利用嵌入式机器学习TinyML技术的口罩检测装置

针对目前市面上口罩检测装置价格昂贵且技术复杂的现状,设计了一款基于嵌入式机器学习TinyML技术的口罩检测装置。该装置由M5Stack UnitV2的AI摄像头结合M5Stack Core2开发套件构成,通过M5Stack UnitV2的摄像头设备检测是否规范佩戴口罩,通过串口通信的方式在M5Stack Core2上显示口罩分类图像并发出声音提醒人们,M5Stack Core2采用M5Stack的UiFlow图像化编程平台编写口罩检测的Blockly程序。在多种场合多次对不同人脸和不同口罩佩戴情况进行测试,结果表明:该装置功耗低、运行稳定、可靠,在保证准确率的情况下大大降低了成本,具有较高的应用价值。本文对口罩检测装置的研究有助于政府在流行病传播期及时对人们进行管控,降低感染的风险。

“扣肉”普及先锋 Core 2 Duo E4300详解

Intel自去年成功推出自己全新架构的Core 2 Duo E6000系列处理器后,以其强大的功能和超低的功耗马上占领了高端市场,不过它高高在上的价格确实把不少主流玩家拒之门外。Intel方面好像也意识到了这点,于近期推出了一款靡价“扣肉”新品——Core 2 Duo E4300,誓要摘掉酷睿2系列高价的帽子。

稳定至上 顶星H—965PN主板

按照Intel的计划，今年将会是全面普及Core2处理器的重要一年，而作为Core2处理器的最佳拍档，众多廉价的独立型的P965主板将会是冲锋陷阵的重要大将。经过半年的洗礼，P965芯片组也已经降到了比较理想的价格，而顶星此时正好以一个较好的价格向市场推出P965主板。

超频新闻

后发同样制人——G0版Core2；如何硬改1333MHzFSB？Radeon2900XT超频信息汇总；

Absorption performance of DMSA modified Fe_3O_4@SiO_2 core/shell magnetic nanocomposite for Pb^(2+) removal

The purpose of this study is to explore the adsorption performance of meso-2,3-dimercaptosuccinic acid(DMSA)modified Fe3O4@SiO2 magnetic nanocomposite(Fe3O4@SiO2@DMSA)for Pb2+ions removal from aqueous solutions.The effects of solution pH,initial concentration of Pb2+ions,contact time,and temperature on the amount of Pb2+adsorbed were investigated.Adsorption isotherms,adsorption kinetics,and thermodynamic analysis were also studied.The results showed that the maximum adsorption capacity of the Fe3O4@SiO2@DMSA composite is 50.5 mg/g at 298 K,which is higher than that of Fe3O4 and Fe3O4@SiO2 magnetic nanoparticles.The adsorption process agreed well with Langmuir adsorption isotherm models and pseudo second-order kinetics.The thermodynamic analysis revealed that the adsorption was spontaneous,endothermic and energetically driven in nature.

Predicting the composition of flux-cored wire claded metal by a neural network

In this paper, an artificial neural network method that can predict the chemical composition of deposited weld metal by CO 2 Shielded Flux Cored Wire Surfacing was studied. It is found that artificial neural network is a good approach on studying welding metallurgy processes that cannot be described by conventional mathematical methods. In the same time we explored a new way to study the no equilibrium welding metallurgy processes.

All-solid-state flexible asymmetric supercapacitors with high energy and power densities based on NiCo_2S_4@MnS and active carbon

Electrode material based on a novel core–shell structure consisting of NiCoS（NCS） solid fiber core and Mn S（MS） sheet shell（NCS@MS） in situ grown on carbon cloth（CC） has been successfully prepared by a simple sulfurization-assisted hydrothermal method for high performance supercapacitor. The synthesized NiCoS@Mn S/CC electrode shows high capacitance of 1908.3 F gat a current density of 0.5 A gwhich is higher than those of NiCoSand Mn S at the same current density. A flexible all-solid-state asymmetric supercapacitor（ASC） is constructed by using NiCoS@Mn S/CC as positive electrode, active carbon/CC as negative electrode and KOH/poly（vinyl alcohol）(PVA) as electrolyte. The optimized ASC shows a maximum energy density of 23.3 Wh kgat 1 A g, a maximum power density of about7.5 kw kgat 10 A gand remarkable cycling stability. After 9000 cycles, the ASC still exhibited67.8% retention rate and largely unchanged charge/discharge curves. The excellent electrochemical properties are resulted from the novel core–shell structure of the NiCoS@Mn S/CC electrode, which possesses both high surface area for Faraday redox reaction and superior kinetics of charge transport. The NiCoS@Mn S/CC electrode shows a promising potential for energy storage applications in the future.

Freshening biases in the freshwater flux of CORE data

The authors investigate biases in the freshwater flux（FWF） of CORE.v2—a common data-set for stand-alone ocean models—based on the results of a set of experiments using an OGCM. The authors identify freshening biases in the FWF in the subtropical regions of the North Pacific, South Pacific, and South Atlantic, which may be caused by the weak surface wind, high specific humidity,or high precipitation in the CORE.v2 data. The authors also find biases in sea surface salinity that are caused by ocean dynamics, such as in the North Atlantic, and that cannot be corrected by correcting surface forcing.

