检索结果-南通市图书馆

Saponins and solvent extracts from Atriplex laciniata L. exhibited high anthelmintic and insecticidal activities

Journal of Traditional Chinese Medicine 2017年第5期37卷 599-606页

作者： Zul Kamal farhat ullah Sajjad Ahmad Muhammad Ayaz Abdul Sadiq Muhammad Imran Shujat Ahmad Faiz Ur Rahman Anwar Zeb Department of Pharmacy Shaheed Benazir Bhutto University Sheringal Dir Upper 18050Pakistan Department of Pharmacy University of Malakand Chakdara Dir Lower 18000 Pakistan Department of Zoology Shaheed Benazir Bhutto University Sheringal Dir Upper 18050 Pakistan

OBJECTIVE: To investigate saponins and various solvent extracts from Atriplex laciniata(A. laciniata)against human parasites and various ***: The samples from A. laciniata used in the activities were crude saponins(*** F) and solvent samples including methanolic extract(*** F), ethyl acetate(*** F), choloroform(*** F),n-hexane(*** F) and water residual(*** F). Anthelmintic potentials of the samples were analyzed against Pheretima posthuma(earthworms) and Ascaridia galli(round worms) using contact toxicity method. Insecticidal activities were performed against Heterotermes indicola(termite), Monomorium pharaonis(pharaoh ant), Tribolium castaneum(flour beetle) and Rhyzopertha dominica(grain borer) using standard ***: In anthelmintic assay, *** F and *** F were most effective against P. posthuma and A. gal-li with average death times of 25.62 and 29.65 min respectively. Likewise the anthelmintic assay, *** F and *** F were most effective against H. indicola causing 90.36% and 73.24% lethality respectively. Furthermore, in anti-Pharaoh activity *** F, *** F, *** F, *** F and *** F exhibited highest activity with LD50 of 78, 220, 260, 330 and > 800 mg/m L respectively. *** F and *** F were highly effective against R. dominica causing 80.11% and71.30% lethality respectively. *** F was found most active against T. ***: Our findings suggest that the *** F, *** F and *** F extracted from *** *** be the best options for the isolation of anthelmintic and bio-insecticidal compounds.

关键词： Saponins Atriplex Parasites Hetero termes indicola Monomorium pharaonis Rhyzopertha dominica Tribolium castaneum

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

黄土塬边坡植被类型对土壤孔隙的影响

引用

草业科学 2020年第4期37卷 625-634页

作者：冯璐丁康屈媛媛 farhat ullah KHAN 杜峰徐学选西北农林科技大学草业与草原学院陕西杨凌712100 西北农林科技大学水土保持研究所陕西杨凌712100 中国科学院水利部水土保持研究所陕西杨凌712100

黄土塬边坡植被建设以固坡为目的,不同植被的土壤孔隙结构有利于增加降水入渗,从而减少坡面产流的水蚀危害。本研究以长武塬黄土塬边坡的侧柏(Platycladus orientalis)林地、沙棘(Hippophae rhamnoides)灌丛、草地和农地4种植被为研究对... 详细信息

黄土塬边坡植被建设以固坡为目的,不同植被的土壤孔隙结构有利于增加降水入渗,从而减少坡面产流的水蚀危害。本研究以长武塬黄土塬边坡的侧柏(Platycladus orientalis)林地、沙棘(Hippophae rhamnoides)灌丛、草地和农地4种植被为研究对象,采集0–30 cm的原状土柱,利用CT扫描和图像处理技术,对其土壤孔隙度、孔隙数目、孔隙成圆率和孔隙分形维数进行定量分析,结合土层样品的理化性质,研究影响土壤孔隙结构的主要因素。结果表明,农地、侧柏孔隙的孔径大小分异不大,而草地、沙棘自身根系互动穿插生成的根孔扩展了孔径分布范围,不仅增加了孔隙度和大孔隙数目,也降低了孔隙成圆率。草地、沙棘有利于降水入渗,是固坡的优先选择。土壤有机质、粘粒含量等性质与孔隙参数之间具有极显著(P<0.001)或显著(P<0.05)相关关系,它们的改变对土壤孔隙特征变化和提高蓄水保土能力具有重要影响。

