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Morpho-anatomical and physicochemical studies of Fumaria indica(Hausskn.)Pugsley 被引量:2
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作者 Prakash Chandra Gupta Ch V Rao 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2012年第10期830-834,共5页
Objective:To study morpho-anatomical characters and physicochemical analysis of Fumaria indica(F.indica)(Hausskn.)Pugsley,(Fumariaceae),an important medicinal plant used extensively for treating a variety of ailments ... Objective:To study morpho-anatomical characters and physicochemical analysis of Fumaria indica(F.indica)(Hausskn.)Pugsley,(Fumariaceae),an important medicinal plant used extensively for treating a variety of ailments in various system of indigenous medicine.Methods:Evaluation of the different parts of the plant was carried out to determine the morphoanatomical,physicochemical,phytochemical and HPTLC fingerprinting profile of F.indica and other WHO recommended methods were performed for standardization.Results:Morphoanatomical studies showed compound and pinnatifid leaf,4 to 6 cm in length,linear and oblong in shape and anomocytic arrangement of stomata,thin walled parenchymatous cells,scattered,sclerenchymatous,capped vascular bundles and radiating medullary rays.Physicochemical studies showed foreign matter 0.2%,loss on drying 6.8%,total ash 16.77%,alcohol and water soluble extractives 8.92%and 20.26%,respectively,sugar 17.75%,starch 22.97%and tannins 2.37%.Phytochemical evaluation revealed the presence of carbohydrate,alkaloids,flavonoids,saponins,tannins and sterol.Thin layer chromatography was carried out with different solvents and the best solvent system was chloroform and methanol in 80:20 ratio and revealed 12 spots with different R_f value under UV light 366λ.Conclusions:The results of the study can serve as a valuable source of information and provide suitable standards for identification of this plant material for future investigations and applications. 展开更多
关键词 morpho-anatomy Transverse sections HPTLC STOMATA XYLEM PHYSICOCHEMICAL
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Screening of Rice Cultivars for Morpho-Physiological Responses to Early-Season Soil Moisture Stress 被引量:3
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作者 Bhupinder SINGH Kambham Raja REDDY +1 位作者 Edilberto Diaz REDONA Timothy WALKER 《Rice science》 SCIE CSCD 2017年第6期322-335,共14页
The majority of rice(Oryza sativa L.) produced in the southern USA is drill-seeded and grown under upland-like conditions because permanent flooding is established after the four-leaf stage. Therefore, rice during the... The majority of rice(Oryza sativa L.) produced in the southern USA is drill-seeded and grown under upland-like conditions because permanent flooding is established after the four-leaf stage. Therefore, rice during the seedling growth stage will be subjected to variable soil moisture content. A greenhouse experiment was conducted to evaluate the performance of 15 rice cultivars commonly grown in Mississippi of USA under early-season soil moisture stress. Twenty