检索结果-南通市图书馆

Mechanical and thermodynamical stability of BiVO4 polymorphs using first-principles study

Chinese Physics B 2017年第3期26卷 395-403页

作者： A K M Farid UI Islam Md Nurul Huda Liton H M Tariqul Islam Md Al helal Md Kamruzzaman Department of Computer Science and Engineering Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Department of Physics Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Department of Chemistry Begum Rokeya University Rangpur Rangpur-5400 Bangladesh Department of Physics and Materials Science and Center of Super-Diamond and Advanced Films (COSDAF) City University of Hong Kong Hong Kong SAR China

First principles calculations of structural, electronic, mechanical, and thermodynamic properties of different poly- morphs of BiVO4 are performed using Bender-type plane/wave ultrasoft pseudopotentials within the generalized gradient approximation （GGA） in the flame of density functional theory （DFT）. The calculated structural and electronic properties are consistent with the previous theoretical and experimental results. The electronic structures reveal that m-BiVO4, op- BiVO4, and st-BiVO4 have indirect band gaps, on the other hand, zt-BiVO4 has a direct band gap. From the DOS and Mulliken＇s charge analysis, it is observed that only m-BiVO4 has 6s2 Bi lone pair. Bond population analysis indicates that st-BiVO4 shows a more ionic nature and a similar result is obtained from the elastic properties. From the elastic prop- erties, it is observed that st-BiVO4 is more mechanically stable than the others, st-BiVO4 is more ductile and useful for high electro-optical and electro-mechanical coupling devices. Our calculated thermodynamic properties confirm the similar characteristics found from electronic and elastic properties, m-BiVO4 is useful as photocatalysts, solid state electrolyte, and electrode and other polymorphs are applicable in electronic device fabrications.

关键词： BiVO4 crystal structure lone pair mechanical stability

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 Performance of Multiple-row Slotted Breakwaters

引用

Journal of Marine Science and Application 2016年第2期15卷 123-135页

作者： Moussa S. Elbisy Ehab M. Mlybari Medhat M. helal Civil Engineering Department Higher Technological Institute Tenth of Ramadan City 44629 Egypt Civil Engineering Department Umm Al-Qura University Makkah 21955 Saudi Arabia Department of Engineering Mathematics and Physics Zagazig University Zagazig 44511 Egypt

这研究检验多重排的垂直 slotted 防波提的水动力学表演。我们基于一个特徵函数扩大方法和一种最少的广场技术开发了一个数学模型为司烧秒顺序波浪。为限制双排和三倍排的墙的格获得的数字结果在对以前的研究的结果和试验性的结果的好... 详细信息

这研究检验多重排的垂直 slotted 防波提的水动力学表演。我们基于一个特徵函数扩大方法和一种最少的广场技术开发了一个数学模型为司烧秒顺序波浪。为限制双排和三倍排的墙的格获得的数字结果在对以前的研究的结果和试验性的结果的好同意。有思考，传播，和驱散系数的试验性的大小的比较(为双排墙的 C r , C T , 和 C E ) 证明建议数学模型足够地复制大多数重要特征。我们发现为双排墙，有增加的 C r 增加挥动数字， kd，并且与减少可渗透的墙部分， dm。C T 跟随相反的趋势。C E 慢慢地为更低的 kd 价值与增加的 kd 增加，到达最大值，然后再减少。另外， dm 的一个增加的孔将显著地减少 C r , 当增加 C T 时。在 kd 的更低的价值，一个减少的孔要不是 kd 的高价值增加 C E , ，一个减少的孔减少 C E 。数字结果显示为三倍排的墙，水动力学特征上的房间宽度的安排的效果不是重要的，除了当时 kd 0.5，在由水平波浪力量可能比一个单身者的小的地方，围。在另一方面，双排之间的差别和三倍排的垂直 slotted 防波提是边缘的。

关键词：水动力性能防波堤槽式数学模型特征函数实验测量低孔隙率最小二乘法

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

Applications of Amplitude versus Offset and Seismic Attributes for Perceiving Messinian reservoirs in Nidoco Field, Nile Delta, Egypt

引用

International Journal of Geosciences 2022年第5期13卷 319-328页

作者： Ahmed Abu El-Saoud Abd El-Nasser helal Justin Matresu Amir M. S. Lala Belayim Petroleum Company (Petrobel) Cairo Egypt Faculty of Science Ain Shams University Cairo Egypt Exploration Team Leader at Eni Cairo Egypt

