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synthesis and enhanced photoluminescence properties of red emitting divalent ion(Ca^(2+))doped Eu:Y_(2)O_(3)nanophosphors for optoelectronic applications

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Journal of Rare Earths 2022年第8期40卷 1187-1198页

作者： Arpita Dwivedi Monika srivastava Ankur Dwivedi Amit srivastava Anurag Mishra s.k.srivastava Department of Physics Institute of ScienceBanaras Hindu University(BHU)Varanasi221005India school of Materials science and Technology Indian Institute of Technology(BHU)Varanasi221005India Department of Mining Engineering Indian Institute of Technology(BHU)Varanasi221005India Department of Physics TDPG College VBS Purvanchal UniversityJaunpur222001India

This work presents the synthesis of Y_(2)O_(3):Eu^(3+),χCa^(2+)(χ=0 mol%,1 mol%,3 mol%,5 mol%,7 mol%,9 mol%,11 mol%)nanophosphors with enhanced photoluminescence properties through a facile solution combustion method for optoelectronic,display,and lighting *** X-ray diffraction(XRD)patterns of the proposed nanophosphor reveal its structural properties and crystalline *** transmission electron microscope(TEM)results confirm the change in the shape of the particle and aggregation of particles after co-doping with Ca^(2+).Fourier transform infrared spectroscopy(FTIR)and Raman vibrations also confirm the presence of Y-O vibration and subsequently explain the crystalline nature,structural properties,and purity of the *** the synthesized nanophosphors samples emit intense red emission at 613 nm(~5D_(0)→~7 F_(2))under excitation with 235,394 and 466 nm wavelengths of Eu^(3+)*** photoluminescence(PL)emission spectra excited with 235 nm illustrate the highest emission peak with two other emission peaks excited with 466 and 394 nm that is 1.4 times higher than 466 nm and 1.9 times enhanced by 394 nm wavelength,*** emission intensity of Y_(2)O_(3):Eu^(3+),χCa^(2+)(5 mol%)is increased 8-fold as compared to Eu:Y_(2)O_(3).Doping with Ca^(2+)ions enhances the emission intensity of Eu:Y_(2)O_(3)nanopho sphors due to an increase in energy transfer in Ca^(2+)→Eu^(3+)through asymmetry in the crystal field and by introduction of radiative defect centers through oxygen vacancies in the yttria *** is also observed that the optical band gap and the lifetime of the~5D_(0)level of Eu^(3+)ions in Y_(2)O_(3):Eu^(3+),xCa^(2+)nanophosphor sample gets changed with a doping conce ntration of Ca^(2+)*** also reveals high thermal stability and quantum yield as estimating activation energy of 0.25 eV and 81%,***,CCT,and color purity values(>98%)show an improved red-emitting nanophosphor in the warm region of light,which m

关键词： Red emission Photoluminescence(PL) Y_(2)O_(3):Eu^(3+),xCa^(2+) Rare earths Nanophosphors LEDs

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Effect of hydrogen plasma treatment on the growth and microstructures of multiwalled carbon nanotubes

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Nano-Micro Letters 2010年第1期2卷 42-48页

作者： s.k.srivastava V.D.Vankar V.kumar Department of Physics Indian Institute of Technology Delhi National Physical Laboratory Dr.K.S.Krishnan Marg

The effect of hydrogen plasma treatment of iron oxide films on the growth and microstructure of carbon nanotubes(CNTs)by microwave plasma enhanced chemical vapor deposition process has been *** plasma was characterized in-situ using optical emission *** of the films was examined by scanning electron *** analysis was carried out by high resolution transmission electron microscopy(HRTEM)equipped with energy dispersive X-ray spectroscopy(EDs)and micro-diffraction *** is found that oxide films without H_2 plasma pretreatment or treated for lesser time resulted in CNT films with high percentage of carbonaceous particles and with embedded particles/nanorods distributed discontinuously in the cavity of the *** embedded particles were found to be of iron carbide(Fe-C)as confirmed by HRTEM,EDs and micro-diffraction *** observations suggested that the iron oxide particles had poor catalytic action for CNT growth and in-situ reduction of oxide clusters to Fe by hydrogen plasma plays a key role in discontinuous filling of the nanotubes by the catalytic particles.

关键词： Carbon nanotubes Chemical vapor deposition Iron carbide MPECVD

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由化肥厂废浆制成的碳素物对重金属离子的吸附

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国外环境科学技术 1990年第3期 53-58,25页

作者： s.k.srivastava 段光才

在印度,一些化肥厂将废浆转化成廉价的含碳吸附剂。此产品对铬、汞、铅有良好的吸附性能,对酮、钼的吸附也具有重要的意义,但不能很好的吸附净化镉、镍、钴、锌。利用等温吸附线可得这一过程的热力学特征函数。并以柱研究考察了金属离... 详细信息

在印度,一些化肥厂将废浆转化成廉价的含碳吸附剂。此产品对铬、汞、铅有良好的吸附性能,对酮、钼的吸附也具有重要的意义,但不能很好的吸附净化镉、镍、钴、锌。利用等温吸附线可得这一过程的热力学特征函数。并以柱研究考察了金属离子的吸附和吸附剂的就地化学再生。

