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91.
92.
Mike Aling 《Architectural Design》2013,83(3):100-105
Mike Aling 's ProunStretcher project engages with the recent global revival of cottage industries, fuelled by the application of digital technologies, as a means to address ‘the manifold social issues present across our rural landscape-as-urban-extension’. 相似文献
93.
提出了一种新的神经计算的方法,其最大的特点是在进行特定的权值调整时无须加入学习率.计算开始时先给出一组随机的权值作为被拟合多项式的系数,由这组权值得到的拟合点上被拟合多项式值与期望值的各误差绝对值之和.依据其小分数的负值直接来调整权值,使各误差之绝对值不断减小,通过反复迭代计算,最终当各误差都在规定范围内时便得到期望的权值.在实际的计算中利用这种方法进行曲线拟合能方便地求出拟合多项式的系数,便于编程,简化了计算过程.将这种方法应用到范德堡函数的多项式拟合中,得到了范德堡函数f=1 0.03237714η-0.04037678η2 0.00857881η3-0.00077693η4 0.00002604η5并画出了曲线. 相似文献
94.
Heinz Fissan B. Stahlmecke C. Asbach T. A. J. Kuhlbusch D. Y. H. Pui W. G. Shin S. C. Kim 《Journal für Verbraucherschutz und Lebensmittelsicherheit》2008,3(3):312-318
Zusammenfassung: Die in vitro- und in vivo-Untersuchungen von Nanopartikeln im Hinblick auf ihre m?glichen toxikologischen Wirkungen erfolgen h?ufig über die Aufgabe
von Suspensionen auf Zellen mit aus der Nanopartikelkonzentration ableitbarer Dosis. Ein wichtiger Weg der Nanopartikelwirkung
aber geht über die Inhalation. Es ist deshalb naheliegend, Nanopartikel in Form von charakterisierten Aerosolen bereitzustellen.
Der Ausgangspunkt sind h?ufig Pulver in Form von Agglomeraten, die ohne Zerlegung in den gasgetragenen Zustand überführt werden
müssen.
Es werden Methoden zur Aerosolisierung von Nanopartikelpulvern vorgestellt, die zur Zeit untersucht werden. Aus der im gasgetragenen
Zustand bestimmbaren Nanopartikelkonzentration kann mit Hilfe von Depositionsmodellen die auf Zellen abgeschiedene Nanopartikeldosis
bestimmt werden. Für in vivo-Untersuchungen am Menschen besteht die M?glichkeit, die im alveolaren und tracheobronchialen Bereich deponierten Nanopartikelkonzentrationen
unter Verwendung des ICRP–Depositionsmodells direkt messtechnisch zu erfassen.
Für alle Verfahrensschritte, von der Aerosolbereitstellung und -charakterisierung bis zur deponierten Dosis, besteht Bedarf
an Standardisierung.
Eingegangen: 31. Januar 2008; angenommen: 4. Februar 2008 相似文献
95.
Seiya Suzuki Takuya Iwasaki K. Kanishka H. De Silva Shigeru Suehara Kenji Watanabe Takashi Taniguchi Satoshi Moriyama Masamichi Yoshimura Takashi Aizawa Tomonobu Nakayama 《Advanced functional materials》2021,31(5):2007038
Germanene, a 2D honeycomb germanium crystal, is grown at graphene/Ag(111) and hexagonal boron nitride (h-BN)/Ag(111) interfaces by segregating germanium atoms. A simple annealing process in N2 or H2/Ar at ambient pressure leads to the formation of germanene, indicating that an ultrahigh-vacuum condition is not necessary. The grown germanene is stable in air and uniform over the entire area covered with a van der Waals (vdW) material. As an important finding, it is necessary to use a vdW material as a cap layer for the present germanene growth method since the use of an Al2O3 cap layer results in no germanene formation. The present study also proves that Raman spectroscopy in air is a powerful tool for characterizing germanene at the interfaces, which is concluded by multiple analyses including first-principles density functional theory calculations. The direct growth of h-BN-capped germanene on Ag(111), which is demonstrated in the present study, is considered to be a promising technique for the fabrication of future germanene-based electronic devices. 相似文献
96.
Deoxyribonucleic acid (DNA) replication can be divided into three major steps: initiation, elongation and termination. Each time a human cell divides, these steps must be reiteratively carried out. Disruption of DNA replication can lead to genomic instability, with the accumulation of point mutations or larger chromosomal anomalies such as rearrangements. While cancer is the most common class of disease associated with genomic instability, several congenital diseases with dysfunctional DNA replication give rise to similar DNA alterations. In this review, we discuss all congenital diseases that arise from pathogenic variants in essential replication genes across the spectrum of aberrant replisome assembly, origin activation and DNA synthesis. For each of these conditions, we describe their clinical phenotypes as well as molecular studies aimed at determining the functional mechanisms of disease, including the assessment of genomic stability. By comparing and contrasting these diseases, we hope to illuminate how the disruption of DNA replication at distinct steps affects human health in a surprisingly cell-type-specific manner. 相似文献
97.
