检索结果-南通市图书馆

Identification and preliminary characterization of non-polyene antibiotics secreted by new strain of actinomycete isolated from sebkha of Kenadsa, Algeria

引用

Asian Pacific Journal of Tropical Biomedicine 2015年第6期5卷 438-443页

作者： Omar Messaoudi Mourad Bendahou Ibrahim Benamar djamal-elddine abdelwouhid Microbiology Laboratory Applied to Food Biomedical and Environmental (LAMAABE) University of Abou bekr Belkaid Faculty of SNV-STU- Ex Imama Biomedical ComplexPB 119 Tlemcen 13000 Algeria Faculty of Science Department of Biology University of Amar Telidji

Objective: To study the antimicrobial activity of actinomycetes isolated from sabkha of Kenadsa and identification of the isolate interesting. Methods: Eighteen strains were isolated, using four culture media from sebkha of Kenadsa(Bechar, Southwestern Algeria). Screening of antimicrobial activity consisted of two steps: in primary screening, antibacterial activity was determined by using the agar plug method against test strains; in secondary screening, better isolate which showed a good activity in the first screening was selected to extract antimicrobial substances. The antimicrobial activities of extracts were evaluated by using Kirby-Bauer disc diffusion method. Partial characterization of antimicrobial products was performed on the basis of chemical revelations, UV-vis spectrometry and infrared spectroscopy. The identification of isolate interesting was performed through morphological, chemical, biochemical and physiological characteristics. Results: All isolates showed antimicrobial activity against at least one microorganism test. One isolate, LAM143 cG 3, was selected for its broad spectrum and high antimicrobial activity. The isolate LAM143 c G3 was identified as Spirillospora sp. The comparison between the species of this genus(Spirillospora rubra and Spirillospora albida) and our isolate indicated the existence of several physiological and biochemical differences which led us to suppose that this was a new member of this genus. Primary characterization of antimicrobial substances produced by the isolate LAM143 c G3 indicated the presence of amines and phenols. The UV–vis spectrum suggested a non-polyenic nature of substances secreted by our isolate, while infrared confirmed the presence of amine ***: The result of the present study revealed that sebkha of Kenadsa was rich in rare actinomycetes, that secreted interesting antimicrobial substance.

关键词： Isolation Actinomycetes Sebkha Kenadsa Non-polyene Identification Spirillospora

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

累积叠轧焊Al/Mg/Al多层复合材料的腐蚀行为

引用

Transactions of Nonferrous Metals Society of China 2024年第1期34卷 122-138页

作者： Ismail BENCHERIFA Khadidja ABIB Khereddine ABDEL YAZID Baya ALILI djamal BRADAI Laboratory of Metallic and Semiconducting Materials(LMSM) Department of Mechanical EngineeringUniversity of BiskraB.P.14507000BiskraAlgeria Laboratory of Materials Physics Faculty of PhysicsUniversity of Sciences and Technology-Houari Boumediene(U.S.T.H.B.)P.O.Box 32El-AliaBab-EzzouarDZ-16111AlgiersAlgeria Center for Development of Advanced Technologies CDTACitédu 20 août 1956Baba-Hassen16303 AlgiersAlgeria

研究累积叠轧焊(ARB)Al1050/AZ31/Al1050多层复合材料的腐蚀行为,腐蚀介质为3.5%Na Cl(质量分数)溶液,分析测试手段包括动电位极化测试(PDP)、电化学阻抗谱(EIS)、扫描电子显微镜(SEM-EDS)、拉曼光谱和X射线衍射(XRD)等。为了深入研究Al... 详细信息

研究累积叠轧焊(ARB)Al1050/AZ31/Al1050多层复合材料的腐蚀行为,腐蚀介质为3.5%Na Cl(质量分数)溶液,分析测试手段包括动电位极化测试(PDP)、电化学阻抗谱(EIS)、扫描电子显微镜(SEM-EDS)、拉曼光谱和X射线衍射(XRD)等。为了深入研究Al1050/AZ31/Al1050多层复合材料的耐腐蚀性和腐蚀产物,对ARB制备的Al1050/Al1050/Al1050多层复合材料进行了相似的测试作为对比。动电位极化曲线和电化学阻抗谱显示,ARB应变水平会显著影响腐蚀速率。与Al1050/Al1050/Al1050样品相比,Al1050/AZ31/Al1050多层复合材料具有更高的腐蚀速率和更低的极化电阻。AZ31层对腐蚀过程起主导作用。拉曼和XRD分析结果表明主要腐蚀产物为Mg(OH)2,且不含任何氯化合物(如(Mg(OH)_(2))·MgCl_(2))。

