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| 1 | Generation of haploid embryonic stem cells from Macaca fascicularis monkey parthenotes显示文摘在从经由单性生殖和男性单性生殖的老鼠的胚胎的干细胞(haESCs ) 启用了在修改基因的动物的哺乳动物的房间和代的基因屏蔽的 haploid 的推导的最近的成功。然而, haESCs 是否能从首领被导出,仍然保持未知。这里,我们从 Macaca fascicularis 猴子的单性生殖的胚囊报导 haESCs 的推导。这些房间,作为 PG-haESCs 称为,是 pluripotent 并且能在 vitro 或在 vivo 区分到三胚胎的细菌层的房间。有趣地,一根猴子 PG-haESC 线(MPH1 ) 的 haploidy 与另一个(MPH2 ) 的相比是更稳定的,作为没有排序的激活荧光的房间(FACS ) ,由 haploid 房间的存在出现超过 140 天 haploid 房间的丰富。重要地,转基因的猴子 PG-haESC 线能被 lentivirus- 和 piggyBac 产生调停 transposon 的基因转移。而且,基因屏蔽在猴子 PG-haESCs 是可行的。我们的结果证明 PG-haESCs 能从猴子被产生,提供为在首领的基因分析的一个理想的工具。 | Hui Yang Zhen Liu Yu Ma Cuiqing Zhong Qi Yin Chikai Zhou Linyu Shi Yijun Cai Hanzhi Zhao Hui Wang Fan Tang Yan Wang Chenchen Zhang Xin-yuan Liu Dongmei Lai Ying Jin Qiang Sun Jinsong Li | 2013 | Cell Research2013，23，10： | 22 |
| 2 | Broadband interferometer observations of a triggered lightning显示文摘The development of positive leader of an artificially triggered lightning has been analyzed based on the data of electric field change, location of radiation source and frequency spectrum obtained by using the broadband interferometer system. The results indicate that radiation from positive leader could be detected within close distance in spite of the relatively weak radiation, while the radiation from negative breakdown processes was relatively stronger. Positive leader developed with few branches, and the initial progression velocity was of the order of 105 m/s. The distribution of power spectrum by 25 MHz high pass filter indicated that the radiation frequency from positive leader maximized at 25-30 MHz, while that from negative breakdown processes maximized at 60-70 MHz. | DONG Wansheng LIU Xinsheng YU Ye ZHANG Yijun | 2001 | Chinese Science Bulletin2001，46，18： | 9 |
| 3 | Assessment of the sources and transformations of nitrogen in a plain river network region using a stable isotope approach显示文摘The great spatial and temporal variability in hydrological conditions and nitrogen(N)processing introduces large uncertainties to the identification of N sources and quantifying N cycles in plain river network regions. By combining isotopic data with chemical and hydrologic measurements, we determined the relative importance of N sources and biogeochemical N processes in the Taige River in the East Plain Region of China. The river was polluted more seriously by anthropogenic inputs in winter than in summer. Manure and urban sewage effluent were the main nitrate(NO-3) sources, with the nitrification of N-containing organic materials serving as another important source of NO-3. In the downstream, with minor variations in hydrological conditions, nitrification played a more important role than assimilation for the decreasing ammonium(NH+4-N) concentrations.The N isotopic enrichment factors(ε) during NH+4utilization ranged from- 13.88‰ in March to- 29.00‰ in July. The ratio of the increase in δ18O and δ15N of river NO-3in the downstream was 1.04 in January and 0.92 in March. This ratio indicated that NO-3assimilation by phytoplankton was responsible for the increasing δ15N and δ18O values of NO-3in winter. The relationships between δ15N of particulate organic nitrogen and isotopic compositions of dissolved inorganic nitrogen indicated that the phytoplankton in the Taige River probably utilized NH+4preferentially and mainly in summer, while in winter, NO-3assimilation by phytoplankton was dominant. | Jingtao Ding Beidou Xi Qigong Xu Jing Su Shouliang Huo Hongliang Liu Yijun Yu Yanbo Zhang | 2015 | Journal of Environmental Sciences2015，27，4： | 9 |
