|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Large-area high quality PtSe2 thin film with versatile polarity显示文摘Two-dimensional(2D)materials have attracted increasing attention for their outstanding structural and electrical properties.However,for mass-production of field effect transistors(FETs)and potential applications in integrated circuits,large-area and uniform 2D thin films with high mobility,large on-off ratio,and desired polarity are needed to synthesize firstly.Here,a transfer-free growth method for platinum diselenide(PtSe2)films has been developed.The PtSe2 films have been synthesized with various thicknesses in centimeter-sized scale.Typical FET made from a few layer PtSe2 show p-type unipolar,with a high field-effect hole mobility of 6.2 cm^(2) V^(−1) s^(−1) and an on-off ratio of 5×10^(3).The versatile semimetal-unipolar-ambipolar transition in synthesized PtSe2 films is also firstly observed as the thickness thinning.This work realizes the large-scale preparation of PtSe2 with prominent electrical properties and provides a new strategy for polarity's modulation. | Wei Jiang Xudong Wang Yan Chen Guangjian Wu Kun Ba Ningning Xuan Yangye Sun Peng Gong Jingxian Bao Hong Shen Tie Lin Xiangjian Meng Jianlu Wang Zhengzong Sun | 2019 | InfoMat2019,1,2: | 5 |
| 2 | Diagenesis and Diagenetic Evolution of Deltaic and Neritic Gas-Bearing Sandstones in the Lower Mingyuefeng Formation of Paleogene, Lishui Sag, East China Sea Shelf Basin: Implications for Depositional Environments and Sequence Stratigraphy Controls显示文摘Gas-bearing deposits in the Lower Mingyuefeng Formation of Paleogene, Lishui Sag, East China Sea Shelf Basin consist of shoreface sandstones of the highstand systems tract(HST) and transgressive systems tract(TST), and deltaic sandstones of the lowstand systems tract(LST) and falling stage systems tract(FSST).Detailed petrographic observations suggest that the diagenetic features and related evolution of these deposits cannot be simply characterized and demonstrated in the depth domain.However, the occurrence of diagenetic minerals systematically depends on the studied interval within the HST, TST, LST, and FSST; therefore, diagenesis in this region can be better constrained when studied in the context of the depositional environments and sequence stratigraphic framework.The eogenetic processes in such settings include:(1) microcrystalline siderite precipitated as concretions in almost all environments and systems tracts, which inhibited further mechanical compaction;(2) grain dissolution and kaolinitization occurred in shoreface HST sandstones and deltaic LST and FSST sandstones;(3) glaucony was locally observed, which did not clearly reflect the controls of facies or sequence stratigraphy; and(4) cementation by pyrite aggregates occurred in the shoreface HST sandstones and deltaic LST sandstones.The mesogenetic diagenesis includes:(1) partial conversion of kaolinite into dickite in deltaic LST sandstones, and minor chlorite cementation in deltaic FSST sandstones;(2) transformation of kaolinite into illite and quartz cementation in deltaic LST and FSST sandstones;(3) frequent precipitation of ankerite and ferroan calcite in shoreface TST sandstones and early HST sandstones, forming baffles and barriers for fluid flow, with common calcite in shoreface HST sandstones as a late diagenetic cement; and(4) formation of dawsonite in the deltaic LST and FSST sandstones, which is interpreted to be a product of the invasion of a CO2-rich fluid, and acts as a good indicator of CO2-bearing reservoirs.This study has thus constructed a reliable conceptual model to describe the spatial and temporal distribution of diagenetic alterations.The results may provide an entirely new conceptual framework and methodology for successful gas exploration in the continental margins of offshore China, thus allowing us to predict and unravel the distribution and quality evolution of clastic reservoirs at a more detailed and reliable scale. | XU Fa ZHANG Penghui ZHANG Jinliang LIU Jinshui HOU Guowei ZHANG Ming LI Jingzhe LIU Shasha GUO Jiaqi MENG Ningning | 2015 | Acta Geologica Sinica(English Edition)2015,89,5: | 5 |
