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29篇 您的检索式:作者名="Pengxiang Liu"
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1Optically pumped terahertz sources显示文摘High-power terahertz(THz) generation in the frequency range of 0.1-10 THz has been a fast-developing research area ever since the beginning of the THz boom two decades ago, enabling new technological breakthroughs in spectroscopy, communication, imaging,etc. By using optical(laser) pumping methods with near-or mid-infrared(IR) lasers, flexible and practical THz sources covering the whole THz range can be realized to overcome the shortage of electronic THz sources and now they are playing important roles in THz science and technology. This paper overviews various optically pumped THz sources, including femtosecond laser based ultrafast broadband THz generation, monochromatic widely tunable THz generation, single-mode on-chip THz source from photomixing, and the traditional powerful THz gas lasers. Full descriptions from basic principles to the latest progress are presented and their advantages and disadvantages are discussed as well. It is expected that this review gives a comprehensive reference to researchers in this area and additionally helps newcomers to quickly gain understanding of optically pumped THz sources.ZHONG Kai SHI Wei XU DeGang LIU PengXiang WANG YuYe MEI JiaLin YAN Chao FU ShiJie YAO JianQuan 2017Science China(Technological Sciences)2017,60,12:9
2Carbon nanotubes prepared by anodic aluminum oxide template method显示文摘One of the most unique structural characteristics of carbon nanotubes(CNTs) differentiating from other carbon materials is their hollow nanochannles,which can be utilized for encapsulating and loading foreign matters.The anodic aluminum oxide(AAO) template technique enables the diameter,length,and cap structure control of the replicated CNTs,and thus shows advantages in pore structure control over the traditional CNT growth approaches.This review details the synthesis of CNTs with tunable diameter,length,wall thickness,and crystalline by using the AAO template method.The doping of heteroatoms and filling of foreign matters into AAO-CNTs are also addressed.Moreover,the main challenges and developing trends of the AAO template method are discussed.HOU PengXiang LIU Chang SHI Chao CHENG HuiMing 2012Chinese Science Bulletin2012,57,2:7
3Effect of wastewater composition on the calcium carbonate precipitation in upflow anaerobic sludge blanket reactors显示文摘Calcium carbonate often precipitates in anaerobic reactors treating wastewater with high calcium content.The aim of this paper is to study the effect of wastewater composition on calcium carbonate precipitation in upflow anaerobic sludge blanket(UASB)reactors.Two laboratory-scale UASB reactors were operated with calcium-containing influents using acetate and carbohydrate as substrate,respectively.There was an obvious accumulation of inorganic precipitate observed in the biogranules.Observations via scanning electron microscope(SEM)and energy dispersive spectroscopy(EDS)showed that the acclimated biogranules in the two reactors differed in microstructure.Calcium carbonate was found to have precipitated on the surface of acetate-degrading biogranules,but precipitated at the core of the carbohydrate-degrading biogranules.The results indicated that substrates had significant influence on the location of calcium carbonate precipitation in anaerobic granular sludge,which was expected due to the different methanogens distribution and pH gradient within the granular sludge degrading various substrates.Moreover,the location of calcium carbonate precipitation substantially affected the specific methanogenic activity(SMA)of the granular sludge.The SMA of the acetate-degrading biogranules dropped from 1.96 gCODCH4·gVSS^(–1)·d^(–1)to 0.61 gCODCH4·gVSS^(–1)·d^(–1)after 180-d of operation in the reactor.However,the SMA of the carbohydrate-degrading biogranules was not adversely affected by calcium carbonate precipitation.Shucheng YANG Yanling HE Yonghong LIU Charles CHOU Pengxiang ZHANG Dongqi WANG 2010Frontiers of Environmental Science & Engineering2010,4,2:6
