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| 1 | Optical frequency divider with division uncertainty at the 10^(-21) level显示文摘Optical clocks with unprecedented accuracy of 10^(-18) promise innovations in many research areas.heir applications rely to a large extent on the ability of precisely converting the frequency from one optical clock to another,or particularly to the frequencies in the iber telecom band for long-distance transmission.his report demonstrates a low-noise,high-precision optical frequency divider,which realizes accurate optical frequency conversion and enables precise measurement of optical frequency ratios.By measuring against the frequency ratio between the fundamental and the second harmonic of a 1064-nm laser instead of a second copy of the same system,we demonstrate that the optical frequency divider has a fractional frequency division instability of 6×10^(-19) at 1 s and a fractional frequency division uncertainty of 1.4×10^(-21).he remarkable numbers can support frequency division of the best optical clocks in the world without frequency-conversion-caused degradation of their performance. | Yuan Yao Yanyi Jiang Hongfu Yu Zhiyi Bi Longsheng Ma | 2016 | National Science Review2016，3，4： | 3 |
| 2 | Progress and trend of narrow-linewidth lasers显示文摘High frequency stability, narrow-linewidth lasers have been long dreamed of since the invention of the laser. They have recently developed dramatically due to the advent of optical clocks. State-of-the-art narrow-linewidth lasers have been constructed by using the Pound-Drever-Hall (PDH) technique to lock the laser frequencies to the resonance of ultra-stable external optical cavities with high finesse. This paper introduces the developments of narrow-linewidth lasers, with a focus on the improvements of length stability of optical reference cavities, including optical cavity designs of vibration insensitivity and low thermal noise. Future trends and alternative methods for narrow-linewidth lasers are also discussed. | CHEN HaiQin JIANG YanYi BI ZhiYi MA LongSheng | 2013 | Science China(Technological Sciences)2013，56，7： | 3 |
| 3 | Optical frequency division显示文摘Frequency can be measured much more precisely than any other physical quantity,and much of precision metrology depends critically on the measurement of frequency and its inverse,timeinterval.Optical electromagnetic waves(or‘light’),oscillating at more than 1014 per second,are at least 1000 times more precise for tim e/length measurement compared to microwave frequencies near 1 GHz.However,electronics do not respond to such rapid optical oscillations.Thus,optical frequencies cannot be measured directly,and must be divided down to the radiofrequency(RF)regime for electronic counting.It has been a historical challenge to realize optical frequency division with arbitrary divisors.In the 1970s;the absolute frequency of a methane-stabilized He-Ne laser was measured by dividing its frequency to the RF region with a frequency chain based on many nonlinear frequency conversions.By measuring the laser frequency,the measurement accuracy of the velocity of light was improved 100 times[1]. | Yuan Yao Yanyi Jiang Longsheng Ma | 2020 | National Science Review2020，7，12： | 2 |
| 4 | Optical frequency synthesizer referenced to an ytterbium optical clock显示文摘Optical clocks with an unprecedented accuracy of 10-18 promise innovations in precision spectroscopy and measurement. To harness the full power of optical clocks, we need optical frequency synthesizers(OFSs) to accurately convert the stabilities and accuracies of optical clocks to other desired frequencies. This work demonstrates such an OFS referenced to an ytterbium optical clock. The OFS is based on an optical frequency comb phase-locked to a commercial rubidium microwave clock;in this way most combs can operate robustly. Despite comb frequency instability at 10^(-11), the synthesis noise and uncertainty reach 6 × 10^(-18)(1 s) and 5 × 10^(-21), respectively, facilitating frequency synthesis of the best optical clocks. In the OFS, the coherence of the OFS internal oscillator at 1064 nm is accurately transferred to a 578 nm laser for resolving the hertz-level-linewidth ytterbium clock transition(unaffected by megahertz-linewidth comb lines) and faithfully referencing the OFS to an ytterbium optical clock. | YUAN YAO BO LI GUANG YANG XIAOTONG CHEN YAQIN HAO HONGFU YU YANYI JIANG LONGSHENG MA | 2021 | Photonics Research2021，9，2： | 1 |
