检索结果-南通市图书馆

Petrography and geochemistry of Jumara Dome sediments, Kachchh Basin: Implications for provenance, tectonic setting and weathering intensity

引用

Chinese Journal Of Geochemistry 2014年第1期33卷 9-23页

作者： ahmad a.h.m Noufal K.N masroor Alam m Tavheed Khan Department of Geology Department of civil Engineering ZH College of Engineering and Technology

In the Kachchh mainland, the Jumara Dome mixed carbonate-siliciclastic succession is represented by the Jhurio and Patcham formations and siliciclastic-dominating Chari Formation(Bathonian to Oxfordian). The Jumara Dome sediments were deposited during sea-level fluctuating, and were interrupted by storms in the shallow marine environment. The sandstones are generally medium-grained, moderately sorted, subangular to subrounded and of low sphericity. The sandstones are mineralogically mature and mainly composed of quartzarenite and subarkose. The plots of petrofacies in the Qt-F-L, Qm-F-Lt, Qp-Lv-Ls and Qm-P-K ternary diagrams suggest mainly the basement uplift source(craton interior) in rifted continental margin basin setting. The sandstones were cemented by carbonate, iron oxide and silica overgrowth. The Chemical Index of Alteration values(73% sandstone and 81% shale) indicate high weathering conditions in the source area. Overall study suggests that such strong chemical weathering conditions are of unconformity with worldwide humid and warm climates during the Jurassic period. Positive correlations between Al2O3 and Fe2O3, TiO2, Na2O, mgO, K2O are evident. A high correlation coefficient between Al2O3 and K2O in shale samples suggests that clay minerals control the major oxides. The analogous contents of Si, Al, Ti, LREE and TTE in the shale to PAAS with slightly depleted values of other elements ascribe a PAAS like source(granitic gneiss and minor mafics) to the present study. The petrographic and geochemical data strongly suggest that the studied sandstones/shales were deposited on a passive margin of the stable intracratonic basin.

关键词：大陆边缘盆地地球化学数据沉积物岩相学风化强度构造背景源区圆顶

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

Electrical and dielectric properties of Na_(1/2)La_(1/2)Cu_3Ti_4O_(12) ceramics prepared by high energy ball-milling and conventional sintering

引用

Chinese Physics B 2016年第12期25卷 474-480页

作者： h mahfoz Kotb mohamad m ahmad Department of Physics College of ScienceKing Faisal University Department of Physics Faculty of ScienceAssiut University

We report on the measurements of the electrical and dielectric properties of Na1/2La1/2Cu3Ti4O12 （NLCTO） ce- ramics prepared by high energy ball-milling and conventional sintering without any calcination steps. The x-ray powder diffraction analysis shows that pure perovskite-like CCTO phase is obtained after sintering at 1025 ℃-1075 ℃. higher sintering temperatures result in multi-phase ceramics due to thermal decomposition. Scanning electron microscope observations reveal that the grain size is in a range of - 3 μm-5 μm for these ceramics. Impedance spectroscopy measurements performed in a wide frequency range （1 hz-10 mhz） and at various temperatures （120 K-470 K） are used to study the dielectric and electrical properties of NLCTO ceramics. A good compromise between high ε′ （5.7 ×10^3 and 4.1 × 10^3 at 1.1 khz and 96 khz, respectively） and low tan δ （0.161 and 0.126 at 1.1 khz and 96 khz, respectively） is obtained for the ceramic sintered at 1050 ℃. The observed high dielectric constant behavior is explained in terms of the internal barrier layer capacitance effect.

关键词： ceramics sintering dielectric loss and relaxation electrical

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

Antimonene-based saturable absorber for a soliton mode-locked and Q-switched fiber laser in the 2 μm wavelength region

引用

Chinese Physics B 2023年第6期32卷 259-269页

作者： h ahmad B Nizamani m Z Samion N Yusoff m F Ismail Photonics Research Centre Universiti Malaya50603 Kuala LumpurMalaysia Physics Department Faculty of ScienceUniversiti Malaya50603 Kuala LumpurMalaysia Distinguished Visiting Professor Universiti Kuala Lumpur British Malaysian Institute(UniKL BMI)Batu 8Jln Sungai Pusu53100SelangorMalaysia