关键词：化肥厂废浆碳素物金属离子吸附

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由化肥厂废浆制成的碳素物对重金属离子的吸附

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环境科学与管理 1990年第3期 53-58+25页

作者： s.k.srivastava 段光才

关键词：重金属离子碳素物废浆吸附剂化肥厂等温吸附线被吸附物

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改进梳棉工艺,消除棉纱短片段不匀率

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国外纺织技术（纺织分册） 1993年第5期 14-17,19页

作者： s.k.srivastava 全振华

短片段不匀如粗节、细节和棉结的高发生率正在成为印度出口棉纱中的主要问题。在从最初的轧棉工艺开始到成品纱的各个加工制造阶段,进行了大量的实验。

关键词：梳棉工艺改进棉纱不匀率

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Flavonoid Myricetin as Potent Anticancer Agent: A Possibility towards Development of Potential Anticancer Nutraceuticals

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Chinese Journal of Integrative Medicine 2024年第1期30卷 75-84页

作者： Anchal Trivedi Adria Hasan Rumana Ahmad sahabjada siddiqui Aditi srivastava Aparna Misra snober s.Mir Department of Biochemistry Era's Lucknow Medical College&HospitalEra UniversityLucknow(226003)India Molecular Cell Biology Laboratory Integral Information and Research Centre-4(IIRC-4)Department of BioengineeringFaculty of EngineeringIntegral UniversityLucknow(226026)India Department of Biotechnology Era's Lucknow Medical College&HospitalEra UniversityLucknow(226003)India Department of Biosciences Faculty of ScienceIntegral UniversityLucknow(226026)India

Good nutrition plays a crucial role in maintaining a balanced lifestyle. The beneficial effects of nutrition have been found to counteract nutritional disturbances with the expanded use of nutraceuticals to treat and manage cardiovascular diseases, cancer, and other developmental defects over the last decade. Flavonoids are found abundantly in plant-derived foods such as fruits, vegetables, tea, cocoa, and wine. Fruits and vegetables contain phytochemicals like flavonoids, phenolics, alkaloids, saponins, and terpenoids. Flavonoids can act as anti-inflammatory, anti-allergic, anti-microbial(antibacterial, antifungal, and antiviral) antioxidant, anti-cancer, and anti-diarrheal agents. Flavonoids are also reported to upregulate apoptotic activity in several cancers such as hepatic, pancreatic, breast, esophageal, and colon. Myricetin is a flavonol which is naturally present in fruits and vegetables and has shown possible nutraceutical value. Myricetin has been portrayed as a potent nutraceutical that may protect against cancer. The focus of the present review is to present an updated account of studies demonstrating the anticancer potential of myricetin and the molecular mechanisms involved therein. A better understanding of the molecular mechanism(s) underlying its anticancer activity would eventually help in its development as a novel anticancer nutraceutical having minimal side effects.

关键词： myricetin flavonoids anticancer nutraceuticals Chinese medicine Ayurveda complementary and alternative medicine

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One-Pot Green synthesis of 1, 4-Dihydropyridine Derivatives Using Polyindole TiO2 Nanocatalyst by solvent Free Method

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Open Journal of Composite Materials 2024年第3期14卷 109-123页

作者： Deepak Babasaheb Phasage sanjay k. sharma Balram Tripathi sonia Chahar srivastava Department of Chemistry JECRC University Jaipur India s. s. Jain subodh PG College Jaipur India

This study used a Polyindole in combination with TiO2 nanocatalyst as an efficient heterogeneous catalyst to carry out a multi-component Hantzsch reaction involving different aromatic aldehydes with methyl acetoacetate, and aqueous ammonium to create 1,4-dihydropyridine derivatives under solvent free condition at ambient temperature. A broad range of aldehydes and methyl acetoacetates, ranging from heteroaromatic to polyaromatic one, with high level of functional group tolerance can be used to provide the desired products possessing relevant medicinal moiety in high yields. This technology has prospective advantages over current protocols, including the utilization of a cheap, stable, recyclable, and safe catalyst, quicker reaction times with higher yields and simple product isolation.

关键词： TiO2 Nanocatalyst Green synthesis surface Morphology

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基于社区的气候变化适应方法与高海拔Garhwal喜马拉雅山脉Bhagirathi地区的生计安全

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Journal of Resources and Ecology 2024年第1期15卷 197-203页

作者： shoryabh srivastava Bindhy Wasini PANDEY Virender singh NEGI 德里大学经济学院地理系印度德里110007 德里大学莎希德·巴加特·辛格学院地理系(E) 印度德里110017

位于Garhwal喜马拉雅山的Bhagirathi(HA-BV)谷地是一个生态和文化重要性极高的地区,但当地居民的生计容易受到气候变化的影响。基于社区的气候变化适应方法(CB-CCA)已成为一种增强地方社区的经济和社会福祉重要策略,并提高了社区发展的... 详细信息

