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| 1 | Holocene aeolian stratigraphic sequences in the eastern portion of the desert belt(sand seas and sandy lands) in northern China and their palaeoenvironmental implications显示文摘This paper presents the environmental history and its responses to palaeoclimatic changes since the start of the Holocene in the eastern portion of the desert belt(sand seas and sandy lands) in northern China by comparing the aeolian sandpalaeosol sequences and their palaeoclimatic proxies. The optically stimulated luminescence(OSL) ages of the aeolian sandpalaeosol sedimentary sequences and a series of palaeoenvironmental proxies show that:(1) The large-scale dune landscape currently in the Kubuqi Sand Sea was formed during the Holocene in general;and the palaeosol was generally developed during the period of 4–2 ka, indicating conditions favorable for vegetation growth, soil development, and organic carbon accumulation due to increased precipitation or effective moisture and weakened aeolian activities;the large-scale expansion of dunes in the recent 2 ka is closely linked to human activities. The variable discharge of the Yellow River with diversions for irrigation may have resulted in a more consistent supply of aeolian particles for dune field expansion.(2) The dune landscape of the Hunshandake Sandy Land was likely formed around 12 ka, and before this, the western part of the Hunshandake Sandy Land would have been covered by a single large lake;it was obviously wetter than today in the sandy land during the period of 9.6–3 ka and the palaeosols were developed at the same time. But the aeolian activities have not been completely dormant in this long-lasting wetter epoch;because the Holocene wetter period was likely time-transgressive across the region.(3) The palaeosol of the Hulunbuir Sandy Land began to develop as early as 14.5 ka, probably continuing until the last 2 ka. The palaeosol development of various dune fields in the eastern portion of the desert belt(sand seas and sandy lands) in northern China is spatially heterogeneous, and even the palaeosol development time in different locations within each sandy land is inconsistent. During the middle Holocene(especially the 7.5–3.5 ka), all the sandy lands were stabilized in general and the intensity of aeolian activities was significantly weakened. The number of palaeoenvironmental records in the eastern portion of the desert belt(sand seas and sandy lands) in northern China has increased rapidly in the past decade, but the amount of published data still does not match the vast extent of the dune fields. It does require much more in-depth palaeoenvironmental studies for a full understanding of the relationship between aeolian activities and climate change in northern China. | Xiaoping YANG Peng LIANG Deguo ZHANG Hongwei LI Patrick RIOUAL Xulong WANG Bing XU Zhibang MA Qianqian LIU Xiaozong REN Fangen HU Yuxin HE Gang RAO Ninghua CHEN | 2019 | Science China Earth Sciences2019，62，8： | 10 |
| 2 | Recent advances in microwave photonics显示文摘微波 photonics (MWP ) 是联合微波工程和 photonics 的二个不同区域的一块学科交差的地。它由转移在光域和微波领域之间的信号有几特色,它为产生导致宽广操作带宽的优点,处理,微波的分发发信号并且为光光谱测量的高分辨率。在这篇论文,我们包括地由从大多数活跃 MWP 研究组介绍代表性的工作在中国考察过去和 MWP 的当前的地位。未来未来也从国家策略被讨论给我们开发了的创新技术调音。 | Ming LI Ninghua ZHU | 2016 | Frontiers of Optoelectronics2016，9，2： | 7 |
| 3 | Fabricating Pd isolated single atom sites on C3N4/rGO for heterogenization of homogeneous catalysis显示文摘Metal isolated single atomic sites catalysts have attracted intensive attention in recent years owing to their maximized atom utilization and unique structure.Despite the success of single atom catalyst synthesis,directly anchoring metal single atoms on three-dimensional(3D)macro support,which is promising to achieve the heterogenization of homogeneous catalysis,remains a challenge and a blank in this field.Herein,we successfully fabricate metal single atoms(Pd,Pt,Ru,Au)on porous carbon nitride/reduced graphene oxide(C3N4/rGO)foam as highly efficient catalysts with convenient recyclability.C3N4/rGO foam features two-dimensional microstructures with abundant N chelating sites for the stabilization of metal single atoms and vertically-aligned hierarchical mesostructure that benefits the mass diffusion.The obtained Pdi/C3N4/rGO monolith catalyst exhibits much enhanced activity over its nanoparticle counterpart for Suzuki-Miyaura reaction.Moreover,the Pdi/C3N4/rGO monolith catalyst can be readily assembled in a flow reactor to achieve the highly efficient continuous production of 4-nitro-1,1'-biphenyl through Suzuki-Miyaura coupling. | Ninghua Fu Xiao Liang Zhi Li Wenxing Chen Yu Wang Lirong Zheng Qinghua Zhang Chen Chen Dingsheng Wang Qing Peng Lin Gu Yadong Li | 2020 | Nano Research2020，13，4： | 5 |
