Design of a low temperature coefficient bandgap reference with a wide temperature range

In order to meet the requirements of different applications and markets for the accuracy and reliability of IoT chips,a low temperature coefficient bandgap reference with a wide temperature range is proposed.On the basis of the traditional Banba bandgap reference structure,the circuit utilizes high-order temperature compensation technology and piecewise temperature compensation technology to improve the curvature of the output reference voltage.The temperature coefficient of the circuit is reduced.At the same time,the operating temperature range of the circuit is extended.The circuit performances are verified in the TSMC 180 nm CMOS process.Test results show that the temperature coefficient of the circuit is as low as 7.2×10^-6/℃ in the range of-40 ℃ to 160 ℃.The power supply rejection ratio at a low frequency is -48.52 dB.The static current under the 1.8 V power supply voltage is 68.38 μA,and the core area of the chip is 0.025 mm².     

Experimental and numerical simulation of lignite chemical looping gasification with phosphogypsum as oxygen carrier in a fluidized bed

Phosphogypsum (PG) is a solid waste produced in the wet process of producing phosphoric acid.Lignite is a kind of promising chemical raw material.However,the high sulfur of lignite limits the utilization of lig-nite as a resource.Based on fluidized bed experiments,the optimal reaction conditions for the production syngas by lignite chemical looping gasification (CLG) with PG as oxygen carrier were studied.The study found that the optimal reaction temperature should not exceed 1123 K;the mole ratio of water vapor to lignite should be about 0.2;the mole ratio of PG oxygen carrier to lignite should be about 0.6.Meanwhile,commercial software Comsol was used to establish a fuel reaction kinetics model.Through computational fluid dynamics (CFD) numerical simulation,the process of reaction in fluidized bed were well captured.The model was based on a two-fluid model and coupled mass transfer,heat transfer and chemical reac-tions.This study showed that the fluidized bed presents a flow structure in which gas and solid coexist.There was a high temperature zone in the middle and lower parts of the fluidized bed.It could be seen from the results of the flow field simulated that the fluidized bed was beneficial to the progress of the gasification reaction.     

准均匀电场下C5F10O/干燥空气与C5F10O/N2的绝缘特性

SF_6因优异的电气特性广泛应用于电器绝缘设备中,但其产生的温室效应对大气环境具有极大损害。近年来,C_5F_(10)O作为一种环保型SF_6潜在替代气体受到国内外科研工作者的关注。为进一步探究C_5F_(10)O/干燥空气与C_5F_(10)O/N_2的绝缘特性,文中利用气体绝缘性能测试平台,对不同气压、不同C_5F_(10)O分压下的2种混合气体在准均匀电场下进行工频击穿试验。实验结果表明,C_5F_(10)O混合气体绝缘强度随气体压强的增大而增大;提高C_5F_(10)O分压亦可提高两类缓冲气体的绝缘强度,且对N_2绝缘强度提升相对值大于干燥空气。从绝缘强度考虑,适当增大C_5F_(10)O混合气体气压和C_5F_(10)O分压,C_5F_(10)O/干燥空气比C_5F_(10)O/N_2混合气体更具潜力替代室内中低压设备中的SF_6。     

双组分高固体丙烯酸聚氨酯涂料的研究

介绍了改性高固体分羟基丙烯酸树脂的合成工艺，通过对引发剂、链转移剂、反应温度及叔碳酸缩水时油酯等因素的讨论，合成了新型的羟基丙烯酸树脂。以其为基料配制了丙烯酸聚氨酯涂料，并讨论了该磁漆的配方设计和各项性能。     

金属闪光外墙乳胶漆的研制及性能研究

以丙烯酸酯及有机硅单体为原料合成了核-壳型硅丙乳液,用自制分散剂将闪光铝粉分散成水性闪光铝粉浆,并成功分散于硅丙乳液中,加入进口助剂,配制成水性金属闪光外墙乳胶漆.讨论了基料的玻璃化温度、单体的加入方式、引发剂、乳化剂、反应温度、聚合工艺和pH等对乳胶漆性能的影响.     

新型无卤阻燃剂六苯胺基环三磷腈的合成

由五氯化磷和氯化铵合成了六氯环三磷腈（Ⅰ），通过亲和取代反应由苯胺和Ⅰ合成了六（苯胺基）环三磷腈（Ⅱ），对反应条件进行了优化，并对化合物Ⅰ、Ⅱ进行了元素分析、IR谱和质谱表征。用化合物Ⅱ与ABS树脂共混制备了阻燃ABS树脂，测试了其氧指数和力学性能等指标。     

中试规模制备L-茶氨酸及其衍生物

报道了中试规模制备L-茶氨酸和L-谷氨酰胺的一种方法。以廉价的L-谷氨酸为原料,采用邻苯二甲酰基作为保护基,保护L-谷氨酸的α-氨基,醋酐回流10 m in使其分子内脱水生成N-邻苯二甲酰-L-谷氨酸酐,在常温、常压条件下,分别与2 mol/L氨水和2 mol/L乙胺水溶液反应生成中间产物N-邻苯二甲酰-L-谷氨酰胺、N-邻苯二甲酰-L-茶氨酸,中间产物在室温条件下与0.5 mol/L水合肼反应48 h脱除保护基,分别以57%、61%的收率得到L-谷氨酰胺和L-茶氨酸。     

Effective naive Bayes nearest neighbor based image classification on GPU

Non-parametric classifier, Naive Bayes nearest neighbor, is designed with no training phase, and its performance outperforms many well-trained learning-based image classifiers. Unfortunately, despite its high accuracy, it suffers from great computational pressure from distance computations in space of local feature. This paper explores accelerating strategies from perspectives of both algorithm design and software development. Our approach integrates space decomposition capability of Product quantization (PQ) and parallel accelerating capability of underlying computational platform, Graphics processing unit (GPU). PQ is exploited to compress the indexed local features and prune the search space. GPU is used to ease most of computational pressure by processing the tasks in parallel. To achieve good parallel efficiency, a new sequential classification process is first designed and decomposed into independent components with high parallelism. Effective parallelization techniques are then presented to make use of computational resources. Parallel heap array is built to accelerate the process of feature quantization. Distance table lookup is built to speed up the process of feature search. Comparative experiments on UIUC-Sport dataset demonstrate that our integrated solution outperforms other implementations significantly on Core-quad Intel Core i7 950 CPU and GPU of NVIDIA Geforce GTX460. Scalability experiment on 80 million tiny images database shows that our approach still performs well when large-scale image database is explored.     

炭黑密相气力输送系统设计

随着橡胶工业的发展，以及气力输送特有的优点，气力输送系统越来越广泛地应用于输送炭黑的过程中。以炭黑气力输送系统为研究对象，详细介绍了系统设计的基本参数确定、气力输送形式的确定、压送罐客积的设计、输送管道的设计，并通过输送系统压力降的计算验证了设计参数的取值是合理的。