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Effect of Supplementary Irrigation on the Yield of Sorghum (Sorghum bicolor L. Moench) in the Context of Climate Change in the Dry Savannahs of Togo
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作者 Adjiwanou Atiglo-Gbenou Yaovi Ouézou Azouma Jean Mianikpo Sogbedji 《American Journal of Climate Change》 2024年第2期163-174,共12页
Under the current context of climate change, supplementary irrigation may be needed for crop production resilience. We determined the effects of supplementary irrigation on sorghum grain yield in the dry Savannah regi... Under the current context of climate change, supplementary irrigation may be needed for crop production resilience. We determined the effects of supplementary irrigation on sorghum grain yield in the dry Savannah region of Togo. A two-year trial was conducted in a controlled environment at AREJ, an agro-ecological center in Cinkassé. The plant material was sorghum variety Sorvato 28. The experimental design was a Completely Randomized Block with three replications and three treatments as follows: T0 control plot (rainfed conditions);T1 (supplementary irrigation from flowering to grain filling stage) and T2 (supplementary irrigation from planting to grain filling stage). Two irrigation techniques (furrow and Californian system) were used under each watering treatment. The results showed that irrigation technique significantly affected panicle length with no effect on 1000 grains mass. Panicle length and grain yields varied from 15.59 to 25.71 cm and 0.0 to 2.06 t∙h−1, respectively, with the highest values (25.66 cm and 2.06 t∙h−1, respectively) under the T2 treatment with the California system-based supplementary irrigation. The comparison of results obtained on treatment T0 and T2, shows that supplementary irrigation increased the yields by at least 68.62%. Supplementary irrigation during sowing and growing season (T2) improved sorghum yields in the dry savannahs of Togo, with a better performance of the California irrigation system. 展开更多
关键词 Climate Change supplementary Irrigation Sorghum Grain Yield Dry Savannah TOGO
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Effects of Supplementary Pollination by Single-rotor Agricultural Unmanned Aerial Vehicle in Hybrid Rice Seed Production 被引量:8
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作者 刘爱民 张海清 +7 位作者 廖翠猛 张青 肖层林 何菊英 张健勇 何研 李继宇 罗锡文 《Agricultural Science & Technology》 CAS 2017年第3期543-547,552,共6页
In 2012-2015, under the conditions of different natural wind speeds, the single-rotor agricultural unmanned aerial vehicle was used for the supplementary pollination during seed production of 10 hybrid combinations wi... In 2012-2015, under the conditions of different natural wind speeds, the single-rotor agricultural unmanned aerial vehicle was used for the supplementary pollination during seed production of 10 hybrid combinations with big parental row ratios in the hybrid rice seed production bases of Hunan, Hainan and Guangdong Province, and the pollination effects were studied through the investigation of pollen density in the field, outcrossing seeding rate of female parent and seed production yield. The results showed that under the parental row ratio of 6:(40-60), the seed setting rate and yields of the supplementary pollination by single-rotor agricultural UAV could reach and even higher than those of artificial pollination, indicating the single-rotor agricultural UAV could be used in supplementary pollination for hybdd rice seed production, which could promote the whole-process mechanization of seed production. 展开更多
关键词 Hybrid rice Seed production Single-rotor agricultural unmanned aerialvehicle supplementary pollination
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Response of Watermelon to Gravel-Mulch and Supplementary Irrigation: Yield, Water Use Efficiency and Root Distribution 被引量:3
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作者 ZHANGZhi-shan LIXin-rong +3 位作者 ZHANGPei-dong ZHANGJing-guang WANGXin-ping LIULi-chao 《Agricultural Sciences in China》 CAS CSCD 2004年第12期914-922,共9页