4Anti-PD-L1/TGF-BR fusion protein (SHR-1701) overcomes disrupted lymphocyte recovery-induced resistance to PD-1/PD-L1 inhibitors in lung cancer显示文摘Background:Second-generation programmed cell death-protein 1/pro-grammed death-ligand 1(PD-1/PD-L1)inhibitors,such as bintrafusp alfa(M7824),SHR-1701,and YM101,have been developed to simultaneously block PD-1/PD-L1 and transforming growth factor-beta/transforming growth factor-beta receptor(TGF-P/TGF-βR).Consequently,it is necessary to identify predictive factors of lung cancer patients who are not only resistant to PD-1/PD-LI inhibitors but also sensitive to bifunctional drugs.The purpose of this study was to search for such predictors.Methods:Multivariable Cox regression was used to study the association between the clinical outcome of treatment with PD-1/PD-L1 inhibitors and lym-phocyte recovery after lymphopenia in lung cancer patients.Murine CMT167 lung cancer cells were engineered to express the firefly luciferase gene and implanted orthotopically in the lung of syngeneic mice.Bioluminescence imag-ing,flow cytometry,and immunohistochemistry were employed to detrmine response to immunotherapy and function of tumor-infiltrating immune cells.Results:For lung cancer patients treated with anti-PD-1/PD-LI antibodies,poor lymphocyte recovery was associated with a shorter progression-free survival(PFS;P<0.001),an accumulation of regulatory T cells(Tregs),and an elimi-nation of CD8+T cells in the peripheral blood.Levels of CD8+T cells and Treg cells were also imbalanced in the tumors and peripheral immune organs of mice with poor lymphocyte recovery after chemotherapy.Moreover,these mice failed to respond to anti-PD-1 antibodies but remained sensitive to the anti-PD-LI/TGF-βR fusion protein(SHR-1701).Consistently,SHR-1701 but not anti-PD-1 antibod-ies,markedly enhanced IFN-γproduction and Ki-67 expression in peripheral CD8+T cells from patients with impaired lymphocyte recovery.Conclusions:Lung cancer patients with poor lymphocyte recovery and suffer-ing from persistent lymphopenia after previous chemotherapy are resistant to anti-PD-1/PD-L1 antibodies but might be sensitive to second-generation agents such as SHR-1701.Bo Cheng Kaikai Ding Pengxiang Chen Jianxiong Ji Tao Luo Xiaofan Guo Wei Qiu Chunhong Ma Xue Meng Jian Wang Jinming Yu Yuan Liu 2022Cancer Communications2022,42,1:5
5High-average-power, high-repetition-rate tunable terahertz difference frequency generation with GaSe crystal pumped by 2 μm dual-wavelength intracavity KTP optical parametric oscillator显示文摘We have demonstrated a high-average-power,high-repetition-rate optical terahertz(THz)source based on difference frequency generation(DFG)in the GaSe crystal by using a near-degenerate 2μm intracavity KTP optical parametric oscillator as the pump source.The power of the 2μm dual-wavelength laser was up to 12.33 W with continuous tuning ranges of 1988.0–2196.2 nm/2278.4–2065.6 nm for two waves.Different GaSe cystal lengths have been experimentally investigated for the DFG THz source in order to optimize the THz output power,which was in good agreement with the theoretical analysis.Based on an 8 mm long GaSe crystal,the THz wave was continuously tuned from 0.21 to 3 THz.The maximum THz average power of 1.66μW was obtained at repetition rate of 10 kHz under 1.48 THz.The single pulse energy amounted to 166 pJ and the conversion efficiency from 2 μm laser to THz output was 1.68×10^(-6).The signal-to-noise ratio of the detected THz voltage was 23 dB.The acceptance angle of DFG in the GaSe crystal was measured to be 0.16°.DEXIAN YAN YUYE WANG DEGANG XU PENGXIANG LIU CHAO YAN JIA SHI HONGXIANG LIU YIXIN HE LONGHUANG TANG JIANCHEN FENG JIANQIN GUO WEI SHI KAI ZHONG YUEN H.TSANG JIANQUAN YAO 2017Photonics Research2017,5,2:5