关键词：累积叠轧焊 Al1050/AZ31/Al1050 多层复合材料腐蚀金属间化合物

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

Feature selection on probabilistic symbolic objects

引用

Frontiers of Computer Science 2014年第6期8卷 933-947页

作者： djamal ZIANI Information Systems Department College of Computer and Information Sciences King Saud University Riyadh 11543 Saudi Arabia

In data analysis tasks, we are often confronted to very high dimensional data. Based on the purpose of a data analysis study, feature selection will find and select the relevant subset of features from the original features. Many feature selection algorithms have been proposed in classical data analysis, but very few in symbolic data analysis （SDA） which is an extension of the classical data analysis, since it uses rich objects instead to simple matrices. A symbolic object, compared to the data used in classical data analysis can describe not only individuals, but also most of the time a cluster of individuals. In this paper we present an unsupervised feature selection algorithm on probabilistic symbolic objects （PSOs）, with the purpose of discrimination. A PSO is a symbolic object that describes a cluster of individuals by modal variables using relative frequency distribution associated with each value. This paper presents new dissimilarity measures between PSOs, which are used as feature selection criteria, and explains how to reduce the complexity of the algorithm by using the discrimination matrix.

关键词： symbolic data analysis feature selection probabilistic symbolic object discrimination criteria data and knowledge visualization.

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

Corrosion behavior of Al/Mg/Al multilayered composite elaborated by accumulative roll bonding

引用

Transactions of Nonferrous Metals Society of China 2022年

作者： Ismail BENCHERIFA Khadidja ABIB Abdel Yazid KHEREDDINE Baya ALILI djamal BRADAI Center for Development of Advanced Technologies， CDTA， Cité du 20 aoét 1956 Laboratory of Metallic and Semiconducting Materials (LMSM)， Department of Mechanical Engineering， University of Biskra Laboratory of Materials Physics， Faculty of Physics， University of Sciences and Technology-Houari Boumediene (U.S.T.H.B.)， P.O.Box 32， El-Alia

The corrosion behavior of an Al1050/AZ31/Al1050 multilayered hybrid composite fabricated by the accumulated roll bonding (ARB) technique up to six cycles in a 3.5% NaCl (wt.%) solution has been studied through potentiodynamic polarization tests (PDP)， electrochemical impedance spectroscopy (EIS)， scanning electron microscopy (SEM-EDS)， Raman spectroscopy and X-ray diffraction (XRD). In order to deeply apprehend the corrosion resistance and corrosion products of the Al1050/AZ31/Al1050 multilayered hybrid composite， almost similar investigation were performed on the Al1050/Al1050/Al1050 multilayered sample elaborated by ARB up to one cycle. Potentiodynamic polarization plots and electrochemical impedance spectroscopy showed that the corrosion rate was strongly affected by the ARB strain level. A higher corrosion rate and reduced polarization resistance were evidenced compared to the Al1050/Al1050/Al1050 multilayered sample. The AZ31 layers seemed to dominate the corrosion process. Raman and XRD analysis did confirm the presence of the main corrosion product that was Mg(OH)and the absence of any chloride such as (Mg(OH))·MgCl

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

电子商务，刚果民主共和国木薯农业发展的重要技术

电子商务，刚果民主共和国木薯农业发展的重要技术

引用

作者： djamal Malitele Wambasa 浙江工商大学

学位级别：硕士

Since the emergence of E-commerce and its implementation in the cooperative world,many cooperate bodies internationally have witnessed its wide and effective contribution to the breathtaking possibility of international trade of variant *** internet has enabled greater visibility into the global supply chain,as buyers and sellers are in short proximity and more effortlessly connected.E-commerce sourced from the benefits of the internet aim at overcoming barriers around customer preferences and logistics to drive online grocery across the *** ultimate goal of this research is to scrutinize how the performance of E-commerce could extend its potential to the development of agriculture of DR Congo’s most cultivated,compared to other countries worldwide and most locally consumed product,namely *** qualitative research method implemented to analyze the relationship that is built between Ecommerce and the evolution of the agriculture,reveals the reasons why E-commerce should be looked at as the solution for agricultural growth and secondly how it can be the solution that will lead to the growth of agriculture of Cassava particularly in DR ***,a thorough data collection process and investigation of the results found regarding the evolution of agriculture in Congo in comparison to other African nations where Cassava has been cultivated,is gathered to highlight the relevant matters of this *** study presented limitations as a result of the lack of previous studies in the research area because it is an unexploited field with short range information.E-commerce in Congo faces obstacles due to the slow adoption of modern agricultural technologies,which have been major drivers of increased agricultural output and profitability in other ***,through this research study,the possibility of E-commerce to bring an undeniable national change in Congo’s agriculture,which will influence other major shifts in the country and inter