morpho-physiological parameters of rice seedlings subjected to three different levels(100%, 66% and 33% field capacity) of soil moisture, from 10 to 30 d after sowing, were measured. Significant moisture stress × treatment interaction(P < 0.001) was observed for most of the parameters. Further, the total drought response index(TDRI) was developed to score the cultivars for drought tolerance with the variation from 26.88 to 36.21. Accordingly, the cultivars were classified into different groups of tolerance. The cultivars CL152 and CL142-AR were classified as the least and the most tolerant to drought based on TDRI and standard deviation, respectively. Even though both total root(R^2 = 0.98) or shoot(R^2 = 0.76) drought responses indices were positively correlated with TDRI, root traits were important in deriving the indices. Therefore, TDRI could be used to select cultivars for drought tolerance in a given environment and develop rice varieties with early-season drought tolerance. However, further research is needed to identify and characterize tolerance at other stages to assist breeding programs in rice. 展开更多
关键词 DROUGHT field capacity morpho-physiological parameter ORYZA SATIVA root SHOOT soil moisture content total DROUGHT response index
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Distinct Morpho-Physiological Responses of Maize to Salinity Stress
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作者 Tshegofatso Bridget Dikobe Boitumelo Mashile +1 位作者 Rotondwa Rabelani Sinthumule Oziniel Ruzvidzo 《American Journal of Plant Sciences》 2021年第6期946-959,共14页
Most plants demonstrate</span><span style="font-family:""> </span><span style="font-family:Verdana;">wide interactive and complex adaptive morphological, biochemical<... Most plants demonstrate</span><span style="font-family:""> </span><span style="font-family:Verdana;">wide interactive and complex adaptive morphological, biochemical</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and physiological responses when subjected to salinity stress. Salt stress negatively impacts agricultural yields more especially cultivated crops throughout the world. Of interest to this study is maize a salt-</span><span style="font-family:""> </span><span style="font-family:Verdana;">sensitive crop that is widely grown worldwide, and receiving most attention due to its significant attributes and ability to serve as a great model for stress response studies. We exposed QN701 maize cultivar, to</span><span style="font-family:""> </span><span style="font-family:Verdana;">simulated salinity stress and investigated its morphological and physiological responses. Salinity negatively induced various morphological responses such as the reduction in plant height, number of leaves, shoot and root (length and biomass)</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and leaf width;however, it significantly increased the leaf area. On the physiological aspect, salt stress decreased the number of stomata, stomatal density</span><span style="font-family:Verdana;">,</span><span style="font-family:Verdana;"> and photosynthesis, while it increased the respiration rate. This study expanded our knowledge o</span><span style="font-family:Verdana;">f</span><span style="font-family:Verdana;"> the morphological and physiological responses of maize to salinity stress. Additionally, these findings may serve as a recommendation for salinity breeding programs in maize and related cereal crops. 展开更多