| 5 | Effects of Different Picking Time and Different Geographical Provenances on Oil Content of Camellia oleifera显示文摘This paper studied effects of different picking time and different geographical provenances on oil content of Camellia oleifera. The results showed that different picking time had significant effects on the oil content of cold dew seeds and frost's descent seeds. With the delay of picking time,the oil content of cold dew seeds,frost's descent seeds,dry seeds and oil content of seed kernels were significantly increased.There was a significantly positive correlation between the oil content of fresh fruit of cold dew seeds and frost's descent seeds and the dry seed yield of fresh seeds and the oil content of fresh fruit( P < 0. 05),and the correlation coefficient was greater than 0. 85. Besides,the oil content of seed kernels of cold dew seeds was closely correlated with the seed yield of fresh seeds,oil content of fresh fruit,and oil content of fresh seeds. In the process of C. oleifera breeding,the thin coat,high seed yield and high oil content can be taken as the key research directions for future breeding. The oil content of ordinary C. oleifera seeds in 18 counties( cities) was 36. 42%-63. 33%,indicating that there were significant differences in the oil content of C. oleifera in different geographical provenances. In conclusion,according to the study of different picking time,the recommended picking time of cold dew seeds in Hunan area is around October 10,while the best picking time of frost's descent seeds is about October 30. The oil content of C. oleifera fruit in different geographical provenances is quite different. During the development of C. oleifera fruit,the cultivation and management of C. oleifera should be strengthened to increase the oil content of C. oleifera. | Xiaoqin MO Zhen ZHANG Yongzhong CHEN Yanming XU Yinghe PENG Longsheng CHEN Li MA Rui WANG Shaofeng PENG Zhigang LI Xiangnan WANG Meiqun LI Wei TANG | 2018 | Asian Agricultural Research2018，10，10： | 1 |
| 6 | Observation of Collimated Atoms by Light Pressure Force in Absorption Cell显示文摘Experimental observation of laser cooling and collimation of moving atoms in an absorption cell by light pressure force of an intense standing light wave field is reported.The hyper fine structure of atomic sodium has been observed due to the cooled and collimated atoms.The mechanism of laser cooling and collimation of atoms is discussed. | WANG Yuzhu YE Chao WU Yongsheng WANG Xiaojuan ZHOU Shanyu CHENG Yudan MA Longsheng DING Liangen | 1993 | Chinese Physics Letters1993，10，4： | 0 |
| 7 | Design, Synthesis and Antitumor Activity of Novel 6,7-Dimethoxyquinazoline Derivatives Containing Diaryl Urea Moiety显示文摘 | HOU Yunlei WU Shasha MA Longsheng BAI Jinying LIU Zijian ZHAO Yanfang | 2015 | Chemical Research in Chinese Universities2015，31，5： | 0 |
| 8 | Transcriptome analysis reveals a potential regulatory mechanism of the lnc-5423.6/IGFBP5 axis in the early stages of mouse thymic involution显示文摘Age-related thymic involution is one of the significant reasons for induced immunity decline.Recent evidence has indicated that lncRNAs are widely involved in regulating organ development.However,the lncRNA expression profiles in mouse thymic involution have not been reported.In this study,we collect mouse thymus at the ages of 1 month,3 months,and 6 months for sequencing to observe the lncRNA and gene expression profiles in the early stages of thymic involution.Through bioinformatics analysis,a triple regulatory network of lncRNA-miRNA-mRNA that contains 29 lncRNAs,145 miRNAs and 12 mRNAs that may be related to thymic involution is identified.Among them,IGFBP5 can reduce the viability,inhibit proliferation and promote apoptosis of mouse medullary thymic epithelial cell line 1(MTEC1)cells through the p53 signaling pathway.In addition,miR-193b-3p can alleviate MTEC1 cell apoptosis by targeting IGFBP5.Notably,lnc-5423.6 can act as a molecular sponge of miR-193b-3p to regulate the expression of IGFBP5.In summary,lnc-5423.6 enhances the expression of IGFBP5 by adsorption of miR-193b-3p,thereby promoting MTEC1 cell apoptosis. | Bingxin Li Yaqiong Ye Longsheng Hong Wanyan Li Qingru Wu Wenjun Liu Yongjiang Ma Danning Xu Yugu Li | 2023 | Acta Biochimica et Biophysica Sinica2023，55，4： | 0 |
| 9 | Optical heterodyne-Zeeman modulation magnetic rotation spectroscopic technique显示文摘Optical heterodyne detection using 500 MHz phase modulation was combined with the Zeeman modulation-magnetic rotation spectroscopy (ZM-MRS) to form a new spectroscopic technique, which effectively reduced the amplitude fluctuation from laser source and greatly improved the signal-to-noise ratio in the detection of transient molecules. | Yangqin Chen Zhiyi Bi Peipei Cai Jingxin Ding Rongjun Wang Jingjing Lu Longsheng Ma | 1999 | Chinese Science Bulletin1999，44，20： | 0 |
