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Quantitative Analysis of Relationships Between Crack Characteristics and Properties of Soda-saline Soils in Songnen Plain, China

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Chinese Geographical Science 2015年第5期25卷 591-601页

作者： REN Jianhua li xiaojie ZHAO Kai Northeast Institute of Geography and Agroecology Chinese Academy of Sciences University of Chinese Academy of Sciences Changchun Jingyuetan Remote Sensing Experiment Station Chinese Academy of Sciences

The Songnen Plain has a typical soda-saline soil, which often shrinks and cracks under natural conditions during water evaporation. This study aims to analyze the relationships between the crack characteristics and the soil properties of soda-saline soils quantitatively, and attempts to establish prediction models for the main soil properties of soda-saline soils based on the results. In order to achieve these objectives, a desiccation cracking test was conducted using 17 soil specimens with different salinity levels under controlled laboratory conditions. Correlation analysis was then performed between the crack characteristics and the soil properties. The results indicate that the crack characteristics can well represent the surface appearances of cracked soils, they also can well distinguish the salinity levels of soda-saline soils while the clay contents and mineralogical compositions of soils are stable. Among the crack characteristics, crack length has the best relationships with the salinity levels of soda-saline soils. Specifically, the crack length has high correlation(R2 > 0.87) with the electrical conductivity(EC), Na+, CO32– and the salinity, it also has reasonable relationship(R2 > 0.68) with HCO3–, this indicates crack length can be well used for the prediction of these properties of soda-saline soils.

关键词： soil salinization soda-saline soil desiccation cracking salinity texture features

Transcriptome analysis of kelp Saccharina japonica unveils its weird transcripts and metabolite shift of main components at different sporophyte developmental stages

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Journal of Oceanology and limnology 2019年第2期37卷 640-650页

作者： DING Haiyan GUO li li xiaojie YANG Guanpin College of Marine life Sciences Ocean University of China Qingdao 266003 China Shandong Oriental Ocean Sci-Tech Co. Ltd. Yantai 264003 China Key Laboratory of Marine Genetics and Breeding of Ministry of Education Ocean University of China Qingdao 266003 China Institutes of Evolution and Marine Biodiversity Ocean University of China Qingdao 266003 China

Saccharina japonica is an economically important cold water brown alga extensively cultivated in China. It is cultivated upside down under a floating rope net with its holdfast and meristematic area facing sunlight and UV irradiation and its blade tip toward dark, and other worse cultivation environmental factors also make S . japonic a face more stresses. In this study, S . japonica transcriptomes corresponding to its four developmental stages were analyzed. In total, 7 800 genes predicted in the genome were transcribed. We found that 1 208 of the 7 800 expressed and 2 697 annotated were virus associating genes. Of 778 diff erentially expressed genes (DEGs), 372 were annotatable and 209 were virus associating. Such portion of virus associating genes indicated that the S . japonica genome contained a large portion of active virus originating genes. It was found that the transcripts abundance associated with sugar biosynthesis was about 2.13 folds of all the expressed, indicating that the biosyntheses of structural and storage sugars were very important cellular processes. The total abundance of genes involved in the biosynthesis of alginate and laminarin were similar among all developmental stages, however, that of genes involved in the biosynthesis of mannitol increased about 2-folds from mushroom and adult stages to mature and aging stages. This trend explained our observation that the content of alginate was almost constant at diff erent development stages, while that of mannitol increased sharply. In addition, we found that a set of defense and cell recurring genes highly expressed and many of them expressed diff erentially among stages. On average, the sum abundance of the transcripts of these genes at four stages were 3.40-and 4.96-folds of all the annotated and all the expressed, respectively. This indicated that S . japonica sporophytes persistently respond possible pathogen and environment stresses. The findings are important for timing S . japonica harvest

关键词： Saccharina japonica transcriptome developmental stage sugar biosynthesis defense

DCT domain filtering method for multi-antenna code acquisition

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Journal of Systems Engineering and Electronics 2013年第5期24卷 734-741页

作者： xiaojie li Luping Xu Shibin Song Hua Zhang School of Electronic Engineering Xidian University

For global navigation satellite system （GNSS） signals in Gaussian and Rayleigh fading channel, a novel signal detection algorithm is proposed. Under the low frequency uncertainty case, after performing discrete cosine transform （DCT） to the outputs of the partial matched filter （PMF） for every antenna, the high order com- ponents in the transforming domain will be filtered, then the equalgain （EG） combination for the inverse discrete cosine transform （IDCT） reconstructed signal would be done subsequently. Thus, due to the different frequency distribution characteristics between the noise and signals, after EG combination, the energy of signals has almost no loss and the noise energy is greatly reduced. The theoretical analysis and simulation results show that the detection algorithm can effectively improve the signal-to-noise ratio of the captured signal and increase the probability of detection under the same false alarm probability. In addition, it should be pointed out that this method can also be applied to Rayleigh fading channels with moving antenna.