关键词 Zea mays Salt Stress Plant morpho-Physiological Response PHOTOSYNTHESIS RESPIRATION
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Morpho-Physical and Psycho-Social Determinants of Low Back Pain in Midwives Population in Benin
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作者 H. Etienne Alagnidé Natta D. Didier Niama +3 位作者 Herman Azanmasso M. Germain Houngbedji E. Eric Dossa G. Toussaint Kpadonou 《Open Journal of Therapy and Rehabilitation》 2017年第4期107-117,共11页
Background: Low back pain is a real public health problem. Lots of studies have been done about it, but not in midwives group. The latter seem to be exposed to low back pain due to morphological, physical and psycho-s... Background: Low back pain is a real public health problem. Lots of studies have been done about it, but not in midwives group. The latter seem to be exposed to low back pain due to morphological, physical and psycho-social factors. We therefore study the place of these factors in the occurrence of low back pain in midwives. Method: Prospective, cross-sectional and analytical study, it is done with 102 midwives of university hospitals in Benin. They were interviewed and examined. An eventual link with their history of low back pain, for at least 3 months during the last 12 months before the study, was checked to their morphological aspects (spinal curvatures, BMI), physical examinations data (strength and muscular flexibility) and psycho-social factors (relationship with colleagues and either, stress, ...). The effect of these factors was assessed using relative risk (RR) with a 95% confidence interval. Results: Different morpho-physical and psychosocial disturbances were observed in midwives. 81% had a history of low back pain. The latter have a statistically significant relationship with the different factors studied. These were mostly exposure factors, but poor midwife relationship with their hierarchical superiors was a protective factor (RR = 0.69 and p = 0.0106). Discussion-Conclusion: In Benin, health workers and especially midwives are very exposed to low back pain. The latter are often associated with different morphological, physical and psycho-social disturbances. The knowledge of those parameters is interesting to reduce this high prevalence of low back pain in midwives. 展开更多
关键词 Low Back Pain MIDWIVES Nursing STAFF PSYCHOSOCIAL Disorders morpho-Physical Disturbances BENIN Cotonou
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Morpho-Syntactic Tagging of Text in “Baoule” Language Based on Hidden Markov Models (HMM)
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作者 Hyacinthe Konan Bi Tra Gooré +1 位作者 Raymond Gbégbé Olivier Asseu 《Journal of Software Engineering and Applications》 2016年第10期516-523,共9页
