检索结果-南通市图书馆

Local Criteria Used by Farmers to Evaluate the Agronomic Performance and the Fertilizing Capacity of Cowpea Varieties: Diversity, Variability and Proximal Relation with Agronomic Measurements in Contrasted sahelian Locations

引用

Agricultural Sciences 2024年第1期15卷 114-131页

作者： Nouhou salifou jangorzo Abdoul-Aziz saïdou Abou-Soufianou sadda Abdoulaye Moussa Mamoudou Hassane Bil-Assanou issoufou Département des Sciences du Sol et Télédétection Université Dan Dicko Dankoulodo de Maradi Maradi Niger. Unité Mixte de Recherche “Diversité et Adaptation des Plantes” (UMR DAP) Université Dan Dicko Dankoulodo de Maradi Maradi Niger Centre imaan de Support en Recherche Transdisciplinaire (imaan Research) Niamey Niger institut de Recherche pour le Développement Niamey Niger Université Boubacar ba de Tillabéri Tillabéri Niger Département des Sciences et Techniques de Productions Végétales Université Dan Dicko Dankoulodo de Maradi Maradi Niger

When contributing to participatory research, farmers usually appreciate the performance of cowpea varieties using qualitative scores. The score they attribute to each variety are based on local knowledge. The specific criteria they individually use to attribute a score are not well described. The objectives of this work were to: 1) identify and describe exhaustively the local criteria used by farmers to measure the agronomic performance of cowpea;2) assess the variability and statistical structure of these farmer criteria across local contexts;3) and analyze the association between these farmer criteria and the classical agronomic measurement. To achieve these objectives, an augmented block design was implemented across fifteen locations in the regions of Maradi, Dosso and Tillabéri, representing a diversity of local contexts. From a set of 36 cowpea varieties, fifteen varieties were sown per location, including five varieties (controls) common to all locations. in each location, two replicates were sown in randomized Fisher’s blocks. After agronomic measurement and participatory evaluation (scoring of varieties by farmers), a group survey (focus group) was conducted in each location to identify the criteria considered by farmers to found their discretional scoring of varieties during the participatory evaluation. The analysis of the data identified, across locations, thirteen criteria defined by farmers to characterize the agronomic performance of cowpea. Some of these criteria were different according to location. Farmers ranked the three varieties with the best performance for each agronomical trait (Top 3 varieties). A comparison of the farmer ranking with the ranking based on agronomic measurements revealed similarity and complementary between both methods. This study highlighted the importance of considering both local and scientific knowledge in local varietal evaluations.

关键词： Agronomic Performance Participatory Research Cowpea Farmers’ Criteria

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Developing Weibull-based diameter distributions for the major coniferous species in Heilongjiang Province,China

引用

林业研究:英文版 2023年第6期34卷 1803-1815页

作者： Qila sa Xingji Jin Timo Pukkala Fengri Li Key Laboratory of Sustainable Forest Ecosystem Management Ministry of EducationNortheast Forestry UniversityHarbin 150040People’s Republic of China University of Eastern Finland 80101 JoensuuFinland

Diameter distribution models play an important role in forest inventories,growth prediction,and *** Weibull probability density function is widely used in *** a number of methods have been proposed to predict or recover the Weibull distribution,their applicability and predictive performance for the major tree species of China remain to be *** in sample plots of three even-aged coniferous species(Larix olgensis,Pinus sylvestris and Pinus koraiensis)were measured both in un-thinned and thinned stands to develop parameter prediction models for the Weibull probability density *** least squares(OLS)and maximum likelihood regression(MLER),as well as cumulative distribution function regression(CDFR)were used,and their performance *** results show that MLER and CDFR were better than OLS in predicting diameter distributions of tree *** produced the best results in terms of fitting *** on the error statistics calculated for different age groups,CDFR was considered the most suitable method for developing prediction models for Weibull parameters in coniferous plantations.