| 4 | Development and validation of an endoscopic images-based deep learning model for detection with nasopharyngeal malignancies显示文摘Background:Due to the occult anatomic location of the nasopharynx and frequent presence of adenoid hyperpla-sia,the positive rate for malignancy identification during biopsy is low,thus leading to delayed or missed diagnosis for nasopharyngeal malignancies upon initial attempt.Here,we aimed to develop an artificial intelligence tool to detect nasopharyngeal malignancies under endoscopic examination based on deep learning.Methods:An endoscopic images-based nasopharyngeal malignancy detection model(eNPM-DM)consisting of a fully convolutional network based on the inception architecture was developed and fine-tuned using separate training and validation sets for both classification and segmentation.Briefly,a total of 28,966 qualified images were collected.Among these images,27,536 biopsy-proven images from 7951 individuals obtained from January 1st,2008,to December 31st,2016,were split into the training,validation and test sets at a ratio of 7:1:2 using simple randomiza-tion.Additionally,1430 images obtained from January 1st,2017,to March 31st,2017,were used as a prospective test set to compare the performance of the established model against oncologist evaluation.The dice similarity coef-ficient(DSC)was used to evaluate the efficiency of eNPM-DM in automatic segmentation of malignant area from the background of nasopharyngeal endoscopic images,by comparing automatic segmentation with manual segmenta-tion performed by the experts.Results:All images were histopathologically confirmed,and included 5713(19.7%)normal control,19,107(66.0%)nasopharyngeal carcinoma(NPC),335(1.2%)NPC and 3811(13.2%)benign diseases.The eNPM-DM attained an overall accuracy of 88.7%(95%confidence interval(CI)87.8%-89.5%)in detecting malignancies in the test set.In the prospective comparison phase,eNPM-DM outperformed the experts:the overall accuracy was 88.0%(95%CI 86.1%-89.6%)vs.80.5%(95%CI 77.0%-84.0%).The eNPM-DM required less time(40 s vs.110.0±5.8 min)and exhibited encouraging performance in automatic segmentation of nasopharyngeal malignant area from the background,with an average DSC of 0.78±0.24 and 0.75±0.26 in the test and prospective test sets,respectively.Conclusions:The eNPM-DM outperformed oncologist evaluation in diagnostic classification of nasopharyngeal mass into benign versus malignant,and realized automatic segmentation of malignant area from the background of nasopharyngeal endoscopic images. | Chaofeng Li Bingzhong Jing Liangru Ke Bin Li Weixiong Xia Caisheng He Chaonan Qian Chong Zhao Haiqiang Mai Mingyuan Chen Kajia Cao Haoyuan Mo Ling Guo Qiuyan Chen Linquan Tang Wenze Qiu Yahui Yu Hu Liang Xinjun Huang Guoying Liu Wangzhong Li Lin Wang Rui Sun Xiong Zou Shanshan Guo Peiyu Huang Donghua Luo Fang Qiu Yishan Wu Yijun Hua Kuiyuan Liu Shuhui Lv Jingjing Miao Yanqun Xiang Ying Sun Xiang Guo Xing Lv | 2018 | Cancer Communications2018，38，1： | 9 |
| 5 | Ocean surface wave measurements from fully polarimetric SAR imagery显示文摘A new method for the retrieval of ocean wave parameters from SAR imagery is developed,based on the shape-from-shading(SFS)technique.Previously,the SFS technique has been used in the reconstruction of 3D landform information from SAR images,in order to generate elevation maps of topography for land surfaces.Here,in order to retrieve ocean wave characteristics,we apply the SFS methodology,together with a method to orient the angular measurements of the azimuth slope and range slope,in the measurement of ocean surface waves.This method is applied to high resolution fine-quad polarization mode(HH,VV,VH and HV)C-band RADARSAT-2 SAR imagery,in order to retrieve ocean wave spectra and extract wave parameters.Collocated in situ buoy measurements are used to validate the reliability of this method.Results show that the method can reliably estimate wave height,dominant wave period,dominant wave length and dominant wave direction from C-band SAR images.The advantage of this method is that it does not depend on modulation transfer functions(MTFs),in order to measure ocean surface waves.This method can be used in monitoring ocean surface wave propagation through open water areas into ice-covered areas,especially the marginal ice zone(MIZ)in polar oceans. | XIE Tao William PERRIE HE YiJun LI HaiYan FANG He ZHAO ShangZhuo YU WenJin | 2015 | Science China Earth Sciences2015，58，10： | 6 |