关键词：黄土塬边坡植被类型 CT扫描土壤孔隙性质参数

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

Facial Image-Based Autism Detection:A Comparative Study of Deep Neural Network Classifiers

引用

Computers, Materials & Continua 2024年第1期78卷 105-126页

作者： Tayyaba farhat Sheeraz Akram Hatoon SAlSagri Zulfiqar Ali Awais Ahmad Arfan Jaffar Faculty of Computer Science and Information Technology The Superior UniversityLahore54600Pakistan Intelligent Data Visual Computing Research(IDVCR) Faculty of Computer Science and Information TechnologyThe Superior UniversityLahore54600Pakistan Information Systems Department College of Computer and Information SciencesImam Mohammad Ibn Saud Islamic University(IMSIU)Riyadh12571Saudi Arabia School of Computer Science and Electronic Engineering(CSEE) University of EssexWivenhoe ParkColchesterCO43SQUK

Autism Spectrum Disorder(ASD)is a neurodevelopmental condition characterized by significant challenges in social interaction,communication,and repetitive *** and precise ASD detection is crucial,particularly in regions with limited diagnostic resources like *** study aims to conduct an extensive comparative analysis of various machine learning classifiers for ASD detection using facial images to identify an accurate and cost-effective solution tailored to the local *** research involves experimentation with VGG16 and MobileNet models,exploring different batch sizes,optimizers,and learning rate *** addition,the“Orange”machine learning tool is employed to evaluate classifier performance and automated image processing capabilities are utilized within the *** findings unequivocally establish VGG16 as the most effective classifier with a 5-fold cross-validation ***,VGG16,with a batch size of 2 and the Adam optimizer,trained for 100 epochs,achieves a remarkable validation accuracy of 99% and a testing accuracy of 87%.Furthermore,the model achieves an F1 score of 88%,precision of 85%,and recall of 90% on test *** validate the practical applicability of the VGG16 model with 5-fold cross-validation,the study conducts further testing on a dataset sourced fromautism centers in Pakistan,resulting in an accuracy rate of 85%.This reaffirms the model’s suitability for real-world ASD *** research offers valuable insights into classifier performance,emphasizing the potential of machine learning to deliver precise and accessible ASD diagnoses via facial image analysis.

关键词： Autism Autism Spectrum Disorder(ASD) disease segmentation features optimization deep learning models facial images classification

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

林草植被恢复类型对黄土团聚体稳定性和入渗特性的影响

引用

水土保持通报 2023年第1期43卷 24-31页

作者：帕力夏提·格明王龙徐学选王维维张连科李梦瑶 farhat ullah Khan 杜锋西北农林科技大学草业与草原学院陕西杨凌712100 中国科学院水利部水土保持研究所陕西杨凌712100 甘肃省科学院地质自然灾害防治研究所甘肃兰州730000

[目的]对比不同林草植被恢复类型下黄土团聚体稳定性和入渗特性的差异,为黄土高原地区生态恢复模式的合理优化提供理论支持。[方法]以黄土区撂荒地(C_(1),对照)、苜蓿地(C_(2))、天然草地(C_(3))、油松+侧柏混交林(L_(1))、刺槐+侧柏混... 详细信息

