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排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Shima Yousefi Zahra Emam-Djomeh Sayed Mohammad Ali Mousavi Gholam Reza Askari 《Food and Bioprocess Technology》2012,5(4):1328-1339
Pomegranate juice was concentrated by conventional heating and microwave heating at different operational pressures (12, 38.5,
and 100 kPa), and their effects on evaporation rate and quality attributes of concentrated juice were investigated. The final
juice concentration of 40° Brix was achieved in 140, 127, and 109 min at 100, 38.5, and 12 kPa, respectively, by using conventional
heating. Applying microwave energy decreased required times to 118, 95, and 75 min. The changes in color, anthocyanin content,
and antioxidant capacity during concentration processes were investigated. L*, a*, and b* parameters were measured to estimate the intensity of color loss. All Hunter color parameters decreased with time. Results
showed that the degradation of color, anthocyanins, and antioxidant activity were more important in conventional heating compared
to microwave heating method. Degradation rates increases by increasing process pressure. A first-order kinetics model was
applied to modeling changes in total solid content, anthocyanin content, and antioxidant capacity. 相似文献
52.
Yixiao Cai Yang Chen Muhammad Akbar Bin Jin Zhengwen Tu Naveed Mushtaq Baoyuan Wang Xiangyang Qu Chen Xia Yizhong Huang 《纳微快报(英文)》2021,(3):66-79
Since colossal ionic conductivity was detected in the planar heterostructures consisting of fluorite and perovskite,heterostructures have drawn great research interest as potential electrolytes for solid oxide fuel cells(SOFCs).However,so far,the practical uses of such promising material have failed to materialize in SOFCs due to the short circuit risk caused by SrTiO3.In this study,a series of fluorite/perovskite heterostructures made of Sm-doped CeO2 and SrTiO3(SDC–STO)are developed in a new bulk-heterostructure form and evaluated as electrolytes.The prepared cells exhibit a peak power density of 892 mW cm−2 along with open circuit voltage of 1.1 V at 550°C for the optimal composition of 4SDC–6STO.Further electrical studies reveal a high ionic conductivity of 0.05–0.14 S cm^−1 at 450–550°C,which shows remarkable enhancement compared to that of simplex SDC.Via AC impedance analysis,it has been shown that the small grain-boundary and electrode polarization resistances play the major roles in resulting in the superior performance.Furthermore,a Schottky junction effect is proposed by considering the work functions and electronic affinities to interpret the avoidance of short circuit in the SDC–STO cell.Our findings thus indicate a new insight to design electrolytes for low-temperature SOFCs. 相似文献
53.
Nikos G. Tsierkezos 《International Journal of Thermophysics》2009,30(3):910-918
Surface tensions (σ) of binary liquid mixtures of acetonitrile (ACN) with 1-propanol (PrOH) were measured over the entire composition range at
eight different temperatures, 278.15 K, 283.15 K, 288.15 K, 293.15 K, 298.15 K, 303.15 K, 308.15 K, and 313.15 K. The lyophobicities
(β) of the surfactant PrOH relative to that of ACN as well as the surface mole fractions () of PrOH at various temperatures were derived using the extended Langmuir model (Langmuir 17, 4261, 2001). The β values indicate the greater affinity of PrOH for the surface, and this trend slightly increases with rising temperature.
The determined values indicate that the surface concentration of PrOH is always higher than its bulk concentration and consequently confirm
that the surface is enriched with PrOH. 相似文献
54.
Ajay Matta Muhammad Zia Karim Hoda Gerami Bettina Zoe Benigno Ivan Cheng Arne Mehrkens William Mark Erwin 《International journal of molecular sciences》2022,23(10)
Background: Tissue sources of pain emanating from degenerative discs remains incompletely understood. Canine intervertebral discs (IVDs) were needle puncture injured, 4-weeks later injected with either phosphate-buffered saline (PBS) or NTG-101, harvested after an additional fourteen weeks and then histologically evaluated for the expression of NGFr, BDNF, TrkB and CALCRL proteins. Quantification was performed using the HALO automated cell-counting scoring platform. Immunohistochemical analysis was also performed on human IVD tissue samples obtained from spinal surgery. Immunohistochemical analysis and quantification of neurotrophins and neuropeptides was performed using an in vivo canine model of degenerative disc disease and human degenerative disc tissue sections. Discs injected with NTG-101 showed significantly lower levels of Nerve Growth Factor receptor (NGFr/TrkA, p = 0.0001), BDNF (p = 0.009), TrkB (p = 0.002) and CALCRL (p = 0.008) relative to PBS injections. Human IVD tissue obtained from spinal surgery due to painful DDD show robust expression of NGFr, BDNF, TrkB and CALCRL proteins. A single intradiscal injection of NTG-101 significantly inhibits the expression of NGFr, BDNF, TrkB and CALCRL proteins in degenerative canine IVDs. These results strongly suggest that NTG-101 inhibits the development of neurotrophins that are strongly associated with painful degenerative disc disease and may have profound effects upon the management of patients living with discogenic pain. 相似文献
55.
Effects of nanocrystalline ferrite particles addition on densification behavior and magnetic properties of the NiCuZn ferrites
were investigated. It was confirmed that nanocrystalline ferrite particles enhanced densification of the samples obviously.