| 6 | Effects of dissolved organic matter from sewage sludge on sorption of tetrabromobisphenol A by soils显示文摘Sorption of tetrabromobisphenol A (TBBPA) by soil influences its fate and transport in the environment. The presence of dissolved organic matter (DOM) may complicate the sorption process in soil. The effects of DOM from sewage sludge on TBBPA sorption by three soils were investigated using batch equilibration experiments in the study. DOM was observed to be sorbed on the soils and the isotherms could be fitted by the Langmuir model. The effects of DOM on TBBPA sorption were dependent on the characteristics of soils and the concentrations of DOM present. TBBPA sorption by Henan (HN) soil (sandy loam) and Liaoning (LN) soil (loamy clay) was promoted in the presence of DOM at low concentration ( 90 mg organic carbon (OC)/L), and the sorption was promoted by HN soil and inhibited by LN soil at DOM added concentration of 180 mg OC/L. TBBPA sorption by Guangxi (GX) soil (silt loam) was always inhibited in the presence of DOM. It was also found that the amount of TBBPA sorbed decreased with the increase in the solution pH value in the absence of DOM. The influencing mechanisms of DOM on the sorption of TBBPA by soils were also discussed. | Zhaohai SUN Hongxia YU | 2008 | Journal of Environmental Sciences2008，20，9： | 6 |
| 7 | 温带草原退化后土壤微生物群落结构和功能的变化显示文摘草原退化是草原生产力维持面临的一个重大挑战,这一过程显著影响着草原生态系统的能量流动和土壤养分变化过程,进而直接或间接地影响着土壤微生物。我们的研究目的首先是调查不同草原退化程度(即未退化、中度退化和严重退化)如何影响着内蒙古温带草原的土壤微生物组成、多样性和功能,其次是阐明哪些生物和非生物因素导致了这些变化。我们的研究主要通过高通量测序技术分析土壤微生物的群落组成,并且采用FAPROTAX工具和FUNGuild工具分别预测细菌群落和真菌群落的功能。研究发现:草原退化显著降低了土壤细菌的多样性,但对真菌多样性影响不大。地下生物量、土壤有机碳和总氮与细菌的多样性变化呈显著正相关关系。草原退化显著增加了绿弯菌门的相对丰度(由2.48%提高到8.40%),降低了厚壁菌门的相对丰度(由3.62%降低到1.08%)。其次,草原退化也显著增加了球囊菌门的相对丰度(从0.17%提高到1.53%),降低了担子菌门的相对丰度(从19.30%降低到4.83%)。致病菌的相对丰度在草原退化过程中显著下降。此外,草原退化对土壤细菌群落的功能有显著的影响,尤其是与土壤碳氮循环相关的土壤细菌群落。我们的结果表明,土壤细菌群落对草原退化的响应比真菌群落更敏感。 | Yang Yu Lang Zheng Yijun Zhou Weiguo Sang Jianing Zhao Lu Liu Chao Li Chunwang Xiao | 2021 | Journal of Plant Ecology2021，14，3： | 5 |
| 8 | Eddy properties in the Pacific sector of the Southern Ocean from satellite altimetry data显示文摘Mesoscale eddies play a key role in the ocean dynamics of the Southern Ocean, and eddy response to the climate changes has also been widely noted. Both eddy kinetic energy(EKE) and eddy detection algorithm are used to study the eddy properties in the Pacific sector of the Southern Ocean. Consistent with previous works,the maps of the EKE illustrate that higher energy confines to the Antarctic Polar Frontal Zone(APFZ) and decreases progressively from west to east. It also shows that the most significant increase in the EKE occurs in the western and central parts of the Pacific sector, where the baroclinicity of the Antarctic Circumpolar Current(ACC) is much stronger. Statistical eddy properties reveal that both of the spatial pattern and interannual variation of the EKE are primarily due to the eddy amplitude and the eddy rotational speed, rather than the eddy number or the eddy radius. In general, these results furtherly confirm that anomalous westerly wind forcing associated with the positive Southern Annular Mode(SAM) index enhances the Southern Ocean eddy activity by strengthening the eddy properties. | DUAN Yongliang LIU Hongwei YU Weidong HOU Yijun | 2016 | Acta Oceanologica Sinica2016，35，11： | 5 |
| 9 | 人工智能辅助会话式编程:一种性别包容的程序设计教学法显示文摘由于对计算机科学和职业的陌生和畏惧,技术落伍群体认识不到与真实世界之间存在的联系,使得将计算机程序设计教学普及到这些群体成为近年来的一项挑战。英国开放大学等机构通过使用技术手段设计开发教育类游戏等方式在STEM领域扩大学生参与度,使技术落伍群体(包括很多女性)提高对计算机编程的兴趣。本文使用以亚马逊语音技能工具包(ASK)为代表的人工智能工具,让学生通过语音会话式交互学习程序设计技术,探讨了如何把序列性会话转换为层次性决策树驱动的交互会话,提供了一种基于知识图谱的教学法,通过个人软件助理——'大声说程序'(Ask Program Aloud)引导人机对话。通过具体案例和用户参与,定性评估了使用'大声说程序'发起对话这个方法的有效性。结果表明,人工智能确实能够提升参与者对学习计算机编程技能的兴趣,既可以支持目前单向会话形式的计算机编程教学,也可以鼓励技术相对落伍的学习者群体获得计算机编程能力,进一步提高社交友好性和技能转化能力。 | 王筱竹 Joseph Osunde Danny Barthaud Yijun Yu | 2018 | 中国远程教育2018，0，8： | 5 |
