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| 1 | Global leaf nitrogen and phosphorus stoichiometry and their scaling exponent显示文摘Leaf nitrogen(N) and phosphorus(P) concentrations constrain photosynthetic and metabolic processes,growth and the productivity of plants. Their stoichiometry and scaling relationships regulate the allocation of N and P from subcellular to organism, and even ecosystem levels, and are crucial to the modelling of plant growth and nutrient cycles in terrestrial ecosystems. Prior work has revealed a general biogeographic pattern of leaf N and P stoichiometric relationships and shown that leaf N scales roughly as two-thirds the power of P. However, determining whether and how leaf N and P stoichiometries, especially their scaling exponents, change with functional groups and environmental conditions requires further verification. In this study, we compiled a global data set and documented the global leaf N and P concentrations and the N:P ratios by functional group, climate zone and continent. The global overall mean leaf N and P concentrations were 18.9 mg g^(-1) and 1.2 mg g^(-1), respectively, with significantly higher concentrations in herbaceous than woody plants(21.72 mg g^(-1) vs. 18.22 mg g^(-1) for N; and 1.64 mg g^(-1) vs. 1.10 mg g^(-1) for P). Both leaf N and P showed higher concentrations at high latitudes than low latitudes. Among six continents, Europe had the highest N and P concentrations(20.79 and 1.54 mg g^(-1)) and Oceania had the smallest values(10.01 and 0.46 mg g^(-1)). These numerical values may be used as a basis for the comparison of other individual studies. Further, we found that the scaling exponent varied significantly across different functional groups,latitudinal zones, ecoregions and sites. The exponents of herbaceous and woody plants were 0.659 and0.705, respectively, with significant latitudinal patterns decreasing from tropical to temperate to boreal zones. At sites with a sample size ≥10, the values fluctuated from 0.366 to 1.928, with an average of 0.841.Several factors including the intrinsic attributes of different life forms, P-related growth rates and relative nutrient availability of soils likely account for the inconstant exponents of leaf N vs. P scaling relationships. | Di Tian Zhengbing Yan Karl J.Niklas Wenxuan Han Jens Kattge Peter B.Reich Yongkai Luo Yahan Chen Zhiyao Tang Huifeng Hu Ian J.Wright Bernhard Schmid Jingyun Fang | 2018 | National Science Review2018，5，5： | 24 |
| 2 | Latitudinal pattern and the driving factors of leaf functional traits in 185 shrub species across eastern China显示文摘Aims To explore the pattern of the leaf functional traits of shrub species along a latitudinal gradient in eastern China and determine the driv-ing factors of leaf trait variation at a large scale.Methods We investigated the leaf thickness(LT),leaf area(LA),specific leaf area(SLA)and leaf dry mass content(LDMC)of 185 shrub species from 13 sites across eastern China.The trends of these four-leaf traits were ana-lyzed with respect to latitude,and the differences between different life forms(e.g.,evergreen and deciduous)and habitats(e.g.,understory and typical)were compared.We quantified the effects of the plant life forms and environmental factors on the leaf traits via mixed-model analyses.Important Findings The LT and LA decreased,whilst and the LDMC increased,as the latitude increased,and significant differences in these traits were observed between the different plant life forms.The LT and LA were smaller,whereas the SLA and LDMC were larger in decidu-ous shrubs than in evergreen shrubs.Among the different habitats,the LA and SLA were larger,while the LDMC was smaller in under-story shrubs than in typical shrub species.These results indicate that typical shrub species are better adapted to drier environments,as indicated by a reduced LT and increased LDMC.Furthermore,general linear models showed that variations in the four-leaf traits with respect to latitude were mainly caused by a shift in plant life forms. | Yongkai Luo Huifeng Hu Mengying Zhao He Li Shangshi Liu Jingyun Fang | 2019 | Journal of Plant Ecology2019，12，1： | 7 |
| 3 | Family-level leaf nitrogen and phosphorus stoichiometry of global terrestrial plants显示文摘Leaf nitrogen(N) and phosphorus(P) concentrations are critical for photosynthesis, growth, reproduction and other ecological processes of plants. Previous studies on large-scale biogeographic patterns of leaf N and P stoichiometric relationships were mostly conducted using data pooled across taxa, while family/genus-level analyses are rarely reported. Here, we examined global patterns of family-specific leaf N and P stoichiometry using a global data set of 12,716 paired leaf N and P records which includes 204 families, 1,305 genera, and 3,420 species. After determining the minimum size of samples(i.e., 35 records), we analyzed leaf N and P concentrations, N:P ratios and N^P scaling relationships of plants for 62 families with 11,440 records. The numeric values of leaf N and P stoichiometry varied significantly across families and showed diverse trends along gradients of mean annual temperature(MAT) and mean annual precipitation(MAP). The leaf N and P concentrations and N:P ratios of 62 families ranged from 6.11 to 30.30 mg g–1, 0.27 to 2.17 mg g–1, and 10.20 to 35.40, respectively. Approximately 1/3–1/2 of the families(22–35 of 