检索结果-南通市图书馆

Acta Geologica Sinica(English Edition) 2016年第5期90卷 1865-1886页

作者： Aftab Alam KHAN Mustaffa kamal SHUIB Department of Geology University of Malaya Department of Geology University of Dhaka

Genesis of the so-called Bentong-Raub Suture of Malay Peninsula does not fit to the model of subduction-related *** has evolved from transpression tectonics resulting closure and exhumation of the inland basin which underwent extensive back-arc extension during *** having similar thickness（average-35 km） below entire Malay Peninsula nagate collision of two separate continental blocks rather supports single continental block that collided with South China continental block during *** subduction of intervening sea（Proto South China Sea） below Malay Peninsula resulted in widespread I- and S-Type granitization and volcanism in the back-arc basins during *** occurrence of Permo-Triassic Pahang volcanics of predominantly rhyolitic tuff suggest its derivation from back-arc ***-arc extension,basin development and sedimentation of the central belt of the peninsula continued until Cretaceous.A-Type granite of metaluminous to peraluminous character indicates their emplacement in an intraplate tectonic *** Peninsula suffered an anticlockwise rotation due to the rifting of Luconia-Dangerous Grounds from the east Asia in the Late Cretaceous-Early *** ductile and brittle deformation including crustal segmentation,pull-apart fracturing and faulting occurred during the closure and exhumation of the basins developed in the peninsula during Late Cretaceous-Early *** shortening in the central belt of the peninsula has been accomodated through strike-slip displacement,shearing and uplift.

关键词： Bentong-Raub fault intra-plate tectonics Triassic back-arc extension Cretaceoustranspression Malay Peninsula

Mitochondrial Ca^(2+) uptake in skeletal muscle health and disease

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2016年第8期59卷 770-776页

作者： Jingsong Zhou kamal Dhakal Jianxun Yi Kansas City University of Medicine and Bioscience Dybedal Research Center

Muscle uses Ca2＋ as a messenger to control contraction and relies on ATP to maintain the intracellular Ca2＋ homeostasis. Mi- tochondria are the major sub-cellular organelle of ATP production. With a negative inner membrane potential, mitochondria take up Ca2＋ from their surroundings, a process called mitochondrial Ca2＋ uptake. Under physiological conditions, Ca2＋ uptake into mitochondria promotes ATP production. Excessive uptake causes mitochondrial Ca2＋ overload, which activates down- stream adverse responses leading to cell dysfunction. Moreover, mitochondrial Ca2＋ uptake could shape spatio-temporal pat- terns of intracellular Ca〉 signaling. Malfunction of mitochondrial Ca2＋ uptake is implicated in muscle degeneration. Unlike non-excitable cells, mitochondria in muscle cells experience dramatic changes of intracellular Ca2＋ levels. Besides the sudden elevation of Ca2＋ level induced by action potentials, Ca2＋ transients in muscle cells can be as short as a few milliseconds during a single twitch or as long as minutes during tetanic contraction, which raises the question whether mitochondrial Ca2＋ uptake is fast and big enough to shape intracellular Ca2＋ signaling during excitation-contraction coupling and creates technical challeng- es for quantification of the dynamic changes of Ca2＋ inside mitochondria. This review focuses on characterization of mito- chondrial Ca2＋ uptake in skeletal muscle and its role in muscle physiology and diseases.

关键词： skeletal muscle mitochondria Ca2+

Anti-wear properties evaluation of frictional sliding interfaces in automobile engines lubricated by copper/graphene nanolubricants

在线全文

学校读者我要写书评

暂无评论

Friction 2020年第5期8卷 905-916页

作者： Mohamed kamal Ahmed ALI Xianjun HOU Mohamed AAABDELKAREEM Hubei Key Laboratory of Advanced Technology for Automotive Components Wuhan University of TechnologyWuhan 430070China Automotive and Tractors Engineering Department Faculty of EngineeringMinia UniversityEl-Minia 61111Egypt Hubei Collaborative Innovation Center for Automotive Components Technology Wuhan 430070China