[目的]对比不同林草植被恢复类型下黄土团聚体稳定性和入渗特性的差异,为黄土高原地区生态恢复模式的合理优化提供理论支持。[方法]以黄土区撂荒地(C_(1),对照)、苜蓿地(C_(2))、天然草地(C_(3))、油松+侧柏混交林(L_(1))、刺槐+侧柏混交林(L_(2))为对象,采用萨维诺夫法和单环双水头法分别测定了水稳性团聚体组成状况、饱和导水率(K_(s))。以平均质量直径(MWD)、几何直径(GMD)、颗粒分形维数(D)、破坏率(PAD)、>0.25 mm水稳性团聚体占比(M w)和饱和导水率为评价指标,分析了不同林草植被恢复类型的土壤团聚体稳定性和入渗特性差异及其影响因素。[结果]①0—30 cm土层范围内,C_(1)的GMD和MWD最低,林草植被恢复类型的GMD,MWD表现为L_(1)和C_(3)>L_(2)和C_(2),而PAD和D则相反。②0—10 cm土层,L_(1)的>0.25 mm水稳定团聚体含量最高(47.24%),其次是C_(3)和L_(2),C_(1)最低(24.00%);而10—30 cm土层,C_(3)的>0.25 mm水稳定团聚体含量最高(10—20 cm处为35.41%,20—30 cm处为27.96%),L_(2)最低(10—20 cm处为11.46%,20—30 cm处为8.00%)。③不同林草植被恢复类型的表层土壤入渗特性变异系数均介于0.001~0.360,L_(1)的K_(s)(0.307 cm/min)最大,C_(1)的K_(s)(0.044 cm/min)最小。④团聚体稳定性指标(PAD除外)和K_(s)均与有机质、孔隙度、容重呈现显著或极显著相关。[结论]林草植被恢复有助于改善黄土团聚体稳定性和入渗特性,长期林地恢复类型(L_(1))的团聚体稳定性和入渗特性优于天然草地(C_(3)),而短期林地恢复类型(L_(2))却不如天然草地(C_(3)),植被恢复应注重时间的积累。

关键词：植被恢复团聚体稳定性入渗特性林草地黄土

来源：

维普期刊数据库博看期刊

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

Mechanical and magneto-electronic properties of europium lanthanide-based cubic perovskites EuYO_(3)(Y=Cr, Mn, Fe): An ab initio study

引用

Journal of Rare Earths 2024年第3期42卷 562-569,I0005页

作者： Hayat ullah Azra Sarwar Sajad Ali Rabah Khenata Abdelmadjid Bouhemadou Saad Bin-Omran Department of Physics Women University of Azad Jammu&Kashmir Bagh 10250Pakistan Department of Physics Abdul Wali Khan UniversityMardan23200KPPakistan LPQ3M Laboratory Institute of Science and TechnologyUniversity of Mascara29000MascaraAlgeria Laboratory for Developing New Materials and Their Characterization Farhat Abbas University Setif l19000SetifAlgeria Department of Physics and Astronomy College of ScienceKing Saud UniversityP.O.Box 2455Riyadh11451Saudi Arabia

Computational calculations using density functional theory(DFT) were performed for the first time using the full potential linearized augmented plane wave plus local orbital method(FP-LAPW + LO) to determine the structural, elastic, electronic and magnetic properties of europium-based cubic perovskites EuYO_(3)(Y=Cr, Mn, Fe). The exchange correlation potentials of GGA along with some analytical methods were adopted for the computation of structural and elastic properties. Moreover, the GGA + U formalism was also added for obtaining more precise electronic and magnetic properties, particularly to address the Eu-4f and Y-3d orientations in the spin-polarized double cell symmetry. The observed lattice parameters of these compounds are consistent with experiment. The observed bulk moduli predict that EuCrO_(3) is harder and less compressible than EuMnO_(3) and EuFeO_(3). The calculated tolerance factors of these compounds are within the cubic symmetry range. Our computed critical radius of EuCrO_(3) shows that EuCrO_(3) has a larger migration energy. Based on their elastic properties, these compounds are ductile in nature. We also computed the thermal properties of these compounds. The band structures and density of states show that these compounds are metallic in character. The lowest ground state energy and magnetic moments of these compounds expose their ferromagnetic nature. The metallic nature and strong ferromagnetism of these compounds make them promising applicants for application in spintronic.

