系统管理IC满足多电压系统的监视和排序要求

在大多数电子设备中,对系统电压进行监视是非常重要的,这样可保证处理器和其它IC在系统上电时被复位,还可以监测到电压的下降,从而把代码执行过程中出现问题的概率降到最小,避免存储器发生冲突或者系统工作不正常。     

NUMERICAL SIMULATION OF OPEN WAVEGUIDE CONVERTERS USING FDTD METHOD

We study 3-dimensional asymmetric diffraction problems for waveguide-based electro-dynamic systems, radiating to infinite free space. For calculations we utilize the FDTD (Finite Difference Time Domain) numerical simulation method with the UPML (Unsplit Perfectly Matched Layer) absorbing boundary conditions. This paper states that the FDTD method, in spite of its relatively low calculation speed, has an approved ability of solving certain problems that cannot be solved by the other traditional numerical simulation methods (the method of integral equation, the method of scattering matrix).     

Incremental diagnosis method for intelligent wearable sensor systems.

This paper presents an incremental diagnosis method (IDM) to detect a medical condition with the minimum wearable sensor usage by dynamically adjusting the sensor set based on the patient's state in his/her natural environment. The IDM, comprised of a naive Bayes classifier generated by supervised training with Gaussian clustering, is developed to classify patient motion in-context (due to a medical condition) and in real-time using a wearable sensor system. The IDM also incorporates a utility function, which is a simple form of expert knowledge and user preferences in sensor selection. Upon initial in-context detection, the utility function decides which sensor is to be activated next. High-resolution in-context detection with minimum sensor usage is possible because the necessary sensor can be activated or requested at the appropriate time. As a case study, the IDM is demonstrated in detecting different severity levels of a limp with minimum usage of high diagnostic resolution sensors.     

将-5V转换为5V的电荷泵

通用的开关电容电荷泵式电压转换器都能将一个正电压源的电压转换为负电压，或使之增加一倍。但是．某些完全由ECL(射极耦合逻辑)电路组成的设备。只能提供一个负电压，如-5.2V。图1说明如何用一只开关电容转换器来获得一个适宜为ECL-TTL电平转换器和其它电路供电的正电源电压。     

用于智能变送器的DAC

描述智能变送器及其对高分辨率，低功率D/A转换器的需求。     

Preparation and properties of exfoliated graphite doped with nickel and cobalt oxides

We report the first synthesis of doped exfoliated graphite through the electrochemical oxidation of natural graphite in aqueous nickel nitrate and cobalt nitrate solutions, followed by heat treatment. The solutions are found to differ in electrochemical behavior during the anodic oxidation of graphite. The thermal properties of the oxidized graphite prepared by this procedure and utilized as a precursor to exfoliated graphite are described. The exfoliated graphite obtained under optimal conditions contains 2–60 wt % metal oxide and has a specific surface of 60–160 m²/g and loose density of 1.5–5 g/l.     

Exocrine function of the pancreas in patients with chronic hepatitis and liver cirrhosis of various etiologies

Exocrinous performance of the pancreatic gland under secretin-pancreozymin stimulation was studied in 76 patients with chronic diffuse diseases of the liver who were distinguished into 6 groups: those who suffered from chronic persistent hepatitis of viral and alcohol origin, chronic active hepatitis of viral origin, cirrhosis of the liver of viral and alcohol origin, primary biliary hepatocirrhosis. The results obtained were correlated with those from 11 normal persons (controls). Out of 76 examinees the disorders of exocrinous performance of the pancreatic gland were revealed in 75 persons. The most characteristic features were: a decrease in the basal and an increase in the stimulated volume of the pancreatic juice; a reduction of both basal and stimulated production of bicarbonates; a decrease in the trypsin and amylase fasting levels and their increment in the stimulated juice of the pancreatic gland. Disorder in the production of bicarbonates was stated as a most characteristic feature in the patients both with viral and alcohol origin of the disease but it was mostly manifest in the patients with hepatocirrhosis. Pronounced elevation of the activity of amylase and trypsin in the pancreatic juice was observed in patients with very high activity of disease development and in the patients who continuously used large amounts of alcohol. The authors suspected that alcohol abuse and the effect of hepatitis virus had an equal pathogenic impact on the liver and pancreatic gland.     