| 10 | Engineering Ruthenium-Based Electrocatalysts for Effective Hydrogen Evolution Reaction显示文摘The investigation of highly effective,durable,and cost-effective electrocatalysts for the hydrogen evolution reaction(HER)is a prerequisite for the upcoming hydrogen energy society.To establish a new hydrogen energy system and gradually replace the traditional fossil-based energy,electrochemical water-splitting is considered the most promising,environmentally friendly,and efficient way to produce pure hydrogen.Compared with the commonly used platinum(Pt)-based catalysts,ruthenium(Ru)is expected to be a good alternative because of its similar hydrogen bonding energy,lower water decomposition barrier,and considerably lower price.Analyzing and revealing the HER mechanisms,as well as identifying a rational design of Ru-based HER catalysts with desirable activity and stability is indispensable.In this review,the research progress on HER electrocatalysts and the relevant describing parameters for HER performance are briefly introduced.Moreover,four major strategies to improve the performance of Ru-based electrocatalysts,including electronic effect modulation,support engineering,structure design,and maximum utilization(single atom)are discussed.Finally,the challenges,solutions and prospects are highlighted to prompt the practical applications of Rubased electrocatalysts for HER. | Yingjie Yang Yanhui Yu Jing Li Qingrong Chen Yanlian Du Peng Rao Ruisong Li Chunman Jia Zhenye Kang Peilin Deng Yijun Shen Xinlong Tian | 2021 | Nano-Micro Letters2021，13，10： | 5 |
| 11 | Precise fabrication of single-atom alloy co-catalyst with optimal charge state for enhanced photocatalysis显示文摘While the surface charge state of co-catalysts plays a critical role for boosting photocatalysis,studies on surface charge regulation via their precise structure control remain extremely rare.Herein,metal-organic framework(MOF)stabilized bimetallic Pd@Pt nanoparticles,which feature adjustable Pt coordination environment and a controlled structure from core-shell to single-atom alloy(SAA),have been fabricated.Significantly,apart from the formation of a Mott-Schottky junction in a conventional way,we elucidate that Pt surface charge regulation can be alternatively achieved by changing its coordination environment and the structure of the Pd@Pt co-catalyst,where the charge between Pd and Pt is redistributed.As a result,the optimized Pd10@Pt1/MOF composite,which involves an unprecedented SAA co-catalyst,exhibits exceptionally high photocatalytic hydrogen production activity,far surpassing its corresponding counterparts. | Yating Pan Yunyang Qian Xusheng Zheng Sheng-Qi Chu Yijun Yang Chunmei Ding Xi Wang Shu-Hong Yu Hai-Long Jiang | 2021 | National Science Review2021，8，1： | 4 |
| 12 | The 5400 a BP extreme weakening event of the Asian summer monsoon and cultural evolution显示文摘We explored a time series of the Asian summer monsoon(ASM) variability during the transition period from the middle to the late Holocene in the marginal Asian monsoon region. We used an absolutely dated ^(230)Th record with only a ~20-year dating error, and oxygen isotope data with an 8-year average temporal resolution from the top 22-mm segment of stalagmite WXB07-4 from Wanxiang Cave, western Loess Plateau. The ASM intensity weakened gradually from 6420 to 4920 a BP, which was mainly characterized by three phases:(1) a strengthening phase with a higher precipitation amount between 6420 and 6170 a BP;(2) a smooth fluctuating interval during 6170–5700 a BP; and(3) a sudden extreme weakening period from 5700 to 4920 a BP. Interestingly, the extreme weakening interval of the ASM occurred during the period between 5700 and 4920 a BP, an abrupt change dated at 5430 a BP, which is known as the 5400 a BP, or 5.4 ka BP, event. The period included 290 years of gradual weakening, and 350 years of slow strengthening. This was synchronous with some cave records from the Asian monsoon region within dating errors. Comparing with Chinese archaeological archives over the past 7000 years, the early decline of the Yangshao Culture in the Yellow River Basin and the Hongshan Culture in the West Liao River Basin occurred during the period of gradual decrease of ASM precipitation. The dramatic decline in precipitation, caused by the extreme weakening of the ASM at 5400 a BP,may have been partly related to the decline of the Miaodigou Culture at the Yangguanzhai site in the Weihe River valley; the middle Yangshao Culture in western Henan in the Yellow River Basin; the early Dawenkou Culture on the lower reaches of the Yellow River; and the middle