ATP1A1 gene mutations that cause CMT2.Mutations located within the helical linker region of human ATP1A1(I592T,A597T,P600T,and D601F)were simultaneously introduced into endogenous Drosophila Atpαby CRISPR/Cas9-mediated genome editing,generating the Atpα^(TTTF)model.In addition,the same strategy was used to generate the corresponding single point mutations in flies(Atpα^(I571T),Atpα^(A576T),Atpα^(P579T),and Atpα^(D580F)).Moreover,a deletion mutation(Atpα^(mut))that causes premature termination of translation was generated as a positive control.Of these alleles,we found two that could be maintained as homozygotes(Atpα^(I571T)and Atpα^(P579T)).Three alleles(Atpα^(A576T),Atpα^(P579)and Atpα^(D580F))can form heterozygotes with the Atpαmut allele.We found that the Atpαallele carrying these CMT2-associated mutations showed differential phenotypes in Drosophila.Flies heterozygous for Atpα^(TTTF)mutations have motor performance defects,a reduced lifespan,seizures,and an abnormal neuronal morphology.These Drosophila models will provide a new platform for studying the function and regulation of the sodium-potassium pump. 展开更多
关键词 ATP1A1 Atpα bang-sensitive paralysis Charcot-Marie-Tooth disease type 2 CRISPR/Cas9 homology-directed repair Na^(+)/K^(+)-ATPase point mutation seizures sodium pump
下载PDF
Classification and Nomenclature of Plant Metallothionein-like Proteins Based on Their Cysteine Arrangement Patterns 被引量:1
12
作者 刘进元 吕暾 赵南明 《Acta Botanica Sinica》 CSCD 2000年第6期649-652,共4页
随着植物基因组研究的进展 ,在基因文库和蛋白文库登录的植物类金属硫蛋白基因已超过 5 0个 ,接近金属硫蛋白总数的 1/ 3,而且有不断上升的趋势。鉴于目前植物类金属硫蛋白命名与分类随意性太大 ,很有必要建立一个统一合理的命名与分类... 随着植物基因组研究的进展 ,在基因文库和蛋白文库登录的植物类金属硫蛋白基因已超过 5 0个 ,接近金属硫蛋白总数的 1/ 3,而且有不断上升的趋势。鉴于目前植物类金属硫蛋白命名与分类随意性太大 ,很有必要建立一个统一合理的命名与分类法。对植物类金属硫蛋白一级结构进行详细分析后 ,发现该蛋白两端富含半胱氨酸的区域内半胱氨酸的排列方式颇具规律性 ,进而提出了以半胱氨酸排列方式为基础的分类及命名法 ,并阐述了采用这种方法的理由及其可行性。 展开更多
关键词 plant metallothionein_like protein cysteine arrangement patterns CLASSIFICATION
下载PDF
Restraints and Countermeasures for the Sustainable Development of China's Modern Flower Arrangement Art
13
作者 陈佳瀛 徐宝莲 《Journal of Landscape Research》 2009年第10期80-84,共5页
Factors that influence the development of China's modern flower arrangement art are analyzed in this study,countermeasures and suggestions are proposed for the future development.
关键词 MODERN FLOWER arrangement ART RESTRAINTS COUNTERMEASURES
下载PDF
The Structural Transformation of Nucleolar DNA and Its Arrangement in Nucleolus of Allium cepa Cells
14
作者 陶伟 张立勇 +3 位作者 黄百渠 焦明大 何孟元 郝水 《Acta Botanica Sinica》 CSCD 2001年第1期6-11,共6页
By using the DNA specific cytochemical staining method (NAMA_Ur) and conventional electron microscopic technique, the authors examined the configuration of intranucleolar DNA in Allium cepa L. cells and found that... By using the DNA specific cytochemical staining method (NAMA_Ur) and conventional electron microscopic technique, the authors examined the configuration of intranucleolar DNA in Allium cepa L. cells and found that nucleolar DNA within the fibrillar center (FC) underwent a structural transformation process from condensed to extended state. The authors' observations also displayed a continuous arrangement process of nucleolar DNA, i.e., the extranucleolar DNA entered FC through the nucleolar organizer region (NOR) channel, then extended to the periphery of FC or to the border between FC and dense fibrillar component (DFC), and distributed along the periphery of FC. Thence, by passing through the NOR channel between FCs, the nucleolar DNA continued to transfer to other FCs and arranged in the same above_mentioned forms. 展开更多
关键词 Allium cepa NUCLEOLUS arrangement of nucleolar DNA fibrillar centers
下载PDF
Research on Arrangement of Urban Garden Plants in the Perspective of Ecological Adaptability
15
作者 朱丽清 《Journal of Landscape Research》 2010年第8期21-24,28,共5页
With the increasing deterioration of urban environment, strengthening construction of garden green land was one of the effective ways to ameliorate urban environment. However, as designers only focused on the landscap... With the increasing deterioration of urban environment, strengthening construction of garden green land was one of the effective ways to ameliorate urban environment. However, as designers only focused on the landscape effect of garden plant arrangement and neglected the relationship between plants and natural environment, it resulted in poor growth of some plant community even the disappearance of some communities. Therefore, good landscaping effect could be achieved only when garden layout requirement was considered and suitable cultivation environment was selected based on plants ecological feature, giving full play to its landscaping and ecological function. The study discussed the arrangement of garden plants mainly in the perspective of temperature, light, water, atmosphere and soil environmental factors which were suitable for garden plants, so as to realize the high unity of scientificity and artistry garden plants arrangement, provide a save, comfortable and healthy living and working environment for residents, achieve virtuous cycling development of urban ecological system and promote sustainable development of the city. 展开更多
关键词 GARDEN PLANTS PLANT arrangement ECOLOGICAL ADAPTABILITY
下载PDF
Arrangement of High-standard Basic Farmland Construction Based on Village-region Cultivated Land Quality Uniformity 被引量:18