Nile Delta which covers approximately 60,000 square kilometers represents the most important gas province in Egypt whereas its fields provide two-thirds of the gas production in Egypt. The Nile Delta province begins to display its hydrocarbon potentiality in the early 1960s. Nidoco field is located in the shallow water offshore Nile delta. Abu Madi formation (Messinian age) is the most important formation through all the section where it represents the main gas producing reservoirs in the Field. The production of the field is coming from two sand reservoir levels;Abu Madi level 2&3 which are characterized by fluvial-deltaic sandstones. The purpose of this paper is to perceive the Messinian gas bearing reservoirs and channelized sand distribution inside Abu Madi formation using seismic attributes and amplitude versus offset (AVO) technique. The results indicated that the seismic attributes and AVO aided to give a complete picture about the Messinian reservoirs distribution and characterization in the field. Also the results show that there are still promising locations of prospective Abu Madi Level 2&3 which are proposed to be drilled in the field.

关键词： AVO Nidoco Field Abu Madi Formation Seismic Attributes

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

Study of a crop-pest-natural enemy model with Z-type control——An approach to pest management

引用

International Journal of Biomathematics 2023年第4期16卷 175-207页

作者： Dibyendu Sekhar Mandal Sudip Samanta rana D.Parshad Abdennasser Chekroun Mohamed helal Joydev Chattopadhyay Department of Mathematics AmityUniversity Maharashtra Mumbai Maharashtra 410206India Agricultural and Ecological research Unit Indian Statistical Institute 203B.T.Road Kolkata 700108India Department of Mathematics Bankura University WestBengal722155India Department of Mathematics Iowa State University AmesIA 50011USA Laboratoire d'Analyse Nonlineaire et Mathematiques Appliquees University of Tlemcen Tlemcen 13000Algeria Biomathematics Laboratory Universite Sidi Bel-Abbes P.B.8922000Algeria

In this study,the Z-type control method is applied to an intraguild crop-pest-natural enemy model,assuming that the natural enemy can predate on both crop and pest *** this purpose,the indirect Z-type controller is considered in the natural enemy *** providing the design function for the crop-pest-natural enemy model with Z-control,we find the analytical expression of the update *** findings indicate that the uncontrolled system can produce chaos through perioddoubling bifurcation due to crop over-consumption by the pest *** draw a Poincare map to confirm the occurrence of chaos and compute the maximum Lyapunov *** the observations further indicate that the pest population can be controlled by using an indirect Z-control mechanism in the natural enemy population,we postulate that,if natural enemy abundance can be governed by the update parameter,any desired pest population abundance can be achieved through the proposed Z-type controller,thus controlling the *** verify these assertions,extensive numerical simulations are performed to explore the potential for practical application of the proposed Z-type controller.

关键词： Crop-pest-natural enemy model Z-type control numerical simulations pest control

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

HBsAg, HBcAg, and combined HBsAg/HBcAg-based therapeutic vaccines in treating chronic hepatitis B virus infection

引用

Hepatobiliary & Pancreatic Diseases International 2013年第4期12卷 363-369页

作者： Sheikh Mohammad Fazle Akbar Mamun Al-Mahtab Mohammad helal Uddin Md. Sakirul Islam Khan Department of Medical Sciences Toshiba General HospitalTokyo Japan Department of Hepatology Bangabandhu Sheikh Mujib Medical UniversityDhaka Bangladesh Clinical research Organization Dhaka Bangladesh Laboratory of Animal Production Faculty of Agriculture Ehime UniversityMatsuyama Japan

BACKGrOUND: As the host immunity is diminished in patients with chronic hepatitis B (CHB), different approaches have been used to up-regulate their immune responses to produce therapeutic effects. But, cytokines, growth factors and polyclonal immune modulators could not exhibit sufficient therapeutic effects in these patients. Immune therapy with HBV-related antigens (vaccine therapy) has been used in CHB patients. But there is a paucity of information about the design of HBV antigen-based immune therapy in these patients. DATA SOUrCE: Preclinical and clinical studies on immune therapy with HBsAg-based vaccine, HBcAg and combination of HBsAg/HBcAg-based vaccines have been discussed. rESULTS: HBsAg-based prophylactic vaccine was used as an immune therapeutic agent in CHB patients; however, monotherapy with HBsAg-based immune therapy could not lead to sustained control of HBV replication and/or liver damages. HBsAg-based vaccine was used as a combination therapy with cytokines, growth factors, and antiviral drugs. HBsAg-based vaccine was also used for cell-based therapy. However, satisfactory therapeutic effects of HBsAg-based vaccine could not be documented in CHB patients. In the mean time, evidences have supported that HBcAg-specific immunity is endowed with antiviral and liver protecting capacities in CHB patients. recent data concentrate on the clinical use of combined HBsAg- and HBcAg-based vaccines in CHB ***: Antigen-based immune therapy with HBV- related antigens may be an alternative method for the treatment of CHB patients but proper designs of antigens, types of adjuvants, dose of vaccinations, and routes of administration need further analyses for the development of an effective regimen of immune therapy against HBV.

