应用于Zigbee通信协议的采用了中和技术的数字控制功率放大器

本文介绍了一种CMOS全片集成的功率放大器,满足802.15.4规范,并采用采用了中和电容技术。采用了一种新型的采用了数字接口的结构,可以使基带信号直接控制PA的输出功率,从而无需DAC。采用中和电容技术以提高反向隔离度。该芯片采用SMIC 0.18um工艺流片。 测试结果表明,在1dB压缩点处,本文所提出的功率放大器具有13.5dB的功率增益,最大3.48dBm的输出功率和35.1%的PAE。核心面积为0.73mm*0.55mm。     

基于互信息和多智能体优化的合成孔径雷达图像配准

提出了一种基于互信息的多智能体优化方法,并将其用于合成孔径雷达(Synthetic Aperture Radar,SAR)图像的配准.采用归一化互信息作为度量准则,直接利用图像的灰度数据进行配准,没有假设图像间灰度值的线性关系,不需要对图像做分割、特征提取等预处理,并利用多智能体优化算法寻找最佳匹配参数,以得到最优的配准结果.实验表明,该算法在SAR图像配准方面有更好的普适性和更高的配准精度.     

一款应用于生物传感器的1.2V-600nW 12bit 2kS/s的增量型模数转换器

This paper presents an ultra-low power incremental ADC for biosensor interface circuits.The ADC consists of a resettable second-order delta–sigma(°/ modulator core and a resettable decimation filter.Several techniques are adopted to minimize its power consumption.A feedforward path is introduced to the modulator core to relax the signal swing and linearity requirement of the integrators.A correlated-double-sampling(CDS)technique is applied to reject the offset and 1/f noise,thereby removing the integrator leakage and relaxing the gain requirement of the OTA.A simple double-tailed inverter-based fully differential OTA using a thick-oxide CMOS is proposed to operate in the subthreshold region to fulfill both an ultra-low power and a large output swing at 1.2 V supply.The signal addition before the comparator in the feedforward architecture is performed in the current domain instead of the voltage domain to minimize the capacitive load to the integrators.The capacitors used in this design are of customized metal–oxide–metal(MOM) type to reach the minimum capacitance set by the k T =C noise limit.Fabricated with a 1P6 M 0.18 m CMOS technology,the presented incremental ADC consumes600 n W at 2 k S/s from a 1.2 V supply,and achieves 68.3 d B signal to noise and distortion ratio(SNDR) at the Nyquist frequency and an FOM of 0.14 p J/conversion step.The core area is 100120 m2.     

基于Metasys系统车间空调机组自动化

为了实现我厂空调系统节能降耗、方便管理、达到工艺要求、提高经济效益等目标,我们选用Johnson Controls(美国江森自控)之Metasys系统对厂区车间的空调进行自控设计。     

Preparation of Uniform,Water‐Soluble,and Multifunctional Nanocomposites with Tunable Sizes

Novel, thiol‐functionalized, and superparamagnetic, silica composite nanospheres (SH‐SSCNs) with diameters smaller than 100 nm are successfully fabricated through the self‐assembly of Fe₃O₄ nanoparticles and polystyrene₁₀₀‐block‐poly(acrylic acid)₁₆ and a subsequent sol‐gel process. The size and magnetic properties of the SH‐SSCNs can be easily tuned by simply varying the initial concentrations of the magnetite nanoparticles in the oil phase. By incorporating fluorescent dye molecules into the silica network, the composite nanospheres can be further fluorescent‐functionalized. The toxicity of the SH‐SSCNs is evaluated by choosing three typical cell lines (HUVEC, RAW264.7, and A549) as model cells, and no toxic effects are observed. It is also demonstrated that SH‐SSCNs can be used as a new class of magnetic resonance imaging (MRI) probes, having a remarkably high spin–spin (T₂) relaxivity (r₂* = 176.1 mM ^?1 S^?1). The combination of the sub‐100‐nm particle size, monodispersity in aqueous solution, superparamagnetism, and fluorescent properties of the SH‐SSCNs, as well as the non‐cytotoxicity in vitro, provides a novel and potential candidate for an earlier MRI diagnostic method of cancer.     

