检索结果-南通市图书馆

Rare earth element geochemistry of the Permo-Carboniferous clastic sedimentary rocks from the Spiti Region,Tethys Himalaya:significance of Eu and Ce anomalies

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

Chinese Journal Of Geochemistry 2015年第2期34卷 252-264页

作者： Javid Ahmad Ganai Shaik abdul rashid Department of Geology Aligarh Muslim University

包括沙岩和联系页岩， Siliciclastic 沉积岩石 NW Tethys Himalaya 从 Permo 含碳的 Kanawar 组织， Spiti 区域，印度 geochemically 被检验在 Himalaya 在上面的大陆人外壳中监视进化变化。岩石被一致稀土元素元素(REE ) 描绘有轻 R... 详细信息

包括沙岩和联系页岩， Siliciclastic 沉积岩石 NW Tethys Himalaya 从 Permo 含碳的 Kanawar 组织， Spiti 区域，印度 geochemically 被检验在 Himalaya 在上面的大陆人外壳中监视进化变化。岩石被一致稀土元素元素(REE ) 描绘有轻 REE 丰富的模式(La N /Yb N ?=?5.328.2) 和完全重的 REE 模式。REE 价值高(多达 281 ? ppm ) 与大否定 Eu 异例(avg。Eu/Eu *?=? 0.57 ) 。沉积的 REE 特征类似于 Archean 以后澳大利亚人页岩和北美的页岩的那些合成。La/Th 价值(avg。2.34 ) 对应于一相对陆上的火的岩石标准的 felsic 作文(G-1 的 La/Th ?=? 2.3 ) 。沉积的发展 felsic 作文可能在来源联系到普遍酸的活动。REE 模式和 Th/U 价值似乎被沉积环境以及由起源影响了。在一些沉积的积极 Ce 异例的存在可以是 post-depositional 过程的结果。而且， Permo 含碳的沉积显示甚至在短运输距离上，水力的排序能够集中足够的附件阶段影响 REE 作文并且开发否定 Eu 异例。高 REE， La/Yb，和 Th/U 内容和大否定 Eu 异例表明沉积在氧化环境被扔，建议地表的环境变得在在印度 craton 的含碳二叠的边界附近氧化。

关键词：稀土元素地球化学特提斯喜马拉雅石炭二叠系 Ce异常碎屑沉积岩 Eu 氧化环境硅质沉积岩

MI-NLMS adaptive beamforming algorithm for smart antenna system applications

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第10期7卷 1709-1716页

作者： MOHAMMAD Tariqul Islam ZAINOL Abidin abdul rashid Department of Electrical Electronics and System Engineering Faculty of Engineering Universiti Kebangsaan Malaysia43600 Bangi Selangor D.E. Malaysia

A Matrix Inversion Normalized Least Mean Square (MI-NLMS) adaptive beamforming algorithm was developed for smart antenna application. The MI-NLMS which combined the individual good aspects of Sample Matrix Inversion (SMI) and the Normalized Least Mean Square (NLMS) algorithms is described. Simulation results showed that the less complexity MI-NLMS yields 15 dB improvements in interference suppression and 5 dB gain enhancement over LMS algorithm, converges from the initial iteration and achieves 24% BER improvements at cochannel interference equal to 5. For the case of 4-element uniform linear array antenna, MI-NLMS achieved 76% BER reduction over LMS algorithm.

关键词： Smart antenna Beamforming algorithm Least Mean Square (LMS) Normalized LMS (NLMS) Matrix InversionNLMS (MI-NLMS)

Financial frictions and the cash flow – external financing sensitivity: evidence from a panel of Pakistani firms

在线全文

学校读者我要写书评

暂无评论

Financial Innovation 2018年第1期4卷 222-241页

作者： abdul rashid Noshaba Jabeen International Institute of Islamic Economics(IIIE) International Islamic University(IIU)H-10Islamabad 44000Pakistan