Hongshan Culture in the west of the Liaohe River valley. During the later period of the 5400 a BP event(5430–4920 a BP), a small amplitude increase and a subsequent sharp decrease of ASM precipitation may have also been linked to the contemporaneous prosperity and disappearance of the late Yangshao and Hongshan cultures; the disappearance of the late Yangshao Culture represented by the Yangguanzhai site in the Guanzhong basin on the Weihe River; the fourth phase of the late Yangshao Culture on the upstream Dadiwan site; the beginning of the middle Dawenkou Culture, the formation of its late stage,and the rise of the Longshan culture; and the rise of the Qujialing and Liangzhu cultures on the lower Yangtze River. Compared with the stalagmite precipitation records on the Qinghai-Tibetan Plateau, the rise and expansion of the Majiayao Culture in the upper Yellow River valley at 5300 a BP may have also been connected to the more dramatic increase of the summer monsoon precipitation at higher, rather than lower, altitudes during the late 5400 a BP event. | BAI YiJun ZHANG PingZhong GAO Tao YU RenZhe ZHOU PengChao CHENG Hai | 2017 | Science China Earth Sciences2017，60，6： | 3 |
| 13 | Physicochemical and tribological properties of gemini-type halogen-free dicationic ionic liquids显示文摘A series of new halogen-free dicationic ionic liquids(ILs)with different alkyl chain lengths were prepared,and the relationship between the alkyl chain length,physicochemical and tribological properties of ILs,and their role as neat lubricant for steel–steel friction pairs,was investigated.Evaluation of stability during hydrolysis and copper strip corrosion test results show that synthetic ILs are stable and not corrosive to metal contacts,due to the halogen-free anions.The friction and wear test results indicate that ILs with long alkyl chains have excellent friction-reducing and anti-wear properties,especially at high temperatures.Based on the surface three-dimensional(3D)profiles,electrical contact resistance,scanning electron microscopy(SEM),energy dispersive X-ray spectroscopy(EDS),and the X-ray photoelectron spectrometry(XPS)analysis of the worn surfaces of steel discs,we can conclude that the efficiency of ILs is due to the formation of high quality tribofilms that consist of both tribochemical reaction and ordered absorption films. | Qiangliang YU Chaoyang ZHANG Rui DONG Yijun SHI Yurong WANG Yanyan BAI Jiaying ZHANG Meirong CAI Feng ZHOU Weimin LIU | 2021 | Friction2021，9，2： | 3 |
| 14 | Grain Growth Behavior of 5Cr21Mn9Ni4N Steel Micro-Alloyed by Rare Earth显示文摘Grain growth behavior of 5Cr21Mn9Ni4NRE steel was experimentally studied at various solid solution treatment temperatures and holding for different times. The experimental results show that the 5Cr21Mn9Ni4NRE steel has the feature of sharp austenite grain coarsening after solid solution treatment at the temperature above 1150 ℃. RE added in the steel has the benefit to restrain grain growth and increase grain growth activation energy. Grain growth mechanism is self-diffusion controlling process. The dispersed carbo-nitride in the steel greatly restrains grain growth. Solid solution treatment at the temperature below 1100 ℃ leads to little increase of grain size and little decrease of Rockwell hardness for mass carbo-nitride undissolved, whereas solid solution treatment at the temperature above 1150 ℃ leads to rapid grain coarsening and Rockwell hardness decrease. Grain growth exponent increases with the increasing solid solution treatment temperature. | Yu Shichang Wu Shenqing Gong Youjun Gong Yuansheng Lian Mingsheng Ye Gang Cheng Yijun | 2006 | Journal of Rare Earths2006，24，1： | 3 |
| 15 | Robust Finite-Time Trajectory Tracking Control of Wheeled Mobile Robots with Parametric Uncertainties and Disturbances显示文摘In this paper, a robust finite-time tracking control scheme is proposed for wheeled mobile robots with parametric uncertainties and disturbances. To eliminate the effect of lumped uncertainties,a nonlinear extended state observer(NESO) is employed to estimate the unknown states as well as uncertainties, and the corresponding coefficients are tuned via pole placement technique. Based on the observation values, the finite-time sliding mode controller is presented to guarantee that both the sliding mode variables and tracking errors converge to zero within finite time. Simulation results are given to demonstrate the effectiveness of the proposed control method. | GUO Yijun YU Li XU Jianming | 2019 | Journal of Systems Science & Complexity2019，32，5： | 3 |
