期刊文献+
共找到6,197篇文章
< 1 2 250 >
每页显示 20 50 100
SlWRKY30 and SlWRKY81 synergistically modulate tomato immunity to Ralstonia solanacearum by directly regulating SlPR-STH2 被引量:2
1
作者 Fengfeng Dang Jinhui Lin +5 位作者 Yajing Li Ruoyun Jiang Yudong Fang Fei Ding Shuilin He Yanfeng Wang 《Horticulture Research》 SCIE CSCD 2023年第5期99-111,共13页
Bacterial wilt is a devastating disease of tomato(Solanum lycopersicum)caused by Ralstonia solanacearum that severely threatens tomato production.Group III WRKY transcription factors(TFs)are implicated in the plant re... Bacterial wilt is a devastating disease of tomato(Solanum lycopersicum)caused by Ralstonia solanacearum that severely threatens tomato production.Group III WRKY transcription factors(TFs)are implicated in the plant response to pathogen infection;however,their roles in the response of tomato to R.solanacearum infection(RSI)remain largely unexplored.Here,we report the crucial role of SlWRKY30,a group III SlWRKY TF,in the regulation of tomato response to RSI.SlWRKY30 was strongly induced by RSI.SlWRKY30 overexpression reduced tomato susceptibility to RSI,and also increased H2O2 accumulation and cell necrosis,suggesting that SlWRKY30 positively regulates tomato resistance to RSI.RNA sequencing and reverse transcription–quantitative PCR revealed that SlWRKY30 overexpression significantly upregulated pathogenesis-related protein(SlPR-STH2)genes SlPR-STH2a,SlPR-STH2b,SlPR-STH2c,and SlPR-STH2d(hereafter SlPR-STH2a/b/c/d)in tomato,and these SlPR-STH2 genes were directly targeted by SlWRKY30.Moreover,four group III WRKY proteins(SlWRKY52,SlWRKY59,SlWRKY80,and SlWRKY81)interacted with SlWRKY30,and SlWRKY81 silencing increased tomato susceptibility to RSI.Both SlWRKY30 and SlWRKY81 activated SlPR-STH2a/b/c/d expression by directly binding to their promoters.Taking these results together,SlWRKY30 and SlWRKY81 synergistically regulate resistance to RSI by activating SlPR-STH2a/b/c/d expression in tomato.Our results also highlight the potential of SlWRKY30 to improve tomato resistance to RSI via genetic manipulations. 展开更多
关键词 directly SYNERGISTIC IMMUNITY
下载PDF
High-speed directly modulated distributed feedback laser based on detuned loading and photon-photon resonance effect
2
作者 张云山 徐逸帆 +3 位作者 郑吉林 李连艳 方涛 陈向飞 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第9期274-281,共8页
A monolithic integrated two-section distributed feedback(TS-DFB)semiconductor laser for high-speed direct modulation is proposed and analyzed theoretically.The grating structure of the TS-DFB laser is designed by the ... A monolithic integrated two-section distributed feedback(TS-DFB)semiconductor laser for high-speed direct modulation is proposed and analyzed theoretically.The grating structure of the TS-DFB laser is designed by the reconstructionequivalent-chirp(REC)technique,which can reduce the manufacturing cost and difficulty,and achieve high wavelength controlling accuracy.The detuned loading effect and the photon-photon resonance(PPR)effect are utilized to enhance the modulation bandwidth of the TS-DFB laser,exceeding 37 GHz,while that of the conventional one-section DFB laser is only 16 GHz.When the bit rate of the non-return-to-zero(NRZ)signal reaches 55 Gb/s,a clear eye diagram with large opening can still be obtained.These results show that the proposed method can enhance the modulation bandwidth of DFB laser significantly. 展开更多
关键词 directly modulated laser(DML) detuned loading effect photon-photon resonance(PPR)effect reconstruction-equivalent-chirp(REC)technique
下载PDF
关于Directly-Riemann积分、Lebesgue积分与Riemann积分的相互关系
3
作者 熊启才 和来香 张志学 《喀什师范学院学报》 2003年第3期18-21,共4页
利用 Directly- Riemann积分、Lebesgue积分及 Riemann积分的有关性质 ,得到了 Directly-Riemann积分可积条件以及它们之间的相互关系 .