Owing to the significance of improving fuel economy, reducing emissions, and extending the durability of engine components, this study focused on the tribological performance of nano-additives. In this study, copper (Cu) and graphene (Gr) nanomaterials were dispersed in a fully formulated engine oil (5W-30) with different concentrations. The tribological trials were investigated under various speeds and loads, utilizing a reciprocating tribometer to mimic the ring/liner interfaces in the engine. The frictional surface morphologies were com-prehensively analyzed using electron probe X-ray microanalysis (EPMA), field emission scanning electron microscopy (FESEM), energy dispersive spectrometer (EDS), and three dimensional (3D) surface profilometry to explore the mechanisms responsible for improving the tribological performance of the frictional sliding parts in the engine. The tribological test results illustrated that lubrication by nano-additives reduced the wear rate (WR) and friction coefficient (COF) by 25%–30% and 26.5%–32.6%, respectively, as compared with 5W-30. The results showed that this is a promising approach for increasing the durability and lifespan of frictional sliding components and fuel economy in automobile engines.

关键词： engine tribology nanomaterial nanolubricant friction wear tribofilm

Cofiniteness of Local Cohomology Modules

在线全文

学校读者我要写书评

暂无评论

Algebra Colloquium 2014年第4期21卷 605-614页

作者： kamal Bahmanpour Reza Naghipour Monireh Sedghi Faculty of Mathematical Sciences Department of Mathematics University of Mohaghegh Ardabili 56199-11367 Ardabil Iran School of Mathematics Institute for Research in Fundamental Sciences (IPM) P.O. Box 19395-5746 Tehran Iran Department of Mathematics University of Tabriz Tabriz Iran Department of Mathematics Azarbaijan Shahid Madani University Tabriz Iran

Let M be a non-zero finitely generated module over a commutative Noetherian local ring （R, m）. In this paper we consider when the local cohomology modules are finitely generated. It is shown that if t≥ 0 is an integer and p C Supp H^t_p （M）, then Hm^t＋dim R/p （M） is not p-cofinite. Then we obtain a partial answer to a question raised by Huneke. Namely, if R is a complete local ring, then H^n_m （M） is finitely generated if and only if 0 ≤ n ￠ W, where W ---- {t ＋ dimR/p丨p ∈ SuppH^t_p（M）／V（m）}. Also, we show that if J C I are 1-dimensional ideals of R, then H^t_I（M） is J-cominimax, and H^t_I（M） is finitely generated （resp., minimax） if and only if H}R, （Mp） is finitely generated for all p C Spec R （resp., p ∈ SpecR／MaxR）. Moreover, the concept of the J-cofiniteness dimension cJ（M） of M relative to I is introduced, and we explore an interrelation between c^I_m（M） and the filter depth of M in I. Finally, we show that if R is complete and dim M/IM ≠ 0, then c^I_m （R） ---- inf{depth Mp ＋ dim R/p 丨 P ∈ Supp M/IM／V（m）}.

关键词： cofinite modules cohomological finiteness dimension cominimax modules,local cohomology minimax modules

One-pot synthesis of various xanthene derivatives using ionic liquid1,3-disulfonic acid imidazolium hydrogen sulfate as an efficient and reusable catalyst under solvent-free conditions

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 Chemical Letters 2014年第2期25卷 341-347页

作者： Farhad Shirini Asieh Yahyazadeh kamal Mohammadi Department of Chemistry College of Science.University of Guilan

In this study, 1,3-disulfonic acid imidazolium hydrogen sulfate （DSIMHS） is used as an efficient and reusable ionic liquid for the green, mild, and efficient synthesis of xanthenes under solvent-free conditions. Simple and easy work-up, low cost, green process, short reaction times and excellent yields of the products are the advantages of this procedure. Further, the catalyst can be recycled and reused at least for four times without a noticeably decrease in its catalytic activity.