A field experiment was conducted to investigate the effect of supplementary irrigation on watermelon (Citullus lanatus) yield, water-use efficiency (WUE) and root distribution in gravel-mulched field in northwest Lo... A field experiment was conducted to investigate the effect of supplementary irrigation on watermelon (Citullus lanatus) yield, water-use efficiency (WUE) and root distribution in gravel-mulched field in northwest Loess Plateau, China, during 2001 and 2002 growing seasons. The results showed that gravel mulch significantly improved seedling emergence, increased yield and WUE, and alleviated the influence of drought on plant growth. Regardless of gravel mulch application, supplementary irrigation increased watermelon yields, average fruit weight and number of fruit, especially yield increased as the amount of irrigation increased (P<0.05). Generally, WUE of irrigated treatments were higher than that of non-irrigation treatment in gravel-mulched field. The effect of water supply on root distribution was different in two years. In 2001, average root length density (RLD) and root weight density (RWD) whole the soil profile increased. In 2002, however, RLD and RWD decreased as water supply increased. The average RLD and RWD in 2001 were significantly higher than those in 2002. Maybe we can interpret the phenomenon with the theory that there is a need to optimize root distribution (in terms of water relations) and aboveground biomass for a given water supply.The yield may not depend as much on root growth as on the amount of water required at critical stages. A significant effect of soil depth on RLD and RWD were observed in both years, but did not rapidly decrease with depth. 展开更多
关键词 Northwest Loess Plateau C. lanatus Gravel-mulch supplementary irrigation
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Supplementary Materials: Ultrafast charge transfer in dual graphene-WS_2 van der Waals quadrilayer heterostructures 被引量:3
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作者 宋宗鹏 朱海鸥 +2 位作者 史文涛 孙大林 阮双琛 《Chinese Physics Letters》 SCIE CAS CSCD 2018年第12期73-75,共3页
1. The transient absorption spectra of the WS2 monolayer sample.In the measurement of the transient absorption spectra of the WS2 monolayer sample, A 400-nm (3.1eV) pump pulse with a peak fluence of about 10μJ/cm2exc... 1. The transient absorption spectra of the WS2 monolayer sample.In the measurement of the transient absorption spectra of the WS2 monolayer sample, A 400-nm (3.1eV) pump pulse with a peak fluence of about 10μJ/cm2excites the electrons from the valence band into the conduction band,the 展开更多
关键词 WS supplementary Materials Ultrafast charge transfer in dual graphene-WS2 van der Waals quadrilayer heterostructures
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Right lower limb apraxia in a patient with left supplementary motor area infarction: intactness of the corticospinal tract confirmed by transcranial magnetic stimulation 被引量:1
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作者 Min Cheol Chang Min Ho Chun 《Neural Regeneration Research》 SCIE CAS CSCD 2015年第2期325-327,共3页
We reported a 50-year-old female patient with left supplementary motor area infarction who presented right lower limb apraxia and investigated the possible causes using transcranial magnetic stimulation. The patient w... We reported a 50-year-old female patient with left supplementary motor area infarction who presented right lower limb apraxia and investigated the possible causes using transcranial magnetic stimulation. The patient was able to walk and climb stairs spontaneously without any assistance at 3 weeks after onset. However, she was unable to intentionally move her right lower limb although she understood what she supposed to do. The motor evoked potential evoked by transcranial magnetic stimulation from the right lower limb was within the normal range, indicating that the corticospinal tract innervating the right lower limb was uninjured. Thus, we thought that her motor dysfunction was not induced by motor weakness, and confirmed her symptoms as aprax- ia. In addition, these results also suggest that transcranial magnetic stimulation is helpful for diagnosing apraxia. 展开更多
关键词 nerve regeneration lower limb apraxia supplementary motor area cerebral infarct transcranial magnetic stimulation corticospinal tract STROKE neural regeneration
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Effects of Supplementary Feed with Different Apple Pomace-to-Alfalfa Meal Ratios on Milk Performance of Dairy Cows 被引量:1
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作者 SUN Pan-feng GAO Teng-yun 《Animal Husbandry and Feed Science》 CAS 2010年第2期20-22,共3页
[Objective] To study the effects of apple pomace on milk performance of dairy cows. ~Method] A total of 48 Holstein dairy cows at the same parity and with close lactation stage and similar daily milk yield were random... [Objective] To study the effects of apple pomace on milk performance of dairy cows. ~Method] A total of 48 Holstein dairy cows at the same parity and with close lactation stage and similar daily milk yield were randomly assigned to six groups. The supplementary feed was composed of apple pomace, alfalfa meal, com and premix, and it was processed into pellets. In the groups I - V, the percentage of apple pomace was 17.5%, 35.0%, 52.5%, 70.0% and 0%, respectively. Each cow was fed with supplementary feed (3 kg/d). [ Result] The milk yield in the group II and group V was increased significantly ( P 〈 0.05), and the fat content in milk of the group III and V was significantly higher than that of the con- trol group (P 〈 0.05). [ Conclusion] The supplementary apple pomace can improve the milk performance of dairy cows effectively. 展开更多