This paper uses a large panel of Pakistani non-financial firms over the period 2000-2013 to examine the role of financial constraints in establishing the relationship between cash flow and external *** results reveal that there exists a negative and significant relationship between external financing and cash *** finding of the substitutionary relation between internal funds availability and external financing has been viewed as evidence supporting the pecking order theory of capital ***,we show that this negative relationship is weak in case of financially constrained *** also analyze how credit multiplier affects external financing decisions of financially constrained and unconstrained *** results show that for financially unconstrained firms,the negative sensitively of external financing increases with asset ***,for financially constrained firms,the negative sensitivity of external financing to cash flow either decreases or turns positive as the tangibility of assets *** finding implies that financially constrained firms benefit more from investing in tangible assets because such assets not only help relax financial constraints but also having a potential to be a direct source of funds in periods of negative cash flow shocks.

关键词： External financing Cash flows Internally generated funds Financial constraints Investment Credit multiplier

New coating formulation for the slow release of urea using a mixture of gypsum and dolomitic limestone

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

Particuology 2015年第6期13卷 62-67页

作者： Farahnaz Eghbali Babadi Robiah Yunus Suraya abdul rashid Mohamad Amran Mohd Salleh Salmiaton Ali Institute of Advanced Technology Universiti Putra Malaysia Selangor 43400 Malaysia Departments of Chemical and Environmental Engineering Faculty of Engineering Universiti Putra Malaysia Selangor 43400 Malaysia

The use of urea and urea-based fertilizers has increased considerably over the past 15 years. They cur- rently account for approximately 51% of the world＇s agricultural nitrogen consumption. However, about 20-70% of the applied urea fertilizer is lost to the environment, causing serious pollution and increasing costs. These losses come from leaching, decomposition, and ammonium volatilization in the soil during handling and storage. Controlled release by coating can be used to increase urea fertilizer efficiency. We studied the use of gypsum, sulfur, and ground magnesium lime as cost-effective coating materials. All these coating materials contain nutrients required by plants. The effects of the coating composition and proportion of sealant on the rate of urea release and the crushing strength of the coated urea were investigated. We found that coated urea with the same proportion of gypsum-ground magnesium lime （GML） exhibited low urea release and high crushing strength. The performance was enhanced when using polyols as a sealant on the surface of the coated urea. A surface morphology analysis indicated a uniform and smooth surface on the coated film. The efficiency of the coated urea improved by 34.2% when using gypsum-GML （ 1：1 ratio） containing 1.1% oolvols.

关键词： Ground magnesium lime Crushing strength Rotary pan SealantPolyol

Infra-tentorial brain tumor subtypes in children and adults--surgical outcome in an ethnic population with a single regional tertiary center

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

Chinese Neurosurgical Journal 2022年第3期8卷 160-168页

作者： abdul rashid Bhat Muhammed Afzal Wani Altaf Rehman Kirmani Department of Neurosurgery Sher-i-Kashmir Institute of Medical Sciences(SKIMS)SrinagarKashmirIndia

Background:To analyze clinically and radiologically the surgical outcome like residual disease,progression of disease,recurrence,disabilities,event-free survival(EFS),and mortality of different infra-tentorial tumor subtypes in children and adults of a strictly non-migratory and ethnic ***:The 410 histologically proved,out of 589,infra-tentorial brain tumor patients were analyzed clinically and by the imaging post-surgically in a single tertiary center for an ethnic *** this analytico-observational study,retrospectively postoperative records of 589 infra-tentorial brain tumors from November 1998 to December 2018(20 years)were retrieved,scrutinized,and *** post-operative clinic-radiological records of 410 patients with proved histopathological examination results were *** law of variance was applied where-ever ***:The 63.2%of the all 410 operated infra-tentorial brain tumors were males while females predominated in meningiomas and *** 31.7%infra-tentorial tumors were children(below 18 years).About 54.1%cases were histologically *** residual tumors comprised 40.2%and symptoms of disease-progression occurred in 10.9%.The tumor recurrence occurred in 14.3%while 6.0%patients developed severe *** overall mortality was 11.4%but 18.9%in malignant *** event-free survival(EFS)for all the patients was 66.0%,patients with malignancies had 47.7%and benign group had 87.7%.Conclusion:The study,surgical outcome of infra-tentorial brain tumor subtypes in children and adults(approx.1/3rd of patients being children),conducted in a tertiary center at a remote land-locked location with non-migratory ethnic population as its catchment area,has a significant epidemiological value for the community and the region.