关键词： Parameter prediction Maximum likelihood regression Cumulative distribution function regression

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Pressure-induced structure,electronic,thermodynamic and mechanical properties of Ti_(2)AlNb orthorhombic phase by first-principles calculations

引用

Rare Metals 2021年第10期40卷 2964-2974页

作者： Zhen-Yi Wei Kang-Ming Hu bai-Sheng sa Bo Wu Multiscale Computational Materials Facility School of Materials Science and EngineeringFuzhou UniversityFuzhou 350100China

Effects of pressure on lattice parameters, electronic, thermodynamic and mechanical properties of the fully ordered Ti_(2)AlNb orthorhombic phase were studied using first-principles calculations based on density functional theory(DFT). The bonding nature for ordering orthorhombic Ti_(2)AlNb was revealed quantitatively through the electronic structure analyzing. The external pressures play limited roles in the elastic anisotropy of the alloy due to the outstanding dynamical and mechanical stabilities under pressure. However, the shear modulus of O phase manifests anisotropic, where {010} shear planes are the easiest planes to cleave among the principal planes under all *** heat capacities, volume expansions and thermal expansion coefficients were calculated using the quasi-harmonic approximation model based on the phonon dispersion curves. Meanwhile, the bulk modulus, Young’s modulus,shear modulus and the hardness are promptly enhanced under pressure. The predicted results give hints to design Ti_(2)AlNb-based alloy as high-pressure applications.

关键词： Ti2AlNb-based orthorhombic phase Pressure-induced effect Thermodynamic properties Mechanical properties First-principles calculations

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

丹参茉莉酸及丹参酮类成分对机械损伤诱导的响应分析

引用

中国中药杂志 2024年第15期49卷 3998-4006页

作者：刘琪虞慕瑶韩洋钱舒怡邰巴达拉胡郑汉黄璐琦南京中医药大学药学院江苏南京210023 中国中医科学院中药资源中心道地药材品质保障与资源持续利用全国重点实验室北京100700 北京中医药大学中药学院北京102488 上海交通大学农业与生物学院上海200240 内蒙古民族大学蒙医药学院内蒙古通辽028000

当植物遭受昆虫取食、极端天气及人为因素等导致的机械性损伤胁迫后,会迅速在转录及代谢水平上启动一系列的应答机制,引起植物内源激素及次生代谢物含量的变化。该研究以药用模式植物丹参为例,评估机械损伤对药用植物代谢的作用。运用qR... 详细信息

当植物遭受昆虫取食、极端天气及人为因素等导致的机械性损伤胁迫后,会迅速在转录及代谢水平上启动一系列的应答机制,引起植物内源激素及次生代谢物含量的变化。该研究以药用模式植物丹参为例,评估机械损伤对药用植物代谢的作用。运用qRT-PCR及LC-MS检测叶片损伤刺激下,胁迫响应的茉莉酸类物质(jasmonates,jas)和丹参酮类成分生物合成基因以及含量的变化情况,得出处理后不同时序叶片与根部在转录和代谢水平上的相关规律,从而探讨丹参对机械损伤胁迫的响应机制。结果显示,机械损伤诱导能够瞬时提高jas生物合成基因的表达,其中AOC与jaR在诱导后开始上升,在2 h达到最高,AOS与OPR3则在4 h达到最高,与之相应的OPDA、ja及ja-ile的含量均在2 h达到最高。丹参酮生物合成中二萜合酶基因CPS1与KSL1均在2 h上升至最高,而后修饰CYP450s基因则均在4 h上升至最高,4种丹参酮的含量则均在8 h内呈现持续上升的趋势。该研究为揭示机械损伤对次生代谢积累的研究提供参考,为进一步了解机械损伤胁迫下jas在增强植物抗性、促进活性成分积累和提高药材品质方面的作用奠定基础。

关键词：丹参机械损伤胁迫响应茉莉酸丹参酮

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于无人机和地面调查的典型草原“种-面积”关系

引用

中国环境科学 2024年第9期44卷 5169-5179页

作者：朱萨宁高吉喜万华伟尤春赫杨雪郭雨桐祝晨佳吕娜中国环境科学研究院生态研究所北京100012 生态环境部卫星环境应用中心北京100094 北京林业大学草业与草原学院北京100091

本研究以呼伦贝尔市典型草原为研究对象,通过传统地面样方调查和无人机调查,系统研究了“种-面积”关系,确定了典型草原地面与无人机调查的最小调查面积.调查结果表明:1)典型草原的物种数量与调查面积呈非线性关系,“种-面积”关系呈现... 详细信息