关键词 directly—Riemann积分 LEBESGUE积分 RIEMANN积分 可积条件 相互关系
下载PDF
Efficacy and safety of combined directly acting antivirals for treatment of Chinese chronic hepatitis C patients in a real-world setting 被引量:5
4
作者 Jian-Hong Chen Zheng Zeng +10 位作者 Xia-Xia Zhang Yu Zhang Ren-Wen Zhang Shuai Wang Chi-Hong Wu Min Yu Dan Liu Hong-Li Xi Yi-Xing Zhou Yao-Yu An Xiao-Yuan Xu 《World Journal of Gastroenterology》 SCIE CAS 2017年第22期4072-4079,共8页
AIM To assess the efficacy and safety of combined directly acting antivirals(DAAs) for the treatment of Chinese chronic hepatitis C(CHC) patients in a real-world setting.METHODS Hospitalized CHC patients who were trea... AIM To assess the efficacy and safety of combined directly acting antivirals(DAAs) for the treatment of Chinese chronic hepatitis C(CHC) patients in a real-world setting.METHODS Hospitalized CHC patients who were treated with DAAs at Peking University First Hospital between January 2015 and December 2016 were enrolled. Samples and clinical data were collected at 0 wk, 2 wk, 4 wk, 8 wk, 12 wk, or 24 wk during DAAs treatment and at 4 wk, 12 wk, and 24 wk after the end of treatment. RESULTS Fifty-four patients who underwent DAAs treatment were included in our study, of whom 83.3%(45/54) achieved rapid virological response at 2 wk after treatment initiation(RVR 2) and 94.4%(51/54)achieved sustained virological response at 24 wk after the end of treatment(SVR 24). Serum creatinine and uric acid levels at the end of treatment were significantly increased compared with baseline levels(83.6 ± 17.9 vs 88.8 ± 19.4, P 01 < 0.001; 320.8 ± 76.3 vs 354.5 ± 87.6, P 01 < 0.001), and no significant improvements were observed at 24 w after the end of treatment(83.6 ± 17.9 vs 86.8 ± 19.1, P 02 = 0.039; 320.8 ± 76.3 vs 345.9 ± 89.4, P 02 = 0.001). The total frequency of adverse events(AEs) during treatment was 33.3%(18/54), with major AEs being fatigue(16.7%), headache(7.4%), anorexia(7.4%), and insomnia(5.6%). CONCLUSION Though based in a small cohort of patients, the abnormal changes in renal function indices and relative high frequency of AEs during combined DAAs treatment should be taken as a note of caution. 展开更多
关键词 Chronic hepatitis C directly acting antivirals EFFICACY Safety China
下载PDF
Grapevine VlbZIP30 improves drought resistance by directly activating VvNAC17 and promoting lignin biosynthesis through the regulation of three peroxidase genes 被引量:7
5
作者 Mingxing Tu Xianhang Wang +6 位作者 Wuchen Yin Ya Wang Yajuan Li Guofeng Zhang Zhi Li Junyang Song Xiping Wang 《Horticulture Research》 SCIE 2020年第1期1061-1075,共15页
Drought stress severely affects grapevine quality and yield,and recent reports have revealed that lignin plays an important role in protection from drought stress.Since little is known about lignin-mediated drought re... Drought stress severely affects grapevine quality and yield,and recent reports have revealed that lignin plays an important role in protection from drought stress.Since little is known about lignin-mediated drought resistance in grapevine,we investigated its significance.Herein,we show that VlbZIP30 mediates drought resistance by activating the expression of lignin biosynthetic genes and increasing lignin deposition.Transgenic grapevine plants overexpressing VlbZIP30 exhibited lignin deposition(mainly G and S monomers)in the stem secondary xylem under control conditions,which resulted from the upregulated expression of VvPRX4 and VvPRX72.Overexpression of VlbZIP30 improves drought tolerance,characterized by a reduction in the water loss rate,maintenance of an effective photosynthesis rate,and increased lignin content(mainly G monomer)in leaves under drought conditions.Electrophoretic mobility shift assay,luciferase reporter assays,and chromatin immunoprecipitation-qPCR assays indicated that VlbZIP30 directly binds to the G-box cis-element in the promoters of lignin biosynthetic(VvPRX N1)and drought-responsive(VvNAC17)genes to regulate their expression.In summary,we report a novel VlbZIP30-mediated mechanism linking lignification and drought tolerance in grapevine.The results of this study may be of value for the development of molecular breeding strategies to produce drought-resistant fruit crops. 展开更多