We demonstrate antimonene as a saturable absorber(SA) to generate an ultrafast mode-locked and Q-switched laser in the 2 μm wavelength region. The two antimonene-based SAs were prepared and inserted separately in a thulium–holmiumdoped fiber laser to produce the pulsed laser. Antimonene was coated onto a tapered fiber to generate soliton mode-locked pulses and used in thin-film form for the generation of Q-switched pulses. The mode-locking was stable within a pump power of 267 m W–511 m W, and the laser operated at a central wavelength of 1897.4 nm. The mode-locked laser had a pulse width of 1.3 ps and a repetition rate of 12.6 mhz, with a signal-to-noise ratio of 64 d B. Q-switched laser operation was stable at a wavelength of 1890.1 nm within a pump power of 312 m W–381 m W. With the increase in pump power from 312 m W to 381 m W, the repetition rate increased to a maximum of 56.63 k hz and the pulse width decreased to a minimum value of 2.85 μs. Wide-range tunability of the Q-switched laser was also realized within the wavelength range of1882 nm–1936 nm.

关键词： mode-locking Q-switched fiber laser optical saturable absorber

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

Optically modulated Tunable O-Band Praseodymium-Doped Fluoride Fiber Laser Utilizing multi-Walled Carbon Nanotube Saturable Absorber

引用

Chinese Physics Letters 2019年第10期36卷 32-35页

作者： h.ahmad m.F.Ismail S.N.Aidit Photonics Research Center University of MalayaKuala Lumpur 50603Malaysia Physics Department Faculty of ScienceUniversity of Malaya50603 Kuala LumpurMalaysia

A tunable and optically modulated fiber laser utilizing a multi-walled carbon nanotube based saturable absorber is demonstrated for operation in the O-band region.A praseodymium-doped fluoride fiber is used as the gain medium and the system is capable of generating modulated outputs at 1300 *** output is observed at pump powers of 511 mW and above,with repetition rates and pulse widths that can be tuned from 41 khz and 3.4μs to 48 khz and 2.4μs,respectively,at the maximum pump power available.A maximum average output power of 100μW with a corresponding single pulse energy of 2.1 nJ is measured,while the tunability of the proposed laser is from 1290 nm to 1308 *** output is stable,with peak power fluctuations of^4 dB from the average value.

关键词： pump fiber Optically

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

Cancer cell cycle heterogeneity as a critical determinant of therapeutic resistance

引用

Genes & Diseases 2024年第1期11卷 189-204页

作者： Ebrahim h.maleki ahmad Reza Bahrami maryam m.matin Department of Biology Faculty of ScienceFerdowsi University of Mashhad*** MashhadIran Jagiellonian Centre for Experimental Therapeutics(JCET) Jagiellonian University31-007 KrakowPoland Doctoral School of Exact and Natural Sciences Jagiellonian University30-348 KrakowPoland Industrial Biotechnology Research Group Institute of BiotechnologyFerdowsi University of Mashhad*** MashhadIran Novel Diagnostics and Therapeutics Research Group Institute of BiotechnologyFerdowsi University of Mashhad***MashhadIran Stem Cell and Regenerative medicine Research Group Iranian Academic Center for EducationCulture and Research(ACECR)Khorasan Razavi Branch917751376 MashhadIran

Intra-tumor heterogeneity is now arguably one of the most-studied topics in tumor biology,as it represents a major obstacle to effective cancer *** tumor cells are highly diverse at genetic,epigenetic,and phenotypic levels,intra-tumor heterogeneity can be assumed as an important contributing factor to the nullification of chemotherapeutic effects,and recurrence of the *** on the role of heterogeneous subpopulations of cancer cells with varying cell-cycle dynamics and behavior during cancer progression and treatment;herein,we aim to establish a comprehensive definition for adaptation of neoplastic cells against *** discuss two parallel and yet distinct subpopulations of tumor cells that play pivotal roles in reducing the effects of chemotherapy:"resistant"and"tolerant"***,this review also highlights the impact of the quiescent phase of the cell cycle as a survival mechanism for cancer *** understanding the mechanisms under-lying the quiescence,it provides an insightful perspective on cancer stem cells(CsCs)and their dual and intertwined functions based on their cell cycle state in response to ***-over,CSCs,epithelial-mesenchymal transformed cells,circulating tumor cells(CTCs),and disseminated tumor cells(DTCs),which are mostly in a quiescent state of the cell cycle are proved to have multiple biological links and can be implicated in our viewpoint of cell cycle heterogeneity in ***,increasing our knowledge of cell cycle heterogeneity is a key to identifying new therapeutic solutions,and this emerging concept may provide us with new opportunities to prevent the dreadful cancer recurrence.