关键词 Apple pomace supplementary feed Dairy cows Milk performance
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Improvement of Supplementary Irrigation Water Quality for Rain-Fed Agriculture in the Semi-Arid Region Using Magnetization Techniques
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作者 Deepak Bornare Ramakrishna Nagarajan Rajiv Barge 《Journal of Water Resource and Protection》 2018年第12期1198-1209,共12页
Rain-fed agriculture depends on the groundwater as a supplementary source of irrigation. The poor quality of water from the hard rock area is applied to the crops to save the crop. Continuous irrigation leads to degra... Rain-fed agriculture depends on the groundwater as a supplementary source of irrigation. The poor quality of water from the hard rock area is applied to the crops to save the crop. Continuous irrigation leads to degradation of soil, drip irrigation system as well plants. This study assessed the damages on the drip irrigation system and soil, inflicted by the use of low-quality irrigation water. The quality of water was improved with reference to raw water in terms of pH (1.57% - 5.88%), EC (3.08% - 10.08%), ions (0.96% - 46%) by using magnetization method, without disrupting the existing irrigation system in the basaltic aquifer in semi-arid to the arid condition. This was demonstrated before the farmers in central India. 展开更多
关键词 supplementary IRRIGATION Low Water Quality Hard Rock AQUIFER Dissolved SALTS SEMI-ARID Region MAGNETIZATION Method
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The Effect of Handedness on Supplementary Motor Area Activation during Complex Motor Tasks
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作者 Amauri Dalla-Corte Carlos M. M. das Neves +2 位作者 Maurício Anés Mirna W. Portuguez Jaderson C. Dacosta 《Journal of Behavioral and Brain Science》 2015年第10期458-469,共12页
Functional magnetic resonance imaging (fMRI) was used to assess the activity of supplementary motor area (SMA) in six right-handed and six left-handed healthy volunteers. Two manual tasks (self-initiated previously pr... Functional magnetic resonance imaging (fMRI) was used to assess the activity of supplementary motor area (SMA) in six right-handed and six left-handed healthy volunteers. Two manual tasks (self-initiated previously practiced and unpredictable visually guided) were used. Quantitative analysis of hemispheric and bilateral SMA activation was described as mean ± standard deviation of hot spots/total spots. The two tasks induced bilateral SMA activation. The laterality of SMA activation was affected by manual dominance. Left SMA was significantly more activated in right- and left-handers while performing the motor tasks with the right hand. Right SMA was more activated in the left-handers when the left hand was used. Task complexity was the most important factor influencing the degree of SMA activation. 展开更多
关键词 Functional Magnetic RESONANCE Imaging MOTOR Control supplementary MOTOR Area LATERALITY HANDEDNESS
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Experimental Study on the Use of Trass as a Supplementary Cementitious Material in Pervious Concrete
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作者 Alireza Joshaghani Alireza Moazenian Richard Abubakar Shuaibu 《Journal of Environmental Science and Engineering(A)》 2017年第1期39-52,共14页
Abstract: The purpose of this paper is to evaluate the suitability of using trass as a supplementary cementing material in pervious concrete. OPC (Ordinary Portland Cement) was replaced in the concrete mix by 15%, ... Abstract: The purpose of this paper is to evaluate the suitability of using trass as a supplementary cementing material in pervious concrete. OPC (Ordinary Portland Cement) was replaced in the concrete mix by 15%, 25% and 35% weight percentages and the results were compared with reference mixtures with 100% Portland cement. The variables in this study were trass content, aggregate size and water to cement ratio. Sixteen eases of concrete mixtures were tested to study physical and mechanical properties of hardened concrete, including porosity, permeability, compressive strength, splitting-tensile strength and flexural strength at various ages. Results indicated that mechanical properties of the pervious concrete marginally decreased with the increased content of trass when compared to the reference mixtures. However, at later ages the differences were insignificant. 展开更多
关键词 Pervious concrete TRASS supplementary cementitious material PERMEABILITY STRENGTH natural pozzolans.
