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51.
电子材料分析中的能谱干扰峰   总被引:2,自引:0,他引:2  
主要阐述了在电子元器件分析中用能谱仪作定性分析时常见的一些干扰峰和容易混淆及误判的一些谱峰。主要有和峰、逃逸峰以及一些在元器件材料分析中常遇到的元素特征峰之间的交错重叠的识别和判定方法,并把这些容易误判的谱线整理列成3种表格,以供参考,这些数据基本覆盖了在X射线能谱仪中可能出现的所有相关的谱峰。  相似文献   
52.
Light emission of 2‐(2,6‐bis((E)‐4‐(diphenylamino)styryl)‐4H‐pyran‐4‐ylidene)malononitrile (TPA‐DCM) is weakened by aggregate formation. Attaching tetraphenylethene (TPE) units as terminals to TPA‐DCM dramatically changes its emission behavior: the resulting fluorogen, 2‐(2,6‐bis((E)‐4‐(phenyl(4′‐(1,2,2‐triphenylvinyl)‐[1,1′‐biphenyl]‐4‐yl)amino)styryl)‐4H‐pyran‐4‐ylidene)malononitrile (TPE‐TPA‐DCM), is more emissive in the aggregate state, showing the novel phenomenon of aggregation‐induced emission (AIE). Formulation of TPE‐TPA‐DCM using bovine serum albumin (BSA) as the polymer matrix yields uniformly sized protein nanoparticles (NPs) with high brightness and low cytotoxicity. Applications of the fluorogen‐loaded BSA NPs for in vitro and in vivo far‐red/near‐infrared (FR/NIR) bioimaging are successfully demonstrated using MCF‐7 breast‐cancer cells and a murine hepatoma‐22 (H22)‐tumor‐bearing mouse model, respectively. The AIE‐active fluorogen‐loaded BSA NPs show an excellent cancer cell uptake and a prominent tumor‐targeting ability in vivo due to the enhanced permeability and retention effect.  相似文献   
53.
Dataflow modeling offers a myriad of tools for designing and optimizing signal processing systems. A designer is able to take advantage of dataflow properties to effectively tune the system in connection with functionality and different performance metrics. However, a disparity in the specification of dataflow properties and the final implementation can lead to incorrect behavior that is difficult to detect. This motivates the problem of ensuring consistency between dataflow properties that are declared or otherwise assumed as part of dataflow-based application models, and the dataflow behavior that is exhibited by implementations that are derived from the models. In this paper, we address this problem by introducing a novel dataflow validation framework (DVF) that is able to identify disparities between an application’s formal dataflow representation and its implementation. DVF works by instrumenting the implementation of an application and monitoring the instrumentation data as the application executes. This monitoring process is streamlined so that DVF achieves validation without major overhead. We demonstrate the utility of our DVF through design and implementation case studies involving an automatic speech recognition application, a JPEG encoder, and an acoustic tracking application.  相似文献   
54.
Lacking rapid and reliable pathogen diagnostic platforms, inadequate or delayed antimicrobial therapy could be made, which greatly threatens human life and accelerates the emergence of antibiotic‐resistant pathogens. In this contribution, a series of simple and reliable sensor arrays based on tetraphenylethylene (TPE) derivatives are successfully developed for detection and discrimination of pathogens. Each sensor array consists of three TPE‐based aggregation‐induced emission luminogens (AIEgens) that bear cationic ammonium group and different hydrophobic substitutions, providing tunable logP (n‐octanol/water partition coefficient) values to enable the different multivalent interactions with pathogens. On the basis of the distinctive fluorescence response produced by the diverse interaction of AIEgens with pathogens, these sensor arrays can identify different kinds of pathogens, even normal and drug‐resistant bacteria, with nearly 100% accuracy. Furthermore, blends of pathogens can also be identified accurately. The sensor arrays exhibit rapid response (about 0.5 h), high‐throughput, and easy‐to‐operate without washing steps.  相似文献   
55.
With rapid developments of digital photography and social networks,users of photo-sharing-supported social networking applications can easily forward photos across different social networks at the cost of their growing privacy concerns.To address this problem,a privacy-preserving photo sharing framework was proposed,which could apply to extended control and privacy invasion tracing.In extended control scheme,the following users on a dissemination chain was restrained by each user’s privacy policy.Then several privacy areas of photos were encrypted and the access control polices were bound to the uploaded photos,so that any privacy areas on the photos could be hidden away from unwanted viewers even across different social networks.On this basis,the behaviors of users were record by tracing scheme of privacy invasion,the integrality of records was protected by using nested signature algorithm.The correctness,security and performance of overhead of the scheme are then thoroughly analyzed and evaluated via detailed simulations.  相似文献   
56.