Chao Wen Alexander G. Banshchikov Yury Y. Illarionov Werner Frammelsberger Theresia Knobloch Fei Hui Nikolai S. Sokolov Tibor Grasser Mario Lanza 《Advanced materials (Deerfield Beach, Fla.)》2020,32(34):2002525
Mechanically exfoliated 2D hexagonal boron nitride (h-BN) is currently the preferred dielectric material to interact with graphene and 2D transition metal dichalcogenides in nanoelectronic devices, as they form a clean van der Waals interface. However, h-BN has a low dielectric constant (≈3.9), which in ultrascaled devices results in high leakage current and premature dielectric breakdown. Furthermore, the synthesis of h-BN using scalable methods, such as chemical vapor deposition, requires very high temperatures (>900 °C) , and the resulting h-BN stacks contain abundant few-atoms-wide amorphous regions that decrease its homogeneity and dielectric strength. Here it is shown that ultrathin calcium fluoride (CaF2) ionic crystals could be an excellent solution to mitigate these problems. By applying >3000 ramped voltage stresses and several current maps at different locations of the samples via conductive atomic force microscopy, it is statistically demonstrated that ultrathin CaF2 shows much better dielectric performance (i.e., homogeneity, leakage current, and dielectric strength) than SiO2, TiO2, and h-BN. The main reason behind this behavior is that the cubic crystalline structure of CaF2 is continuous and free of defects over large regions, which prevents the formation of electrically weak spots. 相似文献
98.
M. Gołąbczak P. Maksim P. Jacquet A. Gołąbczak K. Woźniak C. Nouveau 《Materialwissenschaft und Werkstofftechnik》2019,50(5):611-615
In this article the results concerned influence of processing conditions of the wire electrical discharge machining and vibro‐abrasive machining on the surface layer and morphology of samples made of hard machinable materials used in aircraft industry like: Titanium 5553 β, Inconel 617, Hastelloy X and Magnesium AZ31 have been presented. For this purpose the cubic and cylindrical samples made of hard machinable alloys have been prepared using optimal electric parameters of wire‐cut electrical discharge machining and finally they have been polished using circular vibratory finishing technology and different ceramic shaped stones. 相似文献
99.
Evan J. Telford Avalon H. Dismukes Kihong Lee Minghao Cheng Andrew Wieteska Amymarie K. Bartholomew Yu-Sheng Chen Xiaodong Xu Abhay N. Pasupathy Xiaoyang Zhu Cory R. Dean Xavier Roy 《Advanced materials (Deerfield Beach, Fla.)》2020,32(37):2003240
The recent discovery of magnetism within the family of exfoliatable van der Waals (vdW) compounds has attracted considerable interest in these materials for both fundamental research and technological applications. However, current vdW magnets are limited by their extreme sensitivity to air, low ordering temperatures, and poor charge transport properties. Here the magnetic and electronic properties of CrSBr are reported, an air-stable vdW antiferromagnetic semiconductor that readily cleaves perpendicular to the stacking axis. Below its Néel temperature, TN = 132 ± 1 K, CrSBr adopts an A-type antiferromagnetic structure with each individual layer ferromagnetically ordered internally and the layers coupled antiferromagnetically along the stacking direction. Scanning tunneling spectroscopy and photoluminescence (PL) reveal that the electronic gap is ΔE = 1.5 ± 0.2 eV with a corresponding PL peak centered at 1.25 ± 0.07 eV. Using magnetotransport measurements, strong coupling between magnetic order and transport properties in CrSBr is demonstrated, leading to a large negative magnetoresistance response that is unique among vdW materials. These findings establish CrSBr as a promising material platform for increasing the applicability of vdW magnets to the field of spin-based electronics. 相似文献
100.
Juan Lyu Jing Pei Yuzheng Guo Jian Gong Huanglong Li 《Advanced materials (Deerfield Beach, Fla.)》2020,32(2):1906000
The use of a foreign metallic cold source (CS) has recently been proposed as a promising approach toward the steep-slope field-effect-transistor (FET). In addition to the selection of source material with desired density of states–energy relation (D(E)), engineering the source:channel interface for gate-tunable channel-barrier is crucial to CS-FETs. However, conventional metal:semiconductor (MS) interfaces generally suffer from strong Fermi-level pinning due to the inevitable chemical disorder and defect-induced gap states, precluding the gate tunability of the barriers. By comprehensive materials and device modeling at the atomic scale, it is reported that 2D van der Waals (vdW) MS interfaces, with their atomic sharpness and cleanness, can be considered as general ingredients for CS-FETs. As test cases, InSe-based n-type FETs are studied. It is found that graphene can be spontaneously p-type doped along with slightly opened bandgap around the Dirac-point by interfacing with InSe, resulting in superexponentially decaying hot carrier density with increasing n-type channel-barrier. Moreover, the D(E) relations suggest that 2D transition-metal dichalcogenides and 2D transition-metal carbides are a rich library of CS materials. Graphene, Cd3C2, T-VTe2, H-VTe2, and H-TaTe2 CSs lead to subthreshold swing below 60 mV dec−1. This work broadens the application potentials of 2D vdW MS heterostructures and serves as a springboard for more studies on low-power electronics based on 2D materials. 相似文献