关键词： Cancer stem cells(CSCs) Carcinoma Cell cycle heterogeneity Quiescence Therapy resistance Therapy tolerance Tumor dormancy

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

Q-Switched Erbium-Doped Fiber Laser Using Cadmium Selenide Coated onto Side-Polished D-Shape Fiber as Saturable Absorber

引用

Chinese Physics Letters 2018年第10期35卷 27-30页

作者： m.F.m.Rusdi m.B.h.mahyuddin A.A.Latiff h.ahmad S.W.harun Photonics Engineering Laboratory Department of Electrical Engineering Faculty of EngineeringUniversity of Malaya Faculty of Electronic and Computer Engineering Universiti Teknikal Malaysia Melaka Photonic Research Center University of Malaya Department of Physics Faculty of Science and Technology Airlangga University

A stable Q-switched erbium doped fiber laser emitting at 1558 nm is demonstrated using a cadmium selenide（CdSe） material coated onto a side-polished D-shape fiber as the saturable absorber（SA）. By elevating the input pump power from the threshold of 91 mW to the maximum available power of 136 mW, a pulse train with a maximum repetition rate of 57.44 khz, minimum pulse width of 3.76 us, maximum average output power of7.99 mW, maximum pulse energy of 0.1391 uJ, and maximum peak power of 36.99 mW are obtained. The signalto-noise ratio of the spectrum is measured to be around 75 dB. This CdSe based SA is simple, robust, and reliable,and thus suitable for making a portable pulse laser source.

关键词： SA Q-Switched Erbium-Doped Fiber Laser Using Cadmium Selenide Coated onto Side-Polished D-Shape Fiber as Saturable Absorber

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

malaria prevalence in north-eastern Nigeria:A cross-sectional study houben Ch^(1*),Fleischmann h^2,Gǜckel m^3

引用

Asian Pacific Journal of Tropical medicine 2013年第11期6卷 865-868页

作者： houben Ch Fleischmann h Gckel m Diagnostic Center mmm group & Specialist hospital Yola Hospital RoadP.M.B.2266YolaAdamawa.StateNigeria medical mission Institute Tropical MedicineHermann Schell Str 797074 WrzburgGermany helios Kliniken Schwerin Wismarsche Str 393-39719049 SchwerinGermany

Objective:To assess the prevalence of malaria parasitemia in north-east Nigeria and to evaluate the measures for the prevention of ***:A village in north-eastern Nigeria was selected for the cross sectional study at the height of the rainy season in October 2011.A total of 550 inhabitants of a.h.mlet were recruited for this *** obtaining the consent individuals received a structured interview and were tested for malaria parasites in their blood *** testing positive for malaria were given a course of artemesinin-based combination therapy（ACT）.Results:A total of 497 inhabitants representing approximately 90 percent of the population participated:a quarter of the study group carried malaria parasitesexclusively Plasmodium falciparum（***）-representing a *** parasite rate（PfPR） of 24.5%.Besides,53/138 in the age group of 2 to hildren tested positive for *** representing a PfPR2-10 value of 38.4%.malaria control measures were used in just under a third（157/497） of this *** these measures 28/157（17.8%） still tested positive for ***:The malaria burden is overestimated for this region in north-east *** findings support an intermediate pattern of malaria *** 30%bed nets coverage for malaria control is well below the WhO estimates for 2011.