关键词 directly BREEDING DROUGHT
下载PDF
Effects of Nitrogen Fertilizer Management on Biological Traits and Physiological Indexes at Seedling Stage and Yield of Directly-sown Rapeseed(Brassica napus L.) 被引量:1
6
作者 杨云飞 刘士山 吴永成 《Agricultural Science & Technology》 CAS 2017年第12期2401-2405,2414,共6页
Field experiments were carried out to study the effects of different nitroge- napplication rates and application times on biological traits and physiological indexes of directly-sown rapeseed (Brassica napus L.) at ... Field experiments were carried out to study the effects of different nitroge- napplication rates and application times on biological traits and physiological indexes of directly-sown rapeseed (Brassica napus L.) at the seedling stage and investigate the relationship between these biological traits or physiological indexes at the seedling stage and yield, so as to provide scientific theoretical support for high yield and efficient fertilization management in production of winter rapeseed. Field trials were conducted in Chengdu plain of Sichuan Province under rice-rapeseed rotation system during the period of 2011-2012. The nitrogen application rate trial consisted of five nitrogen levels (0, 90, 180, 270 and 360 kg/hm2) and the nitrogen application time trial included NTl(single application as base fertilized), NT2 (bottom application +one time of topdressing at seedling stage) and NT3 (bottom application+two times of topdressing at seedling stage) under the same nitrogen rate (225 kg/hm2). The results indicated that compared with no nitrogen application (NO) treatment, the in- crease of nitrogen fertilizer is beneficial to the increase of biological traits including plant height, green leaf number, leaf area index and dry weight of rapeseed at the seedling stage, the improvement of physiological indexes including total nitrogen content, chlorophyll content and soluble protein content of functional leaves, and the reduction of soluble sugar content. Nitrogen rate was linearly correlated with various biological traits at the seedling stage and physiological indexes including total nitro- gen content, chlorophyll content and soluble sugar content in functional leaves over- a/I, but in parabolic correlation with soluble protein content. Under the same nitrogen rate, NT2 treatment exhibited biological traits remarkably or significantly higher than NT1 treatment and NT3 treatment. The nitrogen application times were linearly cor- related with the physiological indexes of functional leaves at the seedling stage. The various biological traits and physiological index of functional leaves at the seedlings stage were in quadratic function parabolic correlation with seed yield, and the corre- lation was significant (P〈0.05). Therefore, under the rice-rapeseed rotation system in Chengdu plain, the economic rational nitrogen rate is 180-225 kg/hm2, and the mode of bottom application + one time of topdressing (NT2) is suitable. 展开更多
关键词 Winter rapeseed (Brassica napus L.) Direct seeding Nitrogen fertilizermanaaement Bioloqical traits Physioloqical index YIELD
下载PDF
A facile ionic liquid approach to prepare cellulose fiber with good mechanical properties directly from corn stalks 被引量:3
7
作者 Jiming Yang Xingmei Lu +3 位作者 Yanqiang Zhang Junli Xu Yongqing Yang Qing Zhou 《Green Energy & Environment》 SCIE CSCD 2020年第2期223-231,共9页