16
作者 SONG Wen WU Kening +2 位作者 ZHAO Huafu ZHAO Rui LI Ting 《Chinese Geographical Science》 SCIE CSCD 2019年第2期325-340,共16页
As an important constitute of land consolidation, high-standard basic farmland construction is an important means to protect the quantity, quality and ecological environment of cultivated land. Its target not only lie... As an important constitute of land consolidation, high-standard basic farmland construction is an important means to protect the quantity, quality and ecological environment of cultivated land. Its target not only lies in the increase of cultivated land quantity, but also the improvement of cultivated land quality, agricultural production conditions and ecosystem environments. In the present study, the quality evaluation method and construction arrangement of cultivated land were explored to facilitate the process of decision-making and implementation for high-standard basic farmland construction(HSBFC) with administrative village as the unit. Taking the land comprehensive improvement project area in Quzhou County, Handan City, Hebei Province as a case study, the whole process of the study comprised of three steps: 1) establishment of the evaluation model of cultivated land quality uniformity based on regional optimum cultivated land quality, and construction of the uniformity evaluation index system from the aspects of soil fertility quality, engineering quality, spatial quality and eco-environment quality, according to the new concept of cultivated land quality; 2) calculation of cultivated land quality uniformity by grading indicators, assigning scores and weighting sums, exploring the local homogenization characteristics of regional cultivated land quality through spatial autocorrelation analysis, and analyzing the constraints and transformative potential of barrier factors; 3) arrangement of HSBFC according to the principle of concentration, continuity and priority to the easy operation. The results revealed that the value of farmland quality uniformity for the administrative villages in the study area was between 7.76 and 21.96, and there was a difference between various administrative villages. The regional spatial autocorrelation patterns included High-High(HH), Low-Low(LL), High-Low(HL) and Low-High(LH). These indicate that regional cultivated land quality has local homogenization characteristics. The most restrictive factors in the study area were the medium and low transformation difficulty indexes, including soil organic matter content, farmland shelterbelt network density, field regularity and scale of the field. In addition, there were also high transformation difficulty indicators in some areas, such as sectional configuration. The project area was divided into four partitions: major construction area, secondary construction area, general construction area, and conditional construction area. The cultivated land area of each subarea was 1538.85 ha, 1224.27 ha, 555.93 ha, and 1666.63 ha, respectively. This comprised of 30.87%, 24.56%, 11.15% and 33.42% of the total project area, respectively. The evaluation model and index system could satisfy the evaluation of farmland quality and diagnosis of obstacle factors to facilitate the subsequent construction decision. The present study provides reference for the practice of regional HSBFC, and a new feasible idea and method for related studies. 展开更多
关键词 high-standard basic FARMLAND CULTIVATED land quality UNIFORMITY barrier factor arrangement
下载PDF
Effects of Irrigation Water Quality and Drip Tape Arrangement on Soil Salinity,Soil Moisture Distribution,and Cotton Yield (Gossypium hirsutum L.) Under Mulched Drip Irrigation in Xinjiang,China 被引量:24
17
作者 LIU Mei-xian YANG Jing-song +2 位作者 LI Xiao-ming YU Mei WANG Jin 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2012年第3期502-511,共10页
More and more attention is being focused on saline water utilization in irrigation due to the shortage of fresh water to agriculture in many regions. For purpose of reducing the risks of using of saline water for irri... More and more attention is being focused on saline water utilization in irrigation due to the shortage of fresh water to agriculture in many regions. For purpose of reducing the risks of using of saline water for irrigation, the mechanism of soil moisture and salinity distribution and transport should be well understood for developing optimum management strategies. In this paper, field experiments were carried out at Junggar Basin, China, to study the effects of drip irrigation water quality and drip tape arrangement on distribution of soil salinity and soil moisture. Six treatments were designed, including two drip tape arrangement modes and three irrigation water concentration levels (0.24, 4.68, and 7.42 dS m^-l). Results showed that, soil moisture content (SMC) directly beneath the drip tape in all treatments kept a relatively high value about 18% before boll opening stage; the SMC in the narrow strip in single tape arrangement (Ms) plot was obviously lower than that in the double tapes arrangement (Md) plot, indicating that less sufficient water was supplied under the same condition of irrigation depth, but there was no significant reduction in yield. Mulching had not significant influence on salt accumulation but the drip tape arrangement, under the same condition of irrigation water depth and quality, compared with Md, Ms reduced salt accumulation in root zone and brought about relatively high cotton yield. 展开更多
