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Electric-stimulus rate encoding algorithm of Mandarin tonal information in cochlear implant

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Progress in Natural Science:Materials International 2006年第12期16卷 1315-1321页

作者： GUAN Tian~1, GONG Qin~1 and YE Datian~2**(1. Department of Biomedical Engineering, tsinghua university, Beijing 100084, china 2. Research Center of Biomedical Engineering, graduate school at shenzhen, tsinghua university, shenzhen 518055, china) [a]Department of Biomedical Engineering Tsinghua University Beijing China [b]Research Center of Biomedical Engineering Graduate School at Shenzhen Tsinghua University Shenzhen China

The modern multi-channel cochlear implants usually extract and encode the temporal envelope cues. This kind of algorithms can hardly satisfy the users who speak tonal languages, such as Mandarin. Many studies have tried to enhance the recognition ability of Mandarin through encoding tonal information and made suggestions to frequency-modulate the fixed pulse-rate carrier with the extracted tonal information based on the rate-pitch theory in electric hearing. However, how to encode and deliver the tonal information such as F_0by changing electric-stimulus rate has not got further study in clinical electric-stimulus mode. The present paper focuses on this matter by piecewise calculating the appreciable electric-stimulus rates. Then an electric-stimulus encoding algorithm of Mandarin tone is brought forward and testified through acoustic simulations. Such conclusion can be drawn that this algorithm of electric-stimulus rate could convey tonal information well and help to enhance the Mandarin speech recognition ability.

关键词： cochlear implant tone fundamental frequency electric-stimulus rate.

Aging assessment of large generator insulation based on PD measurements

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Progress in Natural Science:Materials International 2005年第11期15卷 1035-1043页

作者： YUE Bo, CHEN Xiaolin, CHENG Yonghong and XIE Hengkun (State Key Laboratory of Electrical Insulation and Power Equipment, Xi'an Jiaotong university, Xi'an 710049, china graduate school at shenzhen, tsinghua university, shenzhen 518055, china Department of Electrical Engineering, tsinghua university, Beijing 100084, china) State Key Laboratory of Electrical Insulation and Power Equipment Xi''an Jiaotong University Xi''an 710049 China. graduate school Shenzhen Tsinghua University Shenzhen 518055 China. Department of Electrical Engineering Tsinghua University Beijing 100084 China

The statistical parameters of phase resolved partial discharge (PD) distribution and ultra-wideband (UWB) characteristics of PD pulse are proposed for aging assessment of large generator insulation. Multi-stress aging tests of the model generator stator bar specimens were performed and PD measurements were conducted using both digital PD detector with frequency ranging from 40 kHz to 400 kHz and UWB PD detector with bandwidth from 10 MHz to 3 GHz at different aging stages. The test results show that the skewness and UWB frequency characteristics of PD can be taken as the characterization parameters for aging assessment of generator insulation. Furthermore, the measurement results of real generator stator bars show that these methods based on statistical parameters and UWB characteristics of PD are prospective for aging assessment and residual lifetime estimation of large generator stator insulation.

关键词： partial discharge stator insulation multi-stress accelerated aging statistical parameters ultra-wideband aging assessment.

Antisense expression of a rice cellular apoptosis susceptibility gene (OsCAS} alters the height of transgenic rice

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Progress in Natural Science:Materials International 2007年第1期17卷 39-43页

作者： XU Chunxiao and HE Chaozu ( National Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, china graduate university of Chinese Academy of Sciences, Beijing 100039, china shenzhen Laboratory of Superhybrid Rice Research, graduate school at shenzhen, tsinghua university, shenzhen 518055, china) [a]National Key Laboratory of Plant Genomics Institute of Microbiology Chinese Academy of Sciences Beijing China [b]graduate university of Chinese Academy of Sciences Beijing China

Cellular apoptosis susceptibility (CAS) gene plays important roles in mitosis, development and export of importin a from the nucleus, but its function in plant is unknown. In this study, a rice CAS ortholog (OsCAS), which encodes a predicted protein of 983 amino acids with 62% similarity to human CAS, was identified. DNA gel blot analysis revealed a single copy of OsCAS in the rice genome. A 973 bp fragment at the 3' end of OsCAS cDNA was cloned from rice cDNA library and transferred into rice in the antisense direction under the control of CaMV 35S promoter via Agrobacterium-mediated transformation method, 105 transgenic lines were obtained. Expression of OsCAS was suppressed in the antisense transgenic lines as revealed by semi-quantitative RT-PCR. The antisense transgenic lines showed dwarf phenotypes. The results indicated that OsCAS was involved in culm development of rice.

关键词： antisense dwarf ortholog OsCAS rice.