本研究以呼伦贝尔市典型草原为研究对象,通过传统地面样方调查和无人机调查,系统研究了“种-面积”关系,确定了典型草原地面与无人机调查的最小调查面积.调查结果表明:1)典型草原的物种数量与调查面积呈非线性关系,“种-面积”关系呈现为S=aln(ba+1).基于组合样方法,至少要包括8个1m^(2)小样方,才能达到涵盖80%物种的目标,基于巢式样法,需要的最小调查面积为8.63m^(2);2)针对典型草原,无人机调查的平均物种发现率为传统地面调查方法的81.7%,无人机可作为地面调查的辅助手段,提高调查的效率;3)在典型草原物种监测中,可选取1个或2个组合样方,并使用无人机进行4~5次随机拍摄作为补充,此时可发现典型草原物种总数的84.7%~88.3%.该方法相对传统的3~5次重复样方调查,代表性更高,调查效率更高.

关键词： “种-面积”关系无人机地面调查典型草原

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

男性C反应蛋白、纤维蛋白原和心肺适应性与高血压发生风险的相关性

引用

中华高血压杂志 2015年第9期23卷 887-889页

作者： jae SY Kurl S Laukkanen ja Lee CD Choi YH Fernhall B Franklin ba 机构不详

在正常血压和高血压高危人群中,较高的心肺适应性（cardiorespiratory fitness）可预防高血压[1-2]。但高心肺适应性能否降低炎症水平升高的受试者发生高血压的风险,尚不清楚。本研究旨在探讨男性中,独立于肥胖,炎症与高血压发生的相关... 详细信息

在正常血压和高血压高危人群中,较高的心肺适应性（cardiorespiratory fitness）可预防高血压[1-2]。但高心肺适应性能否降低炎症水平升高的受试者发生高血压的风险,尚不清楚。本研究旨在探讨男性中,独立于肥胖,炎症与高血压发生的相关性;心肺适应性、炎症与高血压发生的联合相关性。研究者假设炎症与高血压发生相关,但高心肺适应性可降低这种相关性。

关键词：防高血压发生风险相关性适应性 C反应蛋白纤维蛋白原心肺男性

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

investigation on the crystal structure and mechanical properties of the ternary compound Mg_(11-x)Zn_(x)Sr combined with experimental measurements and first-principles calculations

引用

Journal of Magnesium and Alloys 2023年第3期11卷 1074-1082页

作者： Jian Wang Lingzhong Meng Zhang Zhang baisheng sa Xiaoxiao Fu Liyuan Sheng Daokui Xu Yufeng Zheng School of Mechanical Engineering Yangzhou UniversityYangzhou 225127China Key Laboratory of Eco-materials Advanced Technology College of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China Shenzhen institute Peking UniversityShenzhen518057China PKU-HKUST ShenZhen-HongKong institution Shenzhen 518057China Key Laboratory of Nuclear Materials and safety Assessment Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

A new ternary compound,Mg_(11-x)Zn_(x)Sr in the Mg-Zn-Sr system was observed and studied using Scanning Electron Microscopy(SEM),Energy-Dispersive Spectroscope(EDS),X-Ray Diffraction(XRD)and Transmission Electron Microscopy(TEM).The XRD patterns were refined by the Rietveld refinement method and the results revealed that the crystallized Mg_(11-x)Zn_(x)Sr phase belonged to tetragonal i41/amd space group and had the Cd_(11)ba *** Mg atoms were successfully doped into Zn_(11)Sr crystal lattice by occupying Zn atomic ***,the Rietveld refinement and computational results demonstrated a gradual decrease in the a-axis and c-axis lattice parameters with decreasing concentration levels of Mg coordination substitution in the lattice of Mg_(11-x)Zn_(x)Sr *** elastic constants and modulus of the Mg_(11-x)Zn_(x)Sr compounds calculated by first-principles calculations(FPC)indicated they were increased with the increasing of Zn *** variation of hardness,D-band widths and the total density of states for Mg_(11-x)Zn_(x)Sr compounds with Zn content was discussed.