关键词： Xanthene derivatives One-pot reaction 1,3-Disulfonic acid imidazolium hydrogensulfate Ionic liquid Solvent-free conditions

Shrinking greenery： Land use and land cover changes in Kurram Agency, Kohi Safid Mountains of north-western Pakistan

在线全文

学校读者我要写书评

暂无评论

Journal of Mountain Science 2018年第2期15卷 296-306页

作者： kamal HUSSAIN Fazlul HAQ Fazlur RAHMAN Department of Geography University of Peshawar Peshawar 25000 Pakistan Department of Geography Government College University Faisalabad Faisalabad 38000 Pakistan

Deforestation and other Land Use and Land Cover(LULC) changes, driven by variety of physical and anthropogenic factors, have altered the mountainous environment. Mountains around the world including northern and north western belts of Pakistan are highly sensitive to deforestation and other LULC changes, which have profound impacts on various sectors of bio-physical and socio-economic systems. Assessment of LULC changes has high significance for protection, conservation and monitoring mountainous environment. The present study is an attempt to assess the landscape changes with particular reference to forest cover depletion in Kurram Agency located in the north western mountain belt of Pakistan. For detailed comparative analysis the study area has been divided into three sections, which coincide with the present administrative divisions of the Agency, i.e., Upper,Lower and Central Kurram. Temporal span of this study covers four decades. In this study, land use map of 1970 and land sat satellite imageries of 1987, 2000 and 2014 were used as spatial data sets. The images were processed and classified into six LULC classes through geospatial packages and change detection maps were prepared for each division and time *** of the study reveal two trends in the four major LULC categories. Forest and rangeland have shrunk, on average, by 15% and 7.5% respectively while, bare soil and rocks outcrops have expanded by 89% and agriculture land by 7.2% in Kurram *** water bodies and snow cover have minor fluctuation in its land area. Major causes of shrinking greenery is attributed to high influx of Afghan refugees and high energy demand of growing population. However, with outflow of the refugees from Kurram agency the general trend in forest cover has reverted and deforestation rate has slowed down.

关键词： Pakistan Tribal areas Deforestation Land Use Land Cover Change Resource management Global changes

Study of the Reaction of 5-Aryl-7-hydrazino-2-phenylpyra- zolo[1,5-c]pyrimidines with 1,3-Dicarbonyl Compounds

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2011年第11期29卷 2451-2460页

作者： Atta, kamal F. M. Chemistry Department Faculty of Science Alexandria University lbrahimia P. O. Box 426 Alexandria 21321 Egypt

A novel synthetic method for the preparation of 5-aryl-7-（3,5-dimethyl-lH-pyrazol-l-yl）-2-phenylpyra- zolo[1,5-c]-pyrimidines and 1-（5-aryl-2-phenylpyrazolo[1,5-c]pyrimidin-7-yl）-3-methyl-lH-pyrazol-5-ols is provided by condensative cyclization of 5-aryl-7-hydrazino-2-phenylpyrazolo[1,5-c]pyrimidines with 1,3-dicarbonyl compounds. The study of the more reactive position for electrophilic substitusion reactions on such ring system was also achieved.

关键词： cyclization electrophilic substitution pyrazolylpyrazolopyrimidine IR NMR mass spectrometry

Investigating TiO_(2)-HA-PCL hybrid coating as an efficient corrosion resistant barrier of ZM21 Mg alloy

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

Journal of Magnesium and Alloys 2021年第2期9卷 627-646页

作者： Navdeep Singh Uma Batra kamal Kumar Anil Mahapatro Department of Metallurgical and Materials Engineering Punjab Engineering CollegeChandigarh 160012India Department of Mechanical Engineering Punjab Engineering CollegeChandigarh 160012India Department of Biomedical Engineering Wichita State UniversityWichitaKS 67260United States