It is very difficult to directly spin the lignocellulose without pretreatment.Ionic liquids(ILs)are promising solvent to dissolve lignocellulose to prepare cellulose fiber.However,the degree of cellulose polymerizatio... It is very difficult to directly spin the lignocellulose without pretreatment.Ionic liquids(ILs)are promising solvent to dissolve lignocellulose to prepare cellulose fiber.However,the degree of cellulose polymerization(DP)is reduced when lignocellulose is dissolved in ILs,and the lignin removal rate is low.The elongation at break and tensile strength of the fibers obtained by spinning the lignocellulose dissolved in ILs are poor.In this paper,preparing cellulose fiber directly from lignocellulose based on dissolving corn stalk via[C4mim]Cl-L-arginine binary system is achieved.It shows that the removal rate of lignin can reach 92.35%and the purity of cellulose can reach 85.32%after corn stalk was dissolved at 150℃C for 11.5 h when the mass fraction of arginine is 2.5%.The elongation at break of fiber reached 10.12%and the tensile strength reached 420 MPa.It is mainly due to the fact that L-arginine not only inhibits the degradation of cellulose but also promotes the delignination.Without any pulping or pretreatment,preparing cellulose fibers via direct dissolution and extrusion may provide a simple and effective way to prepare many novel cellulose materials. 展开更多
关键词 Cellulose fibers Ionic liquids Corn stalks DISSOLVING directly spinning
下载PDF
CsMYB60 directly and indirectly activates structural genes to promote the biosynthesis of flavonols and proanthocyanidins in cucumber 被引量:3
8
作者 Jialin Li Qianqian Luan +3 位作者 Jing Han Cunjia Zhang Mengyu Liu Zhonghai Ren 《Horticulture Research》 SCIE 2020年第1期1339-1353,共15页
Flavonols and proanthocyanidins(PAs)are the main pigments in the black spines of cucumber(Cucumis sativus)fruit,and CsMYB60 is a key regulator of the biosynthesis of flavonols and PAs.However,in cucumber,the tissue di... Flavonols and proanthocyanidins(PAs)are the main pigments in the black spines of cucumber(Cucumis sativus)fruit,and CsMYB60 is a key regulator of the biosynthesis of flavonols and PAs.However,in cucumber,the tissue distribution pattern of flavonols and PAs and the mechanism of their biosynthesis regulated by CsMYB60 remain unclear.In this study,we clarified the tissue-specific distribution of flavonoids and the unique transcriptional regulation of flavonoid biosynthesis in cucumber.CsMYB60 activated CsFLS and CsLAR by binding to their promoters and directly or indirectly promoted the expression of CsbHLH42,CsMYC1,CsWD40,and CsTATA-box binding protein,resulting in the formation of complexes of these four proteins to increase the expression of Cs4CL and interact with CsTATA-box binding protein to regulate the expression of CsCHS,thereby regulating the biosynthesis of flavonols and PAs in cucumber.Our data provide new insights into the molecular mechanism of flavonoid biosynthesis,which will facilitate molecular breeding to improve fruit quality in cucumber. 展开更多
关键词 directly BREEDING thereby
下载PDF
35 km amplifier-less four-level pulse amplitude modulation signals enabled by a 23 GHz ultrabroadband directly modulated laser 被引量:2
9
作者 Yaoping Xiao Yu Liu +2 位作者 Yiming Zhang Haotian Bao Ninghua Zhu 《Journal of Semiconductors》 EI CAS CSCD 2020年第3期45-48,共4页
The 4-level pulse amplitude modulation(PAM4)based on an 23 GHz ultrabroadband directly modulated laser(DML)was proposed.We have experimentally demonstrated that based on intensity modulation and direct detection(IMDD)... The 4-level pulse amplitude modulation(PAM4)based on an 23 GHz ultrabroadband directly modulated laser(DML)was proposed.We have experimentally demonstrated that based on intensity modulation and direct detection(IMDD)56 Gbps per wavelength PAM4 signals transferred over 35 km standard single mode fiber(SSMF)without any optical amplification and we have achieved the bit error rate(BER)of the PAM4 transmission was under 2.9×10–4 by using feed forward equalization(FFE). 展开更多
关键词 directly modulated laser PAM4 FFE IMDD
下载PDF
Beyond the 100 Gbaud directly modulated laser for short reach applications 被引量:2
10
作者 Jianou Huang Chao Li +2 位作者 Rongguo Lu Lianyan Li Zizheng Cao 《Journal of Semiconductors》 EI CAS CSCD 2021年第4期67-80,共14页