The label text is a very important tool for the automatic processing of language. It is used in several applications such as morphological and syntactic text analysis, index-ing, retrieval, finished networks determini... The label text is a very important tool for the automatic processing of language. It is used in several applications such as morphological and syntactic text analysis, index-ing, retrieval, finished networks deterministic (in which all combinations of words that are accepted by the grammar are listed) or by statistical grammars (e.g., an n-gram in which the probabilities of sequences of n words in a specific order are given), etc. In this article, we developed a morphosyntactic labeling system language “Baoule” using hidden Markov models. This will allow us to build a tagged reference corpus and rep-resent major grammatical rules faced “Baoule” language in general. To estimate the parameters of this model, we used a training corpus manually labeled using a set of morpho-syntactic labels. We then proceed to an improvement of the system through the re-estimation procedure parameters of this model. 展开更多
关键词 CORPUS the Set of Tags the morpho-Syntactic Tagging “Baoule” Language Hidden Markov Model
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Morpho-tectonic study on late-stage spreading of the Eastern Subbasin of South China Sea 被引量:10
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作者 李家彪 金翔龙 高金耀 《Science China Earth Sciences》 SCIE EI CAS 2002年第11期978-989,共12页
Three NE-trending linear structural zones with different strikes are present in the Eastern Subbasin of the South China Sea. They are distributed in the 350-km-wide central region of both sides of the Scarborough seam... Three NE-trending linear structural zones with different strikes are present in the Eastern Subbasin of the South China Sea. They are distributed in the 350-km-wide central region of both sides of the Scarborough seamount chain, representing a morphological indication of the basement faulting. These three zones correspond respectively to three spreading episodes: the magnetic anomalies 6c -6a (24-21 Ma), 6a - 5e (21 - 19 Ma) and 5e - 5d (5c) (19 - 16 Ma). Instability, subsection and asymmetry characterize the seafloor spreading of the subbasin. The spreading directions change in a continuous way in each of the zones, but abrupt changes by 3°-5° occur when crossing the boundary between the zones, reflecting that the spreading direction has evolutionary characteristics of both gradual and sudden changes. NW-trending transform faults of the spreading become progressively densely distributed from the east to the west, cutting the NE-trending zones into several segments, between which the strikes of the NE-trending zones have marked changes. Such features indicate that the spreading axis is associated with subsection along the strike. Around 21 Ma (magnetic anomaly 6a), there was an important event of spreading acceleration, with the full rate rapidly increasing from 30.54 km/Ma to 42.88 km/Ma. This rate increment event corresponds to the sudden changes in the spreading characteristics of basement faulting, sedimentation, volcano activities, etc. The asymmetry of spreading over the eastern part of the Eastern Subbasin is generally larger than that over the western part, and the spreading rate is markedly larger on the southern side than on the northern side. As a result, the oceanic basin is wide in the east and narrow in the west, forming a significantly asymmetric pattern. 展开更多
