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Nanosecond pulse and dual-wavelength Q-switched 1.5 μm fiber laser using MAX phase Cr2TialC2 saturable absorber

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Optoelectronics Letters 2025年第1期21卷 7-12页

作者： Ahmed Shakir al-HITI Hiba HASSAN Department of Electrical Engineering Faculty of Engineering University of Anbar Department of Laser and Optoelectronics Engineering University of Technology-Iraq

We demonstrated a new type of MAX phase material, chromium titanium aluminum carbide（Cr2TialC2） polymer film, to generate a passively Q-switched erbium-doped fiber laser（EDFL）. The film thickness was measured to be around 45 μm, which was fabricated using the embedding method with polyvinyl alcohol（PVA） polymer as hoster. The saturable absorber（SA） film demonstrates a dual-wavelength passively Q-switched EDFL which operates at 1 531 nm and 1 560.19 nm, respectively. The Q-switching pulse duration could be varied from 2.46 μs to 770 ns, while the repetition rate varied from 92.76 kHz to 106.6 kHz with an increasing input pumping range from 154 mW to 300 mW. The maximum output power and pulse energy of 15.05 mW and 141.18 nJ were obtained at the maximum input power of 300 mW, respectively.

关键词： Saturable absorbers

Comparative chemical sensor for detection of chromium(Ⅵ) in aqueous solution

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Optoelectronics Letters 2025年第1期21卷 21-27页

作者： Sura H.al-REKABI A.A.alWAHIB Electrical Technique Department Al Suwayrah Technical Institute Middle Technical University Laser and Optoelectronics Department University of Technology-Iraq

A process for purifying aqueous solutions containing heavy and toxic metals such as chromium（Cr） has been investigated. One of the extremely harmful pollutants in rivers and seawater is the heavy metal ions due to their direct impacts on human, animals and plants are hexavalent Cr（Ⅵ）. Consequently, highly sensitive sensor to detect Cr is essential. Surface plasmon resonance（SPR） technique has attracted huge research interest in detecting heavy metals specifically. In this study, three types of prism-based SPR sensor, gold（Au）/silver（Ag）, Au/polyaniline（PANI） and Au/titanium dioxide（TiO2） nanostructured films, are investigated as potential sensing material to detect the presence of Cr（Ⅵ） ions in water. The base Au layer with thickness of 48.3 nm is deposited on a glass slide for all sensors. For Au/Ag, Au/PANI nanofibers and Au/TiO2sensor films, the Cr（Ⅵ） concentration is varied from 1 ppm to 15 ppm with sensitivity of 0.270 °ppm-1, 0.082 °ppm-1and 0.039 °ppm-1, respectively. Based on these results, the Au/PANI nanofibers are the most sensitive to Cr（Ⅵ） among the tested sensing materials.

关键词： Titanium dioxide

Effects of P301L-TAU on post-translational modifications of microtubules in human iPSC-derived cortical neurons and TAU transgenic mice

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Neural Regeneration Research 2025年第8期20卷 2348-2360页

作者： Mohamed Aghyad al Kabbani Christoph Köhler Hans Zempel Institute of Human Genetics Faculty of Medicine and University Hospital CologneUniversity of CologneCologneGermany Center for Molecular Medicine Cologne(CMMC) University of CologneCologneGermany Center Anatomy Department ⅡMedical FacultyUniversity of CologneCologneGermany

TAU is a microtubule-associated protein that promotes microtubule assembly and stability in the *** is missorted and aggregated in an array of diseases known as *** are essential for neuronal function and regulated via a complex set of post-translational modifications,changes of which affect microtubule stability and dynamics,microtubule interaction with other proteins and cellular structures,and mediate recruitment of microtubule-severing *** impairment of microtubule dynamics causes neuronal dysfunction,we hypothesize cognitive impairment in human disease to be impacted by impairment of microtubule *** therefore aimed to study the effects of a disease-causing mutation of TAU(P301L)on the levels and localization of microtubule post-translational modifications indicative of microtubule stability and dynamics,to assess whether P301L-TAU causes stability-changing modifications to *** investigate TAU localization,phosphorylation,and effects on tubulin post-translational modifications,we expressed wild-type or P301L-TAU in human MAPT-KO induced pluripotent stem cell-derived neurons(i Neurons)and studied TAU in neurons in the hippocampus of mice transgenic for human P301L-TAU(p R5 mice).Human neurons expressing the longest TAU isoform(2N4R)with the P301L mutation showed increased TAU phosphorylation at the AT8,but not the p-Ser-262 epitope,and increased polyglutamylation and acetylation of microtubules compared with endogenous TAU-expressing neurons.P301L-TAU showed pronounced somatodendritic presence,but also successful axonal enrichment and a similar axodendritic distribution comparable to exogenously expressed 2N4R-wildtype-TAU.P301L-TAU-expressing hippocampal neurons in transgenic mice showed prominent missorting and tauopathy-typical AT8-phosphorylation of TAU and increased polyglutamylation,but reduced acetylation,of microtubules compared with non-transgenic *** sum,P301L-TAU results in changes in micr