It is very attractive to apply a directly modulated laser(DML)-based intensity-modulation and direct-detection(IM/DD)system in future data centers and 5G fronthaul networks due to the advantages of low cost,low system... It is very attractive to apply a directly modulated laser(DML)-based intensity-modulation and direct-detection(IM/DD)system in future data centers and 5G fronthaul networks due to the advantages of low cost,low system complexity,and high energy efficiency,which perfectly match the application scenarios of the data centers and 5G fronthaul networks,in which a large number of high-speed optical interconnections are needed.However,as the data traffic in the data centers and 5G fronthaul networks continues to grow exponentially,the future requirements for data rates beyond 100 Gbaud are challenging the existing DML-based IM/DD system,and the main bottleneck is the modulation bandwidth of the DML.In this paper,the data rate demands and technical standards of the data centers and 5G fronthaul networks are reviewed in detail.With the modulation bandwidth requirements,the technical routes and achievements of recent DMLs are reviewed and discussed.In this way,the prospects,challenges,and future development of DMLs in the applications of future data centers and 5G fronthaul networks are comprehensively explored. 展开更多
关键词 directly modulated laser data center 5G fronthaul network
下载PDF
Hepatitis C virus eradication with directly acting antivirals improves health-related quality of life and psychological symptoms 被引量:2
11
作者 Silvia Nardelli Oliviero Riggio +3 位作者 Davide Rosati Stefania Gioia Alessio Farcomeni Lorenzo Ridola 《World Journal of Gastroenterology》 SCIE CAS 2019年第48期6928-6938,共11页
BACKGROUND Alterations in health-related quality of life(HRQoL)and neuropsychological disorders were described in the hepatitis C virus(HCV)patients.Although several studies investigated the modifications of HRQoL aft... BACKGROUND Alterations in health-related quality of life(HRQoL)and neuropsychological disorders were described in the hepatitis C virus(HCV)patients.Although several studies investigated the modifications of HRQoL after HCV eradication,no data exists on the modifications of neuropsychological symptoms.AIM To investigate the effect of directly acting antivirals(DAAs)treatment on HRQoL and neuropsychological symptoms.METHODS Thirty nine patients with HCV infection underwent a neuropsychological assessment,including Zung-Self Depression-Rating-Scale,Spielberg State-Trait Anxiety Inventory Y1-Y2 and the Toronto-Alexithymia Scale-20 items before and after DAAs treatment.HRQoL was detected by Short-Form-36(SF-36).RESULTS All HRQoL domains,but role limitation physical and bodily pain,significantly improved after treatment.Interestingly,after DAAs treatment,all domains of HRQoL returned similar to those of controls.Each neuropsychological test significantly improved after HCV eradication.A significant correlation was observed among each psychological test and the summary components of SF-36.At multiple linear regression analysis including each psychological test as possible covariates,Zung-Self Depression Rating Scale(Zung-SDS)score was independently and significantly related to summary components of the SF-36 in the basal state and the difference between Zung-SDS score before and after treatment was the only variable significantly and independently related to the modification of HRQoL induced by the treatment.CONCLUSION Neuropsychological symptoms strongly influenced HRQoL in HCV patients and there was a significant improvement of neuropsychological tests and HRQoL after DAAs treatment. 展开更多
关键词 Hepatitis C virus Health related quality of life Depression State and trait anxiety ALEXITHYMIA directly acting antivirals
下载PDF
A new dimmer for alternating-current directly driven light-emitting-diode lamp 被引量:1
12
作者 KIM Jong-hyun RYU Myung-hyo +1 位作者 YOON Hyok-min SONG Eui-ho 《Journal of Central South University》 SCIE EI CAS 2012年第2期374-379,共6页
