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排序方式: 共有950条查询结果,搜索用时 31 毫秒
1.
Arya Sidharthan Neelesh Dahanukar Remya Lathika Sundar Kutty Ranjeet Rajeev Raghavan 《河流研究与利用》2022,38(1):152-159
Riverscape genetics of fish, though extensively studied in temperate regions, have received limited interest in tropical rivers, especially in montane systems which not only harbour several endemic and threatened species, but are also subjected to extensive habitat modifications. We determine the population genetic structure of two endemic balitorid loaches (Bhavania australis and Travancoria elongata) in response to natural (25 m high waterfall) and artificial (23 m high and 290 m long hydropower dam) barriers in a small mountain riverscape in the Western Ghats Hotspot. Population genetics analysis using mitochondrial cytochrome b gene sequence showed low nucleotide diversity, haplotype diversity and genetic differentiation among populations, for both species, suggesting that barriers did not influence genetic structuring. Though migration analysis also revealed that barriers did not affect movement of the two species through the riverscape, patterns in mutation-scaled immigration rates and population sizes differed between the two species supporting our observation that they rarely co-exist in the same habitat, likely as an effect of competitive exclusion. Mismatch distribution and Bayesian skyline plot suggested recent expansion in the populations of B. australis and corresponding population decline in T. elongata in the last 100 years, which probably explains the widespread and abundant distribution of B. australis as opposed to the narrow endemism and rarity of T. elongata. Our results provide novel insights into the ecology of balitorid loaches and their response to riverine barriers in a tropical mountain landscape. 相似文献
2.
Purpose
To explore the safety profile and overall visual improvement over the course of RGP contact lens wear on children with unilateral or bilateral amblyopia resulting from myopia.Methods
This was a retrospective analysis case series study. Clinical records of 15 patients who were fitted with RGP contact lenses at the Shanghai Eye and EENT Hospital of Fudan University between the period of January 2009 to December 2014 were reviewed. The inclusion criteria for review included patients with myopia of ?3.00DS or greater in one or both eyes and an initial best-corrected visual acuity (BCVA) of logMAR 0.4 or worse for 3 year olds, and logMAR 0.3 or worse for 4 years old and above. One or both myopic eyes were fitted with RGP lenses.Results
15 subjects and 22 amblyopic eyes were included. The mean baseline BCVA was logMAR 0.70 ± 0.38, which improved to a VA of 0.23 ± 0.28 at the time of review (p < 0.05). Baseline myopia also increased from ?8.18 ± 2.93DS to ?11.41 ± 3.76DS (p < 0.05). The final visual acuity at the time of this review was correlated with the initial refractive error (r = ?0.695, p < 0.05) as well as the initial BCVA (r = 0.854, p < 0.05). There was also a strong correlation between initial refractive error and initial BCVA (r = 0.?801, p < 0.05)Conclusion
RGP contact lens wear is a safe and effective refractive treatment option in young children with amblyopia due to myopia. 相似文献3.
Daroonparvar Mohammadreza Mat Yajid Muhamad Azizi Bakhsheshi-Rad Hamid Reza Kumar Gupta Rajeev Ismail A. F. 《Protection of Metals and Physical Chemistry of Surfaces》2020,56(3):628-637
Protection of Metals and Physical Chemistry of Surfaces - Single NbSi2 and duplex NbSi2/Nb5Si3 coatings were successfully applied on Nb substrates using halide activated pack cementation (HAPC)... 相似文献
4.
Piezoelectric energy harvesting from mechanical vibrations is a reliable technology to charge low power electronic equipment. It has been reported in the literature that low frequency broadband vibrations cannot be harvested effectively using linear piezoelectric energy harvester (PEH). In this paper a bistable nonlinear PEH with two distinct energy wells generated using repulsive magnetic interactions between a cantilever magnetic proof mass and an external magnet is considered. It has been modeled using finite element method and validated with experimental results. Experimental results verify that, for our study, distance between magnetic proof mass and external magnet of 1.32 T flux density should be less than or equal to 8.5?mm for maintaining bistability. This distance also affects to the resonance frequency of harvester. Maximum efficiency of the harvester has been noticed at 8.5mm. Further it has been shown experimentally that the bistable nonlinear piezoelectric energy harvester takes almost half of the time taken by its linear counterpart to charge a 20 mAh battery. 相似文献
5.
Electromagnetic responses of cement–PZT composites under impact loading have been presented in this work. The values of density, dielectric constant and EMR voltage increase while that of porosity and loss tangent decrease with increase in PZT content. Filler (PZT) concentration dependent dielectric constant as well as loss tangent data shows exponential variation. The emitted EMR voltage as well as average EMR energy release rate for 21?cm height of impact increase from 1.03 V to 2.24 V and 0.10092 V2-sec/sec to 0.4635 V2-sec/sec respectively with the increasing PZT content (5% to 40%). The EMR responses of the composites were also found to be proportional to the height of impact in all the composites tested, indicating that the measurement of EMR responses from the cement based composites may be useful for deformation monitoring. 相似文献
6.