关键词： chronic hepatitis B HBsAg vaccine HBsAg/HBcAg vaccine immune therapy therapeutic vaccines

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 Characteristics of Three rows of Vertical Slotted Wall Breakwaters

引用

Journal of Marine Science and Application 2017年第3期16卷 261-275页

作者： Majed O. Alsaydalani Mohammed A. N. Saif Medhat M. helal Civil Engineering Department Umm Al-Qura University Makkah 21955 Saudi Arabia Department of Engineering Mathematics andPhysics Zagazig University Zagazig 44511 Egypt

In this study, we examine the hydrodynamic characteristics of three rows of vertical slotted wall breakwaters in which the front and middle walls are permeable and partially immersed in a water channel of constant depth, whereas the third wall is impermeable. The wave–structure interaction and flow behavior of this type of breakwater arrangement are complicated and must be analyzed before breakwaters can be appropriately designed. To study the hydrodynamic breakwater performance, we developed a mathematical model based on the eigenfunction expansion method and a least squares technique for predicting wave interaction with three rows of vertical slotted wall breakwaters. We theoretically examined the wave transmission, reflection, energy loss, wave runup, and wave force under normal regular waves. Comparisons with experimental measurements show that the mathematical model results adequately reproduce most of the important features. The results of this investigation provide a better understanding of the hydrodynamic performance of triple-row vertical slotted wall breakwaters.

关键词：水动力学特征 Slotted 垂直 slotted 结构相互作用墙波浪传播数学模型

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

Alterations in sucrose metabolizing enzyme activities and total phenol content of Curcuma longa L. as affected by different triazole compounds

引用

Frontiers in Biology 2009年第4期4卷 419-423页

作者： C.Abdul JALEEL Changxing ZHAO Sedghi MOHAMED Hameed Jasim AL-JUBUrI helal ragab MOUSSA M.GOMATHINAYAGAM r.PANNEErSELVAM Stress Physiology Lab Department of BotanyAnnamalai UniversityTamil NaduIndia DMJM International(Cansult Maunsell/AECOM Ltd.) Consultant of Gardens Sector ProjectsAlain Municipality and Eastern EmiratesP.O.Box 1419Al-AinAbu DhabiUnited Arab Emirates College of Agronomy and Plant Protection Qingdao Agricultural UniversityChunyang RoadChengyang DistrictQingdao 266109China Department of Agronomy and Plant Breeding Faculty of AgricultureUniversity of Mohaghegh ArdabiliArdabilIran radioisotope Department Atomic Energy AuthorityMalaeb El-Gamaa St.P.O.12311DokkiGizaEgypt

Changes in the sucrose metabolism of Cur-cuma longa *** were studied under treatment with different triazole compounds viz.,triadimefon(TDM)and propiconazole(PCZ).Plants were treated with TDM at 15mg/L and PCZ at 10mg/L separately by soil drenching on 80,110,and 140 days after planting(DAP).The plants were harvested randomly on 90,120,and 150DAP to determine the effect of both the triazoles on sucrose metabolizing enzymes and phenol *** sucrose metabolism was studied by analyzing sucrose metaboliz-ing enzymes like sucrose synthase and sucrose phosphate *** the analyses were assayed in leaves and tubers of both control and treated *** was found that both of the triazole compounds had profound effects on these parameters.

