Resistive switching characteristics of ZnO–graphene quantum dots and their use as an active component of an organic memory cell with one diode-one resistor architecture

We investigated the resistive switching characteristics of a polystyrene:ZnO–graphene quantum dots system and its potential application in a one diode-one resistor architecture of an organic memory cell. The log–log I–V plot and the temperature-variable I–V measurements revealed that the switching mechanism in a low-current state is closely related to thermally activated transport. The turn-on process was induced by a space-charge-limited current mechanism resulted from the ZnO–graphene quantum dots acting as charge trap sites, and charge transfer through filamentary path. The memory device with a diode presented a ∼10³ I_ON/I_OFF ratio, stable endurance cycles (10² cycles) and retention times (10⁴ s), and uniform cell-to-cell switching. The one diode-one resistor architecture can effectively reduce cross-talk issue and realize a cross bar array as large as ∼3 kbit in the readout margin estimation. Furthermore, a specific word was encoded using the standard ASCII character code.     

Synchrotron X-ray microdiffraction analysis of proton irradiated polycrystalline diamond films

X-ray microdiffraction is a non-destructive technique that allows for depth-resolved, strain measurements with submicron spatial resolution. These capabilities make this technique promising for understanding the mechanical properties of MicroElectroMechancial Systems (MEMS). This investigation examined the local strain induced by irradiating a polycrystalline diamond thin film with a dose of 2 × 10¹⁷ H⁺/cm² protons. Preliminary results indicate that a measurable strain, on the order of 10^− 3, was introduced into the film near the End of Range (EOR) region of the protons.     

Grid implementation of the Apriori algorithm

The paper presents the implementation of an association rules discovery data mining task using Grid technologies. For the mining task we are using the Apriori algorithm on top of the Globus toolkit. The case study presents the design and integration of the data mining algorithm with the Globus services. The paper compares the Grid version with related work in the field and we outline the conclusions and future work.     

Improved durability of Si/B/N/C random inorganic networks

The inherent high temperature durability as well as the hardness of random inorganic networks composed of Si, B, N and C, can be raised through the incorporation of rigid structural elements (e.g. borazine rings) as well as through an increase of the carbon content. This has been shown by comparison of the high temperature durabilities and micromechanical properties of newly synthesized Si/B/N/C ceramics derived from different acyclic and cyclic single source precursors. Crosslinking of these specially designed monomers with methylamine provides highly homogeneous preceramic polymers, in which the predetermined structural features of the molecular precursors are embedded. Subsequent pyrolysis and calcination up to 1500 °C converts the polymers into all-inorganic amorphous silicon boron carbonitrides. Depending on the constitution of the precursors, the as-obtained materials exhibit a combination of a high carbon content together with borazine rings embedded into the covalent network. Comparing the high temperature stability, hardness and stiffness of the synthesized ceramics, the best performance is achieved when carbon rich borazine derivatives are employed as single source precursors. Thus, the high temperature durability can be raised up to at least 2000 °C, and, at the same time, the microhardness and elastic modulus is maximized up to 14.5 and 127 GPa, respectively. The new materials have been characterized by IR spectroscopy, elemental analysis, XRD, SEM, DTA/TG, and by nanoindentation.     

Time-of-flight secondary ion mass spectrometry as a tool for studying segregation phenomena at nickel–YSZ interfaces

Through a study of Ni–YSZ interfaces it is shown that time-of-flight-secondary ion mass spectrometry (TOF-SIMS) is a powerful and convenient tool for the analysis of ultra thin layers of segregated material at the interfaces and on free surfaces. Two different types of Ni, “pure Ni” (99.995% Ni) and “impure Ni” (99.8% Ni) were investigated. The contact areas on the YSZ and areas outside the contacts were examined with XPS and TOF-SIMS. The impure nickel causes a relatively larger amount of impurities to accumulate at the contact area, e.g. oxides of Mn, Ti, Si and Na. Some impurities migrate to the area outside the contact area. Even though on a larger scale the impurities seem to be homogeneously distributed, detailed analyses in and outside the contact area show the presence of impurity particles, and that the surface species are inhomogeneously distributed amongst the different grains. The extremely low detection limit, the small probe depth, the image capability, and the ease of elemental identification make TOF-SIMS an obvious choice as an analytical tool for studying segregation phenomena at metal–ceramic interfaces such as Ni–YSZ interfaces. XPS, being a quantitative technique, was used as a complementary technique to TOF-SIMS, which is not directly a quantitative technique.     