| 10 | Comparison of mini-probe endoscopic ultrasonography with computed tomography scan in preoperative staging of esophageal cancer显示文摘Objective:To compare mini-probe endoscopic ultrasonography(MCUS)with computed tomography(CT)in pre-operative T and N staging of esophageal cancer,and to find out the MCUS parameters to judge lymph nodes metastasis for esophageal cancer.Methods:Thirty-five patients received both MCUS and CT preoperatively,on both of which the T and N stages were determined.The accuracy,sensitivity,specificity,positive predicting value and negative predicting value were compared with the postoperative pathological results.Results:The accuracy of MCUS was 85.7% in T staging and 85.7% and 80.0% in N staging by two different methods,which were 45.7% and 74.3%,respectively,by CT.Conclusion:MCUS is better than CT in preoperative staging for esophageal cancer.The ratio of short to long axis(S/L)combined with short axis is a useful way to determine lymph nodes metastasis. | Hong Hu Jiaqing Xiang Yawei Zhang Jie Chen Yajia Gu Longsheng Miao Longfei Ma | 2006 | The Chinese-German Journal of Clinical Oncology2006，5，6： | 0 |
| 11 | High-quality Fagopyrum esculentum genome provides insights into the flavonoid accumulation among different tissues and self-incompatibility显示文摘Common buckwheat(Fagopyrum esculentum)and Tartary buckwheat(Fagopyrum tataricum),the two most widely cultivated buckwheat species,differ greatly in flavonoid content and reproductive mode.Here,we report the first high-quality and chromosome-level genome assembly of common buckwheat with 1.2 Gb.Comparative genomic analysis revealed that common buckwheat underwent a burst of long terminal repeat retrotransposons insertion accompanied by numerous large chromosome rearrangements after divergence from Tartary buckwheat.Moreover,multiple gene families involved in stress tolerance and flavonoid biosynthesis such as multidrug and toxic compound extrusion(MATE)and chalcone synthase(CHS)underwent significant expansion in buckwheat,especially in common buckwheat.Integrated multi-omics analysis identified high expression of catechin biosynthesis-related genes in flower and seed in common buckwheat and high expression of rutin biosynthesis-related genes in seed in Tartary buckwheat as being important for the differences in flavonoid type and content between these buckwheat species.We also identified a candidate key rutindegrading enzyme gene(Ft8.2377)that was highly expressed in Tartary buckwheat seed.In addition,we identified a haplotype-resolved candidate locus containing many genes reportedly associated with the development of flower and pollen,which was potentially related to self-incompatibility in common buckwheat.Our study provides important resources facilitating future functional genomics-related research of flavonoid biosynthesis and selfincompatibility in buckwheat. | Qiang He Dan Ma Wei Li Longsheng Xing Hongyu Zhang Yu Wang Cailian Du Xuanzhao Li Zheng Jia Xiuxiu Li Jianan Liu Ze Liu Yuqing Miao Rui Feng Yang Lv Meijia Wang Hongwei Lu Xiaochen Li Yao Xiao Ruyu Wang Hanfei Liang Qinghong Zhou Lijun Zhang Chengzhi Liang Huilong Du | 2023 | Journal of Integrative Plant Biology2023，65，6： | 0 |
| 12 | Magnetic resonance-guided focused ultrasound for essential tremor:a prospective,single center,single-arm study显示文摘The safety and effectiveness of magnetic resonance-guided focused ultrasound thalamotomy has been broadly established and validated for the treatment of essential tremor.In 2018,the first magnetic resonance-guided focused ultrasound system in Chinese mainland was installed at the First Medical Center of the PLA General Hospital.This prospective,single center,open-label,single-arm study was part of a worldwide prospective multicenter clinical trial(ClinicalTrials.gov Identifier:NCT03253991)conducted to confirm the safety and efficacy of magnetic resonance-guided focused ultrasound for treating essential tremor in the local population.From 2019 to 2020,10 patients with medication refractory essential tremor were recruited into this open-label,single arm study.The treatment efficacy was determined using the Clinical Rating Scale for Tremor.Safety was evaluated according to the incidence and severity of adverse events.All of the subjects underwent a unilateral thalamotomy targeting the ventral intermediate nucleus.At the baseline