关键词 COTTON drip tape arrangement mulched drip irrigation water quality
下载PDF
The Supersolvable Order of Hyperplanes of an Arrangement 被引量:4
18
作者 Gao Rui-mei Pei Dong-he Du Xian-kun 《Communications in Mathematical Research》 CSCD 2013年第3期231-238,共8页
This paper mainly gives a sufficient and necessary condition for an order of hyperplanes of a graphic arrangement being supersolvable. In addition, we give the relations between the set of supersolvable orders of hype... This paper mainly gives a sufficient and necessary condition for an order of hyperplanes of a graphic arrangement being supersolvable. In addition, we give the relations between the set of supersolvable orders of hyperplanes and the set of quadratic orders of hyperplanes for a supersolvable arrangement. 展开更多
关键词 quadratic arrangement graphic arrangement supersolvable order of hyperplane quadratic order of hyperplane supersolvable order of vertices
下载PDF
Effects of Magnetic Particles Entrance Arrangements on Mixing Efficiency of a Magnetic Bead Micromixer 被引量:4
19
作者 Reza Kamali Seyed Alireza Shekoohi Alireza Binesh 《Nano-Micro Letters》 SCIE EI CAS 2014年第1期30-37,共8页
In this study, a computer code is developed to numerically investigate a magnetic bead micromixer under different conditions. The micromixer consists of a microchannel and numerous micro magnetic particles which enter... In this study, a computer code is developed to numerically investigate a magnetic bead micromixer under different conditions. The micromixer consists of a microchannel and numerous micro magnetic particles which enter the micromixer by fluid flows and are actuated by an alternating magnetic field normal to the main flow. An important feature of micromixer which is not considered before by researchers is the particle entrance arrangement into the micromixer. This parameter could effectively affect the micromixer efficiency. There are two general micro magnetic particle entrance arrangements in magnetic bead micromixers: determined position entrance and random position entrance. In the case of determined position entrances, micro magnetic particles enter the micromixer at specific positions of entrance cross section. However, in a random position entrance,particles enter the microchannel with no order. In this study mixing efficiencies of identical magnetic bead micromixers which only differ in particle entrance arrangement are numerically investigated and compared.The results reported in this paper illustrate that the prepared computer code can be one of the most powerful and beneficial tools for the magnetic bead micromixer performance analysis. In addition, the results show that some features of the magnetic bead micromixer are strongly affected by the entrance arrangement of the particles. 展开更多
关键词 Magnetic bead micromixer Mixing efficiency Particle entrance arrangement
下载PDF
Experimental Study on Molecular Arrangement of Nanoscale Lubricant Films——A Review 被引量:3
20
作者 ZHANG Shaohua LIU Yuhong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2015年第5期896-903,共8页
In order to understand lubrication mechanism at the nanoscale, researchers have used many physical experimental approaches, such as surface force apparatus, atomic force microscopy and ball-on-disk tribometer. The res... In order to understand lubrication mechanism at the nanoscale, researchers have used many physical experimental approaches, such as surface force apparatus, atomic force microscopy and ball-on-disk tribometer. The results show that the variation rules of the friction force, film thicknessand viscosity of the lubricant at the nanoscale are different from elastohydrodynamic lubrication (EHL). It is speculated that these differences are attributed to the special arrangement of the molecules at the nanoscale. However, it is difficult to obtain the molecular orientation and distribution directly from the lubricant molecules in these experiments. In recent years, more and more attention has been paid to use new techniques to overcome the shortcomings of traditional experiments, including various spectral methods. The most representative achievements in the experimental research of molecular arrangement are reviewed in this paper: The change of film structure of a liquid crystal under confinement has been obtained using X-ray method. The molecular orientation change of lubricant films has been observed using absorption spectroscopy. Infrared spectroscopy has been used to measure the anisotropy of molecular orientation in the contact region when the lubricant film thickness is reduced to a few tens of nanometers. In situ Raman spectroscopy has been performed to measure the molecular orientation of the lubricant film semi-quantitatively. These results prove that confinement and shear in the contact region can change the arrangement of lubricant molecules. As a result, the lubrication characteristics are affected. The shortages of these works are also discussed based on practicable results. Further work is needed to separate the information of the solid-liquid interface from the bulk liquid film. 展开更多
关键词 nano-scale lubricating film in situ measurement molecular arrangement
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部