位于Garhwal喜马拉雅山的Bhagirathi(HA-BV)谷地是一个生态和文化重要性极高的地区,但当地居民的生计容易受到气候变化的影响。基于社区的气候变化适应方法(CB-CCA)已成为一种增强地方社区的经济和社会福祉重要策略,并提高了社区发展的韧性。本文旨在研究HA-BV地区的CB-CCA和生计保障计划,关注应对气候变化所面临挑战的策略。研究认为优先考虑适应该地区崎岖的地形和恶劣的天气条件的可持续生计选择至关重要。例如,与山谷独特的土壤和气候动态相适应,推广温室种植和农林复合种植等替代农业,可能会带来较好的结果;此外,鼓励养蜂、手工艺和生态旅游等替代生计途径不仅可以创收,还能保护该地区的自然环境。为了鼓励当地居民实施这些环境友好的生计措施,政府和利益相关者需要进行战略性投资,基础设施的完善(包括道路建设和电力供应)可为经济增长创造良好的条件。研究结果可为喜马拉雅山地区的可持续发展做出贡献,为类似情境下未来构建气候韧性和保障生计的努力提供参考。

关键词： Bhagirathi谷基于社区的方法气候变化适应生计保障 Garhwal喜马拉雅山

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A near infrared optical reflector using one-dimensional photonic crystal structure containing chalcogenide glasses

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Optoelectronics Letters 2010年第6期6卷 406-411页

作者： sanjeev k.srivastava s k Awasthi s.k.srivastava s.P.Ojha Department of Physics Amity Institute of Applied SciencesAmity University Department of Physics Jaypee Institute of Information TechnologyDeemed University Department of Physics Mahila Maha VidyalayBanaras Hindu University Department of Applied Physics Institute of TechnologyBanaras Hindu University

The reflectivity of one-dimensional chalcogenide photonic crystal(CGPC) structure with the first order reflection band in near infrared(NIR) region is theoretically ***-se and Ge-s chalcogenide glasses are used as high and low refractive index layers respectively,because these materials have zero absorption in NIR *** transfer matrix method(TMM) is employed to calculate the reflective spectra of the proposed *** theoretical results of reflective spectra of bulk chalcogenide materials with the composition of sb40se60 and Ge30s70 for 4,8,12 and 15 layers and thicknesses of 117 nm and 183 nm respectively,at normal incidence,are close agreement with the experimental ***,by increasing the number of layers of sb40se60 and Ge30s70,the reflection bands can be enhanced in the wider range of the NIR region for the polarization at different angles and thus the broadband omnidirectional reflector can be designed.

关键词：一维光子晶体晶体结构硫系玻璃近红外光反射镜红外区域反射光谱计算结果

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Parents’s knowledge and awareness about hepatitis B can influence the vaccination of their children

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World Journal of Virology 2024年第2期13卷 96-106页

作者： Nanda Chhavi Geetika srivastava Mariya Waseem Abhishek Yadav surender singh Rajani singh Amit Goel Department of Paediatrics Era’s Lucknow Medical CollegeLucknow 226003Uttar PradeshIndia Medical Consultant National Disease Control ProgramNational Health MissionLucknow 226003Uttar PradeshIndia Department of Hepatology Sanjay Gandhi Postgraduate Institute of Medical SciencesLucknow 226014Uttar PradeshIndia

BACkGROUND Birth-dose(Hep-BD)followed by three additional doses(Hep-B3)of hepatitis B virus(HBV)vaccine are key to eliminating HBV by ***,Hep-BD and Hep-B3 coverage in our country is *** To studied the parent’s knowledge and awareness about HBV infection,its prevention,consequences and *** Parents of 6 months to 8 years old children were interviewed to assess their knowledge&awareness about hepatitis B,its transmission,prevention,illness caused by this,and *** close-ended questions were admini-stered,and responses were recorded as‘yes’,‘no’,or‘not sure’.HBV knowledge score was calculated based on the sum of correct *** correct response scored one point and incorrect,missing or‘not sure’responses received no *** data are presented as number(%)and numerical data are expressed as *** were compared using Chi2 tests and level of significance was kept as Ps(58.3%mothers)of 384 children(89.9%ages;82%age-appropriately vaccinated)were *** hundred and twenty-two(83.9%)children were Hep-B3 vaccinated.94.3%,87.5%,and 29.2%parents knew about polio,tetanus,and hepatitis B ***,41.2%,15.8%,and 23%parents knew about hepatitis B transmission,consequences of infection,and prevention *** 7.6%parents knew about three-dose schedule of hepatitis B *** 23%parents believed that vaccine could prevent HBV,15.7%knew that HBV affects *** of Hep-B3 vaccinated children were significantly more aware about HBV than the parents of unvaccinated children(Pstions).CONCLUsION The knowledge and awareness among the parents about hepatitis B is *** Increasing knowledge/awareness about HBV among parents may improve Hep-B3 vaccination coverage.

关键词： Hepatitis B Viral hepatitis Cirrhosis Hepatocellular carcinoma Hepatotropic viruses Transfusion transmitted infection Mother to child transmission

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