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On the fouling mechanism of polysulfone ultrafiltration membrane in the treatment of coal gasification wastewater

Frontiers of Chemical Science and Engineering 2016年第4期10卷 490-498页

作者： xue zou Jin Li School of Civil Engineering Beijing Jiaotong University Beijing 100044 China College of Architectural Engineering North China University of Technology Beijing 100144 China

Membrane fouling has been investigated by using a polysulfone ultrafiltration membrane with the molecular weight cutoff of 20 kDa to treat crushed coal pressurized gasification wastewater. Under the conditions of different feed pressures, the permeate flux declines and rejection coefficients of pollutants referring to three parameters （total organic carbon （TOC）, chroma and turbidity） were studied. The membrane fouling mechanism was simulated with three classical membrane fouling models. The membrane image and pollutants were analyzed by scanning electron microscopy and gas chromatography-mass spectrography （GC-MS）. The results indicate that the permeate flux decreases with volume reduction factor before reaching a constant value. The rejection coefficients were also measured： fTOC = 70.5%,fc = 84.9% andfa- = 91%. Further analysis shows that the higher the feed pressure is, the sooner the permeate flux reaches constant value and the more sharply the permeate flux declines. Constant flux indicates a nonlinear growth with feed pressure （PF）： when Pr equals 1.2 bar, the mark for the critical flux, slight membrane fouling occurs; when PF exceeds 1.2 bar, cake layer pollution aggravates. Also the rejection coefficients of global pollutant increases slightly with PF, suggesting the possibility of cake compression when PF exceeds 1.2 bar. Through regression analysis, the fouling of polysulfone ultrafiltration membrane could be fitted very well by cake filtration model. The membrane pollutants were identified as phthalate esters and long-chain alkenes by GC-MS, and a certain amount of inorganic pollutants by X-ray photoelectron spectroscopy.

关键词： membrane fouling ultrafiltration membrane,coal gasification wastewater rejection coefficient

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Co-design for an SoC embedded network controller

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2006年第4期7卷 591-596页

作者： zou Lian-ying zou xue-cheng Department of Electronic Science ＆ Technology Huazhong University of Science ＆ Technology Wuhan 430074 China

With the development of Ethernet systems and the growing capacity of modem silicon technology, embedded communication networks are playing an increasingly important role in embedded and safety critical systems. Hardware/software co-design is a methodology for solving design problems in processor based embedded systems. In this work, we implemented a new 1-cycle pipeline microprocessor and a fast Ethemet transceiver and established a low cost, high performance embedded network controller, and designed a TCP/IP stack to access the Intemet. We discussed the hardware/software architecture in the forepart, and then the whole system-on-a-chip on Altera Stratix EP1S25F780C6 device. Using the FPGA environment and SmartBit tester, we tested the system＇s throughput. Our simulation results showed that the maximum throughput of Ethemet packets is up to 7 Mbps, that of UDP packets is up to 5.8 Mbps, and that of TCP packets is up to 3.4 Mbps, which showed that this embedded system can easily transmit basic voice and video signals through Ethemet, and that using only one chip can realize that many electronic devices access to the Intemet directly and get high performance.

关键词： System-on-Chip (SoC) Embedded Microprocessor Network controller TCP/IP Co-design

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A novel low-voltage high precision current reference based on subthreshold MOSFETs

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第1期8卷 50-55页

作者： YU Guo-yi zou xue-eheng Department of Electronic Science ＆ Technology Huazhong University of Science and Technology Wuhan 430074 China

A novel topology low-voltage high precision current reference based on subthreshold Metal-Oxide-Semiconductor Field Effect Transistors （MOSFETs） is presented. The circuit achieves a temperature-independent reference current by a proper combination current of two first-order temperature-compensation current references, which exploit the temperature characteristics of integrated poly2 resistors and the 1- V transconductance characteristics of MOSFET operating in the subthreshold region. The circuit, designed with the 1 st silicon 0.35 μm standard CMOS logic process technology, exhibits a stable current of about 2.25 μA with much low temperature coefficient of 3 × 10^-4μA/℃ in the temperature range of-40-150 ℃ at 1 V supply voltage, and also achieves a better power supply rejection ratio （PSRR） over a broad frequency. The PSRR is about -78 dB at DC and remains -42 dB at the frequency higher than 10 MHz. The maximal process error is about 6,7% based on the Monte Carlo simulation. So it has good process compatibility.