关键词： Perovskites GGA+U Elastic constants Band structure Magnetic moments Rare earths

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

Refractory ulcerative colitis:Upadacitinib versus other biologics

引用

World Journal of Clinical Cases 2024年第31期12卷 6425-6427页

作者： Said G farhat Jessy G Fadel Department of Gastroenterology Research Saint George University of BeirutBeirut 00000Lebanon Dr.Sulaiman Al Habib Hospital Dubai 00000United Arab Emirates

In this editorial we comment on an article published in World Journal of Clinical Cases in 2024,in which a case of refractory ulcerative colitis(UC)was discussed based on the response to different lines of *** studies showed that different classes of biologics have their advantages and disadvantages in the treatment of refractory *** classes are superior to others and if tried earlier on would lead to a possible change in the outcome.

关键词： Refractory Ulcerative colitis Upadacitinib Ustekinumab Vedolizumab

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

Impact of Drain Effluent on Surficial Sediments in the Mediterranean Coastal Wetland: Sedimentological Characteristics and Metal Pollution Status at Lake Manzala, Egypt

引用

Journal of Ocean University of China 2019年第4期18卷 834-848页

作者： farhat Hassan I. Geology Department Faculty of Science Suez University

Surface sediments were collected from Lake Manzala, the Mediterranean coastal wetland located to the east of the Nile Delta, Egypt, to assess the effect of drain effluent on the spatial variations of sedimentary characteristics and heavy metal pollution. Grain-size compositions, textures, and heavy metal distribution patterns in sediments are presented using GIS technique. Results of the analysis of the sediment showed a clear effect of drain effluent, with an increase in fine fractions and homogeneous suspensions in transportation mode. Lake sediments were dominated by sandy mud textures, and mode of transportation was homogeneous sus- pension and rolling. Spatial distribution of heavy metals (Fe, Mn, Zn, Cu, Ni, Cr, and Pb) was studied in the lake’s surficial sediments, along with their relationship to drain effluent and their contamination status in the ecological system. Heavy metal pollution status was assessed by means of accepted sediment quality guidelines and contamination assessment methods (contamination factor, con- tamination degree, modified contamination degree, geo-accumulation, and enrichment factor). Among the determined heavy metals, Pb had the most ecological risk. Generally, the heavy metals in the surface sediments indicated pollution risk ranging from moderate to considerable, particularly, in those sites facing drains and inlets that had the highest toxic effluent. The results were interpreted by statistical means. A cluster analysis defined areas facing drain discharge and inlets as separated groups. ANOVA indicated that most of the sedimentation and studied metals directed this clustering.

关键词： Lake Manzala Mediterranean wetland metal pollution sedimentological characteristics

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

Recent progress in structural modulation of metal nanomaterials for electrocatalytic CO_(2) reduction

引用

Rare Metals 2021年第6期40卷 1412-1430页

作者： Chen-Huai Yang farhat Nosheen Zhi-Cheng Zhang Tianjin Key Laboratory of Molecular Optoelectronic Sciences Department of ChemistrySchool of ScienceTianjin University&Collaborative Innovation Center of Chemical Science and EngineeringTianjin 300072China Department of Chemistry Division of Science and TechnologyUniversity of EducationLahore 54660Pakistan

The electrochemical CO_(2) reduction(ECR)into value-added products presents an appealing approach to mitigate CO_(2) emission caused by excess consumption of fossil *** obtain high catalytic activity and selectivity toward target product in ECR,designing and developing a stable and efficient electrocatalyst is of significant *** date,metal nanomaterials have been widely applied as electrocatalysts for ECR due to their unique physicochemical *** structural modulation of metal nanomaterials is an attractive strategy to improve the catalytic *** this review,the recent progress of structural modulation,including size,facet,grain boundary,composition,interface,ligand modification,and crystal phase,is systematically summarized from both theoretical and experimental ***,the opportunities and perspectives of structural modulation of metal nanomaterials for ECR are proposed.