Yashvir Singh Abhishek Sharma Nishant Singh Amneesh Singla Pankaj Mohan Rastogi 《国际自然能源杂志》2020,41(13):1534-1547
ABSTRACT Fossil fuel resource is on the draining stage which leads to an increment in the cost of the petroleum products. Nowadays, research is focused on the development of environmental friendly lubricants which are derivatives of renewable sources. Inedible plant oil-driven bio-lubricants are environmentally friendly because they are non-hazardous, biodegradable, as well as there is no emission of toxic gases. This study involves the characterisations, advantages, as well as utilisation of inedible plant oil-driven bio-lubricants as an alternative for tribological applications. This report presents the status about the global lubricant market as well as potential outlook. Inedible plant oil-driven bio-lubricants bear high viscosity, high lubricity, and high viscosity index which can enhance the equipment service life and has the ability to carry high load and results in minimum amount of metal traces during combustion. 相似文献
7.
Pandey Mahendra Kumar Parmar Girish Gupta Rajeev Sikander Afzal 《Microsystem Technologies》2019,25(8):3071-3081
Microsystem Technologies - Due to fast technological development, human beings generally depend upon computer and other digital equipments in different areas of concern/applications. Therefore,... 相似文献
8.
Hang Liu Xiaofeng Zhao Yuancheng Teng Yuxiang Li Xiayu Zheng Shanlin Wang Lang Wu Pritam Kumar Panda Rajeev Ahuja 《Journal of the American Ceramic Society》2022,105(7):4974-4985
LnPO4 · 0.667H2O rhabdophane has been considered as a potential material for the precipitation of actinides from radioactive waste liquid, owing to its outstanding characteristics of high actinide bearing and easy synthesis in acid solutions. However, a comprehensive understanding of the actinide occupation and the precipitation response of rhabdophane to remove actinides has yet to be established. In this study, the effect of ions concentration and pH values on the detailed precipitation reaction of CexNd1-xPO4 · 0.667H2O rhabdophane in acid solutions are systematically investigated. Some specific issues such as structural distortion and flexibility, and occupation mechanism are discussed by combining with experiments and density functional theory (DFT) calculation. The results reveal that ions concentration and pH values have a significant impact on the crystallization nucleation step before 12 h. The obtained removal rate of Nd3+ is more than 99% in pH 1–5 solutions with the ions concentration of 0.05–0.1 mol/L. Moreover, incorporating Nd in CePO4 · 0.667H2O rhabdophane will easily result in the lattice distortion in b-axis. DFT calculation and X-ray photoelectron spectroscopy (XPS) results reveal that Nd is preferentially incorporated in nonhydrated site to form a weaker binding energy of NdO8 polyhedron. 相似文献
9.
Shaimaa M. Aboukhatwa Dr. Thomas W. Hanigan Taha Y. Taha Dr. Jayaprakash Neerasa Dr. Rajeev Ranjan Dr. Eman E. El-Bastawissy Dr. Mohamed A. Elkersh Prof. Dr. Tarek F. El-Moselhy Prof. Dr. Jonna Frasor Prof. Dr. Nadim Mahmud Prof. Dr. Alan McLachlan Prof. Dr. Pavel A. Petukhov 《ChemMedChem》2019,14(11):1096-1107
Histone deacetylase (HDAC) activity is modulated in vivo by post-translational modifications and formation of multiprotein complexes. Novel chemical tools to study how these factors affect engagement of HDAC isoforms by HDAC inhibitors (HDACi) in cells and tissues are needed. In this study, a synthetic strategy to access chemically diverse photoreactive probes (PRPs) was developed and used to prepare seven novel HDAC PRPs 9 – 15 . The class I HDAC isoform engagement by PRPs was determined in biochemical assays and photolabeling experiments in live SET-2, HepG2, HuH7, and HEK293T cell lines and in mouse liver tissue. Unlike the HDAC protein abundance and biochemical activity against recombinant HDACs, the chemotype of the PRPs and the type of cells were key in defining the engagement of HDAC isoforms in live cells. Our findings suggest that engagement of HDAC isoforms by HDACi in vivo may be substantially modulated in a cell- and tissue-type-dependent manner. 相似文献
10.
In this paper, a STATCOM (static synchronous compensator) is used to encounter the potential SSR (subsynchronous resonance) observed by IG (Induction Generator) based series compensated wind farms. The basic controller used for STATCOM control is identical to that of the literature. An idea of a unique meta‐heuristic swarm‐based optimization technique called BFOA (bacterial foraging optimization algorithm) based optimal‐controller is introduced for optimal parameter selection of the basic controller used in the control scheme of the STATCOM. The investigation is carried out with 500 MW IG‐based wind farm exposed to three‐phase LLL‐G fault close to the PCC (point of common coupling) and implemented with MATLAB in both steady and transient states for the three different cases, namely, without STATCOM, with the basic STATCOM controller, and in the presence of the proposed BFOA‐optimal controller‐based STATCOM. In both the states, the observed eigenvalues of the test system, together with the time domain results of the generator rotor dynamics for three distinct cases, reveals the effectiveness of the suggested BFOA‐optimal controller tuned STATCOM in mitigating the potential SSR. 相似文献