关键词： Current reference Curvature-compensation Low voltage Subthreshold CMOS integrated circuit

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Ultra-low power S-Boxes architecture for AES

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The Journal of China Universities of Posts and Telecommunications 2008年第1期15卷 112-117页

作者： XING Ji-peng zou xue-cheng GUO Xu Research Center for VLSI and Systems Department of Electronic Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

It is crucial to design energy-efficient advanced encryption standard （AES） cryptography for low power embedded systems powered by limited battery. Since the S-Boxes consume much of the total AES circuit power, an efficient approach to reducing the AES power consumption consists in reducing the S-Boxes power consumption. Among various implementations of S-Boxes, the most energy-efficient one is the decoder-switchencoder （DSE） architecture. In this paper, we refine the DSE architecture and propose one faster, more compact S-Boxes architecture of lower power： an improved and full-balanced DSE architecture. This architecture achieves low power consumption of 68 μW at 10 MHz using 0.25 ktm *** UMC CMOS technology. Compared with the original DSE S-Boxes, it further reduces the delay, gate count and power consumption by 8%, 14% and 10% respect/vely. At the sane time, simulation results show that the improved DSE S-Boxes has the best performance among various S-Boxes architectures in terms of power-area product and power-delay product, and it is optimal for implementing low power AES cryptography.

关键词： AES S-Boxes DSE cryptography low power

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RS trigger based relaxation oscillator for temperature measurement circuit

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The Journal of China Universities of Posts and Telecommunications 2008年第3期15卷 118-122页

作者： zou Zhi-ge zou xue-cheng JIAN Wen-xiang LEI Jian-ming Department of Electronic Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

Resistance-to-time converter is always used for digital temperature measurement. An reset-set （RS） trigger based, relaxation oscillator based temperature measurement circuit, which is used to convert the change of thermistor sensor into a frequency signal for later processing, has been presented in this article. The RS trigger, which is composed of two inverters designed with distinct logical transition threshold voltages by changing the metal-oxide-semiconductor （MOS） transistor gains, has the same function as the Schmitt trigger in the relaxation oscillator. The advantage of the RS trigger based Schmitt trigger is that it reduces the dependence to supply voltage, chip temperature, and process variation. This temperature measurement circuit has been applied in a clinical thermometer chip that can measure temperature to an accuracy of better than 0.05 ℃ down to 1.1 V battery voltage. It is fabricated in 0.5 μm double metal single poly complementary MOS （CMOS） process.

关键词： temperature measurement relaxation oscillator RS trigger Schmitt trigger

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A Super Performance Bandgap Voltage Reference with Adjustable Output for DC-DC Converter

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The Journal of China Universities of Posts and Telecommunications 2006年第1期13卷 75-78页

作者： YU Hua zou xue-cheng CHEN Chao-yang Department of Electronics Science and Technology Huazhong University of Science and Technology Wuhan 430074 P.R. China State Key Laboratory for Image Processing and Intelligence Control Huazhong University of Science and Technology Wuhan 430074 P.R. China

This paper presents a super performance bandgap voltage reference for DC-DC converter with adjustable output. it generates a wide range of voltage reference ranging from sub- 1V to 1,221 7 V and has a low temperature coefficient of 2.3 × 10 ^5/K over the temperature variation using the current feedback and resistive subdivision. In addition, the power supply rejection ration of the proposed bandgap voltage reference is 78 dB. When supply voltage varies from 2.5 V to 6 V, output VREF is 1,221 685±0.055 mV.

关键词： bandgap voltage reference adjustable output DC-DC converter temperature coefficient PSRR

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New design of sense amplifier for EEPROM memory

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第2期10卷 179-183页

作者： Dong-sheng LIU xue-cheng zou Qiong YU Fan ZHANG Department of Electronic Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

We present a new sense amplifier circuit for EEPROM memory. The topology of the sense amplifier uses a voltage sensing method,having low cost and low power consumption as well as high reliability. The sense amplifier was implemented in an EEPROM realized with an SMIC 0.35-μm 2P3M CMOS embedded EEPROM process. Under the condition that the power supply is 3.3 V,simulation results showed that the charge time is 35 ns in the proposed sense amplifier,and that the maximum average current consumption during the read period is 40 μA. The novel topology allows the circuit to function with power supplies as low as 1.4 V. The sense amplifier has been implemented in 2-kb EEPROM memory for RFID tag IC applications,and has a silicon area of only 240 μm2.