The reason was attributed to the nanocrystalline particles, which spread around the micron-sized ferrite particles, increased
contacting area and inter-diffusion of the particles. When the amount of nanocrystalline particles addition reached to 30 wt%,
the samples obtained an approximate densification behavior as the 1.5 wt% Bi2O3 added samples. Due to relatively bigger grain size, higher sintering density and no different chemical composition sintering
aids added, the sample with 30wt% nanocrystalline ferrite particles got the highest permeability and relatively high Q-factor when sintered at 900. 相似文献
56.
Huaying Ren Huan Wang Li Lin Miao Tang Shuli Zhao Bing Deng Manish Kumar Priydarshi Jincan Zhang Hailin Peng Zhongfan Liu 《Nano Research》2017,10(4):1189-1199
In the chemical vapor deposition growth of large-area graphene polycrystalline thin films,the coalescence of randomly oriented graphene domains results in a high density of uncertain grain boundaries (GBs).The structures and properties of various GBs are highly dependent on the misorientation angles between the graphene domains,which can significantly affect the performance of the graphene films and impede their industrial applications.Graphene bicrystals with a specific type of GB can be synthesized via the controllable growth of graphene domains with a predefined lattice orientation.Although the bicrystal has been widely investigated for traditional bulk materials,no successful synthesis strategy has been presented for growing two-dimensional graphene bicrystals.In this study, we demonstrate a simple approach for growing well-aligned large-domain graphene bicrystals with a confined tilt angle of 30° on a facilely recrystallized single-crystal Cu (100) substrate.Control of the density of the GBs with a misorientation angle of 30° was realized via the controllable rapid growth of subcentimeter graphene domains with the assistance of a cooperative catalytic surface-passivation treatment.The large-area production of graphene bicrystals consisting of the sole specific GBs with a tunable density provides a new material platform for fundamental studies and practical applications. 相似文献
57.
Which studies, theories, and ideas have influenced Eugene Garfield’s scientific work? Recently, the method reference publication year spectroscopy (RPYS) has been introduced, which can be used to answer this and related questions. Since then, several studies have been published dealing with the historical roots of research fields and scientists. The program CRExplorer (http://www.crexplorer.net) was specifically developed for RPYS. In this study, we use this program to investigate the historical roots of Eugene Garfield’s oeuvre. 相似文献
58.
Natacha Kalline de Oliveira Lucyene Miguita Tais Helena Costa Salles Marcos Akira d’Ávila Márcia Martins Marques Maria Cristina Zindel Deboni 《Journal of Materials Science》2018,53(23):15757-15768
The aim of this study was to analyze the influence of nanoporous structure of polymeric biomaterials on the in vitro osteogenic induction of human stem cells. An electronic search in three databases (MEDLINE, SCOPUS, and Web of Science) was performed for articles that were published before May 2018. In vitro studies were included if they met the following criteria: (1) the use of polymeric scaffolds (natural or synthetic); (2) the co-culture of human stem cells with the scaffold; and (3) cell viability, proliferation, and osteogenic differentiation assays. The main characteristics of the published studies were summarized, and a quality assessment tool was used to analyze methodological features. Eighty-eight potential articles were firstly retrieved. Thirteen were eligible for qualitative analysis. Only three studies characterized cell stemness. Nanostructure of the scaffolds showed a significant influence on viability, proliferation, and osteogenic differentiation of human stem cells. Combination of porosity between 72 and 93% and a large range diameter between 50 and 224 μm resulted in more remarkable cellular proliferation and differentiation. Porous polymeric scaffolds can be functionalized by stem cells leading to osteogenic induction. High standards of laboratory practice and accurate methodological reporting are essential for the credibility of the results. 相似文献
59.
For sensible thermal energy storage in Concentrating Solar Power (CSP) plants, a molten salt mixture of 60 wt% sodium nitrate (NaNO3) and 40 wt% potassium nitrate (KNO3), known as Solar Salt, is commonly utilized. The paper presents semi-empirical estimation results of the density of Solar Salt and alternative molten salt mixtures with low melting temperatures in a range from 70 °C to 140 °C. These mixtures are Hitec, HitecXL, LiNO3–KNO3–NaNO3 and a multicomponent mixture. The paper shows that density values of mixtures can be closely predicted from single salt densities. The paper examines different estimation rules for mixtures. The quasilinear volumetric additivity rule (QVAR) is known for ternary reciprocal systems. For the first time, the presented work extends the QVAR to multicomponent mixtures. Temperature-dependent densities of selected salt mixtures of the system Ca,Li,K,Na//NO2,NO3 were estimated. Estimations are motivated by a fast and reliable method compared to time-consuming and error-prone measurements of several mixtures. 相似文献
60.
This paper introduces the Dual Electro/Piezo Property (DEPP) gradient technique via Micro-Fabrication through Co-eXtrusion
(MFCX) which pairs a high displacement lead zirconate titanate (PZT) piezoceramic with a high permittivity barium titanate
(BT) dielectric. By grading with this material combination spatially across an actuator, the electric field is concentrated
in the more active region for improved efficiency, higher displacements, and complex motions. To aid in synthesis and analysis
of any gradient profile, compositional maps are provided for key material properties (density, stiffness, permittivity, and
piezoelectric coefficients). The DEPP technique was validated, independent of the MFCX process, by powder pressing a conventional
bimodal gradient beam which demonstrated through experiments high displacement capabilities at lower driving potentials than
comparable functionally graded piezoceramic actuators. For more complex gradients, the MFCX process was adapted to the DEPP
gradient technique and illustrated by the fabrication of a linearly graded prototype whose monolithic nature and gradual material
variation significantly reduces internal stresses, improves reliability, and extends service lifetime. 相似文献