Fossil fauna and transgressive.sequence from core QC2 in the South Huanghai Sea

According to palaeoenvironmental analysis on the fossil fauna dominated by Foraminifera and Ostracoda, core QC2 contains 8 marine transgressive beds, called (from up to bottom) Transgressive Beds Ⅰ,Ⅱ, Ⅲ, …,Ⅷ respectively. Together with dating data, the transgressive sequence since 1. 7 Ma B. P. has been established, indicating that the core went through middle and late Early Pleistocene, early and late Middle Pleistocene, early and late (Substages A and B) Late Pleistocene and the Holocene transgressions. Within these 8 transgressions, late Middle Pleistocene, early Late Pleistocene and the Holocene transgressions-had rather strong activities proved by shallow sea (of 50 or 20-50 m water depth) deposits in the prime, while 2 of the 8, during middle Early Pleistocene and late Late Pleistocene (Substage A), were much weaker only with supratidal deposits. The transgressive cycles also differ from each other. Transgressions in the Holocene and in Substage B of late Late Pleistocene are made up of 3 and 2 subcycles of marine ingressions and regressions respectively, but most transgressions only have a single ingressive or regressive sequence. With the core, some important problems concerning, the study of Quaternary transgression such as correlation of transgressive beds and climatic periods and dating of the transgressive beds are discussed in this paper.

Synthesis and Structure of a New Dinuclear Molybdenum(I) Compound with Cyclohexanthiolate Ligand, [Mo_2(SC_6H_(11))_2(CO)_6(CH_3CN)_2]

The reaction of [Et4N]2[Mo2(SC6H11)2(CO)8] and I2 in MeCN affords a new dinu- clear molybdenum(I) complex [Mo2(SC6H11)2(CO)6(CH3CN)2] 1 (Mr = 672.46). The crystal and molecular structures have been determined by X-ray single-crystal diffraction. 1 crystallizes in monoclinic, space group P21/c with a = 9.302(1), b = 15.514(2), c = 9.307(1) ?, β = 92.979(2)o, V = 1341.4(3) ?3, Z = 2, Dc = 1.665 g/cm3, μ = 11.28 cm-1, F(000) = 676, R = 0.0461 and wR = 0.1274 for 1702 observed reflections with I > 2σ(I). 1 possesses a rhombic bimetallic core MoS2Mo with the Mo–Mo bond length of 2.9712(4) ? and Mo–S of 2.4821(5) ?.

Design of CERNET2-One of the Core Networks in CNGI

This article presents the network design schemes of CERNET2 including overall architecture, the backbone, core nodes, access solutions and the CNGI peer centers. CERNET2 connects 25 core nodes distributed in 20 cities of China at the speed of 2.5-10 Gb/s. CERNET2 has four unique features. First, its backbone adopts native IPv6 protocols, rather than IPv4/IPv6 dual stack. It is the largest pure IPv6 network in the world. Second, it provides an environment for testing and trial operation of China-made IPv6 core routers. It also allows tests of interconnection, interworking and interoperation among multiple vendors. Third, the large IPv6 address space enables the study on network addresses in a real network environment, which ensures the construction of a secured and trusted CNGI. Last, it is a test-bed for NGI applications.

Dual-ion pre-inserted Mo glycerate template for constructing NiMo-OS core–shell structure with boosting performance in zinc ions hybrid supercapacitors

Zinc ion hybrid supercapacitors(ZHS)have received much attention due to the enhanced potential window range and high specific capacity.However,the appropriate positive materials with high electrochemical performance are still a challenge.Herein,NH_(4)^(+)and glycerate anions pre-inserted Mo glycerate(N-MoG)spheres are synthesized and serve as the template to form NH_(4)^(+)intercalated Ni_(3)S_(2)/Ni_(3)O_(2)(OH)_(4)@MoS_(2)core–shell nanoflower(N-NiMo-OS)in-situ grown on nickel foam(NF)(N-NiMo-OS/NF)by sulfurization treatment.Compared with the product using traditional MoG as a template,N-NiMo-OS/NF inheriting a larger core structure from N-MoG delivers enhanced space for ions transport and volume expansion during the energy storage process,together with the synergistic effects of multi-components and the heterostructure,the as-prepared N-NiMo-OS/NF nanoflower exhibits excellent performance for the battery-type hybrid supercapacitors(BHS)and ZHS devices.Notably,the ZHS device delivers superior electrochemical performance to the BHS device,such as a higher specific capacity of 327.5 mAh·g^(−1)at 1 A·g^(−1),a preeminent energy density of 610.6 Wh·kg^(−1)at 1710 W·kg^(−1),long cycle life.The in-situ Raman,ex-situ X-ray photoelectron spectroscopy(XPS),theoretical calculation demonstrate the extra Zn^(2+)insertion/extraction storage mechanism provides enhanced electrochemical performance for ZHS device.Therefore,the dual-ion pre-inserted strategy can be extended for other advanced electrode materials in energy storage fields.