6Carbon nanotube/silicon heterojunctions for photovoltaic applications显示文摘Photovoltaic devices have rapidly developed in recent years as they seek to address the ever-increasing energy requirements and environmental issues.Due to their simple structure and easy,low-temperature fabrication,heterojunctions of carbon nanotube(CNT)films and silicon(Si)have been used in solar cells,photodetectors and optoelectronic gas sensors.Significant progress has been made on the development of high-performance CNT/Si heterojunction devices,in particular,CNT/Si solar cells.Here,we give a comprehensive overview of state-of-theart CNT/Si heterojunction devices.The effects of the structure of the CNTs,the interface layer and the silicon structure on the performance of CNT/Si solar cells are analyzed.In addition,potential ways to further improve the performance of such photovoltaic devices are proposed.Finally,the key challenges and developing trends in CNT/Si heterojunction photovoltaic devices are discussed.Xiangang Hu Pengxiang Hou Chang Liu Huiming Cheng 2019Nano Materials Science2019,1,3:3
7N-phosphoryl amino acid models for P–N bonds in prebiotic chemical evolution显示文摘Post-translational modification of proteins by N-phosphorylation of the basic amino acid residues plays important roles in biological processes. The high-energy P–N bond might have contributed to the evolution of prebiotic chemistry. N-phosphoryl amino acids(PAAs) can serve as interesting small molecular models for the study of P–N bonds in prebiotic chemical evolution. PAAs are capable of simultaneously producing several important biomolecules such as polypeptides and oligonucleotides under mild reaction conditions. In this review, we describe the chemistry of PAAs, discusse their likely prebiotic origins and their reactivity and how they relate to biological P–N bond species. We also depict a possible prebiotic scenario mediated by PAAs in which PAAs may have acted as one of the essential forces driving prebiotic biomolecules to the first protocell.Feng Ni Chuan Fu Xiang Gao Yan Liu Pengxiang Xu Liu Liu Ye Lv Songsen Fu Ying Sun Daxiong Han Yan-Mei Li Yufen Zhao 2015Science China Chemistry2015,58,3:3
8Mechanism of variations in environmental magnetic proxies of lake sediments from Nam Co, Tibet during the Holocene显示文摘High-resolution environmental records from the Tibetan Plateau are essential to understand past global climatic and environmental changes. Magnetic minerals in lake sediments are important proxies to reconstruct environmental and climatic changes. Nam Co (lake) is a typical great lake in the transitional region of southwest monsoon in the Tibetan Plateau. Previous studies have extensively focused on geochemistry, microfossils, sedimentology and biochemistry analysis of Nam Co, which provides sound interpretation of paleoclimatic and paleoenvironmental changes. However, up to now, no systematic environmental magnetic studies have been carried out. Therefore, high-resolution and systematic magnetic studies combined with geochemical parameters were carried on lake sediments of core NC 08/01 from Nam Co for the Holocene period (11.3 cal ka BP) in order to explore how magnetic properties of the sediments respond to climatic changes. Based on variations of magnetic proxies, the sequence can be separated into 3 units. Unit 1 (236-199 cm, 11.3-7.8 cal ka BP) contains dominantly coarse-grained magnetite with homogeneous grain size. A positive correlation between magnetite and Ti strongly suggests that these coarse-grained detrital magnetites reflect detrital input signals due to insignificant effects of postdepositional dissolution processes on these coarse-grained magnetite particles. For Unit 2 (198-102 cm, 7.8-2.1 cal ka BP), magnetic grain size is finer and the corresponding concentration of magnetite is also reduced. This is mainly due to significant dissolution of these fine-grained detrital magnetite particles, which were