静态随机存储器数据残留特性研究

通常在安全处理系统中,微处理都将密钥储存在静态随机存储器(SRAM)中,如果SRAM的数据在断电后确实完全丢失,那么采取这样的对策是非常安全的,但是SRAM在断电后存在数据残留的问题,是系统的一个重大安全隐患。针对信息系统的安全性,用实验方法进行了SRAM数据残留特性的研究,确定了多种SRAM数据残留的临界温度点,建立了数据残留时间与温度的相关关系,进行了数据残留特性与电参数的相关分析,提取出数据残留特性的特征电参数待机电流Iddsb,有助于进一步研究SRAM数据残留机理。     

振荡限幅器型卫星电视接收解调器

本文着重介绍了振荡限幅器型门限扩展解调器的工作原理及工作条件,同时设计了一种振荡限幅器型卫星电视接收解调器。该解调器具有电路简单,性能良好,具有较低接收门限等特点,可用于接收苏联714MHz卫星电视节目。此解调器特别适用于一些接收场强较弱的地区。实验表明,该解调器门限改善量约可达3dB。     

珂罗版的发展概况（二）

珂罗版自传入中国以来,就被广泛应用于书画艺术作品和挂历的复制中,但是其在国内的发展并不广泛．甚至在上世纪六七十年代还一度停止．掌握此技术的人才也越来越少。目前,只有在北京才能找到珂罗版技术,并且已经得到了政府部门的支持。笔者将在以后的文章中对珂罗版技术的特点和优势,如何发展珂罗版印刷技术,以及珂罗版作品的工艺过程等作一一介绍。     

Anti-inflammatory effects of mung bean protein hydrolysate on the lipopolysaccharide- induced RAW264.7 macrophages

Food Science and Biotechnology - The anti-inflammatory effects of mung bean protein hydrolysate (MBPH) on the lipopolysaccharide (LPS)-induced macrophages were investigated herein. MBPH was shown...     

Expression patterns of hepatic genes involved in lipid metabolism in cows with subclinical or clinical ketosis

Dairy cows with ketosis are characterized by high blood concentrations of ketone bodies and hepatic lipid metabolism disorder. The discrepancies in the abundance of mRNA encoding a variety of hepatic candidate genes in varying degrees of ketotic cows represent specific responses of the liver to the challenge of fatty acids and ketone bodies. Importantly, the expression disorder of hepatic genes involved in lipid metabolism plays a promoting role in the onset and progression of ketosis. Thus, the aim of this study was to investigate the expression patterns of genes involved in the hepatic fatty acids uptake, transport, activation, β-oxidation, synthesis, and esterification in the cows with subclinical ketosis (SCK) or clinical ketosis (CK). Twenty-four cows were selected into control [n = 8, β-hydroxybutyrate (BHB) ≤0.6 mM], SCK (n = 8, 3.0 > BHB ≥ 1.2 mM), and CK (n = 8, BHB ≥3.0 mM) groups according to the blood BHB concentration and clinical symptoms. The accumulation of hepatic lipid, as indicated by triglycerides (TG) contents and Oil Red O and hematoxylin and eosin staining, was pronouncedly exacerbated in the tCK group compared with the control and SCK groups. The hepatic mRNA expression of fatty acids transport and activation genes, liver fatty acid-binding protein (FABP1) and long-chain acyl-CoA synthetase 1 (ACSL1), were both significantly higher in the SCK and CK groups than in the control group. The expression levels of peroxisome proliferator-activated receptor α (PPARA) and its target genes, carnitine palmitoyltransferase 1A (CPT1A) and carnitine palmitoyltransferase 2 (CPT2), were significantly elevated in the SCK group but reduced in the CK group compared with control group. Furthermore, the gene expression level of sterol regulatory element-binding protein 1 (SREBP1) and the protein expression level of sterol regulatory element-binding protein 1c and its target genes acetyl-CoA carboxylase 1 (ACC1), fatty acid synthase (FAS), and stearoyl-CoA desaturase-1 (SCD1) and TG synthesis genes diacylglycerol acyltransferase 1 (DGAT1) and diacylglycerol acyltransferase 2 (DGAT2) were significantly higher in the CK group relative to the control group. In short, the present data indicated that hepatic fatty acids uptake, transport, and activation are significantly increased in cows with SCK and CK, hepatic fatty acids β-oxidation is significantly increased in SCK cows but markedly decreased in CK cows, and hepatic fatty acids and TG synthesis are significantly increased in CK cows, thereby inducing hepatic steatosis in CK cows.