关键词： CO_(2)reduction Structural modulation Electrocatalysis Metal nanomaterial Crystal phase

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

Hydrodynamic mechanisms of aggressive collapse events in leading edge cavitation

引用

Journal of Hydrodynamics 2020年第1期32卷 6-19页

作者： Mohammad Hossein Arabnejad Ali Amini Mohamed farhat Rickard EBensow Department of Mechanics and Maritime Sciences Chalmers University of TechnologyGothenburgSweden Laboratory for Hydraulic Machines EPFLLausanneSwitzerland

Transient cavities generated from unsteady leading-edge cavitation may undergo aggressive collapses which are responsible for cavitation *** this paper,we studied the hydrodynamic mechanisms of these events in the leading edge cavitation fonned over a modified NACA0009 hydrofoil using experimental and numerical *** the experimental investigation,high-speed visualization(HSV)and paint test are employed to study the behavior of the cavitating flow at σ=1.25,α=5°,U∞=20 m/*** the numerical part,the same cavitating flow is simulated using an inviscid density-based compressible solver with a barotropic cavitation *** numerical results are first compared with the experimental HSV to show that the simulation is able to reproduce the main features of the cavitating ***,as the compressible solver is capable of capturing the shock wave upon the collapse of cavities,the location of collapse events with high erosion potential are *** location of these collapse events are compared with the paint test results with a qualitatively good *** is clearly observed,in both the experiments and the numerical simulation,that there exists four distinct regions along the hydrofoil with higher risks of erosion:(1)A very narrow strip at the leading edge,(2)an area of accumulated collapses at around 60 percent of the sheet cavity maximum length,(3)an area around the closure line of the sheet cavity with the highest erosion damage,and(4)a wide area close to the trailing edge with dispersed collapse events.A combined analysis of the experimental and numerical results reveals that the small-scale structures generated by secondary shedding are more aggressive than the large-scale cloud cavities(primary shedding).It is also observed that the high risk of cavitation erosion in regions 2 and 3 is mainly due to the collapses of the small cavity structures that are formed around the sheet cavity closure line or the rolling cloud cavity.

关键词： Hydrodynamic mechanisms aggressive collapse events high-speed visualization(HSV) paint test compressible simulation of cavitating flows

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

Effects of blade aspect ratio and taper ratio on hovering performance of cycloidal rotor with large blade pitching amplitude

引用

Chinese Journal of Aeronautics 2019年第5期32卷 1121-1135页

作者： Yu HU Xuyang FU Hailang ZHANG Gengqi WANG Hussain farhat School of Aeronautics Northwestern Polytechnical University

In recent years, a lot of research work has been carried out on the cycloidal rotors. However, it lacks thorough understanding about the effects of the blade platform shape on the hover efficiency of the cycloidal rotor, and the knowledge of how to design the platform shape of the blades. This paper presents a numerical simulation model based on Unsteady ReynoldsAveraged Navier–Stokes equations(URANSs), which is further validated by the experimental results. The effects of blade aspect ratio and taper ratio are analyzed, which shows that the cycloidal rotors with the same chord length have quite similar performance even though the blade aspect ratio varies from a very small value to a large one. By comparing the cycloidal rotors with different taper ratios, it is found that the rotors with large blade taper ratio outperform those with small taper ratio. This is due to the fact that the blade with larger taper ratio has longer chord and hence better efficiency. The analysis results show that the unsteady aerodynamic effects due to blade pitching motion play a more important role in the efficiency than the blade platform shape. Therefore we should pay more attention to the blade airfoil and pitching motion than the blade platform *** main contributions of this paper include: the analysis of the effects of aspect ratio and taper ratio on the hover efficiency of cycloidal rotor based on both the experimental and numerical simulation results; the finding of the main influencing factors on the hover efficiency; the qualitative guidance on how to design the blade platform shape for cycloidal rotors.

关键词： Blade pitching motion Cyclocopter Cyclogyro Cycloidal rotor Dynamic stall

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

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：