| 4 | Observation of parity-time symmetry in microwave photonics显示文摘Symmetry plays a crucial role in explorations of the laws of nature.Parity-time(PT)symmetry phenomena can lead to entirely real spectra in non-Hermitian systems,which attracts considerable attention in the fields of optics and electronics because these phenomena provide a new tool for the manipulation of oscillation modes and nonreciprocal signal transmission.A potential new field of application is microwave photonics,an interdisciplinary field in which the interaction between microwaves and optical signals is exploited.In this article,we report the experimental use of PT symmetry in an optoelectronic oscillator(OEO),a key microwave photonics system that can generate singlefrequency sinusoidal signals with high spectral purity.PT symmetry is theoretically analyzed and experimentally observed in an OEO with two mutually coupled active oscillation cavities via a precise manipulation of the interplay between gain and loss in the two oscillation cavities.Stable single-frequency microwave oscillation is achieved without using any optical/electrical filters for oscillation mode selection,which is an indispensable requirement in traditional OEOs.This observation opens new avenues for signal generation and processing based on the PT symmetry principle in microwave photonics. | Yanzhong Liu Tengfei Hao Wei Li Jose Capmany Ninghua Zhu Ming Li | 2018 | Light(Science & Applications)2018，7，1： | 5 |
| 5 | Experimental optimization of phase noise performance of optoelectronic oscillator based on directly modulated laser显示文摘The experimental optimization of a 10 GHz optoelectronic oscillator (OEO) based on a 1.55 μm directly modulated distributed feedback (DFB) laser is demonstrated in this paper. The phase noise of the directly modulated laser (DML) based OEO is significantly reduced by proper selection of the laser's bias current and by using a dispersion shifted fiber as a delay line. The phase noise performance of the DML OEO achieved after optimization is close to that of a conventional OEO constructed using a commercial DFB laser and a LiNbO 3 Mach-Zehnder modulator. The DML based OEO is most promising for future realization of a miniature OEO architecture with the components integrated on a semiconductor substrate. | WANG LiXian ZHU NingHua LIU JianGuo LI Wei ZHU HongLiang WANG Wei | 2012 | Chinese Science Bulletin2012，57，31： | 4 |
| 6 | A competitive RT-PCR-based approach to quantifying promoter activity of stress gene显示文摘Chloramphenicol acetyltransferase (CAT) as a stable reporter has been broadly adopted to detect promoter activity of many stress genes in eukaryotic cells. A simplified, convenient and relatively accurate assay to reveal CAT activities driven by heat shock gene promoter upon cell stress is reported here. A CAT mutant control plasmid pMCAT is constructed out of pBLCAT3, with a DNA segment within the CAT gene deleted. The control plasmid pMCAT along with the wild type CAT reporter gene driven by the regulatory sequence of hsp90β gene are co-transfected into Jurkat cells. Following total cellular RNA extracted and reverse transcribed, PCR is carried out to amplify two individual fragments with the same pair of synthesized primers, which bind to the identical sequences in both pMCAT and the CAT reporter plasmids. The two PCR fragments amplified from the reporter and control RNAs are identified by their size differences in agarose gel electrophoresis. The ratio of intensity of the two PCR bands in the same lane is taken as 'relative units of promoter efficiency' of