关键词 morpho-tectonics magnetic LINEATION anomalies SPREADING pattern South China Sea Basin.
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破碎方式对再生骨料性质及形态特征影响研究 被引量:1
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作者 寇长江 陆禹 +3 位作者 王超 康爱红 肖鹏 王芸芸 《中国科技论文》 2025年第3期185-196,共12页
为系统研究废弃混凝土再生骨料的物理性质与形态特征,以鄂式破碎和反击式破碎2种方式生产的再生骨料为研究对象,对其物理技术指标进行测试和分析,并采用数字图像技术对再生骨料的几何形态进行采集和量化。结果表明,与天然骨料相比,再生... 为系统研究废弃混凝土再生骨料的物理性质与形态特征,以鄂式破碎和反击式破碎2种方式生产的再生骨料为研究对象,对其物理技术指标进行测试和分析,并采用数字图像技术对再生骨料的几何形态进行采集和量化。结果表明,与天然骨料相比,再生骨料的表观相对密度小,吸水率高,压碎值高,针片状含量低,清洗后的含泥量能满足使用要求。再生骨料的吸水率、压碎值主要取决于其表面附着砂浆的数量和强度,故其吸水率、压碎值变化与砂浆附着率测试结果一致,受破碎方式影响不大。但破碎方式对表观相对密度影响较大,颚式破碎生产的小粒径再生骨料的表观相对密度高于反击式破碎生产的再生骨料,颚式破碎生产的大粒径再生骨料的表观相对密度低于反击式破碎生产的再生骨料。在几何形态特征方面,受到施工服役及二次破碎过程影响,再生骨料的针度减小,圆度、等效椭圆周长降低,即其针片状含量降低、棱角性变弱,需要通过整形工艺提高其圆度。整体而言,反击式破碎生产的再生骨料颗粒几何形态特性优于鄂式破碎生产的再生骨料。这些结论可为通过破碎工艺优化废弃混凝土再生骨料性能、评估其形态特性提供参考。 展开更多
关键词 再生骨料 鄂式破碎 反击式破碎 物理技术指标 几何形态特征
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中国古代“矩形裆片”开裆裤的形制结构与功能性研究
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作者 张妍 张恩慈 《艺术设计研究》 北大核心 2025年第3期45-54,138,共11页
本文主要运用复原实验法、三重证据法,以现存六条裤装实物为样本,对中国古代“矩形裆片”开裆裤的形制结构、功能性及穿着效果进行了实证研究,以揭示中国古代裤装丰富的文化内涵。研究发现,在中国古代开裆裤的裁剪和结构设计中,蕴藏着... 本文主要运用复原实验法、三重证据法,以现存六条裤装实物为样本,对中国古代“矩形裆片”开裆裤的形制结构、功能性及穿着效果进行了实证研究,以揭示中国古代裤装丰富的文化内涵。研究发现,在中国古代开裆裤的裁剪和结构设计中,蕴藏着古人对“人衣关系”的深度思考,例如:“矩形裆片”的使用解决了“蔽体”与人体舒适性问题,开裆裤的穿用主要是基于人体对下装机能性需求的考虑;古人的“寡裁”,是古代开裆裤宽博疏阔的主要原因。不同历史时期、不同民族的几件裤装实物,在形制结构和功能性上所表现出的同一性,充分体现了中国古代裤装发展过程中多民族交互融通的特征。 展开更多
关键词 古代 矩形裆片 开裆裤 形制结构 功能性
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高渗透环境下添加脯氨酸对华山松幼苗生长的影响 被引量:1
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作者 冯鹏跃 王瑞苓 +2 位作者 卢诗雨 向萍 刘建祥 《亚热带资源与环境学报》 2025年第2期62-68,共7页
通过浸种法处理华山松种子,并在不同浓度的Pro溶液中培养,以评估其对幼苗发芽率、形态生理指标的影响,研究外源性植物生长调节剂脯氨酸(Pro)对华山松幼苗在高渗透环境下生长的影响。结果表明,适量Pro处理能显著提高华山松种子的发芽率... 通过浸种法处理华山松种子,并在不同浓度的Pro溶液中培养,以评估其对幼苗发芽率、形态生理指标的影响,研究外源性植物生长调节剂脯氨酸(Pro)对华山松幼苗在高渗透环境下生长的影响。结果表明,适量Pro处理能显著提高华山松种子的发芽率和发芽势,其中60 nmol·L^(-1)的Pro处理效果最佳,发芽率和发芽势分别比对照组高出89.64%和115.36%。同时,Pro处理显著促进了幼苗的叶长、茎长、茎粗和根长,尤其是在40 nmol·L^(-1)处理下,叶长、茎长和茎粗的增幅最为显著。此外,Pro处理还提高了幼苗的鲜重和干重,增加了叶绿素含量和可溶性糖含量,增强了超氧化物歧化酶活性,降低了丙二醛量,表明Pro能缓解盐胁迫对华山松幼苗的伤害。本研究为华山松在高渗透环境下的栽培和生态恢复提供了理论依据和实践指导。 展开更多
关键词 华山松 高渗透环境 脯氨酸 形态生理指标
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基于大气电场信号特征的雷电风险预警技术研究 被引量:1
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作者 罗志勇 殷启元 李翔 《气象》 北大核心 2025年第2期239-248,共10页
为利用好大气电场信号特征并提高雷电风险预警精准度,文章基于增强经验小波变换和自适应平滑滤波法,提出了一种结合时频域特征和一维形态学的雷电风险预警方法。通过分析大气电场仪安装点周围半径20 km内83天有雷暴过程和123天非雷暴过... 为利用好大气电场信号特征并提高雷电风险预警精准度,文章基于增强经验小波变换和自适应平滑滤波法,提出了一种结合时频域特征和一维形态学的雷电风险预警方法。通过分析大气电场仪安装点周围半径20 km内83天有雷暴过程和123天非雷暴过程对应的全天资料,提出了使用时频域特征的谱宽一阶后向差分和均方差作为雷电和非雷电过程的预警判断特征、能量差作为解除预警判断特征的方法。该方法在雷暴过程中的雷电风险预警准确率(POD)达到了77.11%,平均预警可提前22.27 min;非雷暴过程中POD达到了90.24%;大部分预警解除滞后时间处于0~40 min,平均滞后时间为32 min。根据与前人算法模型比对,该方法预警和解除可满足雷电高影响行业的雷电风险预警使用。 展开更多