| 3 | CMOS-compatible all-optical modulator based on the saturable absorption of graphene显示文摘Graphene resting on a silicon-on-insulator platform offers great potential for optoelectronic devices.In the paper,we demonstrate all-optical modulation on the graphene-silicon hybrid waveguides(GSHWs)with tens of micrometers in length.Owing to strong interaction between graphene and silicon strip waveguides with compact light confinement,the modulation depth reaches 22.7%with a saturation threshold down to 1.38 pJ per pulse and a 30-μm-long graphene pad.A response time of 1.65 ps is verified by a pump-probe measurement with an energy consumption of 2.1 pJ.The complementary metal-oxide semiconductor compatible GSHWs with the strip configuration exhibit great potential for ultrafast and broadband all-optical modulation,indicating that employing two-dimensional materials has become a complementary technology to promote the silicon photonic platform. | HONG WANG NINGNING YANG LIMIN CHANG CHAOBIAO ZHOU SHIYU LI MENG DENG ZHENWEI LI QIANG LIU CHI ZHANG ZHIYONG LI YI WANG | 2020 | Photonics Research2020,8,4: | 4 |
| 4 | A C2-symmetric triple [5]helicene based on N-annulated triperylene hexaimide for chiroptical electronics显示文摘Two diastereoisomers(NTPH-P and NTPH-T1) as a C2-symmetric triple [5]helicene based on N-annulated triperylene hexaimide were synthesized.Aided by nuclear magnetic resonance spectroscopy(NMR) and theoretical calculations,NTPH-P was assigned to three-blade propeller conformation while NTPH-T1 tended to exhibit twisted conformation with pyrrole ring fusing on a bowl-shaped PDI foil.Characterized by circular dichroism(CD) and circular polarized luminescence(CPL) measurements,the enantiomerically pure NTPH-P exhibited fairly good chiral activities both in the absorption and emission range with dissymmetry factors |gabs| of 4.1×10^-3 and |glum| of 1.2×10^-3.The diastereoisomers were further employed as acceptors for organic solar cells with distinct PCEs of 8.11% and 5.24% for NTPH-P and NTPH-T1 based devices,respectively,signifying the prospects in chiroptical electronics by designing molecularly defined aromatics. | Zetong Ma Thorsten Winands Ningning Liang Dong Meng Wei Jiang Nikos L.Doltsinis Zhaohui Wang | 2020 | Science China Chemistry2020,63,2: | 2 |
| 5 | Low-voltage and high-gain WSe_(2)avalanche phototransistor with an out-of-plane WSe_(2)/WS_(2)heterojunction显示文摘The properties of photodetectors based on two-dimensional materials can be significantly enhanced by avalanche effect.However,a high avalanche breakdown voltage is needed to reach impact ionization,which leads to high power consumption.Here,we report the unique features of a low-voltage avalanche phototransistor formed by an in-plane WSe_(2)field effect transistor(FET)with an out-of-plane WSe_(2)/WS_(2)P–N heterojunction(HJ FET).The avalanche breakdown voltage in the device can be decreased from−31 to−8.5 V when compared with that in WSe_(2)FET.The inherent mechanism is mainly related to the redistributed electric field in the WSe_(2)channel after the formation of the out-of-plane P–N heterojunction.When the bias voltage is−16.5 V,the photoresponsivity in the HJ FET is enhanced from 1.5 to 135 A/W,which is significantly higher than that in the WSe_(2)FET because of the obvious reduction of the avalanche breakdown voltage.Moreover,HJ FET shows a higher responsivity than WSe_(2)FET in the range of 400–1,100 nm under low bias voltage.This phenomenon is caused by accelerating electron–hole spatial separation in the heterojunction.These results indicate that the use of an WSe_(2)FET with an out-of-plane WSe_(2)/WS_(2)heterojunction is ideal for high-performance photodetectors with low power consumption. | Lingyao Meng Ningning Zhang Maolong Yang Xixi Yuan Maliang Liu Huiyong Hu Liming Wang | 2023 | Nano Research2023,16,2: | 1 |