A new dimmer using a mental-oxide-semiconductor field-effect transistor (MOSFET) for alternating-current (AC) directly driven light-emitting-diode (LED) lamp was presented. The control method of proposed dimmer is pul... A new dimmer using a mental-oxide-semiconductor field-effect transistor (MOSFET) for alternating-current (AC) directly driven light-emitting-diode (LED) lamp was presented. The control method of proposed dimmer is pulse width control (PWM) method. Compared with the conventional phase-controlled dimmer, the proposed PWM dimmer can produce sine wave and did not cause harmonics problem. Furthermore, the proposed control method did not amplify the light flicker due to the independence of input voltage. Therefore, the PWM dimmer can be used as the dimmer of the AC LED lamp instead of the conventional phase-controlled dimmer. The experimental result shows that the proposed PWM dimmer has good performances. 展开更多
关键词 alternating-current directly driven light-emitting-diode pulse width control total harmonic distortion flicker triac
下载PDF
Analysis on Lightning Strike Cause of Directly Buried Optical Cable in Wind Farm and Its Prevention Methods 被引量:3
13
作者 Yan YANG Zhen CHEN +3 位作者 Yixian QIU Yu HUANG Qiaobin WEI Shaojie YANG 《Meteorological and Environmental Research》 CAS 2022年第3期67-70,共4页
Directly buried metal optical cable is a form of erecting optical fiber ring network communication system in wind farms. Although the directly buried optical cable is much less than the overhead optical cable affected... Directly buried metal optical cable is a form of erecting optical fiber ring network communication system in wind farms. Although the directly buried optical cable is much less than the overhead optical cable affected by lightning, sometimes lightning damaging optical cable and flashover discharge accidents of optical cable port occurred. In this paper, the amplitude spectrum of lightning wave, the breakdown depth and breakdown distance of lightning wave to soil, the metal components of optical cable port and the impedance characteristics of grounding wire are systematically analyzed, and the prevention methods of directly buried optical cable in wind farm to avoid lightning damage are proposed. 展开更多
关键词 Wind farm directly buried optical cable Lightning stroke accident Prevention method
下载PDF
Disease modifying treatment of spinal cord injury with directly reprogrammed neural precursor cells in non-human primates 被引量:1
14
作者 Vladimir P Baklaushev Oleg V Durov +12 位作者 Vladimir A Kalsin Eugene V Gulaev Sergey V Kim Ilya L Gubskiy Veronika A Revkova Ekaterina M Samoilova Pavel A Melnikov Dzhina D Karal-Ogly Sergey V Orlov Alexander V Troitskiy Vladimir P Chekhonin Alexander V Averyanov Jan-Eric Ahlfors 《World Journal of Stem Cells》 SCIE 2021年第5期452-469,共18页
BACKGROUND The development of regenerative therapy for human spinal cord injury(SCI)is dramatically restricted by two main challenges:the need for a safe source of functionally active and reproducible neural stem cell... BACKGROUND The development of regenerative therapy for human spinal cord injury(SCI)is dramatically restricted by two main challenges:the need for a safe source of functionally active and reproducible neural stem cells and the need of adequate animal models for preclinical testing.Direct reprogramming of somatic cells into neuronal and glial precursors might be a promising solution to the first challenge.The use of non-human primates for preclinical studies exploring new treatment paradigms in SCI results in data with more translational relevance to human SCI.AIM To investigate the safety and efficacy of intraspinal transplantation of directly reprogrammed neural precursor cells(drNPCs).METHODS Seven non-human primates with verified complete thoracic SCI were divided into two groups:drNPC group(n=4)was subjected to intraspinal transplantation of 5 million drNPCs rostral and caudal to the lesion site 2 wk post injury,and lesion control(n=3)was injected identically with the equivalent volume of vehicle.RESULTS Follow-up for 12 wk revealed that animals in the drNPC group demonstrated a significant recovery of the paralyzed hindlimb as well as recovery of somatosensory evoked potential and motor evoked potential of injured pathways.Magnetic resonance diffusion tensor imaging data confirmed the intraspinal transplantation of drNPCs did not adversely affect the morphology of the central nervous system or cerebrospinal fluid