关键词 大气电场 雷电风险预警 经验小波变换 自适应滤波 一维形态学
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共时音感与历时蕴含:安阳方言“徽宗语”语音的生成音系学研究
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作者 陈卫恒 《语言科学》 北大核心 2025年第4期388-401,共14页
文章将安阳方言"徽宗语"生成规则简明概括为附加成分ai-k按介音条件分布、变化的规则,从"声介合母"得出合口介音归属判别的具体声韵条件,从单字本音与"徽宗语"形式的不对应得出"儿""二&qu... 文章将安阳方言"徽宗语"生成规则简明概括为附加成分ai-k按介音条件分布、变化的规则,从"声介合母"得出合口介音归属判别的具体声韵条件,从单字本音与"徽宗语"形式的不对应得出"儿""二"等字"徽宗语"形式基于早期单字音生成,说明深层形式兼顾历史的重要性。通过汉语内部的方言比较,得出"徽宗语"设计规则发生、发展的渐进性。通过比较汉藏、印欧语言秘密语,指出:音节结构的声韵二分,不仅属于汉语,作为非线性音系学接受的音节分析原则,也具有普通语言学意义;汉语"徽宗语"同英语Pig Latin密语语音形式分合机理差异的根源,不在语音形式本身,而在语音单位与语法单位的接口关系上,对应的是汉语作为单音节语素语(MonosyllabicMorpheme Language)与英语作为多音节词语(X-syllabicWord Language)的差异,是词根语素音形(Root Form)与词音形(Word Form)的分合机理差异。 展开更多
关键词 共时与历时 表层与底层 安阳方言 徽宗语 生成音系学与形态音系类型学
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Structure and contents of layered classification system of digital geomorphology for China 被引量:28
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作者 CHENG Weiming ZHOU Chenghu LI Bingyuan SHEN Yuancun ZHANG Baiping 《Journal of Geographical Sciences》 SCIE CSCD 2011年第5期771-790,共20页
This paper presents the structure and contents of a standardized layered classification system of digital geomorphology for China.This digital classification method combines landforms characteristics of morphology wit... This paper presents the structure and contents of a standardized layered classification system of digital geomorphology for China.This digital classification method combines landforms characteristics of morphology with genesis.A total of 15 categories of exogenic and endogenic forces are divided into two broad categories:morpho-genetic and morpho-structural landforms.Polygon patches are used to manage the morpho-genetic types,and solitary points,lines and polygons are used to manage the morpho-structural types.The classification method of digital morpho-genetic types can be divided into seven layers,i.e.basic morphology and altitude,genesis,sub-genesis,morphology,micro-morphology,slope and aspect,material and lithology.The method proposes combinations of matrix forms based on layered indicators.The attributes of every landform types are obtained from all or some of the seven layers.For the 15 forces categories,some classification indicators and calculation methods are presented for the basic morphology,the morphologic and sub-morphologic landforms of the morpho-genetic types.The solitary polygon,linear and point types of morpho-structural landforms are presented respectively.The layered classification method can meet the demands of scale-span geomorphologic mapping for the national primary scales from 1:500,000 to 1:1,000,000.The layers serve as classification indicators,and therefore can be added and reduced according to mapping demands,providing flexible expandability. 展开更多
关键词 digital geomorphology classification system morpho-genesis morpho-structure layered classification method
