摘要:
Single nanowire becomes attractive as a basic component of various nanodevices. Nanowire joining is one of the crucial operations in micro-nano manufacturing. Compared with other joining methods, such as electrical current heating and mechanical pressure, laser illumination can yield metallic contacts through local precision nanosoldering. In this paper, the authors report the joining of one single copper nanowire (CuNW) to a silver film by a laser illumination method. They first cut the silver film on a flexible substrate to form a gap of about 1–4 μm by a 1030 nm femtosecond (fs) pulsed laser. Then, they coat CuNWs by dripping nanowire solution onto the gap, bridge the gap, and then join single CuNW with the fs pulsed laser. By comparison with scanning electron microscope images after and before laser illumination, it is found that the local silver film melts, then wraps partial CuNW, and finally crystallizes. So, the joining is through a part of CuNW embedded in a silver film. In addition, the authors further analyze the joining situation by directly measuring the resistance variation between after joining (Ra) and before joining (Rb). It is demonstrated that the resistance ratio of Ra to Rb decreases from 0.835 to 0.172 with increasing laser power from 10 to 40 mW for 3 s of the laser illumination time. The resistance ratio of Ra to Rb decreases from 0.936 to 0.368 with an increment of the laser illumination time from 1 to 4 s at a laser power of 30 mW. Finally, the authors find that the welded single CuNW enables sensing of glucose at a concentration of 10−5M.
作者:
Wang, H. O.;Zhao, P.;Sun, J. J.;Tan, W. S.*;Su, K. P.;...
期刊:
Journal of Materials Science: Materials in Electronics,2018年29(15):13176-13179 ISSN:0957-4522
通讯作者:
Huo, D. X.;Tan, W. S.
作者机构:
[Wang, H. O.; Zhao, P.; Huang, S.; Huo, D. X.; Su, K. P.; Sun, J. J.] Hangzhou Dianzi Univ, Inst Mat Phys, Hangzhou 310018, Zhejiang, Peoples R China.;[Tan, W. S.] Hunan City Univ, Coll Informat & Elect Engn, All Solid State Energy Storage Mat & Devices Key, Yiyang 413002, Peoples R China.;[Tan, W. S.] Nanjing Univ Sci & Technol, Dept Appl Phys, Minist Educ, Key Lab Soft Chem & Funct Mat, Nanjing 210094, Jiangsu, Peoples R China.
通讯机构:
[Huo, D. X.; Tan, W. S.] H;[Tan, W. S.] N;Hangzhou Dianzi Univ, Inst Mat Phys, Hangzhou 310018, Zhejiang, Peoples R China.;Hunan City Univ, Coll Informat & Elect Engn, All Solid State Energy Storage Mat & Devices Key, Yiyang 413002, Peoples R China.;Nanjing Univ Sci & Technol, Dept Appl Phys, Minist Educ, Key Lab Soft Chem & Funct Mat, Nanjing 210094, Jiangsu, Peoples R China.
摘要:
Collaborative enhancements from surface plasmons (SPs) and whispering-gallery modes (WGMs) can induce intense near-field effects with high spatial localization around the surface of a semiconducting material. One can construct a highly efficient hybrid microcavity using semiconducting materials through resonant coupling between SPs and WGMs. Hexagonal ZnO micro-/nanostructures, which have been employed as natural WGM microcavities for ultraviolet (UV) lasing, can be used as ideal platforms to construct such hybrid microcavities. Here, we comprehensively review the recent efforts for improving lasing performance by resonant coupling between SPs and WGMs. Traditional SPs originating from various metals as well as novel SPs originating from atomic layers such as graphene are considered. Moreover, we discuss the mechanism of light-matter interactions beyond the improvements in lasing performance.
摘要:
The identification of overlapping protein complexes in proteinprotein interaction (PPI) networks may elucidate cellular functional organizations and their underlying cellular mechanisms. Recently, many protein complex mining algorithms have been developed for PPI networks. However, the majority of available algorithms primarily depend on mining dense subgraphs as protein complexes, thereby failing to consider the inherent biological meanings between protein pairs. Thus, methods for identifying protein complexes using the biological significance hidden in edges need to be investigated. In this paper, we propose IK-medoids, an improved method that detects overlapping protein complexes from weighted PPI networks based on the rough fuzzy relationships between protein pairs. The presented algorithm is primarily based on the fuzzy relationship that obtains the non-overlapping protein substructure, and then K-medoids is executed from the proteins in the PPI network. Next, the similarity between one protein and each candidate complex is calculated to determine whether the protein belongs to one or multiple complexes with the ration of each similarity to maximum similarity. In the end, overlapped protein complexes are merged to form the final protein complexes. We apply the method to three PPI networks and validate the results using two reference protein complexes retrieved from public databases. Experimental results show that our method outperforms classical algorithms, such as ClusterONE, CMC, MCL, OSLOM, and RFC, and achieves ideal overall performance in terms of F-measure, sensitivity, and accuracy.
摘要:
We experimentally study the spatiotemporal evolution of chirped femtosecond laser pulses at a specific spatial position, such as the modulation peak position (MPP), during small-scale self-focusing (SSSF). It is found that the spatial peak intensity at the MPP increases rapidly initially with increment of input power due to the effect of SSSF, however it becomes saturated at the higher power because the finite energy of the beam restraints increasing of the peak intensity at the MPP. The pulse width at the MPP is compressed gradually with rising power owing to the spatiotemporal coupling effect, which will reach the narrowest when the spatial peak intensity at the MPP reaches the maximum. Further, the influence of chirp on the pulse width evolution at the MPP is discussed theoretically. We find that the negative chirp accelerates the pulse width compression because the negative chirp enhances the process of SSSF, but the positive chirp is counterproductive. Our results may provide some helps for propagation and amplification of broadband laser pulses.