| 6 | Geochemistry of source rocks in the Es_3 and Es_4 members in the Shahejie Formation of the Western Depression, Liaohe Oilfield, China显示文摘The Western Depression of the Liaohe Basin is the major exploration area of the Liaohe Oilfield, and its main source rocks consist of the third and fourth members of the Shahejie Formation (Es3 and Es4). These source rocks are widely distributed in the depression, with semi-deep lake and fan delta as the main sedimentary facies, brown oil shale and black gray-dark gray mudstone as the main rocks, and a total thickness of 270-1450 m. The kerogens are mainly of the types I and IIA, and partly of the type IIB and least of the type III. The Ro values range from 0.4%-0.8%, indicating an evolution stage from immature to mature. The maturity of Es4 source rocks is rela-tively high, reaching the early mature stage, but their distribution and thickness are lower than those of Es3. Besides, according to biomarker analysis, it is thought that the source rocks of Es3 and Es4 are characterized by mixed input, and most of the source rocks were formed in the brackish water-saline and strongly oxygen-free environment. Fur-thermore, the Qingshui, Niuxintuo and Chenjia sags are believed to possess greater potential for hydrocarbon gen-eration and expulsion, for they are source rocks with a larger thickness, have higher organic carbon contents, belong to better organic matter types and possess higher maturities. | WANG Weili LIU Luofu JIANG Zhenxue ZHONG Ningning WANG Ying WANG Ping WU Lin MENG Jianghui ZHOU Jieli GUO Yongqiang | 2011 | Chinese Journal Of Geochemistry2011,30,4: | 1 |
| 7 | Determination of rimantadine in rat plasma by liquid chromatography/electrospray mass spectrometry and its application in a pharmacokinetic study显示文摘 | Meijuan Xu Wenzheng Ju Xiaoyan Xia Hengshan Tan Min Chen Jun Zhang Ningning Xiong Meng Jiang Lei Chen Lixiu Gong | 2008 | Journal of Chromatography B2008,,1: | 1 |
| 8 | A novel long-term intravenous combined with local treatment with human amnion-derived mesenchymal stem cells for a multidisciplinary rescued uremic calciphylaxis patient and the underlying mechanism显示文摘Calciphylaxis is a rare disease characterized histologically by microvessel calcification and microthrombosis,with high mortality and no proven therapy.Here,we reported a severe uremic calciphylaxis patient with progressive skin ischemia,large areas of painful malodorous ulcers,and mummified legs.Because of the worsening symptoms and signs refractory to conventional therapies,treatment with human amnion-derived mesenchymal stem cells(hAMSCs)was approved.Preclinical release inspections of hAMSCs,efficacy,and safety assessment,including cytokine secretory ability,immunocompetence,tumorigenicity,and genetics analysis in vitro,were introduced.We further performed acute and long-term hAMSC toxicity evaluations in C57BL/6 mice and rats,abnormal immune response tests in C57BL/6 mice,and tumorigenicity tests in neonatal Balbc-nu nude mice.After the preclinical research,the patient was treated with hAMSCs by intravenous and local intramuscular injection and external supernatant application to the ulcers.When followed up to 15 months,the blood-based markers of bone and mineral metabolism improved,with skin soft tissue regeneration and a more favorable profile of peripheral blood mononuclear cells.Skin biopsy after 1-month treatment showed vascular regeneration with mature noncalcified vessels within the dermis,and 20 months later,the re-epithelialization restored the integrity of the damaged site.No infusion or local treatment-related adverse events occurred.Thus,this novel long-term intravenous combined with local treatment with hAMSCs warrants further investigation as a potential regenerative treatment for uremic calciphylaxis due to effects of inhibiting vascular calcification,stimulating angiogenesis and myogenesis,anti-inflammatory and immune modulation,multidifferentiation,re-epithelialization,and restoration of integrity. | Lianju Qin Jing Zhang Yujie Xiao Kang Liu Yugui Cui Fangyan Xu Wenkai Ren Yanggang Yuan Chunyan Jiang Song Ning Xiaoxue Ye Ming Zeng Hanyang Qian Anning Bian