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Effects of Light Intensity on Growth, Development and Formation on Fagopyrum cymosum 被引量:1
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作者 华劲松 戴红燕 《Agricultural Science & Technology》 CAS 2014年第3期363-366,共4页
Effects of light intensity on growth, development and formation on Fagopy- rum cymosum were explored with natural light intensities at 100%(A), 85.2%(B), 75.8%(C) and 59.7%(D). The results showed that the decl... Effects of light intensity on growth, development and formation on Fagopy- rum cymosum were explored with natural light intensities at 100%(A), 85.2%(B), 75.8%(C) and 59.7%(D). The results showed that the decline of light intensity re- duced nutrient growth period, so that plant growth stage entered in advance and extended, which indicated that the decline of light intensity would lower leaf number and area, the number of twigs from the stem, as well as photosynthate. Further- more, the reduction degree increased upon light intensity decrease degree, and the proper shading improved stem height and leaf area enhanced before growth term. 展开更多
关键词 Fagopyrum cymosum Light intensity Growth and development morpho- logical characters
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鄂尔多斯盆地周边地带新构造演化及其区域动力学背景 被引量:95
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作者 张岳桥 廖昌珍 +1 位作者 施炜 胡博 《高校地质学报》 CAS CSCD 北大核心 2006年第3期285-297,共13页
基于卫星遥感影像解释、野外构造测量和构造-地貌分析,综述了鄂尔多斯盆地周边地带新牛代伸展断陷历史,初步论证了盆地周边地区新构造时期的下限为8~9Ma,并将新构造时期划分为3个构造-地貌演化阶段:(1)新构造前奏阶段(中新世晚... 基于卫星遥感影像解释、野外构造测量和构造-地貌分析,综述了鄂尔多斯盆地周边地带新牛代伸展断陷历史,初步论证了盆地周边地区新构造时期的下限为8~9Ma,并将新构造时期划分为3个构造-地貌演化阶段:(1)新构造前奏阶段(中新世晚期至上新世早期),以鄂尔多斯红粘土盆地的发育和山西地堑系的形成为标志,整个地区处于走滑伸展心力环境;(2)新构造主变动阶段(上新世晚期至中更新世),经历了多幕次构造变动事件,主要表现为沿西南缘弧形构造带的幕式挤压、周缘地堑盆地的持续伸展、鄂尔多斯盆地整体抬升、晋陕黄河峡谷段侵蚀盆地的形成和河流高阶地发育;(3)最新构造变动阶段(中晚更新世以来),以周缘地带的走滑挤压和走滑伸展变形为主要特征,盆地内部差异性隆升和河流下切侵蚀作用加强。新构造时期断裂运动方式主要有伸展、走滑和挤压逆冲活动,鄂尔多斯地块本身发生绕直立轴旋转,并为周缘地带地壳伸展变形所调节。鄂尔多斯地区新构造阶段性演化与青藏高原晚新生代快速向北扩展和高原物质向东构造挤出作用存在密切的动力学联系。 展开更多
关键词 鄂尔多斯盆地 新构造 构造地貌 新构造阶段划分
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优化栽培模式对水稻根-冠生长特性、水氮利用效率和产量的影响 被引量:15
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作者 褚光 徐冉 +4 位作者 陈松 徐春梅 刘元辉 章秀福 王丹英 《中国水稻科学》 CAS CSCD 北大核心 2021年第6期586-594,共9页
【目的】探明优化栽培模式对水稻根冠发育以及产量与肥水利用效率的影响。【方法】以甬优1540(三系籼/粳杂交稻)为材料,设置3个处理:0N(空白)栽培模式、当地农户习惯栽培模式(对照)以及优化栽培模式。【结果】优化栽培处理两年的平均产... 【目的】探明优化栽培模式对水稻根冠发育以及产量与肥水利用效率的影响。【方法】以甬优1540(三系籼/粳杂交稻)为材料,设置3个处理:0N(空白)栽培模式、当地农户习惯栽培模式(对照)以及优化栽培模式。【结果】优化栽培处理两年的平均产量为11.5t/hm^(2),与对照差异不显著;但其氮肥偏生产力、产谷利用率以及水分利用率较对照显著提高。与对照相比,优化栽培处理改善了水稻根系形态与生理特征,降低了根系生物量与根-冠比,提高了深根比与比根长,增加了齐穗期与灌浆中期根系活跃吸收表面积,提高了灌浆中后期根系氧化力与根系伤流液中玉米素(Z)+玉米素核苷(ZR)的浓度。此外,与对照相比,优化栽培处理显著提高了灌浆中后期剑叶净光合速率、叶片中Z+ZR含量以及籽粒中蔗糖-淀粉代谢途径关键酶活性。【结论】优化与集成现有栽培技术,可以改善水稻根系形态与生理特征,提高地上部生理活性,进而实现肥水利用效率的提高。 展开更多
关键词 水稻 产量 肥水利用效率 优化栽培 根系形态生理特征
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不同养分环境下邻株竞争对木荷和杉木生长、细根形态及分布的影响 被引量:21
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作者 姚甲宝 楚秀丽 +3 位作者 周志春 童建设 王晖 余家中 《应用生态学报》 CAS CSCD 北大核心 2017年第5期1441-1447,共7页