assessment,the estimated marginal mean of the Clinical Rating Scale for Tremor total score was 58.3±3.6,and this improved after treatment to 23.1±6.4 at a 12-month follow-up assessment.A total of 50 adverse events were recorded,and 2 were defined as serious.The most common intraoperative adverse events were nausea and headache.The most frequent postoperative adverse events were paresthesia and equilibrium disorder.Most of the adverse events were mild and usually disappeared within a few days.Our findings suggest that magnetic resonance-guided focused ultrasound for the treatment of essential tremor is effective,with a good safety profile,for patients in Chinese mainland. | Rui Zong Xuemei Li Chunyu Yin Jianfeng He Dekang Zhang Xiangbing Bian Lichao Huang Jiayou Zhou Zhipei Ling Lin Ma Xin Lou Longsheng Pan Xinguang Yu | 2024 | Neural Regeneration Research2024，19，9： | 0 |
| 13 | Wearable multilead ECG sensing systems using on-skin stretchable and breathable dry adhesives显示文摘Electrocardiogram(ECG)monitoring is used to diagnose cardiovascular diseases,for which wearable electronics have attracted much attention due to their lightweight,comfort,and long-term use.This study developed a wearablemultilead ECG sensing system with on-skin stretchable and conductive silver(Ag)-coated fiber/silicone(AgCF-S)dry adhesives.Tangential and normal adhesion to pigskin(0.43 and 0.20 N/cm2,respectively)was optimized by the active control of fiber density and mixing ratio,resulting in close contact in the electrode–skin interface.The breathableAgCF-S dry electrodewas nonallergenic after continuous fit for 24 h and can be reused/cleaned(>100 times)without loss of adhesion.The AgCF encapsulated inside silicone elastomers was overlapped to construct a dynamic network under repeated stretching(10%strain)and bending(90°)deformations,enabling small intrinsic impedance(0.3,0.1 Hz)and contact impedance variation(0.7 k)in high-frequency vibration(70 Hz).All hard/soft modules of the multilead ECG system were integrated into lightweight clothing and equipped with wireless transmission for signal visualization.By synchronous acquisition of I–III,aVR,aVL,aVF,and V4 lead data,the multilead ECG sensing system was suitable for various scenarios,such as exercise,rest,and sleep,with extremely high signal-to-noise ratios. | Yingxi Xie Longsheng Lu Wentao Wang Huan Ma | 2024 | Bio-Design and Manufacturing2024，7，2： | 0 |
| 14 | Physical and mechanical properties of hydroponic lettuce for automatic harvesting显示文摘To design an automatic harvesting machine for hydroponic lettuce(Lactuca sativa L.),physical and mechanical properties of hydroponic lettuce were investigated and analyzed.Moisture content of stem,root and leaf,geometric characteristics,pulling force,and root cutting force were studied for harvesting hydroponic lettuce.The pulling force was examined by a tensile experiment,while the root cutting force was investigated by a shear experiment on the electronic universal testing machine.The moisture content of hydroponic lettuce was obtained by direct drying.Experiment data were processed using regression analysis and mathematical statistics method.A regression equation and the law of numerical distribution were obtained.The results showed that the geometric size of different hydroponic lettuce had little difference,and the distribution of physical parameters was concentrated.Moisture content was found statistically similar in stem and root(around 91%),while the highest moisture content was found in the leaf of 95.73%.The root cutting force decrease with the increase of cutting speed and decrease with the cutting position move downward.The minimum average root cutting force in the experiment was 1.41 N.The average pulling force was 13 N.This study provides adequate theoretical support for the design of the automatic harvesting machine of hydroponic lettuce. | Wenqi Wang Yidong Ma Longsheng Fu Yongjie Cui Yaqoob Majeed | 2021 | Information Processing in Agriculture2021，8，4： | 0 |