transported under reduced water flow conditions during this period. For Unit 3 (101-0 cm, 2.1-0 cal ka BP), the bulk magnetic properties are dominated by a mixture of single domain biogenic magnetite and detrital magnetite. The concentration of magnetic minerals is not correlated with the Ti content. In conclusion, the preservation of magnetic minerals in the lake sediment and thus the corresponding magnetic properties are related to the initial grain size. Combination of magnetic properties (including variation of grain size and concentration) and other proxies of detrital inputs (e.g. Ti) can be used to infer the variation of redox conditions in Nam Co. These results provide a viable framework for reconstructing the paleoenvironmental changes of this lake.SU YouLiang GAO Xing LIU QingSong HU PengXiang DUAN ZongQi JIANG ZhaoXia WANG JunBo ZHU LiPing DOBERSCHüTZ Stefan MUSBACHER Roland DAUT Gerhard HABERZETTL Torsten 2013Chinese Science Bulletin2013,58,13:2
9Bulk growth and separation of single-walled carbon nanotubes from rhenium catalyst显示文摘Bulk synthesis of single-walled carbon nanotubes(SWNTs)using solid catalyst has been challenging,despite of recent breakthrough in the chirality-specific growth on the flat substrate surface.In this work,we propose a porous magnesia support rhenium catalyst for bulk synthesis of SWNTs.It is found that the well-dispersed catalyst with a high melting point and the optimal chemical vapor deposition reaction conditions account for the growth of SWNTs.Detailed characterizations reveal the produced SWNTs are dominant in(n,n−1)and(n,n−2)species.Furthermore,by using a multicolumn chromatography post-growth separation method,SWNTs with three defined diameter ranges were obtained.This work guides the design of porous oxide supported catalyst for bulk synthesis and diameter-dependent sorting of SWNTs,which will ultimately help harness the extraordinary properties of SWNTs.Chen Ma Yumin Liu Lili Zhang Liu Qian Yiming Zhao Ying Tian Qianru Wu Dong Li Nan Zhao Xueting Zhang Liantao Xin Huaping Liu Pengxiang Hou Chang Liu Maoshuai He Jin Zhang 2022Nano Research2022,15,7:2
10Testing the magnetic proxy χ FD /HIRM for quantifying paleoprecipitation in modern soil profiles from Shaanxi Province, China显示文摘Zhifeng Liu Qingsong Liu José Torrent Vidal Barrón Pengxiang Hu 2013Global and Planetary Change2013,,:1
11Structural and fractal characteristics of biofilm attached on the surfaces of aquatic plants and gravels in the rivers and lakes reusing reclaimed wastewater显示文摘Liang Mingchao Wang Tianzhi Li Yunkai Yang Peiling Liu Chengcheng Li Pengxiang Zhao Wei 2013Environmental Earth Sciences2013,,5:1
12An invasive zone in human liver cancer identified by Stereo-seq promotes hepatocyte–tumor cell crosstalk,local immunosuppression and tumor progression显示文摘Dissecting and understanding the cancer ecosystem,especially that around the tumor margins,which have strong implications for tumor cell infiltration and invasion,are essential for exploring the mechanisms of tumor metastasis and developing effective new treatments.Using a novel tumor border scanning and digitization model enabled by nanoscale resolution-SpaTial Enhanced REsolution Omics-sequencing(Stereo-seq),we identified a 500µm-wide zone centered around the tumor border in patients with liver cancer,referred to as“the invasive zone”.We detected strong immunosuppression,metabolic reprogramming,and severely damaged hepatocytes in this zone.We also identified a subpopulation of damaged hepatocytes with increased expression of serum amyloid A1 and A2(referred to collectively as SAAs)located close to the border on the paratumor side.Overexpression of CXCL6 in adjacent malignant cells could induce activation of the JAK-STAT3 pathway in nearby hepatocytes,which subsequently caused SAAs’overexpression in these hepatocytes.Furthermore,overexpression and secretion of SAAs by hepatocytes in the invasive zone could lead to the recruitment of macrophages