摘要:
When a low-power finite-energy Airy pulse (FEAP) and a high-power soliton pulse simultaneously propagate in an optical fiber, we numerically study the evolution of the FEAP affected by higher-order effects, including third-order dispersion (TOD), Raman scattering and self-steepening (SS). It is found that shedding solitons are generated from the FEAP due to the effect of cross-phase modulation (XPM). The TOD only affects the center position of the shedding soliton, but does not change the spectrum structure. The truncation coefficient of a FEAP, TOD and SS can be used to manipulate the Raman-induced frequency shift (RIFS). It is demonstrated that the RIFS is suppressed obviously by both positive TOD, SS and a small truncation coefficient, but the RIFS is enhanced by the negative TOD and a larger truncation coefficient. Further, we comparatively study the simultaneous contributions of TOD, Raman, and SS to the evolution of a FEAP and a Sech pulse, respectively. It is shown that the FEAP generates some static solitons besides the conventional Raman soliton and the whole spectrum is broadened that extended towards to the blue-shifted side besides the conventional red-shifted components. Our results indicate that the FEAP has potential application in supercontinuum generation and broadband sources.
关键词:
Synergistic drug combinations;Computational methods;Feature;Similarity measure;Machine learning;Network.
摘要:
Synergistic drug combinations play an important role in the treatment of complex diseases. The identification of effective drug combination is vital to further reduce the side effects and improve therapeutic efficiency. In previous years, in vitro method has been the main route to discover synergistic drug combinations. However, many limitations of time and resource consumption lie within the in vitro method. Therefore, with the rapid development of computational models and the explosive growth of large and phenotypic data, computational methods for discovering synergistic drug combinations are an efficient and promising tool and contribute to precision medicine. It is the key of computational methods how to construct the computational model. Different computational strategies generate different performance. In this review, the recent advancements in computational methods for predicting effective drug combination are concluded from multiple aspects. First, various datasets utilized to discover synergistic drug combinations are summarized. Second, we discussed feature-based approaches and partitioned these methods into two classes including feature-based methods in terms of similarity measure, and feature-based methods in terms of machine learning. Third, we discussed network-based approaches for uncovering synergistic drug combinations. Finally, we analyzed and prospected computational methods for predicting effective drug combinations.
摘要:
For large-scale sparse matrices, SpMV cannot be processed on GPU using the common storage formats because of the memory limitation. In addition, the parallel effect is poor using general formats for the sparse matrices with extremely uneven distribution of non-zero elements, which leads to performance deterioration. This paper presents an optimal partitioning strategy based on the distribution of non-zero elements in a sparse matrix to improve the performance of SpMV, and uses a hybrid format, which mixes CSR and ELL formats, to store the blocks partitioned from the sparse matrix. The hybrid blocked format has better compression effect and more uniform distribution of non-zero elements, which can be suitable for more types of sparse matrices. Our partitioning strategy is proven to be optimal, which can yield the minimum parallel execution time on GPU. We develop an optimal partitioning strategy to improve the performance of SpMV.We present a reordering algorithm in which the time complexity is only O(Nlog2k).We employ a hybrid format to store a blocked sparse matrix partitioned by our optimal partitioning strategy. For large-scale sparse matrices, SpMV cannot be processed on GPU using the common storage formats because of the memory limitation. In addition, the parallel effect is poor using general formats for the sparse matrices with extremely uneven distribution of non-zero elements, which leads to performance deterioration. This paper presents an optimal partitioning strategy based on the distribution of non-zero elements in a sparse matrix to improve the performance of SpMV, and uses a hybrid format, which mixes CSR and ELL formats, to store the blocks partitioned from the sparse matrix. The hybrid blocked format has better compression effect and more uniform distribution of non-zero elements, which can be suitable for more types of sparse matrices. Our partitioning strategy is proven to be optimal, which can yield the minimum parallel execution time on GPU. We develop an optimal partitioning strategy to improve the performance of SpMV.We present a reordering algorithm in which the time complexity is only O(Nlog2k).We employ a hybrid format to store a blocked sparse matrix partitioned by our optimal partitioning strategy.
摘要:
In this paper, we theoretically and experimentally investigate the initial temporal characterization and the temporal evolution of a picosecond laser pulse by a synchronized femtosecond laser pulse. After theoretically analyzing the measurement principle, we experimentally measure the initial temporal characterization of the picosecond laser pulse. Further, the temporal evolution of the picosecond laser pulse propagating in different lengths of a carbon disulfide (CS2) is measured. We find that the initial temporal shape of the picosecond laser pulse is smooth and clean. As increasing of the CS2 length, the pulse width of the picosecond laser pulse has a trend of slight narrow owing to the spatiotemporal coupling effect.
关键词:
Airy pulses;Pulse propagation and temporal solitons;Nonlinear optics
摘要:
We analytically and numerically investigate the propagation dynamics of initially chirped symmetric Airy pulses in an optical fiber. The results show that the positive chirps act to promote the interference in generating a focal point on the propagation axis, while the negative chirps tend to suppress the focusing effect, as compared to conventional unchirped symmetric Airy pulses. The numerical results demonstrate that the linear propagation of chirped symmetric Airy pulses depend considerably on the chirp parameter and the primary lobe position. In the anomalous dispersion region, positively chirped symmetric Airy pulses first undergo an initial compression, and reach a foci due to the opposite acceleration, and then experience a lossy inversion transformation, and come to the opposite facing focal position. The impact of truncation coefficient and Kerr nonlinearity on the chirped symmetric Airy pulses propagation is also disclosed separately.