关键词： human induced pluripotent stem cell microtubules P301L pR5 mice TAU tauopathy tubulin code

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Partially Overlapping Channel Assignment Using Bonded and Non-Bonded Channels in IEEE 802.11n WLAN

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Computers, Materials & Continua 2022年第5期71卷 3161-3178页

作者： MdSelim al mamun Fatema Akhter Graduate School of Natural Science and Technology Okayama UniversityOkayama700-8530Japan Computer Science and Engineering Jatiya Kabi Kazi Nazrul Islam UniversityMymensingh2224Bangladesh

Nowadays,wireless local area network(WLAN)has become prevalent Internet access due to its low-cost gadgets,flexible coverage and hasslefree simple wireless *** facilitates wireless Internet services to users with mobile devices like smart phones,tablets,and laptops through deployment of multiple access points(APs)in a network *** AP operates on a frequency band called *** wireless standard such as IEEE 802.11n has a limited number of channels where frequency spectrum of adjacent channels overlaps partially with each *** a crowded environment,users may experience poor Internet services due to channel collision i.e.,interference from surrounding APs that affects the performance of the WLAN ***,it becomes a challenge to maintain expected performance in a crowded environment.A mathematical model of throughput considering interferences from surrounding APs can play an important role to set up a WLAN system *** set up,assignment of channels considering interference can maximize network *** this paper,we investigate the signal propagation of APs under interference of partially overlapping channels for both bonded and non-bonded ***,a throughput estimation model is proposed using difference of operating channels and received signal strength indicator(RSSI).Then,a channel assignment algorithm is introduced using proposed throughput estimation ***,the efficiency of the proposal is verified by numerical experiments using *** results show that the proposal selects the best channel combination of bonded and non-bonded channels that maximize the performance.

关键词： Wireless local area network partially overlapping channel throughput estimation model channel assignment algorithm

Investigating ionic liquids for optimizing lithium metal anode

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Green Energy & Environment 2022年第2期7卷 173-175页

作者： Lei Zhang Mohammad al-mamun Centre for Clean Environment and Energy Griffith UniversityGold Coast CampusGold CoastQLD 4222Australia

Developing renewable energy technology is an effective way to address the global warming and air pollution problems derived from depleting fossil *** to the high theoretical capacity(3860 m Ah g-1) and low electrochemical potential of lithium metal anode,lithium metal batteries(LMBs) have attracted tremendous research attention with the scalable application and vigorous deployment of electric ***,the further commercialization of Li metal anode is hindered by the random growth of Li dendrites during the lithium plating/stripping processes,leading to the continuous consumption of active Li and the puncture on the *** recently,Ma’s group proposed a new approach to systematically investigate the relationship between functional groups and Li dendrite generation during the Li plating/stripping *** proposed new approach could be of an effective tool to gain new insights into functional groups in the electrolyte additives and Li dendrites formation,highly valuable for the rational structural design of highperformance Li metal electrode materials.

关键词： lithium stripping electrolyte

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Urbanization reduces resource use efficiency of phytoplankton community by altering the environment and decreasing biodiversity

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Journal of Environmental Sciences 2022年第2期34卷 140-151页

作者： Yigang Yang Huihuang Chen mamun abdullah al Jean Claude Ndayishimiye Jun R Yang alain Isabwe Anqi Luo Jun Yang Aquatic EcoHealth Group Fujian Key Laboratory of Watershed EcologyKey Laboratory of Urban Environment and HealthInstitute of Urban EnvironmentChinese Academy of SciencesXiamen 361021China University of Chinese Academy of Sciences Beijing 100049China Engineering Research Center of Ecology and Agricultural Use of Wetland(Ministry of Education) College of AgricultureYangtze UniversityJingzhou 434025China

Urbanization often exerts multiple effects on aquatic and terrestrial organisms,including changes in biodiversity,species composition and ecosystem ***,the impacts of urbanization on river phytoplankton in subtropical urbanizing watersheds remain largely ***,we explored the effects of urbanization on phytoplankton community structure(i.e.,biomass,community composition and diversity)and function(i.e.,resource use efficiency)in a subtropical river at watershed scale in southeast China over 6 years.A total of 318 phytoplankton species belonging into 120 genera and 7 phyla were identified from 108 *** biomass showed an increasing trend with increasing urbanization *** phytoplankton community shifted from Chlorophyta dominance in rural upstream waters to Bacillariophyta dominance in urbanized downstream ***,phytoplankton diversity and resource use efficiency(RUE=phytoplankton biomass/total phosphorus)were significantly decreased with increasing urbanization level from upstream to *** RUE exhibited a significant positive correlation with species richness,but a negative correlation with phytoplankton *** variation in environmental factors(turbidity,total nitrogen,NH_(4)^(+)-N,total phosphorus,PO_(4)^(3-)-P and percentage urbanized area)was significantly correlated with phytoplankton diversity and ***,our results revealed the influence of urbanization on phytoplankton community structure and ecosystem function was due to its altering the environmental ***,human-driven urbanization may play crucial roles in shaping the structure and function of phytoplankton communities in subtropical rivers,and the mechanism of this process can provide important information for freshwater sustainable uses,watershed management and conservation.