Effective use of the spectral information in speech processing of cochlear implant

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Progress in Natural Science:Materials International 2007年第3期17卷 334-339页

作者： GUAN Tian, GONG Qin and YE Datian ( Joint Research Centre for Biomedical Engineering, Department of Electronic Engineering, The Chinese university of Hong Kong, Hong Kong, china Research Centre of Biomedical Engineering, graduate school at shenzhen, tsinghua university, shenzhen 518055, china) [a]Joint Research Centre for Biomedical Engineering Department of Electronic Engineering The Chinese University of Hong Kong Hong Kong China [b]Research Centre of Biomedical Engineering Graduate School at Shenzhen Tsinghua University Shenzhen China

Based on the results of the acoustic research on Mandarin, two novel algorithms using the spectral information in speech processing of cochlear implants are purposed and certified effectively by the spectral information of tonal language in acoustic simulation experiments. We bring forward novel algorithms conveying the spectral information based on the choices of the frequency bands. These new algorithms can not only improve the speech recognition ability of cochlear implant users in the noisy environments but also reduce the complexity of computing and the memory occupied, and make it more suitable to be carried out in clinical practice.

关键词： cochlear implant speech signal processing signal processing.

A novel synthetic route for LiFePO_4/C cathode materials by addition of starch for lithium-ion batteries

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Chinese Chemical Letters 2007年第2期18卷 237-240页

作者： Shao Hua Luo, Zi Long Tang, Jun Biao Lu, Zhong Tai Zhang State Key Laboratory of New Ceramics and Fine Processing, Department of Materials Science and Engineering, tsinghua university, Beijing 100084, china graduate school at shenzhen, tsinghua university, shenzhen 518055, china [a]State Key Laboratory of New Ceramics and Fine Processing Department of Materials Science and Engineering Tsinghua University Beijing 100084 China [b]graduate school at shenzhen Tsinghua University Shenzhen 518055 China

LiFePO4/Carbon composite cathode material was prepared using starch as carbon source by spray-pelleting and subsequent pyrolysis in N2. The samples were characterized by XRD, SEM, Raman, and their electrochemical performance was investigated in terms of cycling behavior. There has a special micro-morphology via the process, which is favorable to electrochemical properties. The discharge capacity of the LiFePO4.C composite was 170 mAh g-1, equal to the theoretical specific capacity at 0.1 C rate. At 4 C current density, the specific capacity was about 80 mAh g-1, which can satisfy for transportation applications if having a more flat discharge flat.

关键词： Lithium-ion batteries Cathode material Carbon coated LiFePO4 Spray-pelleting

VEGF-specific siRNAs modified with 2′-deoxy effectively suppress VEGF expression and inhibit growth of nasopharyngeal carcinoma xenograft in a mouse model

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Science china(Life Sciences) 2008年第2期51卷 104-110页

作者： CHEN ShanYi1, GAO GuoFeng1, CHEN Wei1, Lü Qing2, TANG Shen2, HUA Zhong2, YE WenBin2, GU DaYong2, WANG ShaYan1 & ZHANG YaOu2 1 shenzhen People’s Hospital, Clinical Medical College of Jinan university, shenzhen 518020, china 2 Life Science Division, graduate school at shenzhen, tsinghua university, shenzhen 518055, china 1. shenzhen People’s Hospital Clinical Medical College of Jinan University Shenzhen 518020 China 2. Life Science Division Graduate School at Shenzhen Tsinghua University Shenzhen 518055 China

Vascular endothelial growth factor (VEGF) is up-regulated in the vast majority of human tumors. The up-regulation of VEGF not only plays important roles in tumor angiogenesis, but also provides a target for tumor treatment with small interfering RNA (siRNA) that targets VEGF; however, it is unclear whether a quite high up-regulation of VEGF will affect the efficiency of RNA interference strategies targeting VEGF. A high level expression of VEGF was found in CNE cells from a nasopharyngeal carcinoma cell line. In this study, we investigate whether VEGF-specific siRNAs can effectively suppress VEGF expression in CNE cells, and study the methods for the use of VEGF-specific siRNAs as potential therapeutic agents. CNE cells with high VEGF expression induced by hypoxia were transfected with VEGF-specific siRNAs. The expression of VEGF was effectively suppressed by VEGF-specific siRNAs, measured by ELISA, Western blot analysis and RT-PCR. Furthermore, experiments in nude mice bearing nasopharyngeal carcinoma xenograft were initiated 5 d after injection of CNE cells. VEGF-specific siRNAs were modified with 2′-deoxy, then injected into the tumors, and a liposome-mediated siRNA transfection system and ultrasound exposure were used to help delivery of the siRNAs. Tumor growth was reduced significantly after 3 weeks' treatment. These studies suggest that VEGF-specific siRNAs still can effectively suppress VEGF expression even in tumor cell lines with a relatively high level of VEGF expression, such as CNE, and VEGF-specific siRNAs modified with 2′-deoxy can be used as potential agents for tumor therapy.