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Study on the Expansion of a Cement-Based System Containing Sap Polymer and Supplementary Cementing Materials
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作者 Tatiana L. ávalos-Rendón Carlos Javier Mendoza 《Materials Sciences and Applications》 2017年第2期123-134,共12页
In this paper, the addition of admixed superabsorbent polymer (SAP) improved the microstructure and durability-related properties in a cement-based system with supplementary materials. This is an important issue in re... In this paper, the addition of admixed superabsorbent polymer (SAP) improved the microstructure and durability-related properties in a cement-based system with supplementary materials. This is an important issue in real construction projects when good durability properties are required. This study investigates the effect of SAP on the systems using cement replacement by fly ash and silica fume considering the strength properties and durability properties of paste under sulfate attack of cement-based system. The replacement considered in the study was of 10% silica fume and 20% fly ash in each case, the dosage of SAP was 0.25% of the total amount of cementitious material. The results showed that the addition of SAP in the cement-based system improved the compressive strength and reduced expansion to sulfate attack. Scanning electron micrographs showed that utilization of fly ash with silica fume and silica fume with SAP resulted in a much denser microstructure, thereby, leading to an increase in compressive strength and lower expansion under sulfate attack. 展开更多
关键词 SAP POLYMER supplementary Materials SULFATE ATTACK Durability
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Sensory Evaluation Acceptability for a Food Supplementary Chickpea-Based Ready-to-Use among Moderately Malnourished Children Aged 6-59 Months
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作者 Abinet Tekele Masresha Tessema +7 位作者 Tesfaye Hailu Aregash Samuel Tsehay Assefa TibebuMoges Biniyam Tesfaye Dilnesaw Zerfu Barbara Nalubanga Tembo Aweke Kebede 《Journal of Agricultural Science and Technology(B)》 2015年第3期216-230,共15页
The objective of this study was to assess sensory acceptability of locally-produced chickpea-based ready-to-use supplementary foods (RUSF) among moderately malnourished children (6-59 months). A quantitative descr... The objective of this study was to assess sensory acceptability of locally-produced chickpea-based ready-to-use supplementary foods (RUSF) among moderately malnourished children (6-59 months). A quantitative descriptive analysis using a five point hedonic scale among a total of 140 mother-baby pairs was conducted in five hotspot priority one district. The target groups were sampled from 10 sites of five districts (two sites per district). The child-mother pairs per district were selected through systematic random sampling. The selection criteria included children aged 6-59 months with moderate acute malnutrition (MAM) and not suffering from any illness. Half of the respondents (46%) were farmers, while 29% were housewives; only 21% had formal education. Both sexes were equally represented in the sample size among children with 46% being males while 54% females. About half (46%) of households had four or more children with median maternal age during child birth reported at 28.6 ± 5.9 years. About 89% of children consumed complementary food from starchy staple food; 17% consumed from vitamin A rich foods; 57% consumed from dark green leafy vegetables; no child consumed meat, fish and eggs; 49.3% consumed legumes, nuts and seeds; 36.4% consumed milk and milk products and the mean dietary diversity was rated at two out of the nine food groups. The amount of RUSF consumed by children from 48-59 months was higher than children who were 6-11 months. Amhara region had accepted chickpea only and chickpea + maize+ soy the two products more than the other four regions with an average mean value of 4.8 and 4.6 by mother/caregiver and interviewer, respectively. Mothers' perception of the appearance of the products and their overall acceptability was similar in most regions except South Nation Nationality People Region (SNNPR) where the rating of the two products was low with an average mean value of 4.6. Two of the products were well accepted by the study of the participants. The purchase for progress (P4P) programme could utilize this opportunity to support cooperative unions to make chickpeas available on the market given importance to. 展开更多
关键词 ACCEPTABILITY supplementary products sensory evaluation.