关键词： acquisition detection fading discrete cosine transform (DCT) partial matched filter (PMF) probability of false alarm probability of detection.

Structural engineering design of carbon dots for lubrication

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Chinese Chemical Letters 2021年第9期32卷 2693-2714页

作者： Chuang He Shuang E Honghao Yan xiaojie li State Key Laboratory of Structural Analysis for Industrial Equipment Dalian University of TechnologyDalian 116024China Research Center for Analytical Sciences Northeastern UniversityShenyang 110819China

Carbon dots(CDs)have opened up a new field of carbon nanomaterials and successively attracted increasing attention since their discovery in *** to their ultrasmall size,tunable surface functional groups,excellent dispersibility,attractive stability,low toxicity,environmental friendliness,facile synthesis and low-cost precursors,CDs have been developed as green and promising frictionreducing and anti-wear materials in lubrication science,applied to energy conservation and extension of mechanical service life in recent ***,there are few reviews focusing on the application of CDs in the important field of *** this review,we comprehensively summarize the development of CDs in lubrication for the first ***,three strategies for structural engineering design of CDs to improve their tribological characteristics are fully analyzed,in terms of size and shape control,surface modification and heteroatom ***,the advance in lubrication application of CDs,including CDs as additives for lubricants,greases,gel and magnetorheological fluids as well as CDs as lubricating coatings,is systematically ***,the lubricating mechanisms of CDs as additives are introduced in ***,the remaining major challenges and opportunities for CDs in lubrication field are discussed and outlined.

关键词： Carbon dots Lubrication Tribological characteristics Lubricating mechanism

Degradation of dissolved organic matter in effluent of municipal wastewater plant by a combined tidal and subsurface flow constructed wetland

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Journal of Environmental Sciences 2021年第8期33卷 171-181页

作者： Chunjian Lyu Ruixia liu xiaojie li Yonghui Song Hongjie Gao Basin Research Center for Water Pollution Control Chinese Research Academy of Environmental SciencesBeijing 100012China College of Water Sciences Beijing Normal UniversityBeijing 100875China

Dissolved organic matter(DOM)is an important constituent of wastewater treatment plant(WWTP)effluent.A novel combined tidal and subsurface flow constructed wetland(TF-SSFCW)of 90 L was constructed for a ten-month trial of advanced treatment of the WWTP *** emission matrix(EEM)fluorescence spectroscopy,parallel factor(PARAFAC)analysis and a two end-member mixing model were employed to characterize the composition and removal process of the effluent DOM(EfOM)from the *** results showed that the TF-SSF-CW performed an efficient EfOM removal with dissolved organic carbon(DOC)removal rate of 88%and dissolved organic nitrogen(DON)removal rate of 91%.Further analysis demonstrated that the EfOM consisted mainly of two protein moieties and two humic-like groups;protein moieties(76%)constituted the main content of EfOM in raw water and humic-like groups(57%)became the dominating contributor after *** EfOM from the WWTP was mainly of aquatic bacterial origin and evolved to a higher proportion of terrigenous origin with higher humification in the TF-SSF-CW effluent.A common controlling treatment-related factor for determining the concentrations of the same kind of substances(protein groups or humic-like groups)was revealed to exist,and the ratio of removal rates between the same substances in treatment was *** study demonstrates that the TF-SSF-CW can be a novel and effective treatment method for the EfOM from WWTPs,and is helpful for understanding of the character of EfOM in wetland treatment.

关键词： Constructed wetland Effluent organic matter Excitation emission matrices PARAFAC analysis

Orbit determination and prediction for Beidou GEO satellites at the time of the spring/autumn equinox

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Science China(Physics,Mechanics & Astronomy) 2015年第8期58卷 86-94页

作者： li xiaojie ZHOU JianHua HU XiaoGong liU li GUO Rui ZHOU ShanShi Beijing Satellite Navigation Center Shanghai Key Laboratory of Space Navigation and Position Techniques Shanghai Astronomical Observatory Chinese Academy of Sciences