Fan Li Guang Yang Shaowen Tang Zhihong Zhang Juncheng Dai Jing Guo Qiang Wang Bin Sun Yifei Ge Chun Ouyang Xueqiang Xu Jing Wang Yaoyu Huang Hongqing Cui Jing Zhou Meilian Wang Zhonglan Su Yan Lu Di Wu Jingping Shi Wei Liu Li Dong Yinbing Pan Baiqiao Zhao Ying Cui Xueyan Gao Zhanhui Gao Xiang Ma Aiqin Chen Jie Wang Meng Cao Qian Cui Li Chen Feng Chen Youjia Yu Qiang Ji Zhiwei Zhang Mufeng Gu Xiaojun Zhuang Xiaolin Lv Hui Wang Yanyan Pan Ling Wang Xianrong Xu Jing Zhao Xiuqin Wang Cuiping Liu Ningxia Liang Changying Xing Jiayin Liu Ningning Wang | 2022 | Journal of Molecular Cell Biology2022,14,2: | 1 |
| 9 | Clinical characteristics and treatments of cap polyposis:a single center case series显示文摘Introduction Cap polyposis is a rare benign disease of the digestive tract,characterized by inflammatory polyps with a cap of inflammatory granulation tissue.First described in 1985 by Williams et al.[1],cap polyposis is now still introduced in case reports.The clinical course and pathogenesis of this disease are yet to be elucidated and specific therapies have not been established. | Yanhua Zhou Rui Cheng Ningning Dong Ying Meng Chuntao Liu Ye Zong | 2023 | Gastroenterology Report2023,11,1: | 0 |
| 10 | Symmetry-Induced Orderly Assembly Achieving High-Performance Perylene Diimide-Based Nonfullerene Organic Solar Cells显示文摘Controllable assembly of organic semiconductors has opened an avenue for an in-depth perception of their structure–property relationships;however,a detailed investigation of their molecular controllability remains challenging.Discerning the assembly of organic semiconductors could enable the attainment of a significant improvement of performance. | Shangshang Chen Dong Meng Jiachen Huang Ningning Liang Yan Li Feng Liu He Yan Zhaohui Wang | 2021 | CCS Chemistry2021,3,8: | 0 |
| 11 | ON THE BOUNDEDNESS OF A CLASS OF NONLINEAR DYNAMIC EQUATIONS OF THE THIRD ORDER显示文摘In this paper, a modified nonlinear dynamic inequality on time scales is used to study the boundedness of a class of nonlinear third-order dynamic equations on time scales. These theorems contain as special cases results for dynamic differential equations, difference equations and q-difference equations. | Ningning Zhu Fanwei Meng | 2017 | Annals of Applied Mathematics2017,33,1: | 0 |
| 12 | Percolation-induced resistivity drop in lutetium dihydride with controllable electrical conductivity over six orders of magnitude显示文摘The recent report of near-ambient superconductivity in the nitrogen-doped lutetium hydride has attracted considerable attention.Subsequent follow-up studies confirmed the pressure-induced color changes in both N-free and N-doped LuH_(2) but failed to reproduce superconductivity. It remains a puzzle why the samples in the original report exhibited pronounced resistance anomaly reminiscent of the superconducting transition. Here, we show that percolation of metallic grains with high conductivity through the insulating surfaces in cold-pressed LuH_(2) samples can occasionally produce sharp resistance drops, which even display magnetic field and/or current dependences but stay far from zero resistance. The insulating surface of LuH2grain should be attributed to the modification of hydrogen stoichiometry or the contamination by oxygen/nitrogen, resulting in an increase of resistance by over six orders of magnitude. Such an effect is more significant than that discovered recently in LaH_(3±x), which may indicate that LuH_(2) can be a potential superionic conductor. Our results call for caution in asserting the resistivity drops as superconductivity and invalidate the background subtraction in analyzing the corresponding resistance data. | Ningning Wang Jun Hou Ziyi Liu Tenglong Lu Pengfei Shan Congcong Chai Shifeng Jin Liang Ma Lifen Shi Xiao Wang Youwen Long Yue Liu Hua Zhang Xiaoli Dong Sheng Meng Miao Liu Jinguang Cheng | 2023 | Science China(Physics,Mechanics & Astronomy)2023,66,9: | 0 |