关键词： EEPROM Sense amplifier (SA) Voltage sensing Bidirectional conduction

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A Novel Method for Prediction of Protein Domain Using Distance-Based Maximal Entropy

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Journal of Bionic Engineering 2008年第3期5卷 215-223页

作者： Shu-xue zou Yan-xin Huang Yan Wang Chun-guang Zhou Key Laboratory of Symbol Computation and Knowledge Engineering of Ministry of Education College of Computer Science and Technology Jilin University Changchun 130012 P. R. China

Detecting the boundaries of protein domains is an important and challenging task in both experimental and computational structural biology. In this paper, a promising method for detecting the domain structure of a protein from sequence information alone is presented. The method is based on analyzing multiple sequence alignments derived from a database search. Multiple measures are defined to quantify the domain information content of each position along the sequence. Then they are combined into a single predictor using support vector machine. What is more important, the domain detection is first taken as an imbal- anced data learning problem. A novel undersampling method is proposed on distance-based maximal entropy in the feature space of Support Vector Machine （SVM）. The overall precision is about 80%. Simulation results demonstrate that the method can help not only in predicting the complete 3D structure of a protein but also in the machine learning system on general im- balanced datasets.

关键词： protein domain boundary SVM imbalanced data learning distance-based maximal entropy

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Phosphorylation at Ser28 stabilizes the Arabidopsis nitrate transporter NRT2.1 in response to nitrate limitation

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Journal of Integrative Plant Biology 2020年第6期62卷 865-876页

作者： xue zou Meng-Yuan Liu Wei-Hua Wu Yang Wang State Key Laboratory of Plant Physiology and Biochemistry College of Biological SciencesChina Agricultural UniversityBeijing 100193China

Nitrate is one of the main inorganic nitrogen sources for *** absorption from soils is achieved through the combined activities of specific nitrate *** transporter 2.1(NRT2.1)is the major component of the root high-affinity nitrate transport system in Arabidopsis *** to date have mainly focused on transcriptional control of ***,we show that NRT2.1 protein stability is also regulated in response to nitrogen nutrition *** seedlings were transferred to nitrate-limited conditions,the apparent half-life of NRT2.1 in roots increased from 3 to 9 *** stabilization of NRT2.1 protein occurred rapidly,even prior to the transcriptional stimulation of ***,we revealed that phosphorylation at serine28(Ser28)of NRT2.1 is involved in regulating the stability of this *** of Ser28 by alanine resulted in unstable NRT2.1,and this loss-of-phosphorylation mutant(NRT2.1S28A)failed to complement the growth-restricted phenotype of the nrt2.1 mutant when a low concentration of nitrate was the sole nitrogen *** results demonstrate that phosphorylation at Ser28 is crucial for NRT2.1 protein stabilization and accumulation in response to nitrate limitation.

关键词： nitrate Arabidopsis stabilization

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High performance white LED driver with single-wire serial-pulse digital dimming

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The Journal of China Universities of Posts and Telecommunications 2009年第1期16卷 95-99,110页

作者： YU Kai zou xue-cheng LONG Shuang WANG Wei-xu Department of Electronic Science and Technology Huazhong University of Science and Technology Wuhan 430074 China

A high performance white light emitter diode （LED） driver based on boost converter with novel single-wire serial-pulse digital dimming （SWSP） is proposed. The driver uses external serial programmed pulses and internal clock to simplify brightness control By embedding a 5-bit digital analog converter （DAC） into the driver, wide dimming range is achieved. Moreover, a new dynamic slope compensation circuit is presented and other key circuits of the driver are optimized to get higher efficiency and fast transition response. A practical circuit is implemented with 0.6 um bipolar complementary-metal-oxide-semiconductor double-diffused-metal-oxide-semiconductor （BCD） technology. The simulation results show that the driver can provide both wide output current from 1.3 mA to 42 mA with 32-level digital dimming and higher efficiency up to 83% while it works at 1 MHz switching frequency with the input voltage variation from 2.7 V to 5.5 V.

关键词： White LED driver boost converter single-wire serial-pulse digital dimming dynamic slope compensation

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