关键词：

来源：

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Multi-wavelength fibril dynamics and oscillations above sunspot– I. morphological signature

引用

Research in Astronomy and Astrophysics 2015年第11期15卷 1843-1856页

作者： Emanuel Sungging Mumpuni Dhani Herdiwijaya Mitra djamal Thomas djamaluddin Graduate Program in Astronomy Faculty of Mathematics and Natural Sciences Bandung Institute of TechnologyGedung CAS Lt. 6 ITB Jl. Ganesha 10 Bandung 40132 Indonesia Space Science Center LAPAN Graduate Program in Physics Faculty of Mathematics and Natural Sciences Bandung Institute of Technology Department of PhysicsJl. Ganesha 10 Bandung 40132 Indonesia

In this work we selected one particular fibril from a high resolution observation of the solar chromosphere with the Dutch Open Telescope, and tried to obtain a broad picture of the intricate mechanism that might be operating in the multiple layers of the solar atmosphere visible in high cadence multi-wavelength observations. We analyzed the changing fibril pattern using multi-wavelength tomography, which consists of both the Hα line center and the blue wing, Doppler signal, Ca II H, and the G-band. We have found that the intermittent ejected material through the fibril from Doppler images has clearly shown an oscillation mode, as seen in the Hα blue *** oscillations in the umbrae and penumbrae magnetic field lines that are above the sunspot cause a broadening and the area forms a ring shape from 3 to 15 minute oscillations as a function of height. These made a distinct boundary between the umbrae and penumbrae which suggests a comb structure, and indicates that the oscillations could propagate along the inclined magnetic flux tubes from below. The 3 minute oscillations strongly appeared in the broadly inclined penumbrae magnetic field lines and showed a clear light bridge. The well known 5 minute oscillations were dominant in the umbrae-penumbrae region boundary. The long 7 minute oscillations were transparent in the Hα blue wing, as well as the 10 and 15 minute oscillations. They were concentrated in the inner-penumbrae, as seen in the Hα line center. From these findings we propose that the fibril acts as a fabric for interaction between the layers,as well as related activities around the active region under investigation.

关键词： minute morphological signature picture propagate fabric Figure sector visible concentrated

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

Statistical improvement in detection level of gravitational microlensing events from their light curves

引用

Research in Astronomy and Astrophysics 2018年第4期18卷 43-58页

作者： Ichsan Ibrahim Hakim L.Malasan Chatief Kunjaya Anton Timur Jaelani Gerhana Puannandra Putri Mitra djamal Department of Astronomy Institute of Technology Bandung Bandung Indonesia Department of Physics Department of Astronomy Institute of Technology Bandung Bandung Indonesia Bosscha Astronomical Observatory Department of Astronomy Institute of Technology Bandung LembangIndonesia Department of Informatics STMIK-Indonesia Mandiri Bandung Indonesia Universitas Ma Chung Malang Indonesia Faculty of Shariah Institut Agama Islam Ternate Ternate North Molucca Indonesia Astronomical Institute Tohoku University Sendai Japan

In astronomy,the brightness of a source is typically expressed in terms of ***,the magnitude is defined by the logarithm of received *** relationship is known as the Pogson *** received flux with a small signal to noise ratio（S/N）,however,the formula gives a large magnitude *** investigate whether the use of Inverse Hyperbolic Sine function（hereafter referred to as the Asinh magnitude）in the modified formulae could allow for an alternative calculation of magnitudes for small S/N flux,and whether the new approach is better for representing the brightness of that *** study the possibility of increasing the detection level of gravitational microlensing using 40 selected microlensing light curves from the 2013 and 2014 seasons and by using the Asinh *** data of the selected events are obtained from the Optical Gravitational Lensing Experiment（OGLE）.We found that utilization of the Asinh magnitude makes the events brighter compared to using the logarithmic magnitude,with an average of about 3.42×10^（-2）magnitude and an average in the difference of error between the logarithmic and the Asinh magnitude of about 2.21×10（-2）*** microlensing events OB140847 and OB140885 are found to have the largest difference values among the selected *** a Gaussian fit to find the peak for OB140847 and OB140885,we conclude statistically that the Asinh magnitude gives better mean squared values of the regression and narrower residual histograms than the Pogson *** on these results,we also attempt to propose a limit in magnitude value for which use of the Asinh magnitude is optimal with small S/N data.