Surface modification for improving corrosion resistance of Mg alloys is highly demanded for degradable orthopedic and cardiovascular *** research reports the design and development of TiO_(2)–HA composite and novel TiO_(2)–HA–PCL hybrid coating belonging to the unique class of inorganic organic hybrid with striking features that are explored for the first time in the corrosion resistance of Mg ***–gel dip coating combined with non-solvent induced phase separation is used to create the hybrid ***_(2)–HA–PCL hybrid coating introduces strong hydrogen bonding between TiO_(2)–HA inorganic matrix and PCL organic layer in addition to the Vander wall electrostatic interaction of the later with the Mg substrate which in turn enhance adhesion strength to about 1.5 times of TiO_(2)–HA *** corrosion potentials for TiO_(2)–HA–PCL and TiO_(2)–HA were found to be-0.407 V and-1.017 V(vs Ag/Ag Cl),*** current densities of TiO_(2)–HA–PCL and TiO_(2)–HA were found to be 7.31×10^(-8)A/cm^(2)and 4.03×10^(-4)A/cm^(2)*** corrosion resistance of coatings was confirmed by immersion testing by weight loss,pH changes and H_(2)evolution measurements at interval of 7 days till 28 *** present TiO_(2)–HA–PCL coating in comparison to TiO_(2)–HA coating demonstrate nearly 6%less weight *** outcome of the present work was compared with the similar coatings in recent *** work done ingresses enhancing the corrosion resistance of Mg alloys,which fulfill the dreams of future degradable orthopedic and cardiovascular devices.

关键词： Corrosion resistance TiO_(2)-HA-PCL Contact angle Adhesion strength

Evaluation of corrosion resistance, mechanical integrity loss and biocompatibility of PCL/HA/TiO_(2) hybrid coated biodegradable ZM21 Mg alloy

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第11期10卷 3179-3204页

A novel PCL/HA/TiO_(2)hybrid coating on ZM21 Mg alloy substrate has been investigated for corrosion resistance, biocompatibility and mechanical integrity loss in terms of bending, compressive and tensile strength in physiological media. The prepared hybrid coating was dip coated over ZM21 from HA/TiO_(2)and PCL solutions followed by creating a microporous PCL layer by utilizing Non-solvent Induced Phase Separation(NIPS) technique. The electrochemical measurement and in-vitro degradation study in SBF after 28 days showed that the PCL/HA/TiO_(2) hybrid coating reduced H2 evolution rate, weight loss, and corrosion rate by 64, 116 and 118 times respectively, as compared to uncoated ZM21 samples. The surface studies carried out using SEM-EDX, FTIR and XRD revealed formation of highly stable 3d flower-like HA crystals with Ca/P ratio of 1.60 in the PCL micropores. This dense apatite growth effectively protected the PCL/HA/TiO_(2)hybrid coated samples to maintain the good mechanical integrity even after 28 days of immersion as compared to HA/TiO_(2)composite coated, As-polished(A/P) and As-machined(A/M) samples. The failure analysis of samples under mechanical loading were performed using *** in-vitro cellular viability of L929 fibroblast cells on PCL/HA/TiO_(2)hybrid coating was found 50.47% higher with respect to control group,whereas bacterial viability was supressed by 57.15 and 62.35% against gram-positive Staphylococcus aureus and gram-negative Escherichia coli bacterial models. The comprehensive assessment indicates PCL/HA/TiO_(2)hybrid coating as a suitable candidate to delay early degradation and mechanical integrity loss of Mg-based alloys for devising biodegradable orthopaedic implant.

关键词： Magnesium alloy Surface modification Hybrid coating Mechanical integrity loss Degradation rate Biocompatibility

Finite element simulation of stress intensity factors in elastic-plastic crack growth

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8期7卷 1336-1342页

作者： ALSHOAIBI Abdulnaser M ARIFFIN Ahmad kamal Computational Mechanics Research Group Department of Mechanical and Materials Engineering Faculty of Engineering Universiiy Kebangsaan Malaysia Bangi 43600 Malaysia

A finite element program developed elastic-plastic crack propagation simulation using Fortran language. At each propagation step, the adaptive mesh is automatically refined based on a posteriori h-type refinement using norm stress error estimator. A rosette of quarter-point elements is then constructed around the crack tip to facilitate the prediction of crack growth based on the maximum normal stress criterion and to calculate stress intensity factors under plane stress and plane strain conditions. Crack was modelled to propagate through the inter-element in the mesh. Some examples are presented to show the results of the implementation.

关键词： Crack propagation Nodal displacement Stress intensity factor Adaptive mesh Finite element method (FEM)