circulation.Subsequent immunohistochemical analysis showed that drNPCs maintained SOX2 expression characteristic of multipotency in the transplanted spinal cord for at least 12 wk,migrating to areas of axon growth cones.CONCLUSION Our data demonstrated that drNPC transplantation was safe and contributed to improvement of spinal cord function after acute SCI,based on neurological status assessment and neurophysiological recovery within 12 wk after transplantation.The functional improvement described was not associated with neuronal differentiation of the allogeneic drNPCs.Instead,directed drNPCs migration to the areas of active growth cone formation may provide exosome and paracrine trophic support,thereby further supporting the regeneration processes. 展开更多
关键词 Direct cell reprogramming Neural precursor cells directly reprogrammed neural precursor cells Spinal cord injury Nonhuman primates Regenerative therapy Evoked potentials
下载PDF
The Impact of Directly Observed Therapy on Preventive Treatment for Latent Tuberculosis Infection among Students in Dalian, China 被引量:1
15
作者 CHEN Qi WANG Xue Mei +5 位作者 QI Yi LIU Xiao Fang JIANG Li Ping HOU Wen ZHOU Ling LU Xi Wei 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2015年第8期611-615,共5页
Preventive treatment has an essential effect on latent tuberculosis infection(LTBI)[purified protein derivative(PPD)induration≥15 mm].Between2010 and 2013,there were 6 tuberculosis(TB)outbreaks in the universities in... Preventive treatment has an essential effect on latent tuberculosis infection(LTBI)[purified protein derivative(PPD)induration≥15 mm].Between2010 and 2013,there were 6 tuberculosis(TB)outbreaks in the universities in Dalian,China.So far,in Dalian,the directly observed therapy(DOT)and 展开更多
关键词 TB The Impact of directly Observed Therapy on Preventive Treatment for Latent Tuberculosis Infection among Students in Dalian China
下载PDF
Research of variable speed directly driven SRG wind power system position sensorless based on DFNN by FEA 被引量:1
16
作者 YI Ling-zhi WANG Gen-ping WU Jiang-liao 《Journal of Coal Science & Engineering(China)》 2011年第1期107-112,共6页
A new method of switched reluctance wind power generation position sensorless based on DFNN by FEA was proposed, Through current and magnetic linkage to get the angle of SRG rotor position, the nonlinear mapping of cu... A new method of switched reluctance wind power generation position sensorless based on DFNN by FEA was proposed, Through current and magnetic linkage to get the angle of SRG rotor position, the nonlinear mapping of cur- rent-magnetic linkage-angle was built, By training these sample data from FEA, the angle of SRG rotor position was replaced by the output of DFNN to achieve SRG position sensorless. Simulation results show that the error between actual rotor position and estimate rotor position is small; SRG can commutate with great accuracy; and the output voltage of SRG wind power system under variable wind speed is essentially constant. 展开更多
关键词 variable speed directly driven switched reluctance generation(SRG) dynamical Fuzzy neuro-network(DFNN) finite element analysis(FEA)
下载PDF
Temperature-Dependent Photoluminescence Characteristics of InAs/GaAs Quantum Dots Directly Grown on Si Substrates
17
作者 王霆 刘会赟 张建军 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第4期52-55,共4页
The first operation of an electrically pumped 1.3μm InAs/GaAs quantum-dot laser was previously reported epitaxially grown on Si (100) substrate. Here the direct epitaxial growth condition of 1.3μm InAs/OaAs quantu... The first operation of an electrically pumped 1.3μm InAs/GaAs quantum-dot laser was previously reported epitaxially grown on Si (100) substrate. Here the direct epitaxial growth condition of 1.3μm InAs/OaAs quantum on a Si substrate is further investigated using atomic force microscopy, etch pit density and temperature-dependent photoluminescence (PL) measurements. The PL for Si-based InAs/GaAs quantum dots appears to be very sensitive to the initial OaAs nucleation temperature and thickness with strongest room-temperature emission at 40000 (17Onto nucleation layer thickness), due to the lower density of defects generated under this growth condition, and stronger carrier confinement within the quantum dots. 展开更多