62) showed a decrease in leaf N and P concentrations and N:P ratios with increasing MAT or MAP, while the remainder either did not show a significant trend or presented the opposite pattern. Family-specific leaf N^P scaling exponents did not converge to a certain empirical value, with a range of 0.307–0.991 for 54 out of 62 families which indicated a significant N^P scaling relationship. Our results for the first time revealed large variation in the family-level leaf N and P stoichiometry of global terrestrial plants and that the stoichiometric relationships for at least one-third of the families were not consistent with the global trends reported previously. The numeric values of the family-specific leaf N and P stoichiometry documented in the current study provide critical synthetic parameters for biogeographic modeling and for further studies on the physiological and ecological mechanisms underlying the nutrient use strategies of plants from different phylogenetic taxa. | Di Tian Zhengbing Yan Suhui Ma Yuehong Ding Yongkai Luo Yahan Chen Enzai Du Wenxuan Han Emoke Dalma Kovacs Haihua Shen Huifeng Hu Jens Kattge Bernhard Schmid Jingyun Fang | 2019 | Science China(Life Sciences)2019，62，8： | 7 |
| 4 | Release Connection Fingerprints in Social Networks Using Personalized Differential Privacy显示文摘In social networks, different users may have different privacy preferences and there are many users with public identities. Most work on differentially private social network data publication neglects this fact. We aim to release the number of public users that a private user connects to within n hops, called n-range Connection fingerprints(CFPs), under user-level personalized privacy preferences. We proposed two schemes, Distance-based exponential budget absorption(DEBA) and Distancebased uniformly budget absorption using Ladder function(DUBA-LF), for privacy-preserving publication of the CFPs based on Personalized differential privacy(PDP),and we conducted a theoretical analysis of the privacy guarantees provided within the proposed schemes. The implementation showed that the proposed schemes are superior in publication errors on real datasets. | LI Yongkai LIU Shubo LI Dan WANG Jun | 2018 | Chinese Journal of Electronics2018，27，5： | 5 |
| 5 | Differentially Private Spatial Decompositions for Geospatial Point Data显示文摘Technological advancements in data analysis and data releasing have put forward higher security requirements, such as privacy guarantee and strictly provable security, this new area of research is called differential privacy. As for geospatial point data, the exiting methods use the tree structure to split the data space to enhance the data utility and usually adopt uniform budgeting method. Different from this, we propose a novel non-uniform allocation scheme for privacy budget which is a parameter to specify the degree of privacy guarantee. Firstly, the spatial data is indexed by quadtree, then, different privacy budget is allocated to each layer of quadtree using Fibonacci series features, and we designate this budgeting method as Fibonacci allocation. Experimental results show that Fibonacci allocation is significantly more accurate in data queries than the state-of-the-art methods under the same privacy guarantee level and fits for arbitrary range queries. Furthermore, data utility can be improved by post-processing and threshold determination. | WANG Jun LIU Shubo LI Yongkai CAO Hui LIU Mengjun | 2016 | China Communications2016，13，4： | 5 |
| 6 | Pore structure of selected Chinese coals with heating and pressurization treatments显示文摘Pore structure of Chinese coals with heating and pressurization treatments was studied using small angle X-ray scattering(SAXS),N2adsorption/desorption isotherms and scanning electron microscope(SEM).SAXS was performed for some samples after heat treatment at seven elevated temperatures from 25 to 250°C at 0 MPa and for other samples with hydrostatic pressure treatment at 0,5,10,15 and 20 MPa at the room temperature.The results show that N2adsorption isotherm together with SAXS could be a comprehensive method to evaluate the pore shape and the pore size distribution:the pore shapes are generally spherical for low rank coal and they are mainly ellipsoidal for high rank coal.All these measurements were then interpreted using the fractal theory to reveal relationship between surface fractals and coal rank,and the evolution of surface fractals under heating and pressurization treatments.The results show that surface fractal dimension(Ds)changes with different treating temperature and pressure and maximum vitrinite reflectance(Ro,m).Especially in the bituminous stage,Ds shows an increasing trend with Ro,m under varied temperatures.Moreover,Ds shows an increasing trend with increasing temperature before 200°C,and a decreasing trend after 200°C.Furthermore,the results show that Ds has a more complex relationship with Ro,m under varied treating temperature than that under varied treating pressure. | CAI YiDong LIU DaMeng PAN ZheJun YAO YanBin LI JunQian QIU YongKai | 2014 | Science China Earth Sciences2014，57，7： | 5 |