Geostationary(GEO) satellites form an indispensable component of the constellation of Beidou navigation system(BDS). The ephemerides, or predicted orbits of these GEO satellites(GEOs), are broadcast to positioning, navigation, and timing users. User equivalent ranging error(UERE) based on broadcast message is better than 1.5 m(root formal errors: RMS) for GEO satellites. However, monitoring of UERE indicates that the orbital prediction precision is significantly degraded when the Sun is close to the Earth's equatorial plane(or near spring or autumn Equinox). Error source analysis shows that the complicated solar radiation pressure on satellite buses and the simple box-wing model maybe the major contributor to the deterioration of orbital precision. With the aid of BDS' two-way frequency and time transfer between the GEOs and Beidou time(BDT, that is maintained at the master control station), we propose a new orbit determination strategy, namely three-step approach of the multi-satellite precise orbit determination(MPOD). Pseudo-range(carrier phase) data are transformed to geometric range(biased geometric range) data without clock offsets; and reasonable empirical acceleration parameters are estimated along with orbital elements to account for the error in solar radiation pressure modeling. Experiments with Beidou data show that using the proposed approach, the GEOs' UERE when near the autumn Equinox of 2012 can be improved to 1.3 m from 2.5 m(RMS), and the probability of user equivalent range error(UERE)<2.0 m can be improved from 50% to above 85%.

关键词： Beidou system (BDS) Beidou time (BDT) geostationary (GEO) satellite spring equinox/autumn equinox solar radia-tion pressure time synchronization user equivalent ranging error

A novel algorithm to identifying vehicle travel path in elevated road area based on GPS trajectory data

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Frontiers of Earth Science 2012年第4期6卷 354-363页

作者： Xianrui XU xiaojie li Yujie HU Zhongren PENG School of Transportation Engineering Tongji University Shanghai 201804 China ZTE Corporation Nanji-ng 210012 China Department of Geography and Anthropology Louisiana State University Baton Rouge LA 70803 USA Department of Urban and Regional Planning University of Florida Gainesville FL 32611 USA

In recent years, the increasing development of traffic information collection technology based on floating car data has been recognized, which gives rise to the establishment of real-time traffic information dissemina- tion system in many cities. However, the recent massive construction of urban elevated roads hinders the processing of corresponding GPS data and further extraction of traffic information （e.g., identifying the real travel path）, as a result of the frequent transfer of vehicles between ground and elevated road travel. Consequently, an algorithm for identifying the travel road type （i.e., elevated or ground road） of vehicles is designed based on the vehicle traveling features, geometric and topological characteristics of the elevated road network, and a trajectory model proposed in the present study. To be specific, the proposed algorithm can detect the places where a vehicle enters, leaves or crosses under elevated roads. An experiment of 10 sample taxis in Shanghai, China was conducted, and the comparison of our results and results that are obtained from visual interpretation validates the proposed algo- rithm.

关键词： GPS trajectory trajectory segmentation road road vehicle status identification network modeling elevated

Multiple Mobile Sinks Data Dissemination Mechanism for Large Scale Wireless Sensor Network

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China Communications 2014年第A01期11卷 1-8页

作者： XIE Dongliang WU xiaojie li Dan SUN Jia StateKeyLaboratoryofNetworkingandSwitchingTechnology BeijingUniversityofPostsandTelecommunicationsBeijing100876China.

WSN has been developing from traditional environment monitoring applications to the ubiquitous information services such as the Congestion-oriented Intelligent Transportation System （ColTS）. However, the mobility of nodes makes data dissemination a hard nut to crack. In this paper, we propose MSDD, a multiple mobile sinks data dissemination mechanism for solving the dissemination problem. The main ideas of MSDD are constructing a two-tier grid structure by a designated sink, exploiting a hierarchical monitoring mechanism, and employing a global agent to track the sink locations in order to make the emergencies reported to the sinks immediately, In addition, MSDD supports the query-driven data dissemination. Being compared with TTDD, MSDD is theoretically proved to have less communication overhead. We also validate MSDD outperforms TTDD in reliability and the emergency delivery latency bv simulations.

关键词： ubiquitous information services multiple-mobile sink hierarchical monitoring two-tier grid global agent query-driven

Application of naturalβ-glucans as biocompatible functional nanomaterials

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Food Science and Human Wellness 2019年第4期8卷 315-319页

作者： xiaojie li Peter Chi Keung Cheung Food and Nutritional Sciences School of Life SciencesThe Chinese University of Hong KongHong KongChina

Naturally-occurringβ-glucans are mostly investigated for their antitumor activity and immunomodulatory *** have been widely regarded as a natural source for functional foods and ***,the physico-chemically stable and biocompatible properties ofβ-glucans are rarely explored as a coating material for nanomaterials to overcome the problems of aggregation and *** article reviews on the exploration ofβ-glucans,in particular those derived from mushrooms,as a natural coating material to modify the surface properties of bioactive substances as a relatively simple and cost-effective strategy to produce stable and biocompatible nanohybrids used for biopharmaceutical *** is envisaged that suchβ-glucan-based coating method will provide new opportunities to design biocompatible functional nanomaterials for wider clinical applications.

关键词： β-Glucans Biocompatibility Biopharmaceuticals Nanohybrids