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31.
Ju-Hyun Ahn 《Applied Surface Science》2007,253(21):8588-8591
Electrochemical synthesis of photoactive cadmium-indium-selenide (CdIn2Se4) thin films at ambient temperature was reported. The nanocrystalline nature and 1:2:4 elemental chemical stoichiometric ratio for Cd, In and Se were obtained from the X-ray diffraction and energy dispersive X-ray analysis, respectively. Irregular shaped islands of about 400-500 nm in sizes composed of large number of small (∼30-40 nm) spherical grains were confirmed from the atomic force microscopy and the scanning electron microscopy images. The photoelectrochemical measurement of CdIn2Se4 film electrode in presence of 1 M polysulphide electrolyte revealed 0.42% photoelectrochemical device conversion efficiency, under the light illumination intensity of 80 mW/cm2. 相似文献
32.
由Hsu提出的利用胞映射进行最优控制的方法可以发展成实用的工程控制技术.本文以研究算法为出发点,利用胞映射的特性,结合实际的计算与可能,作了一系列旨在提高计算速度和节省内存的改进;并给出了简单有效的区分同耗最优控制对的统一的方法.使用平常的微型计算机也能有效地解决实际工程问题的最优控制. 相似文献
33.
采用美国滨州大学研发的AMPS-1D软件,模拟了TCO与非晶硅界面势垒对TCO/a-Si:H(p+)/a-Si:H(i)/c-Si(n) /a-Si:H(i) /a-Si:H(n+) /TCO双面HIT异质结太阳电池光伏特性的影响。结果表明太阳电池的TCO/p+前接触界面势垒(对于电子)越高,越易形成欧姆接触,且电池的短波响应增强,使电池性能变好。模拟还发现,n+ /TCO背接触界面势垒(对于电子)越低,电池性能越好。若背场重掺杂,在背接触势垒小于等于0.5ev时,电池的转换效率不会受到背接触势垒的影响;若背场低掺杂,在背接触势垒很小的情况下,也能达到与重掺杂相同的转换效率。 相似文献
34.
提出了一种工作在C波段的新型平面结构异向介质,它除了带宽宽和损耗小外,还具有体积小、结构简单的优点,而且能够实现工作频段的平移,频率平移范围为4—20 GHz.基于电磁波由自由空间入射半无限大异向介质平板的传输和反射数据,计算出了电波在其中传播时的相速随频率的变化曲线,结果表明所讨论的异向介质确实在预想的频段上表现出后向波特性;同时利用相位观察法进一步验证了上述的后向波特性,从而肯定了异向介质的存在.
关键词:
异向介质
宽频带
小单元
后向波特性 相似文献
35.
36.
Mohammad Razavi Seyed Majid Saberi Fathi Jack Adam Tuszynski 《Entropy (Basel, Switzerland)》2022,24(1)
The underlying mechanism determining the size of a particular cell is one of the fundamental unknowns in cell biology. Here, using a new approach that could be used for most of unicellular species, we show that the protein synthesis and cell size are interconnected biophysically and that protein synthesis may be the chief mechanism in establishing size limitations of unicellular organisms. This result is obtained based on the free energy balance equation of protein synthesis and the second law of thermodynamics. Our calculations show that protein synthesis involves a considerable amount of entropy reduction due to polymerization of amino acids depending on the cytoplasmic volume of the cell. The amount of entropy reduction will increase with cell growth and eventually makes the free energy variations of the protein synthesis positive (that is, forbidden thermodynamically). Within the limits of the second law of thermodynamics we propose a framework to estimate the optimal cell size at division. 相似文献
37.