Supramolecular approaches have opened up vast possibilities to construct versatile materials, especially those with stimuli-responsiveness and integrated functionalities of multi-modal diagnosis and synergistic therapeutics. In this study, a hybrid theranostic nanosystem named TTPY-Py⊂CP5@AuNR is constructed via facile host–guest interactions, where TTPY-Py is a photosensitizer with aggregation-induced emission and CP5@AuNR represents the carboxylatopillar[5]arene (CP5)-modified Au nanorods. TTPY-Py⊂CP5@AuNR integrates the respective advantages of TTPY-Py and CP5@AuNR such as the high performance of reactive oxygen species generation and photothermal conversion, and meanwhile shows fluorescence responses to both temperature and pH stimuli. The successful modification of CP5 macrocycles on AuNRs surfaces can eliminate the cytotoxicity of AuNRs and enable them to serve as the nanocarrier of TTPY-Py for further theranostic applications. Significantly, in vitro and in vivo evaluations demonstrate that this supramolecular nanotheranostic system possesses multiple modalities including intensive fluorescence imaging (FLI), photoacoustic imaging (PAI), efficient photodynamic therapy (PDT), and photothermal therapy (PTT), indicating its great potential for FLI-PAI imaging-guided synergistic PDT-PTT therapy. Moreover, TTPY-Py can be released upon activation by the acidic environment of lysosomes and then specifically light up mitochondria. This study demonstrates a new strategy for the design of versatile nanotheranostics for accurate tumor imaging and cancer therapies.  相似文献   
57.
Aligned with the recent revolution of smart cities concept, a lot of work has been done to support the education process in direct or indirect way. In countries like Lebanon, in which the choice of school does not depend on the residence location, parents are becoming more and more selective in the quality of schools they are choosing for their children. This fact may lead parents to choose a modern and good school even if it is far from their residence. On the other hand, and even if the school was close enough, the traffic congestion would make the on-feet journey of the kid to the school very risky. Driving children to school is a solution. However, it consumes a lot of time and effort each day in the morning and the afternoon. Hence, school buses are commonly used by all schools to take the student from and to his home. Nevertheless, waiting the bus each day to arrive is an exhausting and a time-wasting mission. In this paper we present a smart transportation system for school buses that helps in saving parents’ time, by avoiding waiting school buses in the morning and then in the afternoon to return kids back, especially with the increasing traffic jams at these hours. The proposed mobile and web application is designed to help parents, school and the bus to communicate automatically and easily via the application in order to detect kids’ arrival time. The bus application side will notify parents few minutes before its approaching to their homes. Furthermore, the system will allow parents to inform the school and hence the bus application side about the absence of their kid. The system has been efficiently and dynamically designed and implemented so it can be hosted and used by any school administration without the need to any major modifications. It has been tested on a summer school to prove its efficiency and marked an important positive feedback from the school and the parents’ sides.  相似文献   
58.
The association between vascular wall shear stress (WSS) and the local development of atherosclerotic plaque makes estimation of in vivo WSS of considerable interest. Three-dimensional ultrasound (3DUS) combined with computational fluid dynamics (CFD) provides a potentially valuable tool for acquiring subject-specific WSS, but the interoperator and intraoperator variability associated with WSS calculations using this method is not known. Here, the accuracy, reproducibility and operator dependence of 3DUS-based computational fluid dynamics were examined through a phantom and in vivo studies. A carotid phantom was scanned and reconstructed by two operators. In the in vivo study, four operators scanned a healthy subject a total of 11 times, and their scan data were processed by three individuals. The study showed that with some basic training, operators could acquire accurate carotid geometry for flow reconstructions. The variability of measured cross-sectional area and predicted shear stress was 8.17% and 0.193 N/m/sup 2/ respectively for the in vivo study. It was shown that the variability of the examined parameters was more dependent on the scan operators than the image processing operator. The range of variability of geometrical and flow parameters reported here can be used as a reference for future in vivo studies using the 3DUS-based CFD approach.  相似文献   
59.
Thanks to advances in the computing capabilities and added functionalities of modern mobile devices, creating and consuming digital media on the move has never been so easy and popular. Most of the DTN routing protocols proposed in the literature to enable content sharing have been exploiting users’ mobility patterns, in order to maximise the delivery probability, while minimising the overall network overhead (e.g., number of message replicas in the system, messages’ path length). Common to all these protocols has been the assumption that devices are willing to participate in the content distribution network; however, because of battery constraints, participation cannot be taken for granted, especially if the very same subset of devices are continuously selected as content carriers, simply because of their mobility properties. Indeed, we demonstrate that state-of-the-art DTN routing protocols distribute load in a highly unfair manner, with detrimental effects on delivery once the assumption of unconditional participation is lifted. To overcome this limitation, we propose a load-balancing mechanism whereby nodes maintain local estimates of network workload, and use them to direct traffic towards the least loaded portion of the network. We implement the mechanism on top of a source-based DTN routing protocol, and demonstrate, by means of simulation using a variety of real mobility traces, that high delivery is now achieved without compromising fairness.  相似文献   
60.
This comment is related to the recently published article entitled “On ‘Discussion on Barkhausen and Nyquist stability criteria’, Analog Integrated circuits and signal processing, Vol. 70, pp. 443–449, 2012. In this article the authors considered one of the possible four alternatives of the Wien-bridge oscillator that was previously considered in the article entitled “Discussion on Barkhausen and Nyquist stability criteria”, Analog Integrated Circuits and Signal Processing, Vol. 62, pp. 327–332, 2010, which depicts the failure of Barkhausen criterion concerning the determination of the condition of oscillation startup of sinusoidal oscillation. In the above mentioned articles the operational amplifier used is assumed ideal. In this comment it will be shown that the Wien-bridge oscillator circuit used in the above mentioned articles can behave as a sinusoidal oscillator only at relatively high frequencies when the operational amplifier can be considered non-ideal. At relatively low frequencies; when the operational amplifier can be considered ideal, the same circuit behaves as a relaxation oscillator with a square wave output rather than a sinusoidal output.  相似文献   
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