关键词： Mg-Zn-Sr system Crystal structure Hardness Elastic constants Modulus

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Computational Prediction of Micro RNAs from Toxoplasma gondii Potentially Regulating the Hosts' Gene Expression

引用

Genomics, Proteomics & Bioinformatics 2014年第5期12卷 228-238页

作者： Müs?erref Duygu saar Caner bagc? Jens Allmer Molecular Biology and Genetics Izmir Institute of Technology Urla Izmir 35430 Turkey Biotechnology Izmir Institute of Technology Urla Izmir 35430 Turkey Bionia incorporated IZTEKGEB A8 Urla Izmir 35430 Turkey

MicroRNAs （miRNAs） were discovered two decades ago, yet there is still a great need for further studies elucidating their genesis and targeting in different phyla. Since experimental discovery and validation of miRNAs is difficult, computational predictions are indispensable and today most computational approaches employ machine learning. Toxoplasma gondii, a parasite residing within the cells of its hosts like human, uses miRNAs for its post-transcriptional gene reg- ulation. it may also regulate its hosts＇ gene expression, which has been shown in brain cancer. Since previous studies have shown that overexpressed miRNAs within the host are causal for disease onset, we hypothesized that T. gondii could export miRNAs into its host cell. We computationally predicted all hairpins from the genome of T. gondii and used mouse and human models to filter possible candidates. These were then further compared to known miRNAs in human and rodents and their expression was examined for T. gondii grown in mouse and human hosts, respectively. We found that among the millions of potential hairpins in T. gondii, only a few thousand pass filtering using a human or mouse model and that even fewer of those are expressed. Since they are expressed and differentially expressed in rodents and human, we suggest that there is a chance that T. gondii may export miRNAs into its hosts for direct regulation.

关键词： Toxoplasma gondii MicroRNA Regulation Host interaction Parasite

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

他汀类药物治疗与颈动脉粥样硬化斑块炎症状态的持续改变无关

引用

中国处方药 2006年第7期5卷 29-30页

作者： Verhoeven ba Moll FL Koekkoek ja

背景和目的:在他汀类药物治疗出现以后,心血管事件的减少部分取决于抗炎治疗的质量.我们研究了在颈动脉内膜剥离术中采集到的动脉粥样硬化斑块表现型与先前临床中使用他汀类药物之问的关系.

关键词：颈动脉粥样硬化斑块他汀类药物药物治疗炎症状态心血管事件抗炎治疗术中采集颈动脉内表现型膜剥离

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Engineering flexible and green electromagnetic interference shielding materials with high performance through modulating WS_(2) nanosheets on carbon fibers

引用

Journal of Materiomics 2022年第2期8卷 327-334页

作者： Huibin Zhang Tingting Liu Zehao Huang Junye Cheng Honghan Wang Deqing Zhang Xuewei ba Guangping Zheng Ming Yan Maosheng Cao School of Materials Science and Engineering Qiqihar UniversityQiqihar 161006China Department of Mechanical Engineering Hong Kong Polytechnic UniversityHung HomKowloonHong KongChina Department of Materials Science and Engineering And Shenzhen Key Laboratory for Additive Manufacturing of High-performance MaterialsSouthern University of Science and TechnologyShenzhen 518055China School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081China

Flexible and wearable electromagnetic interference(EMi)shielding material is one of the current research focuses in the field of EMi *** this work,for the first time,WS_(2)-carbon fiber(WS_(2)-CF)composites are synthesized by implanting WS_(2),which has a multiphase structure and a large number of defects,onto the surface of carbon fiber(CF)by using a simple one-step hydrothermal method,and are applied to protect electronic devices from *** is found that the EMi shielding performance of WS_(2)-CF is significantly improved,especially for those at Se and *** 2 GHz,the EMi shielding efficiency could reach 36.0 dB at a typical thickness of 3.00 mm of the composite,which is much better than that of pure CF(25.5 dB).Besides paving a novel avenue to optimize the electromagnetic shielding performance of flexible and wearable CF-based EMi shielding materials,which have great potential in the practical application for EMi shielding,this work provides a new paradigm for the design and synthesis of EMi shielding materials which have a broad application prospect.

关键词： Flexible electromagneic shielding Carbon fibers WS_(2) Conductive networks

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：