| 16 | A critical literature review of bioretention research for stormwater management in cold climate and future research recommendations显示文摘 | Hannah Kratky Zhan Li Yijun Chen Chengjin Wang Xiangfei Li Tong Yu | 2017 | Frontiers of Environmental Science & Engineering2017，11，4： | 3 |
| 17 | Dynamic Response of Phragmites australis and Suaeda salsa to Climate Change in the Liaohe Delta Wetland显示文摘Because of its unique geographical location and ecological function, the Liaohe Delta Wetland is important in maintaining regional ecological balance and security. Monitoring and evaluating changes in the wetland are therefore of great importance. We used medium-and high-resolution satellite data, meteorological station data, and site measurement data to analyze changes in the area and spatial distribution of Phragmites australis and Suaeda salsa in the Liaohe Delta Wetland from 1998 to 2017, as well as their growth response to the climate change. The results showed that during 1998–2017, the areas of both P. australis and S. salsa wetlands alternated through periods of decreasing,increasing, and then decreasing trends. The annual change in the area and spatial distribution range of S. salsa fluctuated more than that of P. australis. The annual variation of normalized difference vegetation index(NDVI) in P. australis wetland showed an upward trend from 1998 to 2017. The area of P. australis cover that was improved, unchanged, and decreased accounted for 81.8%, 12.3%, and 5.9%, respectively, of the total area;evaporation and wind speed were the main meteorological factors affecting the NDVI;and contribution rates of the climate change and human activities to the NDVI were 73.2% and 26.8%, respectively. The area with vegetation cover being mainly S.salsa that was improved, unchanged, and decreased accounted for 63.3%, 18.3%, and 18.4%, respectively, of the total area;and no meteorological factors significantly affected the NDVI of S. salsa in the region. The interaction between vegetation growth and meteorological factors may help to explain the increasing trend in vegetation cover.The improvement in wetland vegetation also led to carbon sequestration and an increase in sequestration capacity. | Yushu ZHANG Wenying YU Ruipeng JI Yijun ZHAO Rui FENG Qingyu JIA Jinwen WU | 2021 | Journal of Meteorological Research2021，35，1： | 3 |
| 18 | On the dynamics and control of the Sun-Earth L_(2) tetrahedral formation显示文摘The dynamics and control of a tetrahedral spacecraft formation flying in the Sun-Earth L2 region is initiatively studied,based on the circular restricted three-body problem(CR3BP).Driven by the science goal of identifying extra-solar terrestrial planets and the requirement of imaging optics,a conceptional four-spacecraft triangular pyramid configuration has been proposed for the Multiple-spacecraft Exoplanet Aperture sYnthetic INterferometer(MEAYIN)project,China’s first mid-infrared interferometric imaging mission.Although it looked promising from an optical perspective,the configuration has not been verified dynamically.The formation is required to be virtually“rigid”,because its mutual distances and inertial pointing direction must be maintained with very high accuracy during each observation.In this study,the spatial geometrical relationship between the four spacecraft was established by introducing the parameters of lengths,angles,and a reference vector.The first contribution is that a compact set of normalized factors and critical time indices are defined,which can provide a complete description of the drift of the shape and pointing direction of the configuration,caused by the unstable dynamical environment.Five design variables are isolated and analyzed,and their