关键词： Plankton Community functioning Subtropical river Urbanization gradient Land use Watershed ecology

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Rough singular integrals associated to surfaces of revolution on product spaces

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Acta Mathematica Sinica,English Series 2025年

作者： Hussain al-QASSEM Leslie CHENG Yibiao PAN Mathematics Program Department of Mathematics Statistics and Physics College of Arts and Sciences Qatar University Department of Mathematics Bryn Mawr College Department of Mathematics University of Pittsburgh

We study the Lpboundedness of singular integral operators along surfaces of revolution on product spaces. The Lpboundedness for these operators are obtained under very weak conditions on kernels. Our results are new and they improve several previously known results. Furthermore, they are natural extensions of many known results on singular integrals in the one-parameter setting and they subsume many other corresponding results on the product space setting.

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Structural, electronic, and optical studies of chalcogenides stannite Cu2CdSnX4（X=S, Se, and Te）: insights from the DFT study

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Optoelectronics Letters 2025年第2期21卷 69-76页

作者： Jamal GUERROUM Mohamed al-HATTAB Lhoucine MOUDOU Khalid RAHMANI Youssef LACHTIOUI Omar BAJJOU Laboratory of Engineering in Chemistry and Physics of Matter Faculty of Sciences and Technics Sultan Moulay Slimane University Ecole Normale Supérieure Mohammed V University in Rabat College of Graduate Studies University of South Africa

In this paper,we have calculated the structural,electronic,and optical properties of chalcogenide stannite Cu2CdSnX4（X=S,Se,Te） *** calculations are based on the density functional theory （DFT） method and are performed using the Cambridge sequential total energy package （CASTEP） code included in the Biovia Material Studio 20 *** optical properties have been studied in a domain that extends energetically from 10 meV to 40 *** results show that Cu2CdSnX4（X=S,Se,Te） stannite exhibits absorption in the visible region,the refractive index decreases with increasing energy,and the refractive index values are n=3.2,3.73 and 3.75 for Cu2CdSnS4,Cu2CdSnSe4and Cu2CdSnTe4,*** show also high conductivity,which implies that this material is promising for solar *** results argue in favor of the use of these materials in various potential *** density of state,band structures,and structural properties of Cu2CdSnX4（X=S,Se,and Te） stannite are also studied in this work.

关键词： Refractive index

Genes and proteins expressed at different life cycle stages in the model protist Euplotes vannus revealed by both transcriptomic and proteomic approaches

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Science China Life Sciences 2025年第1期68卷 232-248页

作者： Yaohan Jiang Xiao Chen Chundi Wang Liping Lyu Saleh A.al-Farraj Naomi A.Stover Feng Gao Key Laboratory of Evolution & Marine Biodiversity (Ministry of Education) and Institute of Evolution & Marine Biodiversity Ocean University of China Marine College Shandong University Zoology Department College of ScienceKing Saud University Department of Biology Bradley University Laboratory for Marine Biology and Biotechnology Qingdao Marine Science and Technology Center

Sexual reproduction first appeared in unicellular protists and has continued to be an essential biological process in almost all *** protists, which contain both germline and somatic genomes within a single cell, have evolved a special form of sexual reproduction called conjugation that involves mitosis, meiosis, fertilization, nuclear differentiation, genome rearrangement, and the development of unique cellular structures. The molecular basis and mechanisms of conjugation vary dramatically among ciliates, and many details of the process and its regulation are still largely unknown. In order to better comprehend these processes and mechanisms from an evolutionary perspective, this study provides the first comprehensive overview of the transcriptome and proteome profiles during the entire life cycle of the newly-established marine model ciliate Euplotes vannus. Transcriptome analyses from 14 life cycle stages(three vegetative stages and 11 sexual stages) revealed over 26,000 genes that are specifically expressed at different stages, many of which are related to DNA replication,transcription, translation, mitosis, meiosis, nuclear differentiation, and/or genome rearrangement. Quantitative proteomic analyses identified 338 proteins with homologs associated with conjugation and/or somatic nuclear development in other ciliates, including dicer-like proteins, Hsp90 proteins, RNA polymerase Ⅱ and transcription elongation factors, ribosomal-associated proteins, and ubiquitin-related proteins. Four of these homologs belong to the PIWI family, each with different expression patterns identified and confirmed by RT-qPCR,which may function in small RNA-mediated genome rearrangement. Proteins involved in the nonhomologous end-joining pathway are induced early during meiosis and accumulate in the developing new somatic nucleus, where more than 80% of the germline sequences are eliminated from the somatic genome. A number of new candidate genes and proteins likely t

关键词： sexual reproduction transcriptomic proteomic genome rearrangement PIWI NHEJ