关键词： malaria control malaria endemicity malaria prevalence malaria transmission

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

A Q-Switched Erbium-Doped Fiber Laser with a Carbon Nanotube Based Saturable Absorber

引用

Chinese Physics Letters 2012年第11期29卷 67-69页

作者： S.W.harun m.A.Ismail F.ahmad m.F.Ismail R.m.Nor N.R.Zulkepely h.ahmad Department of Electrical Engineering University of Malaya 50603 Kuala LumpurMalaysia Photonics Research Center Department of PhysicsUniversity of Malaya50603 Kuala LumpurMalaysia Department of Physics University of Malaya50603 Kuala LumpurMalaysia

We demonstrate a simple,compact and low cost Q-switched erbium-doped fiber laser(EDFL)using single-wall carbon nanotubes(CNTs)as a saturable absorber for possible applications in metrology,sensing,and medical *** EDFL operates at around 1560 nm with repetition rates of 16.1 khz and 6.4 khz with saturable absorbers SA1 and SA2 at a pump power of 120 *** absorbers are constructed by optically driven deposition and normal deposition *** is observed that the optical deposition method produces a Q-switched EDFL with a lower threshold of 70 mW and better Q-switching performance compared to that of the normal deposition *** EDFL also has pulse energy of 90.3 nJ and pulse width of 11.6μs at 120 mW pump power.

关键词： pump switched Erbium

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

Passively Q-Switched EDFL Using a multi-Walled Carbon Nanotube Polymer Composite Based on a Saturable Absorber

引用

Chinese Physics Letters 2014年第3期31卷 69-72页

作者： F. ahmad h. haris R. m. Nor N. R. Zulkepely h. ahmad S. W. harun Department of Electrical Engineering University of Malaya Kuala Lumpur 50603 Malaysia Photonics Research Centre University of Malaya Kuala Lumpur 50603 Malaysia Department of Physics University of Malaya Kuala Lumpur 50603 Malaysia

A stable passive Q-switched erbium-doped fiber laser （EDFL） operating at 1563.5 nm is demonstrated by using a multi-walled carbon nanotube （mWCNT） polymer composite film based saturable absorber for the first time. The composite is prepared by mixing the mWCNTs homogeneous solution into a dilute PEO polymer solution before it is left to dry at room temperature to produce thin film. Then the film is sandwiched between two FC/PC fiber connectors and is integrated into the laser cavity for Q-switching pulse generation. The EDFL generates a stable pulse train with repetition rates ranging from 4.5 khz to 20.0 khz by varying the 1480 nm pump power from 35 mW to 53 mW. At the 53 mW pump power, the pulse width and pulse energy are 8.8 μs and 15.3 nJ, respectively.

关键词： FIBER lasers RESEARCh SEmICONDUCTOR doping ERBIUm CARBON nanotubes PhYSICS research

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

Petrographical and geochemical signatures of Jurassic rocks of Chari Formation, Western India： implications for provenance and tectonic setting

引用

Acta Geochimica 2016年第2期35卷 184-202页

作者： Shaista Khan A. h. m. ahmad m. masroor Alam Adnan Quasim Department of Geology Aligarh Muslim University AligarhUP. India Geology Section Civil Engineering Z.H. College of Engineering and Technology Aligarh Muslim UniversityAligarh UP India

members The sandstones of the Ridge and Athleta of Chari Formation （Callovian-Oxfordian） exposed at Jara have been analyzed for their petrographical and geochemical studies. Texturally, these sandstones are medium to coarse grained, poorly to well sorted, sub-an- gular to sub-rounded, and show low to medium sphericity. These sandstones were derived from a mixed provenance including granites, granite-gneisses, low and high-grade metamorphic, and some basic rocks of Aravalli range and Nagarparkar massif. The petrofacies analysis reveals that these sandstones belong to the continental block and recycled orogen tectonic regime. The studied sandstones are modified by paleoclimate, distance of transport, and diagenesis. mineralogically and geochemically, sandstones are classified as quartzarenite, subarkose, arkose, sublithic arenite, and wacke, respectively. The A-CN-K ternary plot and CIA, CIW, PIA, and ICV values suggest that the similar source rocks suffered moderate to high chemical weathering under a hot-humid climate in an acidic envi- ronment with higher Pco2. Generally good to strong cor- relations between AI2O3 and other oxides in these sediments indicate clay mineral control. The K2O/Na2O versus SiO2 diagram indicates that the studied samples occupy passive margin fields but the SiO2/A12O3 versus K2O/Na20 plot suggests that the Athleta Sandstone and Ridge Sandstone fall within the passive margin field, while Ridge Shale falls within the active continental margin field.

关键词： Petrography Geochemistry Jurassic rocks Chari Formation Kachchh Gujarat

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：