| 13 | Prevalence and risk factors for minimal hepatic encephalopathy in cirrhotic patients with different etiologies显示文摘Aims:Minimal hepatic encephalopathy(MHE)significantly affects the prognosis of patients with cirrhosis.This study was performed to determine whether there is a difference in the prevalence of MHE among patients with cirrhosis of different etiologies and whether the etiology directly influences the occurrence of MHE.Methods:This multicenter,cross-sectional study enrolled 1879 patients with confirmed cirrhosis at 40 hospitals from October 25,2021,to January 10,2023(Trial registration:http://gffzzd3f38a9638994581swponkf0k06qp6uvu.ffgz.tsg.suse.edu.cn/[NCT05140837]).The patients'demographics,etiologies of cirrhosis,and laboratory test results were collected.The psychometric hepatic encephalopathy score(PHES)was determined in all patients to screen for MHE.Multivariate logistic analyses were performed to identify the risk factors for MHE.Results:In total,736 patients with cirrhosis were analyzed.The prevalence of MHE was 42.0%(n=309).The primary etiology among all patients was hepatitis B virus(HBV)-related cirrhosis(71.9%[529/736]).The prevalence of MHE was significantly higher in patients with alcoholic cirrhosis(57.1%[40/70])than in those with HBV-related cirrhosis(40.6%[215/529],p=0.009)or hepatitis C virus(HCV)-related cirrhosis(38.2%[26/68],p=0.026).Age(odds ratio[OR],1.042;95%confidence interval[CI],1.024-1.059;p<0.001),duration of education(OR,0.935;95%CI,0.899-0.971;p=0.001),etiology(OR,1.740;95%CI,1.028-2.945;p=0.039),and high MELD-Na scores(OR,1.038;95%CI,1.009-1.067;p=0.009)were independent risk factors for MHE.When patients with cirrhosis of different etiologies were analyzed separately,the results showed that age(OR,1.035;95%CI,1.014-1.057;p=0.001)and duration of education(OR,0.924;95%CI,0.883-0.966;p=0.001)were risk factors for MHE among patients with HBV-related cirrhosis,whereas age(OR,1.138;95%CI,1.033-1.254;p=0.009)and creatinine concentration(OR,16.487;95%CI,1.113-244.160;p=0.042)were risk factors for MHE in patients with HCV-related cirrhosis.No risk factors for MHE were found in patients with autoimmune cirrhosis.For patients with alcoholic cirrhosis,the platelet count(OR,1.014;95%CI,1.000-1.027;p=0.045)was a risk factor for MHE.The PHES subtest results were inconsistent among patients who had MHE with cirrhosis of different etiologies.Patients with HBV-related cirrhosis performed better on Number Connection Test B and the serial dotting test than those with alcoholic cirrhosis(p=0.007 and p<0.001),better on Number Connection Test B than those with HCV-related cirrhosis(p=0.020),and better on the line tracing test than those with autoimmune cirrhosis(p=0.037).Conclusion:The etiology of cirrhosis affected the prevalence of MHE and risk factors for MHE.The domains of major cognitive impairment varied among patients with cirrhosis of different etiologies.Further studies are required to verify these findings. | Xiaoyan Li Shanghao Liu Huiling Xiang Qingge Zhang Ying Guo Hongmei Zu Jing Wang Jiaojian Lv Xiaoning Zhang Fanping Meng Jiahuan Li Jie Li Yangzhen Bianba Jia Shang Guo Zhang Fei Liu Zhaowei Tong Chuang Lei Wei Ye Qiaohua Yang Ningning Wang Ying Song Wei Fu Ziyue Li Yanjing Gao Yongping Zhang Jiafang Chen Caiyun Wu Qi Zheng Fang Wang Jiali Yu Lianjie Lin Chuanlong Yang Xiaoting Yang Xiaomin Ye Xiangmei Wang Xuelan Zhao Xiaolong Qi Fusheng Wang Junliang Fu | 2023 | Portal Hypertension & Cirrhosis2023,2,4: | 0 |
| 14 | Development of a duplex real-time PCR method for the detection of influenza C and D viruses显示文摘Influenza viruses are major respiratory pathogens known to infect human and a variety of animals and are widely prevalent worldwide.Genome structure of influenza D virus(IDV)is identical to that of influenza C virus(ICV),and phylogenetic analyses suggest that IDV and ICV share a common ancestry and high homology.To date,the prevalence of ICV and IDV in China is unclear,but these viruses represent a potential threat to public health due to cross-species transmission and zoonotic potential.To efficiently monitor ICV and IDV,it is necessary to establish a dual detection method to understand