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Supplementary Irrigation and Soil Amendment Management with Sorghum on Khor Abu Habil (Sudan)
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作者 M.A. Omer E.M. Alamin 《Journal of Environmental Science and Engineering》 2011年第8期1079-1083,共5页
This research was conducted for 3 cropping seasons at Elobeid Research Station in Western Sudan. The objectives were to improve the irrigation water and soil management and crop yield by evaluating the response of sor... This research was conducted for 3 cropping seasons at Elobeid Research Station in Western Sudan. The objectives were to improve the irrigation water and soil management and crop yield by evaluating the response of sorghum crop to different supplementary irrigation regimes and soil amendments management in flood basin irrigated scheme. The existing flood irrigation practice was basically conducive to late planting, weed growth, late season water stress and pest and diseases attack. Four levels of each irrigation regimes and farm yard manure (FYM) treatments arranged in split-plot design were tested. Rainfall, field capacity, irrigation water added, profile water content, plant height, yield components and water use efficiency were measured. Grain yield was significantly increased (p 〈 0,01) with irrigation treatments where 1919, 1870 and 878 kg/ha were obtained for one, two and no irrigation treatments, respectively. The 3 irrigations treatment has produced relatively lower grain yield (1679 kg/ha). FYM treatment up to 4-8 t/ha showed increase in grain yield. Water added in 1, 2 and 3 irrigation treatments amounts to 4475, 5302 and 6035 m3/ha, respectively which supplmented the rainfall by 23%, 45% and 65%, respectively. Water use efficiency was greater with 1 and 2 irrigation treatments and 4 t/ha FYM which reached 0.43, 0.35 and 0.28 kg/m3, respectively. The result concludes that providing supplementary irrigation from crop establishment to mid season was found sufficient to improve crop productivity. 展开更多
关键词 supplementary irrigation SORGHUM water stress
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Preliminary Study on the Legal Conflict of our Country Marriage Alternative Provisions and Supplementary Provisions in the National Autonomous Areas
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作者 ZHAO Yingpeng 《International Journal of Technology Management》 2015年第8期129-132,共4页
The national autonomous areas exercise an important way of autonomy power to make adaptive or supplementary provisions to the existing laws, and the diversity between different ethnic groups determines the adaptive or... The national autonomous areas exercise an important way of autonomy power to make adaptive or supplementary provisions to the existing laws, and the diversity between different ethnic groups determines the adaptive or supplementary provisions that are bound to the existence of conflict in the legislative content and legal application. On the basis of adaptive or supplementary provisions, this paper carries out the analysis on the law conflict problems of marriage adaptive or supplementary provisions, hoping to start a discussion, and make scholars foeusing on the conflict of national regional autonomy law. 展开更多
关键词 Marriage ALTERNATIVE provisions supplementary provisions LEGAL conflict.
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THE SUPPLEMENTARY RELATIONS BETWEEN THE PROTEINS OF MOTTLED GRAM BEAN AND CERTAIN OTHER CEREALS
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作者 罗登义 《营养学报》 CAS CSCD 北大核心 2006年第5期370-372,共3页
关键词 THE supplementary RELATIONS BETWEEN THE PROTEINS OF MOTTLED GRAM BEAN AND CERTAIN OTHER CEREALS
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The Ming Dynasty Printing and Dissemination of Wang Yangming’s Works in Guizhou:On the 1535 Guiyang Edition of A New Supplementary Edition of Master Wang Yangming’s Writings
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作者 Zhang Xinmin 《孔学堂》 2020年第3期I0004-I0015,共12页
After Wang Yangming experienced the revelation of Confucian philosophy at Longchang,he disseminated his heart-mind doctrine by engaging in teaching.A great number of scholars in Guizhou followed him and formed the Qia... After Wang Yangming experienced the revelation of Confucian philosophy at Longchang,he disseminated his heart-mind doctrine by engaging in teaching.A great number of scholars in Guizhou followed him and formed the Qian sub-school of the heartmind philosophy,the earliest of local Yangming sub-schools in the country.roughout the Zhengde and Wanli periods of the Ming dynasty,Yangming scholars and local ocials in favor of the heart-mind philosophy worked in collaboration to collate and print six books of Wang’s works in Guizhou.Among these,A New Supplementary Edition of Master Wang Yangming’s Writings represents the most fruitful e ort by both government ocials(Wang Xing)and local scholars(Chen Wenxue and Ye Wu).As an o print block-carving edition of Wang Yangming’s collections in the early years,it is extremely treasured for its rarity of edition and historical value.e profusion of printing of Wang’s works in Guizhou re ects the wide circulation of his heart-mind doctrines in China’s southwest frontier regions,vividly mirroring the growth of Wang’s philosophy outside cultural centers as well as the complicated history of interactive in uence between Chinese marginal and central cultures. 展开更多