关键词： Infra-tentorial brain tumors Histological subtypes Ethnic population Surgical outcome

Challenges in laser-assisted milling of titanium alloys

在线全文

学校读者我要写书评

暂无评论

International Journal of Extreme Manufacturing 2021年第1期3卷 71-84页

作者： Matthew S Dargusch Tharmalingam Sivarupan Michael Bermingham Rizwan abdul Rahman rashid Suresh Palanisamy Shoujin Sun Centre for Advanced Material Processing and Manufacturing(AMPAM) School of Mechanical and Mining EngineeringThe University of QueenslandBrisbaneAustralia DMTC Ltd. HawthornMelbourneVictoriaAustralia Faculty of Science Engineering and TechnologySwinburne University of TechnologyHawthornMelbourneVictoriaAustralia School of Engineering and Built Environment Griffith UniversityGold CoastQueenslandAustralia

Several detailed studies have comprehensively investigated the benefits and limitations of laser-assisted machining(LAM)of titanium *** studies have highlighted the positive impact of the application of laser preheating on reducing cutting forces and improving productivity but have also identified the detrimental effect of LAM on tool *** paper seeks to evaluate a series of the most common cutting tools with different coating types used in the machining of titanium alloys to identify whether coating type has a dramatic effect on the dominant tool wear mechanisms active during the *** findings provide a clear illustration that the challenges facing the application of LAM are associated with the development of new types of cutting tools which are not subjected to the diffusion-controlled wear processes that dominate the performance of current cutting tools.

关键词： laser-assisted machining tool life tool wear titanium alloys

Absorbed dose estimations of ^(131)I for critical organs using the GEANT4 Monte Carlo simulation code

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2012年第11期36卷 1150-1156页

作者： Ziaur Rahman Shakeel ur Rehman Waheed Arshed Nasir M Mirza abdul rashid Jahan Zeb Health Physics Division Pakistan Institute of Nuclear Science & TechnologyNiloreIslamabad 45650Pakistan Department of Physics & Applied Mathematics Pakistan Institute of Engineering & Applied SciencesNiloreIslamabad 45650Pakistan

The aim of this study is to compare the absorbed doses of critical organs of 131I using the MIRD （Medical Internal Radiation Dose） with the corresponding predictions made by GEANT4 simulations. S- values （mean absorbed dose rate per unit activity） and energy deposition per decay for critical organs of 131I for various ages, using standard cylindrical phantom comprising water and ICRP soft-tissue material, have also been estimated. In this study the effect of volume reduction of thyroid, during radiation therapy, on the calculation of absorbed dose is also being estimated using GEANT4. Photon specific energy deposition in the other organs of the neck, due to 131I decay in the thyroid organ, has also been estimated. The maximum relative difference of MIRD with the GEANT4 simulated results is 5.64% for an adult＇s critical organs of 131I. Excellent agreement was found between the results of water and ICRP soft tissue using the cylindrical model. S-values are tabulated for critical organs of 131I, using 1, 5, 10, 15 and 18 years （adults） individuals. S-values for a cylindrical thyroid of different sizes, having 3.07% relative differences of GEANT4 with Siegel ＆ Stabin results. Comparison of the experimentally measured values at 0.5 and 1 m away from neck of the ionization chamber with GEANT4 based Monte Carlo simulations results show good agreement. This study shows that GEANT4 code is an important tool for the internal dosimetry calculations.