关键词： gravitational lensing micro — methods data analysis

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

中国共产党是南南合作的重要推动者

引用

当代世界 2022年第9期 77-78页

作者： [科摩罗]穆萨·阿里·卡马尔科摩罗复兴公约党

自1949年新中国成立以来,中国共产党始终牢牢把握国家和民族的前途命运,团结带领中国人民英勇斗争、不懈奋斗,将中国建设成为富强民主的世界强国,中华民族也迎来从站起来、富起来到强起来的伟大飞跃。在中国共产党历代领导人的英明领导... 详细信息

自1949年新中国成立以来,中国共产党始终牢牢把握国家和民族的前途命运,团结带领中国人民英勇斗争、不懈奋斗,将中国建设成为富强民主的世界强国,中华民族也迎来从站起来、富起来到强起来的伟大飞跃。在中国共产党历代领导人的英明领导下,加之全体中国人民的勇敢和智慧,新中国从一穷二白、封闭落后走向繁荣富强、自信开放。中国已全面建成小康社会,消除绝对贫困,实现经济快速增长和人民生活极大改善,并日益走近世界舞台的中央。

关键词：世界强国全体中国人民绝对贫困南南合作英明领导英勇斗争世界舞台历代领导人

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

新型青光眼引流装置——Paul青光眼植入物在印度尼西亚人群中应用的早期经验

引用

国际眼科杂志 2023年第10期23卷 1603-1608页

作者： Emma Rusmayani Viona Viona Iwan Soebijantoro Rini Sulastiwaty Arini Safira Nurul Akbar Muhammad Yoserizal Zeiras Eka djamal Widya Artini Wiyogo 雅加达眼科中心青光眼科印度尼西亚雅加达15520 雅加达眼科中心研究中心印度尼西亚雅加达15520

目的:探究Paul青光眼植入物(PGI)在短期随访期间的安全性和有效性,分享新型房水引流装置在印度尼西亚人群中应用的首次经验。方法:回顾性分析2022-04/2022-12期间使用PGI植入物的患者21例22眼,随访至少2mo。主要结局指标为手术失败,定... 详细信息

目的:探究Paul青光眼植入物(PGI)在短期随访期间的安全性和有效性,分享新型房水引流装置在印度尼西亚人群中应用的首次经验。方法:回顾性分析2022-04/2022-12期间使用PGI植入物的患者21例22眼,随访至少2mo。主要结局指标为手术失败,定义为眼压(IOP)超过21mmHg,或连续2次就诊较基线水平降低小于20%,需行其他青光眼手术或移除植入物。结果:纳入患者的随访时间为2-6mo,平均IOP降低52.27±22.94%(9-90)%,总体成功率为59%,有青光眼手术史和未接受过青光眼手术的患者手术完全成功率分别为50%和59%。并发症有复视(2例)、早期低眼压(1例)、前房积血(1例)及引流管暴露(2例)。结论:植入PGI的完全成功率为57%。未发生严重术后并发症,低眼压术后早期消退1例。

关键词：保罗青光眼植入物青光眼分流管青光眼引流植入物青光眼手术印度尼西亚人

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

Topology Control and Routing in Large Scale Wireless Sensor Networks

引用

Wireless Sensor Network 2010年第8期2卷 584-598页

作者： Ines Slama Badii Jouaber djamal Zeghlache 不详

In this paper, a two-tiered Wireless Sensor Network (WSN) where nodes are divided into clusters and nodes forward data to base stations through cluster heads is considered. To maximize the network lifetime, two energy efficient approaches are investigated. We first propose an approach that optimally locates the base stations within the network so that the distance between each cluster head and its closest base station is decreased. Then, a routing technique is developed to arrange the communication between cluster heads toward the base stations in order to guaranty that the gathered information effectively and efficiently reach the application. The overall dynamic framework that combines the above two schemes is described and evaluated. The experimental performance evaluation demonstrates the efficacy of topology control as a vital process to maximize the network lifetime of WSNs.

关键词： Wireless Sensor Networks Routing Topology Control Base Stations Placement Energy

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：