关键词 Wang Yangming’s works A New supplementary Edition of Master Wang Yangming’s Writings Yangming scholars of the Qian sub-school frontier culture intellectual dissemination
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Supplementary motor area deactivation impacts the recovery of hand function from severe peripheral nerve injury 被引量:2
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作者 Ye-chen Lu Han-qiu Liu +4 位作者 Xu-yun Hua Yun-dong Shen Wen-dong Xu Jian-guang Xu Yu-dong Gu 《Neural Regeneration Research》 SCIE CAS CSCD 2016年第4期670-675,共6页
Although some patients have successful peripheral nerve regeneration,a poor recovery of hand function often occurs after peripheral nerve injury.It is believed that the capability of brain plasticity is crucial for th... Although some patients have successful peripheral nerve regeneration,a poor recovery of hand function often occurs after peripheral nerve injury.It is believed that the capability of brain plasticity is crucial for the recovery of hand function.The supplementary motor area may play a key role in brain remodeling after peripheral nerve injury.In this study,we explored the activation mode of the supplementary motor area during a motor imagery task.We investigated the plasticity of the central nervous system after brachial plexus injury,using the motor imagery task.Results from functional magnetic resonance imaging showed that after brachial plexus injury,the motor imagery task for the affected limbs of the patients triggered no obvious activation of bilateral supplementary motor areas.This result indicates that it is difficult to excite the supplementary motor areas of brachial plexus injury patients during a motor imagery task,thereby impacting brain remodeling.Deactivation of the supplementary motor area is likely to be a serious problem for brachial plexus injury patients in terms of preparing,initiating and executing certain movements,which may be partly responsible for the unsatisfactory clinical recovery of hand function. 展开更多
关键词 nerve regeneration peripheral nerve injury brachial plexus injury neuronal plasticity supplementary motor area premotor area magnetic resonance imaging motor preparation motor imagery clinical restoration of hand function cortical remodeling block design neural regeneration
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Liquid-solid grinding system:Grinding kinetics of coal fly ash as ultrafine supplementary cementitious materials
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作者 Jin Yang Yong Huang +3 位作者 Xingyang He Ying Su Tao Huang Bohumír Strnadel 《Particuology》 SCIE EI CAS CSCD 2024年第11期109-119,共11页
Wet-milling in liquid-solid system can achieve ultra-fine mechanical dissociation of solid wastes with low energy consumption,thereby efficiently improving the potential pozzolanic reactivity.However,the wet-milling k... Wet-milling in liquid-solid system can achieve ultra-fine mechanical dissociation of solid wastes with low energy consumption,thereby efficiently improving the potential pozzolanic reactivity.However,the wet-milling kinetics of ultrafine dissociation in liquid-solid system has not been fully investigated.This paper systematically investigates the wet-milling kinetics of fly ash(FA).Results showed that before wet-milling of FA for 360 min,no agglomeration effect was observed.The particle dissociation of FA during wet-milling can be divided into three stages:rapid dissociation,slow dissociation and stabilization.The evolution process of particle size distribution during wet-milling is consistent with the Rosin-Rammler-Bennet distribution.Both the particle uniformity coefficient and fractal dimension showed highly positive linear correlation with the strength activity index of wet-milled FA.The grey correlation analysis showed that FA particles between 1.1 and 3.1μm had the greatest impact on both the early and late strength activity index.Simultaneously,D10 of wet-milled FA has the largest impact on strength activity index at each age,while D100 has the least impact.Therefore,D10 and proportion of particles in 1.1–3.1μm can be an important basis for judging the reactivity of wet-milled FA as ultrafine supplementary cementitious materials. 展开更多
关键词 Wet-milling Liquid-solid system Grey correlational analysis Fly ash Ultrafine supplementary cementitious MATERIALS
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Supplementary Control for Mitigation of Successive Commutation Failures Considering the Influence of PLL Dynamics in LCC-HVDC Systems 被引量:3
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作者 Jun Lu Xiaoming Yuan +1 位作者 Meiqing Zhang Jiabing Hu 《CSEE Journal of Power and Energy Systems》 SCIE EI CSCD 2022年第3期872-879,共8页