关键词： mean absorbed dose rate GEANT4 Monte Carlo simulation and 131I critical organs

Synthesis, characterization and electrochemical evaluation of anticorrosion property of a tetrapolymer for carbon steel in strong acid media

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2019年第4期27卷 965-978页

作者： Shamsuddeen A.Haladu Saviour A.Umoren Shaikh A.Ali Moses M.Solomon abdul-rashid I.Mohammed Department Basic Sciences and Humanities College of Engineering Imam Abdulrahman Bin Faisal University Dammam 31451 Saudi Arabia Centre of Research Excellence in Corrosion Research Institute King Fahd University of Petroleum and Minerals Dhahran 31261 Saudi Arabia Department of Chemistry King Fahd University of Petroleum & Minerals Dhahran 31261 Saudi Arabia Centre for Engineering Research Research Institute King Fahd University of Petroleum and Minerals Dhahran 31261 Saudi Arabia

A novel tetrapolymer(TP) consisting of carboxylate, sulphonate, phosphonate and sulfur dioxide based comonomers was synthesized using Butler cyclopoymerization technique. The synthesized tetrapolymer was characterized using FTIR,1H-NMR,13CNMR and elemental analysis. The performance of the tetrapolymer as a corrosion inhibitor for St37 carbon steel in 15% HCl and 15% H2SO4 acid media was assessed using electrochemical impedance spectroscopy(EIS), linear polarization resistance(LPR), potentiodynamic polarization(PDP) and electrochemical frequency modulation(EFM) techniques. The influence of addition of a small amount of KI on the corrosion inhibition efficiency of TP was also assessed. Results obtained showed that the tetrapolymer moderately inhibited the corrosion of St37 steel in the acid media with protection efficiency of 79.5% and 61.1% at the optimum concentration of 1000 mg·L^-1 studied in HCl and H2SO4 media respectively. On addition of 5 mmol·L^-1 KI to the optimum tetrapolymer concentration, the protection efficiency was upgraded to 90.6% and 93.5% in HCl and H2SO4 environment, respectively. The enhanced performance of the polymer in the presence of KI is due to synergistic action deduced from synergism parameter(S1) which was found to be greater than *** tetrapolymer afforded the corrosion inhibition of St37 steel in the acid media by virtue of adsorption of the polymer molecules on the steel surface which was confirmed by ATR-FTIR analysis of the adsorbed film extracted from the steel surface. TP + KI formed complex with St37 steel surface in H2SO4 solution but not in HCl solution.

关键词： Tetrapolymer Metal Acid corrosion Corrosion inhibition Adsorption Synergism

Realization of laser textured brass surface via temperature tuning for surface wettability transition

在线全文

学校读者我要写书评

暂无评论

光电工程 2017年第6期44卷 587-592页

作者： Huangping Yan Mohamed Raiz B abdul rashid Si Ying Khew Fengping Li Minghui Hong School of Aerospace Engineering Xiamen University Department of Electrical and Computer Engineering National University of Singapore School of Mechanical and Electrical Engineering Wenzhou University

Superhydrophobic surfaces have attracted extensive interests and researches into their fundamentals and potential *** texturing provides the convenience to fabricate the hierarchical micro/nanostructures for ***,after laser texturing,long wettability transition time from superhydrophilicity to superhydrophobicity is a barrier to mass production and practical industrial *** stimuli have been applied to change the surface composition and/or the surface morphology to reduce wettability transition ***,by temperature tuning,wettability transition of laser textured brass surfaces is *** electron microscopy and surface contact angle measurement are employed to characterize the surface morphology and wettability behavior of the textured brass *** low-temperature heating(100℃~150℃),partial deoxidation of the top Cu O layer occurs to form hydrophobic Cu_***,superhydrophobicity without any chemical coating and surface modification could be achieved in a short ***,after low-temperature heating,the low adhesive force between the water droplet and the sample surface is demonstrated for the laser textured brass *** study provides a simple method to fabricate the micro/nanostructure surfaces with controllable wettability for the potential applications.

关键词：纳米结构激光技术发展现状润湿性