a gene. The transcripts instead of CAT activity thus detected, may not only provide a closer look at the promoter activity of the stress gene but also normalize the efficiency of transfection simultaneously. With experimental conditions optimized, visible and reliable results can be obtained without using any sophisticated instruments. Since the results obtained with the RT-PCR approach are reproducible, much less troublesome and time-consuming, and comparable to our previous data, we thus take it as a conventional procedure for promoter activity assay of human hsp gene upon heat shock. Additionally, results from the assay have recently provided the first evidence that Rac, MEKK and JNK signals participate in the heat shock-induced expression of hsp90β gene. | MO Zhicheng, LI Xiaoyan, LI Hongfan, CHENG Xiaokuan, WU Ninghua and SHEN Yufei(National Laboratory of Medical Molecular Biology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100005, China) | 2002 | Progress in Natural Science:Materials International2002，12，10： | 4 |
| 7 | Synaptic development in the injured spinal cord cavity following co-transplantation of fetal spinal cord cells and autologous activated Schwann cells显示文摘Transplantation of activated transgenic Schwann cells or a fetal spinal cord cell suspension has been widely used to treat spinal cord injury. However, little is known regarding the effects of co-transplantation. In the present study, autologous Schwann cells in combination with a fetal spinal cord cell suspension were transplanted into adult Wistar rats with spinal cord injury, and newly generated axonal connections were observed ultrastructurally. Transmission electron microscopic observations showed that the neuroblast first presented cytoplasmic processes, followed by pre- and postsynaptic membranes with low electron density forming a dense projection. The number and types of synaptic vesicles were increased. Synaptic connections developed from single cell body-dendritic synapses into multiple cell body-dendritic and dendrite-dendritic synapses. In addition, the cell organs of the transplanted neuroblast, oligodendroblast and astroblast matured gradually. The blood-brain barrier appeared subsequently. Moreover, neurofilament, histamine, calcitonin-gene-related peptides, and glial fibrillary acidic protein positive fibers were observed in the transplant region. These findings demonstrate that fetal spinal cord cells in the presence of autologous activated Schwann cells can develop into mature synapses in the cavity of injured spinal cords, suggesting the possibility of information exchange through the reconstructed synapse between fetal spinal cord cells and the host. | Wendong Ruan Yuan Xue Ninghua Li Xiaotao Zhao Huajian Zhao Peng Li | 2010 | Neural Regeneration Research2010，5，19： | 4 |
| 8 | Ultra-low V_(pp)and high-modulation-depth InP-based electro-optic microring modulator显示文摘A modulator is an essential building block in the integrated photonics,connecting the electrical with optical signals.The microring modulator gains much attention because of the small footprint,low drive voltage and high extinction ratio.An ultra-low V_(pp)and high-modulation-depth indium phosphide-based racetrack microring modulator is demonstrated in this paper.The proposed device mainly comprises one racetrack microring,incorporating a semiconductor amplifier,and coupling with a bus waveguide through a multimode interference coupler.Traveling wave electrodes are employed to supply bidirectional bias ports,terminating with a 50-Ω impedance.The on/off extinction ratio of the microring reaches 43.3 dB due to the delicately tuning of the gain.An 11 mV V_(pp),a maximum 42.5 dB modulation depth and a 6.6 GHz bandwidth are realized,respectively.This proposed microring modulator could enrich the functionalities and designability of the fundamental integrated devices. | Dapeng Liu Jian Tang Yao Meng Wei Li Ninghua Zhu Ming Li | 2021 | Journal of Semiconductors2021，42，8： | 3 |