Line commutated converter based high voltage direct current(LCC-HVDC)links are widely employed for long distance bulk power transmission and asynchronous alternating current(AC)grid connections.However,LCC-HVDC system... Line commutated converter based high voltage direct current(LCC-HVDC)links are widely employed for long distance bulk power transmission and asynchronous alternating current(AC)grid connections.However,LCC-HVDC systems often suffer from commutation failures when AC voltage is distorted,oscillating or reduced by AC faults,which leads to overheating of converter valves and interruptions in transmitted power.All of which can have an adverse impact on the safety and stability of the entire power system.This paper proposes a supplementary control for mitigation of successive commutation failures on the basis of analyzing the influence of phase-locked loop(PLL)dynamics on the commutation process.By analyzing the impact of PLL dynamics on the actual leading angle,it is found that changes in the AC voltage phase remarkably influence commutation.Accordingly,the error between the AC voltage phase and PLL’s output angle is added to the output of the extinction angle or DC voltage control to mitigate the successive commutation failures of LCC-HVDC stations.Simulations conducted on the CIGRE benchmark model in PSCAD/EMTDC validate the performance of the supplementary control,which effectively mitigates successive commutation failures. 展开更多
关键词 Commutation failure DYNAMICS LCC-HVDC MITIGATION PLL supplementary control
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RE-USE OF SPENT CATALYST FROM OIL-CRACKING REFINERIES AS SUPPLEMENTARY CEMENTING MATERIAL 被引量:3
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作者 S. K. Antiohos E. Chouliara S. Tsimas 《China Particuology》 SCIE EI CAS CSCD 2006年第2期73-76,共4页
Advanced technological achievements and the continuous growth of economy have made the disposal, recycle and reuse of industrial by-products a severe challenge. The cement industry is considered one of the key sectors... Advanced technological achievements and the continuous growth of economy have made the disposal, recycle and reuse of industrial by-products a severe challenge. The cement industry is considered one of the key sectors in this effort in successfully (in terms of not extenuating but improving some of the properties of the final product) absorbing large quantities of solid wastes, either as aggregates or as secondary cementitious materials. This not only contributes to the creation of an energy and CO2-emission depository (as commonly used raw materials are spared), but also simultaneously alleviates the acute environmental burden caused by the irresponsible disposal of such by-products. In this study, the possibility of reusing spent fluid catalytic-cracking catalyst (FCC) as a supplementary cementing material (SCM) was examined. A series of tests were conducted, initially aiming at characterizing the material and thereafter evaluating its pozzolanic activity and its effect on the mechanical properties of blended cements. Major findings in this investigation revealed that the use of FCC as a mineral admixture in cement is feasible, strengthening the belief that siliceous glassy residues should represent a steady supply for the construction sector. 展开更多
关键词 spent catalyst supplementary cementing material reactive silica efficiency factor blended cement
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Supplementary Tutoring for Compulsory Education Students in China:Status and Trends 被引量:5
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作者 Haiping Xue Chenchen Fang 《ECNU Review of Education》 2018年第3期36-68,共33页
Purpose-The purpose of this paper is to explore the current status of,and developmental trends affecting,the participation in supplementary tutoring by compulsory education students in China.Design/Approach/Methods-Ba... Purpose-The purpose of this paper is to explore the current status of,and developmental trends affecting,the participation in supplementary tutoring by compulsory education students in China.Design/Approach/Methods-Based on the data from the China Family Panel Study(CFPS)conducted by the Peking University Institute of Social Science Survey in 2010,2012,2014,and 2016,the paper uses the method of multilevel linear model to comprehensively analyze problems involving a multilevel data structure.Findings-The paper finds that the proportion of compulsory education students participating in supplementary tutoring(and the expenditure on such tutoring)increased annually before declining in 2016.Students with higher socioeconomic status,higher school quality,and better academic performance have a higher tutoring participation rate and also spend more on tutoring.Students in China’s three northeastern provinces and eastern coastal areas have higher participation rates in tutoring and higher tutoring expenditures.Originality/Value-Supplementary tutoring in China already has its own developmental patterns and trends;however,few scholars have empirically studied the developmental patterns and trends of supplementary tutoring in compulsory education based on longitudinal survey data. 展开更多
关键词 Compulsory education supplementary tutoring shadow education developmental trends
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