Effect of Magnetotactic bacteria on the susceptibility in Chinese loess–paleosol sequences

A simulated experiment of Magnetotactic bacteria (MB) effect on susceptibility in the samples from the 5th to 6th loess layers (L₅–S₅–L₆) in Xifeng and Duangjiapo sections was performed. It is demonstrated that MB can increase the susceptibility of the samples and promote newly produced magnetic minerals from paleosol layers under the suitable condition. The tiny magnetic particles and arranged as a chain in the minerals less than 30 μm were found in the paleosol sample of Duangjiapo section.     

Machine-learning paradigms for selecting ecologically significant input variables

Harmful algal blooms, which are considered a serious environmental problem nowadays, occur in coastal waters in many parts of the world. They cause acute ecological damage and ensuing economic losses, due to fish kills and shellfish poisoning as well as public health threats posed by toxic blooms. Recently, data-driven models including machine-learning (ML) techniques have been employed to mimic dynamics of algal blooms. One of the most important steps in the application of a ML technique is the selection of significant model input variables. In the present paper, we use two extensively used ML techniques, artificial neural networks (ANN) and genetic programming (GP) for selecting the significant input variables. The efficacy of these techniques is first demonstrated on a test problem with known dependence and then they are applied to a real-world case study of water quality data from Tolo Harbour, Hong Kong. These ML techniques overcome some of the limitations of the currently used techniques for input variable selection, a review of which is also presented. The interpretation of the weights of the trained ANN and the GP evolved equations demonstrate their ability to identify the ecologically significant variables precisely. The significant variables suggested by the ML techniques also indicate chlorophyll-a (Chl-a) itself to be the most significant input in predicting the algal blooms, suggesting an auto-regressive nature or persistence in the algal bloom dynamics, which may be related to the long flushing time in the semi-enclosed coastal waters. The study also confirms the previous understanding that the algal blooms in coastal waters of Hong Kong often occur with a life cycle of the order of 1–2 weeks.     

三网融合的技术现状和未来发展

三网融合是网络发展的主要方向,无线网络是接入有线网络的一个重要途径。本文主要概述了因特网、电信网络、有线电视网络和无线网络的技术现状;分析在三网融合的形势下,它们各自都可以为发展未来包含现在由三种网络提供的所有服务的综合业务网提供核心技术的能力;指出没有单个网络技术能够成为无争议的赢家:融合的网络将具有异构网络集合的特征,提供多种多样的服务;然后在更广阔的视野上阐明了在三网融合之后的未来全局多媒体网络的特征以及建立具有这样的特征的网络所面临的挑战和所需要的变革和创新。     

Design of composite data acquisition gateway based on 5G network

The integrated data collection system hasn't changed much over the years. Their growth is dominated by digital filtering, and they get a new avionics bus. Time division multiplexing is still used to communicate with the system's data collector. These schemes make use of commands and data buses. While this method works, it has many drawbacks. These shortcomings are overwhelming the strict system architecture, system bandwidth limits, and expertise to only obtain an avionics bus, otherwise system bandwidth and one-way flow of data and control. This lead for high-end video recorders. To quietly monitor our actions and valuable information provides important warnings. However, it is usually completed by a device with this small processing power, which tracks the device, stores the data of the user's data, and is limited in processing. Therefore, it is important to store and process user data in the cloud to track 5 G network activity. This article proposes a simple 5G network gateway solution for custom user monitoring equipment. Collects charge data on Network 5G and Charging-aware multi-mode based routing protocol (CMRP). The CMRP routing mechanism is not yet stable, but the changes depend on the state of the energy charge sensor. This cannot be complemented by energy-efficient sensors and routing protocols that consume less energy.