以木荷和杉木为试验材料,模拟异质和同质两种森林土壤养分环境,设计单植、两株纯植和两株混植3种栽植方式,开展盆栽试验研究木荷与杉木混交造林增产及木荷生长竞争优势形成的原因.结果表明:与同质养分环境相比,异质养分环境中木荷与杉... 以木荷和杉木为试验材料,模拟异质和同质两种森林土壤养分环境,设计单植、两株纯植和两株混植3种栽植方式,开展盆栽试验研究木荷与杉木混交造林增产及木荷生长竞争优势形成的原因.结果表明:与同质养分环境相比,异质养分环境中木荷与杉木混植时两树种均具有较高的苗高和干物质积累量,且木荷竞争优势明显,这与其根系可塑性强有关.混植的木荷各径级细根大量增生,其根系总长度、表面积和体积比杉木高80%~180%.木荷细根在垂直方向上采用了补偿性的生长策略,即除占据富养表层外,还在低养分斑块中大量增殖以获得更大的竞争优势.木荷与杉木的细根在土壤中的拓殖深度不同,生态位分化,缓解了两树种根系对养分的强烈竞争,提高了混植产量.纯植的木荷由于根系自我识别作用,抑制了根系的生长,使得纯植产量较低.细根在空间上错开和均匀分布可能是木荷纯林结构稳定的原因之一.建议在生产中采用块状整地和表层施肥等措施,改善土壤养分分布状况,营建混交林促进木荷和杉木生长,而对已营造的木荷人工纯林,可以及时调控林分密度促进林木生长. 展开更多
关键词 木荷 杉木 邻株竞争 细根 形态可塑性
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词汇识别中歧义词素语义加工:ERP研究 被引量:12
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作者 赵思敏 吴岩 +1 位作者 李天虹 郭庆童 《心理学报》 CSSCI CSCD 北大核心 2017年第3期296-306,共11页
结合掩蔽启动范式和ERP技术,利用歧义词素的加工,本研究探讨了歧义词素语义的激活。实验采用3×2两因素被试内设计,歧义词素两含义互为启动刺激和目标刺激,两变量分别为启动词类型(歧义词素含义1 vs.含义2 vs.无关词)和目标词类型(... 结合掩蔽启动范式和ERP技术,利用歧义词素的加工,本研究探讨了歧义词素语义的激活。实验采用3×2两因素被试内设计,歧义词素两含义互为启动刺激和目标刺激,两变量分别为启动词类型(歧义词素含义1 vs.含义2 vs.无关词)和目标词类型(歧义词素含义1 vs.含义2)。行为结果发现启动词类型和目标词类型存在交互作用,即只有当共享词素同形同义的情况下,目标词的加工才可能被启动,共享词素同形不同义时并没有产生启动效应。ERP结果进一步肯定了行为结果,在N250和N400两个脑电成分上都发现了启动类型和目标类型交互作用有关的效应,当启动词和目标词共享词素同形同义时,同时引发了N250和N400的变化;当共享词素同形不同义时,时程分析时虽然也发现了N250的变化,但是N250的效应较小,小于同形同义所引发的N250效应,持续时间也较短。实验结果说明,在词汇识别中歧义词素语义可以激活,并对目标词汇加工的早期加工阶段发挥作用。 展开更多
关键词 歧义词素 词素语义 掩蔽启动 ERPS
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山西地堑湖盆湖退-湖侵的地貌沉积响应及其构造指示意义 被引量:12
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作者 胡小猛 卢海龙 +1 位作者 吴冰 吴洁利 《第四纪研究》 CAS CSCD 北大核心 2011年第6期1067-1076,共10页
针对区域第四纪环境的特点,本文首先提炼和归纳了山西地堑湖盆湖退-湖侵的地貌沉积响应一般表现;然后,依据一些保留比较清晰的区域地貌沉积遗存,对区域第四纪,特别是第四纪中晚期的湖退-湖侵历史进行了分析和追溯。分析结果显示,自S_8... 针对区域第四纪环境的特点,本文首先提炼和归纳了山西地堑湖盆湖退-湖侵的地貌沉积响应一般表现;然后,依据一些保留比较清晰的区域地貌沉积遗存,对区域第四纪,特别是第四纪中晚期的湖退-湖侵历史进行了分析和追溯。分析结果显示,自S_8古土壤或L_8黄土层发育或堆积以来,区域湖盆曾在对应于古土壤S_8,S_5,S_1和S_1发育时期发生过4次快速的湖退;而在相邻两次湖退期间发生的是缓慢湖侵。结合区域构造运动的特点,本文最后对区域湖退-湖侵过程与区域构造运动的关系进行了分析,指出盆地中湖泊的快速湖退→缓慢湖侵→再次快速湖退…,这样的变化过程是与区域上地幔强烈上隆→减弱或渐趋稳定→再次强烈上隆…构造循环相对应的。 展开更多
关键词 湖退-湖侵 地貌沉积响应 湖盆泄水门槛 地幔上隆
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基于形态学的新的汉字字形自动生成方法 被引量:10
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作者 刘文予 万菲 朱光喜 《计算机学报》 EI CSCD 北大核心 1999年第3期235-240,共6页
电子印刷、桌面出版、艺术、广告等领域对不同风格汉字的需要,迫切要求一种自动的汉字字形生成方法.传统方法只适用于两种字形相差不大的字体进行合成,并且需人工干预,本文通过对字体的凸剖分,并建立两种不同字体的子凸集映射,提... 电子印刷、桌面出版、艺术、广告等领域对不同风格汉字的需要,迫切要求一种自动的汉字字形生成方法.传统方法只适用于两种字形相差不大的字体进行合成,并且需人工干预,本文通过对字体的凸剖分,并建立两种不同字体的子凸集映射,提出了一种全新的基于形态变换的汉字字形自动生成方法,解决不同构汉字字型的合成问题,对合成的汉字没有任何限制.理论上证明了此方法的正确性,讨论了不同剖分对生成字形的影响.通过不同字体的变形及选择不同的结构元实现不同的字体的合成及衍生,此方法也可用于三维字体的变形和衍生,如三维字的圆角等. 展开更多
关键词 汉字字形 自动生成 形态学 汉字信息处理
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青藏高原东缘中更新世伸展作用及其新构造意义 被引量:16
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作者 张岳桥 李海龙 李建华 《地质论评》 CAS CSCD 北大核心 2010年第6期781-791,共11页
基于区域TM遥感影像资料解译和野外构造地貌调查以及晚第四纪沉积物光释光测年分析,论述了青藏高原东缘复杂地貌边界带晚第四纪伸展构造及其构造地貌特征。结果显示,伸展构造主要见于下列几个构造带:沿南北走向的安宁河谷地、大凉山构... 基于区域TM遥感影像资料解译和野外构造地貌调查以及晚第四纪沉积物光释光测年分析,论述了青藏高原东缘复杂地貌边界带晚第四纪伸展构造及其构造地貌特征。结果显示,伸展构造主要见于下列几个构造带:沿南北走向的安宁河谷地、大凉山构造带、若尔盖盆地、岷江断裂带等。其典型的地貌特征表现为充填晚第四纪沉积物的狭窄河谷。根据盆地沉积物的地层时代和年龄推断,正断作用主要发生在中更新世时期,大约起始于早更新世末期(1.2~0.9Ma),结束于中更新世晚期(100~200ka)。晚更新世以来,构造体制转化为走滑—逆冲机制。青藏东缘中更新世伸展构造作用可能与该地貌边界带晚新生代造山后的高原垮塌有关。 展开更多
关键词 青藏高原东缘 中更新世 正断层 构造地貌 伸展作用 造山后垮塌
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