and M2 polarization,further promoting local immunosuppression,potentially resulting in tumor progression.Clinical association analysis in additional five independent cohorts of patients with primary and secondary liver cancer(n=423)showed that patients with overexpression of SAAs in the invasive zone had a worse prognosis.Further in vivo experiments using mouse liver tumor models in situ confirmed that the knockdown of genes encoding SAAs in hepatocytes decreased macrophage accumulation around the tumor border and delayed tumor growth.The identification and characterization of a novel invasive zone in human cancer patients not only add an important layer of understanding regarding the mechanisms of tumor invasion and metastasis,but may also pave the way for developing novel therapeutic strategies for advanced liver cancer and other solid tumors.Liang Wu Jiayan Yan Yinqi Bai Feiyu Chen Xuanxuan Zou Jiangshan Xu Ao Huang Liangzhen Hou Yu Zhong Zehua Jing Qichao Yu Xiaorui Zhou Zhifeng Jiang Chunqing Wang Mengnan Cheng Yuan Ji Yingyong Hou Rongkui Luo Qinqin Li Liang Wu Jianwen Cheng Pengxiang Wang Dezhen Guo Waidong Huang Junjie Lei Shang Liu Yizhen Yan Yiling Chen Sha Liao Yuxiang Li Haixiang Sun Na Yao Xiangyu Zhang Shiyu Zhang Xi Chen Yang Yu Yao Li Fengming Liu Zheng Wang Shaolai Zhou Huanming Yang Shuang Yang Xun Xu Longqi Liu Qiang Gao Zhaoyou Tang Xiangdong Wang Jian Wang Jia Fan Shiping Liu Xinrong Yang Ao Chen Jian Zhou 2023Cell Research2023,33,8:1
13Widely tunable and monochromatic terahertz difference frequency generation with organic crystal DSTMS显示文摘Pengxiang Liu Degang Xu Yin Li Xinyuan Zhang Yuye Wang Jianquan Yao Yicheng Wu 2014EPL (Europhysics Letters)2014,,6:1
14Highly selective oxidation of amines to imines by Mn2O3 catalyst under eco-friendly conditions显示文摘Enhancing the selectivity of imines for the oxidative self-coupling of primary amines was found to be challenging in the heterogeneous catalysis.Three different manganese oxides(M-3,M-4,M-5) were synthesized by controlling the calcination temperature using a simple template-free oxalate route.The prepared manganese oxides were systematically characterized using XRD,N2 sorption,SEM,TEM,XPS,H2-TPR techniques.M-4 gave 96.2% selectivity of imine at 100% conversion of benzylamine,which was far more superior than other existing protocols.Mn^3+/Mn^4+ ratio was found to affect the selectivity of the imines.The probable reaction pathway for amines oxidation catalyzed by manganese oxides was proposed for the first time.Fushan Chen Tao Yang Songlin Zhao Taotao Jiang Lu Yu Houfeng Xiong Chuankun Guo Yufang Rao Yan Liu Liu Liu Jian Zhou Pengxiang Tu Jun Ni Qunfeng Zhang Xiaonian Li 2019Chinese Chemical Letters2019,30,12:1
15Modeling Tracer Flow Characteristics in Different Types of Pores: Visualization and Mathematical Modeling显示文摘Structure of porous media and fluid distribution in rocks can significantly affect the transport characteristics during the process of microscale tracer flow.To clarify the effect of micro heterogeneity on aqueous tracer transport,this paper demonstrates microscopic experiments at pore level and proposes an improved mathematical model for tracer transport.The visualization results show a faster tracer movement into movable water than it into bound water,and quicker occupancy in flowing pores than in storage pores caused by the difference of tracer velocity.Moreover,the proposed mathematical model includes the effects of bound water and flowing porosity by applying interstitial flow velocity expression.The new model also distinguishes flowing and storage pores,accounting for different tracer transport mechanisms(dispersion,diffusion and adsorption)in different types of pores.The resulting analytical solution better matches with tracer production data than the standard model.The residual sum of squares(RSS)from the new model is 0.0005,which is 100 times smaller than the RSS from the standard model.The sensitivity analysis indicates that the dispersion coefficient and flowing porosity shows a negative correlation with the tracer breakthrough time and the increasing slope,whereas the superficial velocity and bound water saturation show a positive correlation.Tongjing Liu Weixia Liu Pengxiang Diwu Gaixing Hu TingXu Yuqi Li Zhenjiang You Runwei Qiao Jia Wang 2020Computer Modeling in Engineering & Sciences2020,,6:1