| 9 | Reconfigurable single-shot incoherent optical signal processing system for chirped microwave signal compression显示文摘We propose and demonstrate a reconfigurable and single-shot incoherent optical signal processing system for chirped microwave signal compression, using a programmable optical filter and a multiwavelength laser(MWL). The system is implemented by temporally modulating a specially shaped MWL followed by a suitable linear dispersive medium. A microwave dispersion value up to 1.33 ns/GHz over several GHz bandwidth is achieved based on this approach. Here we demonstrate a singleshot compression for different linearly chirped microwave signals over several GHz bandwidth. In addition, the robustness of the proposed system when input RF signals are largely distorted is also discussed. | Ming Li Shuqian Sun Antonio Malacarne Sophie LaRochelle Jianping Yao Ninghua Zhu Jose Azana | 2017 | Science Bulletin2017，62，4： | 3 |
| 10 | Optical length-change measurement based on an incoherent single-bandpass microwave photonic filter with high resolution显示文摘An optical length-change measurement technique is proposed based on an incoherent microwave photonic filter(MPF).The optical length under testing is inserted into an optical link of a single-bandpass MPF based on a polarization-processed incoherent light source.The key feature of the proposed technique is to transfer the length measurement in the optical domain to the electrical domain.In the electrical domain,the measurement resolution is extremely high thanks to the high-resolution measurement of microwave frequency response.In addition,since the MPF is a single-bandpass MPF,the optical length is uniquely determined by the central frequency of the MPF.A detailed investigation of the relation between the center frequency of the MPF and the optical length change is implemented.A measurement experiment is also demonstrated,and the experimental results show that the proposed technique has a measurement sensitivity of 1 GHz/mm with a high length-measurement resolution of 1 pm in theory.The proposed approach has the advantages of high sensitivity,high resolution,and immunity to power variation in electronic and optical links. | Ye Deng Ming Li Ningbo Huang Hui Wang Ninghua Zhu | 2014 | Photonics Research2014，2，4： | 3 |
| 11 | Recent progresses on optical arbitrary waveform generation显示文摘这份报纸在光任意的波形产生(美国线规) 上考察最近的进步技术,它能被用来为波形产生打破电子学技术的速度和带宽瓶颈。为光学地产生的主要启用技术光并且微波波形在这被介绍并且考察纸例如印射技术的 wavelength-to-time , space-to-time 印射技术,塑造的时间的脉搏( TPS )系统,光电子振荡器( OEO ),可编程的光过滤器,光微分器和综合者和万用的电镀物品眼的调整实现。这些光美国线规技术的主要优点和挑战也被讨论。 | Ming LI Jose AZANA Ninghua ZHU Jianping YAO | 2014 | Frontiers of Optoelectronics2014，7，3： | 2 |
| 12 | Serial time-encoded amplified microscopy for ultrafast imaging based on multi-wavelength laser显示文摘In this paper,a serial time-encoded amplified microscopy(STEAM)by employing a multi-wavelength laser as the light source is proposed and experimentally demonstrated.This system achieves ultrafast optical imaging with a tunable frame rate.The measuring range depends on the spectrum width of the multi-wavelength laser.Through tuning the speed of the modulating signal,the frame rate ranges from 100to 250 MHz.In addition,the spatial resolution can be improved by increasing the group velocity dispersion and reducing the wavelength spacing.Finally,with the development of photonic integrate circuits(PIC),the multi-wavelength laser source has the potential for integration on a photonic chip and thus the size of the proposed STEAM could be reduced in the future. | Ye Deng Ming Li Ningbo Huang JosAzana Ninghua Zhu | 2014 | Chinese Science Bulletin2014，59，22： | 2 |
| 13 | Comparison of postural control between healthy subjects and individuals with nonspecific low back pain during exposure to visual stimulus显示文摘 | Li Rui Wang Ninghua Yan Xiang Wei Kunlin | 2014 | Chinese Medical Journal2014，，7： | 2 |
| 14 | Prevalence rate of osteoporosis in the mid-aged and elderly in selected parts of China显示文摘 | Li Ninghua Ou Pinzhong Zhu Hanmin | 2002 | Clin Med J (Engl)2002，115，5： | 1 |
| 15 | Study on the preva- lence of primary osteopomsis in the elderly population in some areas of China显示文摘 | Li Ninghua Zhu Hanmin Ou Pinzhong | 2001 | Chinese Journal of Department of orthopedics2001，5，： | 1 |