their prevalence and conduct in-depth research.A duplex real-time PCR method for the simultaneous detection of ICV and IDV was developed.TaqMan fluorescent probes and specific primers targeting NP gene of ICV and PB1 gene of IDV were designed.This method exhibited good specificity and sensitivity,and the detection limit reached 1 × 10^(1) copies/pL of plasmid standards of each pathogen.Thirty-one clinical swine samples and 10 clinical cattle samples were analyzed using this method.One positive sample of IDV was detected,and the accuracy of clinical test results was verified by conventional PCR and DNA sequencing.The duplex real-time PCR detection method represents a sensitive and specific tool to detect IG/and IDV,It provides technical support for virus research and clinical diagnosis of ICV and IDV.This information will benefit animal and human health. | Letian Zhang Meng Lu Jiaxuan Lu Ningning Wang Zhongzhou Pan Shuo Su | 2021 | Animal Diseases2021,1,3: | 0 |
| 15 | Atomically precise coreless AuCu bimetallic nanoclusters for Ullmann C-O coupling显示文摘Bimetallic nanocluster with atomic precision has gained widespread attention due to its unique synergism.The coreless Au_(4)Cu_(5)bimetallic nanoclusters were selected as models to explore the relationship between their microstructure and performance,and compare with the coreless monometallic nanoclusters,core–shell nanoclusters,and single atom catalyst(SAC).The experimental results show that the coreless bimetallic nanocluster catalyst Au_(4)Cu_(5)/activated carbon(AC)exhibits high activity and stability in the Ullmann C–O coupling reaction,much higher than coreless monometallic nanoclusters(Au_(11)/AC and Cu_(11)/AC),core–shell nanoclusters(Au_(25)/AC,Cu_(25)/AC,and Au_(1)Cu_(24)/AC),and single atom catalysts(Au SAC and Cu SAC).Moreover,the coreless Au_(4)Cu_(5)/AC catalyst efficiently catalyzed the Ullmann C–O coupling of benzyl alcohol for the first time.This structure–activity relationship was successfully extended to other coreless bimetallic systems,such as Au_(4)Cu_(4)/AC nanocluster,and it is expected to provide new insights for the design of bimetallic catalysts with well-defined performance. | Yapei Yun Lin Li Manman Zhou Meng Li Ningning Sun Haifeng Li Shan Jin Chunshan Zuo Hongting Sheng Manzhou Zhu | 2023 | Nano Research2023,16,8: | 0 |
| 16 | Primary central nervous system lymphoblastic B cell lymphoma located at cerebellum in a child: A case report and literature review显示文摘Introduction:Primary central nervous system lymphoma(PCNSL)is extremely rare in pediatric population.We reported a case of PCNSL in a 3-year-old girl and reviewed the literature in the past three decades.Case presentation:A 3-year-old girl presented with gait disturbance.A contrast-enhanced magnetic resonance image of the brain showed a solitary bulky mass in the left cerebellar hemisphere,hydrocephalus and cerebellar tonsillar hernia.Surgical resection was performed and the patient was diagnosed with primary central nervous system lymphoblastic B cell lymphoma.Then the patient received regular chemotherapy,including 6 cycles of chemotherapy containing high-dose methotrexate(HD-MTX).The patient remains alive 15 months after the diagnosis with no evidence of active disease,but suffered twice chronic subdural hematoma,which was treated by burr hole drainage.Conclusion:Lymphoblastic B cell lymphoma is a rare histologic subtype of pediatric PCNSL.Chemotherapy containing HD-MTX remains the most effective treatment.The patient should avoid head impact after surgical resection of the tumor to prevent chronic subdural hematoma. | Xueliang Yang Yanlong Duan Chunju Zhou Ling Jin Ningning Zhang Shuang Huang Meng Zhang Jing Yang Yonghong Zhang | 2021 | Pediatric Investigation2021,5,4: | 0 |
| 17 | Syntheses and Antiproliferative Evaluation of 6-Thienyl, 6-Polyphenyl Aryl and 6-Naphthyl Derivatives of 2,4-Diaminopyrido [3,2-d] pyramidine as Non-classical Antifolate Targeting DHFR显示文摘 | YANG Jiajia WANG Meng LI Xia FAN Ningning XUE Liangmin LI Hao TIAN Chao WANG Xiaowei LIU Junyi ZHANG Zhili | 2017 | Chemical Research in Chinese Universities2017,33,4: | 0 |