16Roles of short amine in preparation and sizing performance of partly hydrolyzed ASA emul- sion stabilized by Laponite particles 显示文摘Ding Pengxiang Liu Wenxia Zhao Zhenghuan 2011Colloids and Surfaces A: Physicochemical and Engineering Aspects2011,384,3:1
17Power flow analysis on simplified feeder model- ing 显示文摘Jian Liu Bi Pengxiang Zhang Yanqing 2004IEEE Transactions Power Delivery2004,19,1:1
18Roles of short amine in preparation and sizing performance of partly hydrolyzed ASA emul- sion stabilized by Laponite particles 显示文摘Ding Pengxiang Liu Wenxia Zhao Zhenghuan 2011Colloids and Surfaces A: Physicochemical and Engineering Aspects2011,384,13:1
19THz source based on optical Cherenkov radiation显示文摘Terahertz(THz)technique has attracted considerable interest due to its broad application prospects.THz source is a crucial part of THz science and technology.Optical Cherenkov radiation in electro-optic crystals is a promising method of THz generation,because phase-matching is automatically satisfied.In this paper,we introduced two types of THz source based on optical Cherenkov radiation:both broadband and tunable monochromatic.The mechanism of radiation was analyzed and recent development was reviewed in detail.The future of THz source based on optical Cherenkov radiation was also forecasted.YAO JianQuan LIU PengXiang XU DeGang LV YingJin LV Da 2012Science China(Information Sciences)2012,55,1:1
20Angiopoietin-like 4 promotes epidermal stem cell proliferation and migration and contributes to cutaneous wound re-epithelialization显示文摘Proliferation and migration of epidermal stem cells(EpSCs)are essential for epithelialization during skin wound healing.Angiopoietin-like 4(ANGPTL4)has been reported to play an important role in wound healing,but the mechanisms involved are not fully understood.Here,we investigate the contribution of ANGPTL4 to full-thickness wound re-epithelialization and the underlying mechanisms using Angptl4-knockout mice.Immunohistochemical staining reveals that ANGPTL4 is significantly upregulated in the basal layer cells of the epidermis around the wound during cutaneous wound healing.ANGPTL4 deficiency impairs wound healing.H&E staining shows that ANGPTL4 deficiency significantly reduces the thickness,length and area of the regenerated epidermis postwounding.Immunohistochemical staining for markers of EpSCs(α6 integrin andβ1 integrin)and cell proliferation(PCNA)shows that the number and proliferation of EpSCs in the basal layer of the epidermis are reduced in ANGPTL4-deficient mice.In vitro studies show that ANGPTL4 deficiency impedes EpSC proliferation,causes cell cycle arrest at the G1 phase and reduces the expressions of cyclins D1 and A2,which can be reversed by ANGPTL4 overexpression.ANGPTL4 deletion suppresses EpSC migration,which is also rescued by ANGPTL4 overexpression.Overexpression of ANGPTL4 in EpSCs accelerates cell proliferation and migration.Collectively,our results indicate that ANGPTL4 promotes EpSC proliferation by upregulating cyclins D1 and A2 expressions and accelerating the cell cycle transition from G1 to S phase and that ANGPTL4 promotes skin wound re-epithelialization by stimulating EpSC proliferation and migration.Our study reveals a novel mechanism underlying EpSC activation and re-epithelialization during cutaneous wound healing.Yuan Yang Chenghao Yu Yingying Le Weijuan Gong Jihui Ju Guangliang Zhang Pengxiang Ji Rui Zuo Zhe Liu Ping Zhang Ruixing Hou Yi Fu 2023Acta Biochimica et Biophysica Sinica2023,55,8:0
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