| 16 | Optoelectronic parametric oscillator显示文摘Oscillators are one of the key elements in various applications as a signal source to generate periodic oscillations.Among them,an optical parametric oscillator(OPO)is a driven harmonic oscillator based on parametric frequency conversion in an optical cavity,which has been widely investigated as a coherent light source with an extremely wide wavelength tuning range.However,steady oscillation in an OPO is confined by the cavity delay,which leads to difficulty in frequency tuning,and the frequency tuning is discrete with the minimum tuning step determined by the cavity delay.Here,we propose and demonstrate a counterpart of an OPO in the optoelectronic domain,i.e.,an optoelectronic parametric oscillator(OEPO)based on parametric frequency conversion in an optoelectronic cavity to generate microwave signals.Owing to the unique energy-transition process in the optoelectronic cavity,the phase evolution in the OEPO is not linear,leading to steady single-mode oscillation or multimode oscillation that is not bounded by the cavity delay.Furthermore,the multimode oscillation in the OEPO is stable and easy to realize owing to the phase control of the parametric frequency-conversion process in the optoelectronic cavity,while stable multimode oscillation is difficult to achieve in conventional oscillators such as an optoelectronic oscillator(OEO)or an OPO due to the mode-hopping and mode-competition effect.The proposed OEPO has great potential in applications such as microwave signal generation,oscillator-based computation,and radio-frequency phase-stable transfer. | Tengfei Hao Qizhuang Cen Shanhong Guan Wei Li Yitang Dai Ninghua Zhu Ming Li | 2020 | Light(Science & Applications)2020，9，1： | 1 |
| 17 | Photonic phase shifter based on wavelength dependence of Brillouin frequency shift显示文摘 | Li Wei Zhu Ninghua Wang Lixian | 2011 | IEEE Photonics Technology Letters2011，23，14： | 1 |
| 18 | Prevalence rate of osteoporosis in the mid-aged elderly in selected parts of China显示文摘 | LI NINGHUA OU PINZHONG ZHU HANMIN | 2002 | Chin Med J2002，115，5： | 1 |
| 19 | Large-scale coherent Ising machine based on optoelectronic parametric oscillator显示文摘Ising machines based on analog systems have the potential to accelerate the solution of ubiquitous combinatorial optimization problems.Although some artificial spins to support large-scale Ising machines have been reported,e.g.,superconducting qubits in quantum annealers and short optical pulses in coherent Ising machines,the spin stability is fragile due to the ultra-low equivalent temperature or optical phase sensitivity.In this paper,we propose to use short microwave pulses generated from an optoelectronic parametric oscillator as the spins to implement a large-scale Ising machine with high stability.The proposed machine supports 25,600 spins and can operate continuously and stably for hours.Moreover,the proposed Ising machine is highly compatible with high-speed electronic devices for programmability,paving a low-cost,accurate,and easy-to-implement way toward solving real-world optimization problems. | Qizhuang Cen Hao Ding Tengfei Hao Shanhong Guan Zhiqiang Qin Jiaming Lyu Wei Li Ninghua Zhu Kun Xu Yitang Dai Ming Li | 2022 | Light(Science & Applications)2022，11，12： | 0 |
| 20 | All-optical temporal fractional order differentiator using an in-fiber ellipsoidal air-microcavity显示文摘An all-optical temporal fractional order differentiator with ultrabroad bandwidth(~1.6 THz) and extremely simple fabrication is proposed and experimentally demonstrated based on an in-fiber ellipsoidal air-microcavity.The ellipsoidal air-microcavity is fabricated by splicing a single mode fiber(SMF) and a photonic crystal fiber(PCF) together using a simple arc-discharging technology. By changing the arc-discharging times, the propagation loss can be adjusted and then the differentiation order is tuned. A nearly Gaussian-like optical pulse with 3 dB bandwidth of 8 nm is launched into the differentiator and a 0.65 order differentiation of the input pulse is achieved with a processing error of 2.55%. | Lihong Zhang Shuqian Sun Ming Li Ninghua Zhu | 2017 | Journal of Semiconductors2017，38，12： | 0 |
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