Anna Luise Grab Dirk Hose Patrick Horn Elisabetta Ada Cavalcanti-Adam Anja Seckinger Martin Müller 《Particle & Particle Systems Characterization》2021,38(3):2000263
In the malignant plasma cell disease multiple myeloma (MM), bone lesions and resulting fractures caused by MM cell (MMC) accumulation represent a major cause of morbidity and mortality. Despite recent advantages in systemic treatment, residual MMCs remain, especially in bone lesions. Therefore an interfacial delivery system for local treatment of MM and induced bone disease based on polyelectrolyte complex nanoparticles (PEC NP) loaded with bone morphogenetic protein 6 (BMP-6) inducing de-novo bone formation and MMC apoptosis is presented herein. BMP-6 loaded PEC NP are fabricated by defined mixing bio-related cationic and anionic polysaccharides and BMP-6 according to molar ratio of BMP-6/PEC-NP of 1/3. BMP-6/PEC NP bound to a model substrate releases 10% BMP-6 sustainably within two weeks as accessed by infrared spectroscopy. BMP-6 loaded PEC NP adheres to cell membranes of MMCs and MSCs and activated phosphorylation of Smad 1/5. Osteogenic differentiation (ALP-concentration) is enhanced in MSCs (p < 0.05). All patient samples (10/10) of MMCs show significant induction of apoptosis (median 84%, p < 0.05). Finally, BMP-6/PEC NP are successfully integrated in a commercial hyaluronic acid based hydrogel material revealing MMC death as principal proof for the local treatment of MM induced bone lesions. 相似文献
38.
Maeva Chaupard Marta de Frutos Ruxandra Gref 《Particle & Particle Systems Characterization》2021,38(9):2100022
Drug nanocarriers (NCs) with sizes usually below 200 nm are gaining increasing interest in the treatment of severe diseases such as cancer and infections. Characterization methods to investigate the morphology and physicochemical properties of multifunctional NCs are key in their optimization and in the study of their in vitro and in vivo fate. Whereas a variety of methods has been developed to characterize “bulk” NCs in suspension, the scope of this review is to describe the different approaches for the NC characterization on an individual basis, for which fewer techniques are available. The accent is put on methods devoid of labelling, which could lead to artefacts. For each characterization method, the principles and approaches to analyze the data are presented in an accessible manner. Aspects related to sample preparation to avoid artefacts are indicated, and emphasis is put on examples of applications. NC characterization on an individual basis allows gaining invaluable information in terms of quality control, on: i) NC localization and fate in biological samples; ii) NC morphology and crystallinity; iii) distribution of the NC components (drugs, shells), and iv) quantification of NCs’ chemical composition. The individual characterization approaches are expected to gain increasing interest in the near future. 相似文献
39.
为了实现回旋速调管放大器的快速设计,基于经典的回旋管的稳态单模非线性理论方法,开展了回旋速调管放大器的束波作用效率的理论模拟研究。由于单模理论无法匹配回旋速调管放大器的输入腔、中间腔两端的突变边界条件,所以输入腔与中间腔都只能采用给定场法进行求解。回旋速调管的输出腔的功率输出端通常采用缓变结构,这种腔体可以采用单模自洽理论进行求解。对两腔毫米波回旋速调管放大器进行了理论模拟,并与商业粒子模拟软件的结果进行对比,验证了该数值理论模拟方法的有效性。 相似文献
40.
在太阳能电池效率的评价中,电池材料、掺杂浓度、扩散长度等都是比较重要的参数,合理地改变相关参数可以优化太阳能电池的性能,提高电池效率。此外,在太阳能电池表面镀一层具有减反作用的光学薄膜(简称减反膜)也是提高电池效率的重要手段。以提高电池效率为目标,对单晶硅太阳能电池的掺杂浓度和扩散长度等微观参数进行计算优化,分析了掺杂浓度和扩散长度变化对电池效率的影响。并在此基础上分析了不同类型的减反膜对于电池效率的影响,给出了最佳减反膜材料及其膜系厚度,并且结合镀膜后电池量子效率的变化验证了其准确性。结果表明,在优化电池掺杂浓度和扩散长度的基础上,选择合适的减反膜,电池效率最高可达20.35%,相比于优化前提高了8.25%。 相似文献