Structural Basis of Glycan Recognition in Globally Predominant Human P[8]Rotavirus

Rotavirus(RV)causes acute gastroenteritis in infants and children worldwide.Recent studies showed that glycans such as histo-blood group antigens(HBGAs)function as cell attachment factors affecting RV host susceptibility and prevalence.P[8]is the predominant RV genotype in humans,but the structural basis of how P[8]RVs interact with glycan ligands remains elusive.In this study,we characterized the interactions between P[8]VP8~*s and glycans which showed that VP8~*,the RV glycan binding domain,recognized both mucin core 2 and H type 1 antigens according to the ELISA-based oligosaccharide binding assays.Importantly,we determined the structural basis of P[8]RV-glycans interaction from the crystal structures of a Rotateq P[8]VP8~*in complex with core 2 and H type 1 glycans at 1.82.3?,respectively,revealing a common binding pocket and similar binding mode.Structural and sequence analysis demonstrated that the glycan binding site is conserved among RVs in the P[Ⅱ]genogroup,while genotype-specific amino acid variations determined different glycan binding preference.Our data elucidated the detailed structural basis of the interactions between human P[8]RVs and different host glycan factors,shedding light on RV infection,epidemiology,and development of anti-viral agents.

Facile aqueous synthesis and thermal insulating properties of low-density glass/TiO_2 core/shell composite hollow spheres

TiO2 shells assembled on hollow glass microspheres （HGM） with tunable morphologies were suc- cessfully prepared through a controllable chemical precipitation method with urea as the precipitator. Thus, glass/TiO2 core/shell composite hollow spheres with low particle density （0.40 g/cm3） were fabri- cated. The phase structures, morphologies, particle sizes, shell thicknesses, and chemical compositions of the composite microspheres were characterized by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and energy dispersive X-ray spectroscopy （EDS）. The morphology of the TiO2 shell can be tailored by properly monitoring the reaction system component and parameters. The probable growth mecha- nism and fabrication process of the core/shell products involving the nucleation and oriented growth of TiO2 nanocrystals on hollow glass microspheres was proposed. A low infrared radiation study revealed that the radiation properties of the products are greatly influenced by the unique product shell structures. A thermal conductivity study showed that the TiO2/HGM possess low thermal conductivity that is similar to that of the pristine HGMs. This work provides an additional strategy to prepare low-density thermal insulating particles with tailored morphologies and properties.

Synthesis and photocatalytic properties of core–shell TiO^2@ZnIn_2S_4 photocatalyst

A novel core–shell TiO2@ZnIn2S4composite has been synthesized successfully by a simple and flexible hydrothermal route using TiO2as precursors.The as-synthesized samples were characterized by X-ray diffraction,UV–vis diffuse reflectance spectra and transmission electron microscopy.The photocatalytic properties of samples were tested by degradation of aqueous methylene blue（MB）under visible light irradiation.It was found that the as-synthesized TiO2@ZnIn2S4photocatalyst was more effcient than TiO2and ZnIn2S4in the photocatalytic degradation of MB.Moreover,TEM images confrmed the TiO2@ZnIn2S4nanoparticles possessed a well-proportioned core–shell morphology.

疯狂的四核——英特尔全球首颗台式机四核处理器Core 2 Extreme QX6700

在本刊上期内容中．我们为大家翻译了PC World实验室【美】对英特尔首颗台式机四核处理器的测试结果．今天．这颗处理器来到了我们PC World中国实验室,接受了我们的测试。

2D/2D atomic double-layer WS_(2)/Nb_(2)O_(5)shell/core nanosheets with ultrafast interfacial charge transfer for boosting photocatalytic H_(2)evolution

Low-efficiency charge transfer is a critical factor to limit the photocatalytic H_(2)evolution activity of semiconductor photocatalysts.The interface design is a promising approach to achieve high chargetransfer efficiency for photocatalysts.Herein,a new 2 D/2 D atomic double-layer WS_(2)/Nb_(2)O_(5)shell/core photocatalyst(DLWS/Nb_(2)O_(5))is designed.The atom-resolved HAADF-STEM results unravel the presence of an unusual 2 D/2 D shell/core interface in DLWS/Nb_(2)O_(5).Taking advantage of the advanced femtosecond-resolved ultrafast TAS spectra,the average lifetime of charge carriers for DLWS/Nb_(2)O_(5)(180.97 ps)is considerably shortened as compared to that of Nb_(2)O_(5)(230.50 ps),strongly indicating that the 2 D/2 D shell/core interface enables DLWS/Nb_(2)O_(5)to achieve ultrafast charge transfer from Nb_(2)O_(5)to atomic double-layer WS_(2),thus yielding a high photocatalytic H_(2)evolution rate of 237.6 mmol/h,up to10.8 times higher than that of pure Nb_(2)O_(5)nanosheet.This study will open a new window for the development of high-efficient photocatalytic systems through the interface design.