New Apatite‐Type Oxide Ion Conductor,Bi2La8[(GeO4)6]O3: Structure,Properties, and Direct Imaging of Low‐Level Interstitial Oxygen Atoms Using Aberration‐Corrected Scanning Transmission Electron Microscopy

The new solid electrolyte Bi₂La₈[(GeO₄)₆]O₃ is prepared and characterized by variable‐temperature synchrotron X‐ray and neutron diffraction, aberration‐corrected scanning transmission electron microscopy, and physical property measurements (impedance spectroscopy and second harmonic generation). The material is a triclinic variant of the apatite structure type and owes its ionic conductivity to the presence of oxide ion interstitials. A combination of annular bright‐field scanning transmission electron microscopy experiments and frozen‐phonon multislice simulations enables direct imaging of the crucial interstitial oxygen atoms present at a level of 8 out of 1030 electrons per formula unit of the material, and crystallographically disordered, in the unit cell. Scanning transmission electron microscopy also leads to a direct observation of the local departures from the centrosymmetric average structure determined by diffraction. As no second harmonic generation signal is observed, these displacements are non‐cooperative on the longer length scales probed by optical methods.     

Synthesis,Crystal Structure,and Enhanced Luminescence of Garnet‐Type Ca3Ga2Ge3O12:Cr3+ by Codoping Bi3+

Garnet‐type compound Ca₃Ga₂Ge₃O₁₂ and Cr³⁺‐doped or Cr³⁺/Bi³⁺ codped Ca₃Ga₂Ge₃O₁₂ phosphors were prepared by a solid‐state reaction. The crystal structure of Ca₃Ga₂Ge₃O₁₂ host was studied by X‐ray diffraction (XRD) analysis and further determined by the Rietveld refinement. Near‐infrared (NIR) photoluminescence (PL) and long‐lasting phosphorescence (LLP) emission can be observed from the Cr³⁺‐doped Ca₃Ga₂Ge₃O₁₂ sample, and the enhanced NIR PL emission intensity and LLP decay time can be realized in Cr³⁺/Bi³⁺ codped samples. The optimum concentration of Cr³⁺ in Ca₃Ga₂Ge₃O₁₂ phosphor was about 6 mol%, and optimum Bi³⁺ concentration induced the energy‐transfer (ET) process between Bi³⁺ and Cr³⁺ ions was about 30 mol%. Under different excitation wavelength from 280 to 453 nm, all the samples exhibit a broadband emission peaking at 739 nm and the intensity of NIR emission increases owing to the ET behavior from Bi³⁺ to Cr³⁺ ions. The critical ET distance has been calculated by the concentration‐quenching method. The thermally stable luminescence properties were also studied and the introduction of Bi³⁺ can also improve the thermal stability of the NIR emission.     

Preparation,Structure, and Up‐Conversion Luminescence of Yb3+/Er3+ Codoped SrIn2O4 Phosphors

SrIn₂O₄, which shows lower phonon energy than CaIn₂O₄, is not only a good photocatalyst but also can be an excellent up‐conversion (UC) host to exhibits UC luminescence. In this work, Yb³⁺ and/or Er³⁺ doped SrIn₂O₄ phosphors were synthesized, and their UC luminescence properties were studied and compared with those in the CaIn₂O₄ host. The structure of SrIn₂O₄: 0.01Er³⁺ and SrIn₂O₄: 0.1Yb³⁺/0.01Er³⁺ samples were refined by the Rietveld method and found to that SrIn₂O₄: 0.1Yb³⁺/0.01Er³⁺ showed increasing unit cell parameters and cell volume, indicating In³⁺ sites were substituted successfully by Yb³⁺ and/or Er³⁺ ions. From the UC luminescence spectra and diffuse reflection spectra, Er³⁺‐doped SrIn₂O₄ showed very weak luminescence due to ground state absorption of Er³⁺; Yb³⁺/Er³⁺ codoped SrIn₂O₄ presented strong green (550 nm) and red (663 nm) UC emissions which were assigned to energy transfer from Yb³⁺ transition ²F_7/2→²F_5/2 to the Er³⁺ transition ⁴S_3/2 → ⁴I_15/2 and ⁴F_9/2 → ⁴I_15/2. Comparing with CaIn₂O₄, Yb³⁺/Er³⁺ codoped SrIn₂O₄ showed obvious advantages with higher UC luminescent intensity. The pumping powers study showed that UC emissions in Yb³⁺/Er³⁺ codoped SrIn₂O₄ were attributed to energy transfer of Yb³⁺→Er³⁺ with a two‐photon process. The possible UC luminescent mechanism of Yb³⁺/Er³⁺‐doped SrIn₂O₄ was discussed.