关键词： Curcuma longa triadimefon propiconazole sucrose synthase sucrose phosphate synthase total phenol

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

Oxidative leaching kinetics of molybdenum-uranium ore in H2SO4 using H2O2 as an oxidizing agent

引用

Frontiers of Chemical Science and Engineering 2013年第1期7卷 95-102页

作者： T. A. Lasheen M. E. EI-Ahmady H. B. Hassib A. S. helal Nuclear Materials Authority Cairo Egypt Chemistry Department Faculty of Science Cairo University Giza Egypt

The processing of molybdenum-uranium ore in a sulfuric acid solution using hydrogen peroxide as an oxidant has been investigated. The leaching temperature, hydrogen peroxide concentration, sulfuric acid concentration, leaching time, particle size, liquid-to-solid ratio and agitation speed all have significant effects on the process. The optimum process operating parameters were： temperature： 95℃; H2O2 concentration： 0.5 M; sulfuric acid concentration： 2.5 M; time： 2 h; particle size： 74 gm, liquid-to-solid ratio： 14 ： 1 and agitation speed： 600 rpm. Under these experimental conditions, the extraction efficiency of molybdenum was about 98.4%, and the uranium extraction efficiency was about 98.7%. The leaching kinetics of molybdenum showed that the reaction rate of the leaching process is controlled by the chemical reaction at the particle surface. The leaching process follows the kinetic model 1 - （1-X）1/3 = kt with an apparent activation energy of 40.40 kJ/mole. The temperature, concentrations of H202 and H2SO4 and the mesh size are the main factors that influence the leaching rate. The reaction order in H2SO4 was 1.0012 and in H202 it was 1.2544.

关键词： leaching of molybdenum leaching of uranium kinetics

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

Pre-formed endotracheal tube and stepwise insertion for more successful intubation with video laryngoscopy

引用

World Journal of Anesthesiology 2021年第2期10卷 7-15页

作者： Ahmed A Shorrab Moustafa A helal Department of Anesthesia University Hospital SharjahSharjah POB 72772United Arab Emirates Faculty of Medicine Mansoura UniversityMansoura 35516Egypt University Hospital Sharjah SharjahUnited Arab Emirates

BACKGrOUND In anesthesia practice,orotracheal intubation remains the primary concern of the *** introduction of video laryngoscopy(VL)has increased the success rate of orotracheal intubation;however,conflicting results have been reported regarding the usefulness of the current technique with VL in clinical *** To describe a modification to improve intubation with VL,followed by evaluation of the practice in *** First,a mannequin trial was conducted with operators having different experience and ***,a retrospective analysis was performed for an>1-year period with patients who underwent general anesthesia with orotracheal *** endotracheal tube used had been pre-formed with two *** intubation had been performed with direct eye vision,followed by screen assistance and rotation of the tube as needed to direct it toward the *** the mannequin trial,the outcome measures were quantification of torque(force with angular acceleration during levering),need for external maneuvers,and time to *** the clinical experience,orotracheal intubation used VL(pre-formed tube)or direct laryngoscopy(DL)at the anesthetist’s discretion and throat discomfort was reported by the *** In the mannequin trials using VL,there was less torque with the pre-formed tube than with a regular tube(8%and 65%,respectively).The first-pass rate was higher with the pre-formed tube(95%)than with a regular tube(81%).However,the time to intubate was longer with the pre-formed tube than with a regular tube(22 s and 12 s,respectively).In clinical practice,562 patients underwent surgery under general anesthesia with orotracheal intubation using either VL(n=244)or DL(n=318)at the discretion of the attending *** was specifically planned in 62 of the patients,due to anticipated *** attempts by readjustment of the curve of the tube were significantly fewer with VL than with DL(10%vs 18%).Throat discom

关键词： Intubation Glottis view Airway Indirect laryngoscopy Torque

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

Fuzzy Estimation Analysis of Photovoltaic Model Parameters

引用

Journal of Power and Energy Engineering 2015年第7期3卷 39-43页

作者： helal Al-Hamadi Department of Information Science College of Computing Sciences and Engineering Kuwait University Kuwait Kuwait

One of the challenges in accurately estimating Photovoltaic (PV) cell electric performance is the uncertainty of the model equivalent circuit parameters. The parameters considered in the study are the series resistance, shunt resistance, photo current, saturation current, and diode ideality factor. Parameter estimation for the PV cell equivalent circuit model is challenging due to the implicit transcendental relationship of the I-V characteristics of the cell. This paper presents a fuzzy logic based study for estimating the uncertainty of the cell parameters. The model parameters change with temperature and irradiance, are the source of uncertainties. Mathematical programming is used to estimate the fuzzy parameters. The approach is performed on practical data and the results of the analysis provide the estimation of the PV cell parameters. results of this research yielding better estimated parameters compared with other methods using the Absolute Mean Error (AME).

关键词： Photovoltaic Cell Parameter Sensitivity Fuzzy Logic Diode Model Modeling

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：