individual impacts on the uncontrolled evolution of the formation are studied.The main results obtained reveal that the dimensions of the rigid configuration allow a free drift for a time period on the order of tens of hours,while the inertial pointing direction will be lost within merely tens of seconds.Therefore,to form a rigid configuration,the control challenge lies in the fact that control efforts are frequently required for each spacecraft in the fleet,owing to the diverging dynamics.As a second contribution,a simple and feasible control algorithm is proposed to maintain the rigidity of the formation configuration.The results indicate that the associated energy cost is merely 0.05 m/s per observation on average. | Yijun Lian Zhuoxi Huo Yu Cheng | 2021 | Astrodynamics2021，5，4： | 2 |
| 19 | Analysis of the relationship between bile duct and duodenal microbiota reveals that potential dysbacteriosis is the main cause of primary common bile duct stones显示文摘Bacteria play an important role in the formation of primary Common Bile Duct(CBD)stones.However,the composition and function of the microbiota of bile duct in patients with primary CBD stones remained to be explored.We utilized the 16S rRNA gene high-throughput sequencing technology to analyze the microbial diversity and community composition of biliary and duodenal microbiota in 15 patients with primary CBD stones and 4 patients without biliary tract diseases.Alpha diversity analysis showed that the microbiota richness was similar in bile and intestinal fluid;Beta diversity analysis showed that there were differences in the composition between biliary microbiota and the duodenal microbiota,but the abundance of the main groups showed similarities.The composition of the biliary microbiota from gallstone patients was more complex,as was the duodenal microbiota.Proteobacteria and Firmicutes were the dominant bacteria at phylum level,accounting for at least 75%of the total reads in each subgroup.Pseudomonas and EscherichiaShigella were the major genus among subgroups,but Escherichia-Shigella had increased abundance in duodenal microbiota with primary choledocholithiasis,which may play an important role in stone formation.It is noteworthy that Clostridiumsensu_stricto,Lachnospiraceae_UCG-008,Butyrivibrio and Roseburia which could produce short chain fatty acids(SCFAs),were significantly decreased in biliary microbiota with primary CBD stones(p<0.05).Our study provided new insights into the compositional of normal biliary microbiota.The micro-ecology of biliary and duodenal in patients with stones is complex and closely related,and there is a potential for dysbacteriosis.The decrease in abundance of certain major acid-producing bacteria affects the health of the biliary tract and thus leads to the formation of stones. | Zhitang Lyu Tingting Yu Lichao Zhang Xiaona Xu Yijun Zhang Jihong Li Zhirong Li Wei Zhang Senlin Hou | 2021 | Synthetic and Systems Biotechnology2021，6，4： | 2 |
| 20 | Single atomic cobalt electrocatalyst for efficient oxygen reduction reaction显示文摘Robust oxygen reduction reaction(ORR)catalysts are essential for energy storage and conversion devices,but their development remains challenging.Herein,we design a single-atom catalyst featuring isolated Co anchored on nitrogen-doped carbon(Co-SAC/NC)via a highly efficient“plasma-bombing”strategy.With a high loading(up to 2.5wt%),the well-dispersed single Co atoms in Co-SAC/NC give it robust ORR performance in an alkaline medium.It also demonstrates excellent battery performance when implemented as the air-cathode catalyst in a zinc-air battery(ZAB).Theoretical calculations reveal that the Co-N_(4)moiety experiences an“extraction/recovery”structural evolution during the ORR process,and the reaction's rate-determining step is the formation of OOH∗(reaction intermediate).This work provides a new strategy for designing robust ORR catalysts for high-performance ZABs and other energy-conversion devices. | Peng Rao Daoxiong Wu Tian-Jiao Wang Jing Li Peilin Deng Qi Chen Yijun Shen Yu Chen Xinlong Tian | 2022 | eScience2022，2，4： | 2 |
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