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51.
52.
We present a two-dimensional optical coherence vibration tomography (2DOCVT) system with an ultra-precision displacement resolution of ~0.1 nm that is capable of in site real-time absolute displacement measurement of structural line vibrations. Experimental results of sinusoidal, sweep and impulse vibrations were reported. The key figures of merit such as the 2DOCVT system could obtain fast line vibration measurement without scanning and it also could be used to capture structural modal parameters in one single impulse excitation measurement without any vibration excitation input information, making it attractive for the application in low-frequency vibration measurement and response-only modal analysis. 相似文献
53.
Quinones are electroactive species that have shown great promise for redox flow batteries due to the ability to tune their properties and to act as both negative and positive electrolytes. The following review outlines highlights of work in the last couple of years working to provide materials with higher stability, solubility, and performance. Developments toward stable negolytes have provided opportunities for potential commercial opportunities when paired with alternate chemistries. However, the stability of quinones in high potential electrolytes is still not sufficient and the number of potential quinones limited. 相似文献
54.
A divergence‐free moving particle semi‐implicit framework has been formulated for modeling of multiple miscible fluids having small density ratios (≤ 1.10) in the presence of free surface. A density‐weighted pressure gradient along with a hybrid free‐surface treatment is specifically adopted to incorporate the effect of marginal density difference through a higher‐order kernel. The hybrid free‐surface treatment reduces error in velocity divergence and resulting spurious velocity fluctuation in the vicinity of free surface for low‐velocity system. Scalar transport equation is resolved to update density associated with the particles at every time step. A total of 9 cases of lock‐exchange flow with different lock positions and density ratios have been utilized to validate the proposed framework. The model performs satisfactorily irrespective of lock positions and low density variations (3%‐9%). 相似文献
55.
Isomotive dielectrophoresis (isoDEP) is a unique DEP geometrical configuration where the gradient of the field-squared () is constant. IsoDEP analyzes polarizable particles based on their magnitude and direction of translation. Particle translation is a function of the polarizability of both the particles and suspending medium, the particles’ size and shape, and the frequency of the electric field. However, other electrokinetics act on the particles simultaneously, including electrothermal hydrodynamics. Hence, to maximize the DEP force relative to over electrokinetic forces, design parameters such as microchannel geometry, fabrication materials, and applied electric field must be properly tuned. In this work, scaling law analyses were developed to derive design rules, relative to particle diameter, to reduce unwanted electrothermal hydrodynamics relative to DEP-induced particle translation. For a particle suspended in 10 mS/m media, if the channel width and height are below ten particle diameters, the electrothermal-driven flow is reduced by ∼500 times compared to a channel that is 250 particles diameters in width and height. Replacing glass with silicon as the device's underlying substrate for an insulative-based isoDEP reduces the electrothermal induced flow approximately 20 times less. 相似文献
56.
Nagwa Abo El-Maali Asmaa Y. Wahman Aref A.M. Aly Ahmed Y. Nassar Douaa M. Sayed 《应用有机金属化学》2020,34(6):e5594
Lanthanide complexes are of increasing importance in cancer diagnosis and therapy. In the present study 1:1 and 1:3 solid complexes of La (III)–5-FU (5-fluorouracil) were prepared and characterized. In solution, the formation of 1:1 La (III) and Eu (III) complexes enabled the enhancement of 5-FU's effectiveness. Binding constants of the 1:1 complexes of both metals were estimated using spectrophotometry and HPLC with fluorescence detection methods. The thermodynamic parameters ΔG ° , ΔH ° and ΔS ° were calculated using differential scanning calorimetry. Evaluation of the cytotoxic activity of the 1:1 La (III)- and Eu (III)–5-FU complexes was performed through two methodologies, trypan blue for cell viability where La (III)- and Eu (III)–5-FU complexes were found to have 52,000 and 80,000 dead cells, respectively, and via flow cytometric analysis to measure the apoptotic values, which were found to be 59.87 and 86.86% respectively. 相似文献
57.
58.
Luyao Tong Pengcheng Li Fupeng Li Yongjia Wang Qingfeng Li Fanxin Liu 《中国物理C(英文版)》2020,44(7):074103-074103-8
By incorporating an iso spin-dependent form of the momentum-dependent potential in the ultra-relativistic quantum molecular dynamics(UrQMD) model,we systematically investigate effects of the neutron-proton effective mass splitting m*_(n-p)=m*_n-m*_p/m and the density-dependent nuclear symmetry energy E_(sym)(ρ) on the elliptic flow v_2 in~(197)Au+~(197) Au collisions at beam energies from 0.09 to 1.5 GeV/nucleon.It is found that at higher beam energies(≥0.25 GeV/nucleon) with the approximately 75 MeV difference in slopes of the two different E_(sym)(ρ),and the variation of m*_(n-p) ranging from-0.03 to 0.03 at saturation density with isospin asymmetry δ=(ρ_n-ρ_p)/ρ-0.2,the E_(sym)(ρ) has a stronger influence on the difference in v_2 between neutrons and protons,i.e.,v_2~n-v_2~p,than m*_(n-p) has.Meanwhile,at lower beam energies(≤0.25 GeV/nucleon),v_2~n-v_2~p is sensitive to both the E_(sym)(ρ) and the m*_(n-p).Moreover,the influence of m*_(n-p) on v_2~n-v_2~p is more evident with the parameters of this study when using the soft,rather than stiff,symmetry energy. 相似文献
59.
The flow behavior in non-parallel walls is an important factor of any physical model including cavity flow and canals, which is applicable for diverging/converging channel. The present communication explains that the flow of the hybrid nanomaterial subjected to the convergent/divergent channel has non-parallel walls. It is assumed that the hybrid nanomaterial movement is in the porous region. A Darcy-Forchheimer medium of porosity is considered to interpret the porosity features. A useful similarity function is adopted to get the strong ordinary coupled equations. Numerical solutions are achieved through the Runge-Kutta-Fehlberg(RKF) fourth-fifth order method, and they are validated with the existing results. Physical nature of the involving constraints is reported with the help of plots. It is explored that the velocity of divergent channel decreases, and convergent channel enhances for the higher solid volume faction. Further, the presence of inertia coefficient and porosity parameter amplifies the velocity at the wall. 相似文献
60.
天然气水合物作为一种储量大、无污染的清洁能源近些年受到了广泛关注. 近20年来,中国进行了较大范围的陆海域天然气水合物储层勘探与储量预测.2017年,中国地质调查局牵头对南海神狐海域的天然气水合物进行了基于降压渗流原理的试验性开采.国内外已进行的水合物试采工程面临着气体产量低、出砂较多等问题,其最主要的原因之一是开发过程中沉积物内复杂多相渗流机理尚不明晰.本文综述了平行毛细管模型、Kozeny模型等广泛应用于天然气水合物开发渗流分析的理论模型,对比分析了水合物开发多尺度渗流过程模拟方法,简述了国内外含水合物沉积物渗透率测试、渗流过程中沉积物物性演变以及水合物开采室内模拟等方面的渗流实验进展,总结了矿场尺度的天然气水合物储层开采过程中产气数值模拟手段,展望了多相渗流模型、储层原位含水合物样品室内测试及结构与物性演化、矿场尺度数值模拟与水平井压裂技术等应用研究的未来方向与挑战. 相似文献