关键词： small interfering RNA vascular endothelial growth factor (VEGF) nasopharyngeal carcinoma 2′-deoxy modification ultrasound

Electrochemical Corrosion Behavior of Arc Sprayed Zn and Zn15Al Coatings in Simulated Salina Soil and Neutral Meadow Soil Solutions

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Journal of Wuhan university of Technology(Materials Science) 2011年第6期26卷 1152-1156页

作者：林碧兰 graduate school at shenzhen Tsinghua University

Arc sprayed Zn and Zn15Al coatings were chosen to protect the metal ends of prestressed high-strength concrete （PHC） pipe piles against corrosion of salina soil in northern china and neutral meadow soil in northeast china. The corrosion behavior of the coated Q235 steel samples in two simulated soil solutions were investigated by potentiodynamic polarization and electrochemical impedance spectroscopy （EIS） methods. The experimental results show that the corrosion of the matrix Q235 steel in both simulated solutions is remarkably inhibited by Zn and Zn15Al coatings. The corrosion products on Zn and Zn15Al are thick, compact, firm and protective. The corrosion current density icorr of both Zn and Zn15Al-coated samples is decreased evidently with corrosion time, and the charge transfer resistance Rct is increased greatly. The corrosion resistance indexes of Zn and Zn15Al in simulated neutral meadow soil solution are more outstanding than those in salina soil. The corrosion resistance of Zn15Al in salina soil is slightly superior to that of Zn. When the sprayed coatings are sealed with epoxy resin, the corrosion resistance of the coatings is further enhanced markedly.

关键词： arc spray coating soil corrosion electrochemical

Methods for Increasing Creditability of Anomaly Detection System

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Methods for Increasing Creditability of Anomaly Detection Sy...

Singchia and Gunnaria,two new genera of Orchidaceae

The 1st Chinese Conference on Trusted Computing and Information Security

作者： YAN Qiao graduate school at shenzhen, tsinghua university, shenzhen 518055,Guangdong,china

＜正＞ Based on Bayes’ theorem we point out that the false positive rate must be lower than the intrusion base rate in order to make the Alarm Credibility Probability of the intrusion detection system exceed 50%. We present the methods that have been used in our developing intrusion detection system AIIDS （artificial immune intrusion detection systems） to increase the creditability of anomaly detection system. These methods include increasing the regularities of the system call trace by use of Hidden Markov Model （HMM）, making every antibody or detector has finite lifetime, offering the detector a co-stimulate signal to illustrate whether there is damage in the system according to the integrity, confidentiality, or availability of the system resource.

关键词： intrusion detections creditability false positive rate

来源： cnki会议评论

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Journal of Systematics and Evolution 2009年第6期47卷 599-604页

作者： ~(1,2,3)Zhong-Jian LIU~* ~1Li-Jun CHEN 1(The National Orchid Conservation Center of china(The Orchid Conservation & Research Center of shenzhen),shenzhen 518114,china) 2(The Center for Biotechnology and BioMedicine,graduate school at shenzhen,tsinghua university,shenzhen 518055,china) 3(College of Forestry,South china Agricultural university,Guangzhou 510642,china) (College of Forestry South China Agricultural University Guangzhou 510642 China)

Singchia *** & ***,a new orchid genus,is established based on the new species *** *** & *** found in southeast Yunnan,*** new genus is related to Pteroceras,from which it differs by having a lip with its basal margins immovably adnate to the lower part of the pendent column foot,a thin-walled spur,and very unequally and deeply split pollinia,each with a distinct *** addition to a discussion on Ascocentrum pusillum,a species of questionable placement,another new genus,namely Gunnaria *** ex *** & ***,is set up and a new combination,namely ***(Aver.) *** & ***,is *** new genus Gunnaria differs from its ally Ascocentrum by having a cross-shaped pollinarium,sulcate or split pollinia, each with a distinct caudicle attached to a common linear stipe much longer than either pollinia or viscidium,and strongly incurved side lobes of the lip.

关键词： china G.pusilla(Aver.) Z.J.Liu & L.J.Chen Gunnaria S.C.Chen ex Z.J.Liu & L.J.Chen new combination new genera new species S.malipoensis Z.J.Liu & L.J.Chen Singchia Z.J.Liu & L.J.Chen Yunnan