| 18 | On-chip ultrafast pulse generation based on graphene-silicon hybrid waveguides显示文摘On-chip ultrafast mode-locking lasers are basic building blocks for the realization of a chip-based optical frequency comb.In this paper,an ultrafast saturable absorber made up of a graphene pad on top of a silicon waveguide is applied to implement an ultrafast pulse laser.Benefiting from the small mode area of the graphene/silicon hybrid waveguide,the saturable pulse energy is reduced by two orders of magnitude compared with the fiber.A mode-locked pulse with a duration of 542 fs and a repetition rate of 54.37 MHz is realized.Pump–probe measurement shows that the carrier relaxation process of free carrier recombination with atomic-thin graphene/silicon junctions is three orders of magnitude faster than silicon,which plays a fundamental role in pulse narrowing.The chip-scale silicon ultrafast laser lays a foundation for a new class of nonlinear devices,in which a combination with multiple functional silicon photonic circuits enables efficient nonlinear interaction at the micrometer scale and less than 1 W of power consumption. | MENG DENG ZICHUN LIAO YANKAI CHEN NINGNING YANG XU YAN CHI ZHANG NENGLI DAI YI WANG | 2021 | Photonics Research2021,9,9: | 0 |
| 19 | Seamless Indoor-Outdoor Switching Localization Algorithm based on CKF显示文摘To solve the problem of large positioning error and discontinuous positioning of special forces members when moving in cross-region indoors and outdoors, and to compensate for the linearization error and local convergence problem that may exist in the extended Kalman filter(EKF)in nonlinear systems, that is,the iterative results may be trapped in a local optimum situation, a seamless indoor-outdoor switching localization algorithm based on cubature Kalman filter (CKF) is proposed. CKF does not require the computation of Jacobian matrices, which can improve computational efficiency and filtering accuracy to a certain extent. In the system, an inertial measurement unit (IMU) is employed to correct the positioning errors of ultra-wideband (UWB)and BeiDou navigation satellite system(BDS).The positioning data from UWB and BeiDou in cross-region are weighted fused and then fused with the data from the IMU using CKF to obtain the final accurate positioning information. This study designs a scene-switching mechanism to achieve seamless switching between indoor and outdoor positioning scenes. By jointly analyzing the positioning accuracy of UWB and BeiDou,the positioning scene is determined, and appropriate counting thresholds are set to avoid frequent erroneous scene switches. Experimental results show that the proposed algorithm achieves a positioning accuracy of approximately 21.7 cm in cross-region,which can enable seamless integration of indoor and outdoor positioning,avoid positioning jumps, and enhance positioning accuracy. | Gang Yang Guodong Hou Ningning Feng Weida Meng | 2024 | Journal of Communications and Information Networks2024,9,1: | 0 |
| 20 | Simulation on Peak-to-Average Power Ratio for Orthogonal Frequency Division Multiplexing显示文摘Clipping is a simple and convenient PAPR (peak-to-average power ratio) reduction method for high speed OFDM (orthogonal frequency division multiplexing) communication system. In this paper, we propose a new PAPR reduction method for Wireless-MAN(metropolitan area network)-OFDM system based on IEEE 802.16, which is over-sampling clipping arithmetic. Simulation and performance of the over-samples clipping’s PAPR reduction capability, BER effect is given. The simulation indicates that the PAPR of at least 99.9% OFDM symbol is below 6dB after 2 Nyquist rate clipping, and the performance of BER has 1dB SNR(signal noise ratio) loss. The results prove that this method has better capacity to reducing PAPR. So it can be well used in WMAN-OFDM system. | SHAN Weifeng MENG Baohong LIU Ningning LI Hui ZHANG Hongwei | 2006 | Wuhan University Journal of Natural Sciences2006,11,6: | 0 |