| 15 | Management of esophageal mucosa with high-grade dysplasia显示文摘Objective:Early detection and treatment in patients with esophageal cancer is the most effective way to improve the prognosis. Patients with high-grade dysplasia(HGD) in esophageal mucosa might be involved with early esophageal cancer,but the management of the disease is controversial. The purpose of our study was to explore the management of esophageal mucosa with HGD. Methods:We retrospectively analyzed 10 patients with HGD in esophageal mucosa,who underwent esophagectomy in Cancer Hospital of Fudan University from 1999 to 2006. The surgical approach,postoperative morbidity,in-hospital complications and pathological results of the patients were analyzed. Basing on our data together with other studies,we aimed at looking for an appropriate management for patients with HGD. Results:Of the 10 patients who received esophagectomy,the pathological results showed that 2(20%) cases were in situ carcinoma and 8(80%) cases were invasive cancer with no regional lymph nodes involved. 30-day mortality was 0. One patient experienced cervical anastomotic leakage,but healed in 2 weeks. There was no pulmonary complication. Conclusion:Most patients with HGD actually have occult carcinoma. High percentage of patients with HGD would develop into cancer during their lifetime. Esophagectomy is now a selective approach for the treatment of the patients with HGD. | Jiaqing Xiang,Hecheng Li,Shilei Liu,Yawei Zhang,Hong Hu,Longfei Ma,Longsheng Miao Department of Thoracic Surgery,Cancer Hospital of Fudan University Department of Oncology,Shanghai Medical College,Fudan University,Shanghai 200032,China | 2008 | The Chinese-German Journal of Clinical Oncology2008，7，3： | 0 |
| 16 | Effects of cutter parameters on shearing stress for lettuce harvesting using a specially developed fixture显示文摘To investigate the optimal parameters combination of reciprocating cutter for harvesting hydroponic lettuce automatically,a shear fixture was designed for cutting lettuce stems on a universal materials tester.Effects of blade distance,sliding cutting angle,skew cutting angle,and shearing angle on shearing stress were investigated in this study.The orders of the significance of a single factor and double factors were analyzed using the response surface methodology(RSM).A scanning electron microscope was used to observe the microstructure of the lettuce stem to analyze the shearing characteristics at the microscopic level.The RSM results showed that the order of significance for single factors was(i)sliding cutting angle,(ii)shearing angle,(iii)skew cutting angle,and(iv)blade distance.The sliding cutting angle had a highly significant influence on the shearing stress.The order of significance for double factors was(i)blade distance and shearing angle,(ii)sliding cutting angle and skew cutting angle,and(iii)the sliding cutting angle and shearing angle.A quadratic model of the factors and shearing stress was built according to the response-surface results.The optimized combination of factors that gives the minimum shearing stress was observed that it reduced 69.9%of the maximum shearing stress value.This research can provide a reference for designing lettuce-cutting devices. | Yongjie Cui Wenqi Wang Minghui Wang Yidong Ma Longsheng Fu | 2021 | International Journal of Agricultural and Biological Engineering2021，14，4： | 0 |
| 17 | Coherent link between a Ti:sapphire comb and a 1.5μm laser via nonlinear interaction in photonic crystal fiber显示文摘Optical clock networks have distinct advantages for the dissemination of time/frequency,geodesy,and fundamental research.To realize such a network,the telecom band and optical atomic clocks have to be coherently bridged.Since the telecom band and optical atomic clocks reside in a distinct spectral region,second-harmonic generation is usually introduced to bridge the large frequency gap.In this paper,we introduce a new method to coherently link a 1550 nm continuous wave laser with a Ti:sapphire mode-locked laser-based optical frequency comb.By coupling the 1550 nm continuous wave laser light and the Ti:sapphire comb light together into a photonic crystal fiber,nonlinear interaction takes place,and new comblike frequency components related to the 1550 nm laser frequency are generated in the visible region.Consequently,we can detect beat notes between two combs in the visible region with a signal-to-noise ratio of more than 40 dB in a resolution bandwidth of300 kHz.With this signal,we realize an optical frequency divider for converting the frequency of optical clocks in the visible region to the telecom band at 1.55μm.An out-of-loop measurement shows that the additional noise and uncertainty induced in optical frequency conversion are 5×10^(-18)at 1 s averaging time and 2.2×10^(-19),respectively,which are limited by the uncompensated light path fluctuation but fulfill precision measurement using state-of-the-art optical clocks. | YUAN YAO HAOSEN SHI GUANG YANG BO LI CONGYU WANG HONGFU YU LONGSHENG MA YANYI JIANG | 2024 | Photonics Research2024，12，2： | 0 |
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