关键词 GAAS INAS Temperature-Dependent Photoluminescence Characteristics of InAs/GaAs Quantum Dots directly Grown on Si Substrates of SI on
下载PDF
Widely Tunable Two-Section Directly Modulated DBR Lasers for TWDM-PON System
18
作者 周代兵 梁松 +2 位作者 韩良顺 赵玲娟 王圩 《Chinese Physics Letters》 SCIE CAS CSCD 2017年第3期38-40,共3页
Wavelength tunable and directly modulated distributed Bragg reflector (DBR) lasers with butt-joint technology are designed, fabricated and characterized. The DBR laser consists of a gain section and a DBR section. T... Wavelength tunable and directly modulated distributed Bragg reflector (DBR) lasers with butt-joint technology are designed, fabricated and characterized. The DBR laser consists of a gain section and a DBR section. To increase the electrical isolation between the gain section and the DBR section, parts of a p-doped material in the isolation region are etched off selectively. Over 2kΩ isolation resistance is realized ultimately without the need of ion implantation, which simplifies the fabrication process. The laser exhibits high speed modulation with a large tunable range. The 3dB direct modulation bandwidth of the device is over 8GHz in a 12nm tunable range. This widely tunable DBR laser with the simple structure is promising as a colorless light source for the next-generation time and wavelength division multiplexed passive optical network (TWDM-PON) systems. 展开更多
关键词 DBR PON Widely Tunable Two-Section directly Modulated DBR Lasers for TWDM-PON System
下载PDF
Synthesis,Structure and Optical Properties of CdO Nanocrystals Directly Grown on Cd Foil
19
作者 李勇 凌虹 +3 位作者 高磊 宋月丽 田明丽 周丰群 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第10期127-129,共3页
Semiconductor nanocrystals directly grown on the conducting metal can lower the contact resistance and can benefit the electron transfer between the semiconductor and the metal. In the present work, CdO nanocrystals a... Semiconductor nanocrystals directly grown on the conducting metal can lower the contact resistance and can benefit the electron transfer between the semiconductor and the metal. In the present work, CdO nanocrystals are directly synthesized on the conducting Cd foil through a simple solvothermal method. Cd foil is used as the Cd2+ source and the substrate. The average size of CdO nanocrystals is -23.1 nm by analyzing the XRD data. Moreover the growth mechanism is discussed. A hierarchic structure characterized by the nano rods and nano particles in the top and bottom layers, respectively, can be observed. From the UV-vis absorption analyzed by Taucs relation, the two different optical band gaps are obtained. The photoluminescence spectrum is obtained and studied. 展开更多
关键词 CDO Synthesis Structure and Optical Properties of CdO Nanocrystals directly Grown on Cd Foil
下载PDF
Improved modal truncation error in the directly analytical method for damage identification of frame structures
20
作者 Yang Youfa Xu Dian +1 位作者 Huang Jing Liang Wenguang 《Engineering Sciences》 EI 2010年第4期91-96,共6页
The damage identification is made by the numerical simulation analysis of a five-storey-and-two-span RC frame structure, using improved and unimproved direct analytical method respectively; and the fundamental equatio... The damage identification is made by the numerical simulation analysis of a five-storey-and-two-span RC frame structure, using improved and unimproved direct analytical method respectively; and the fundamental equations were solved by the minimal least square method (viz. general inverse method). It demonstrates that the feasibility and the accuracy of the present approach were impoved significantly, compared with the result of unimproved damage identification. 展开更多
关键词 frame structures the directly analytical method damage identification the modal truncation error the minimal least square method
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部