| 7 | A new synthetic chelating collector for the flotation of oxidized-lead mineral显示文摘A new synthetic reagent DPTUHP [diphenyl α-(3-phenylthioureido) hexylphosphonate] containing a hydrocarbon chain nonpolar group, a thioureido, and a phosphonate easter chelating group, has proven to be an effective collector for the flotation of cerussite mineral. The synthetic method utilized the Mannich-type reaction of an N-monosubstituted thiourea, an aldehyde, and tri- phenyl phosphate in glacial acetic acid solution. The experimental results of flotation of the cerussite mineral show that the collector has stronger collecting ability and higher selectivity in a neutral and a slightly alkaline medium, especially in the pulp of pH=8. Using the measurements by infrared spectroscopy (IR) and X-ray photoelectron spectroscopy (XPS) of the cerussite mineral, the collector, as well as the cerussite treated with the collector, the flotation mechanism of cerussite has been discussed. It is concluded that the adsorp- tion of collector on cerussite is a chemical adsorption through the electron donor atoms of the collector chelating the Pb (Ⅱ) of cerussite to form chelate. | Yongkai Zhu Chuanyao Sun Weiguo Wu | 2007 | Journal of University of Science and Technology Beijing2007，14，1： | 4 |
| 8 | Synergism of essential oils with lipid based nanocarriers: emerging trends in preservation of grains and related food products显示文摘Grains are one of the major food staples in the world.The cereal grains are easily susceptible to damage by moisture content,flour beetles and food pathogens during storage,harvesting and post harvesting.Food preservative techniques namely drying,freezing,and dehydration,acquire little advantages.However,they cause few undesirable alterations in the organoleptic and nutritional properties of the preserved food items.Therefore,there is a continuous search for new preservation techniques in food industries,to satisfy the customer demands on the addition of natural food preservatives,devoid of pathogenic contaminants and without changes in organoleptic properties.Essential oils(EOs)have been predicted as“natural food additives”in the preservative process.The synergistic potential of EOs with various nanocarriers plays an emerging role in the food industry.Therefore,the present review has focused on the lipid based nanocarriers,and the methods used for the functionalization or encapsulation of EOs and applications in the preservation of food items such as cooked rice,rice flour,grains,sliced breads have also been discussed.The present review ascertains the antimicrobial significance of active EOs loaded lipid nanocarriers in the form of nano emulsions,solid lipid nanoparticles and liposomes for preserving grains and flours. | Satyavani Kaliamurthi Gurudeeban Selvaraj Lifen Hou Zhao Li Yongkai Wei Keren Gu Dongqing Wei | 2019 | Grain & Oil Science and Technology2019，2，1： | 4 |
| 9 | Privacy-preserving Distributed Location Proof Generating System显示文摘The rapid development of location-based service(LBS) drives one special kind of LBS, in which the service provider verifies user location before providing services. In distributed location proof generating schemes, preventing users from colluding with each other to create fake location proofs and protecting user's location privacy at the same time, are the main technical challenges to bring this kind of LBS into practical. Existing solutions tackle these challenges with low collusion-detecting efficiency and defected collusion-detecting method. We proposed two novel location proof generating schemes, which inversely utilized a secure secret-sharing scheme and a pseudonym scheme to settle these shortcomings. Our proposed solution resists and detects user collusion attacks in a more efficient and correct way. Meanwhile, we achieve a higher level of location privacy than that of previous work. The correctness and efficiency of our proposed solution is testified by intensive security analysis, performance analysis, as well as experiments and simulation results. | LIU Mengjun LIU Shubo ZHANG Rui Li Yongkai WANG Jun CAO Hui | 2016 | China Communications2016，13，3： | 3 |
| 10 | FINITE ELEMENT ANALYSIS OF TRASINENT TWO DIMENSIONAL CHANNEL FLOW WITH A SUDDEN EXPANSION显示文摘The finite element method is employed to simulate incompressible viscous unsteady flow in two dimensional channel with a sudden expansion. The streamline patterns and the velocity vector plots are presented at different expansion ratios and at different moment. The results obtained have certain significance to analyze the formation of eddies and energy loss in a sudden expansion channel flow and other complex channel flow. | Gao Dianrong Zhao Yongkai Wang Yiqun (Yanshan University) | 1999 | Chinese Journal of Mechanical Engineering1999，12，4： | 3 |
| 11 | Hydrological Impacts of Climate Change on Streamflow of Dongliao River Watershed in Jilin Province,China显示文摘The impacts of future climate change on streamflow of the Dongliao River Watershed located in Jilin Province,China have been evaluated quantitatively by using a general circulation model(HadCM3)coupled with the Soil and Water Assessment Tool(SWAT)hydrological model.The model was calibrated and validated against the historical monitored data from 2005 to 2009.The streamflow was estimated by downscaling HadCM3 outputs to the daily mean temperature and precipitation series,derived for three 30-year time slices,2020s,2050s and 2080s.Results suggest that daily mean temperature increases with a changing rate of 0.435℃per decade,and precipitation decreases with a changing rate of 0.761 mm per decade.Compared with other seasons,the precipitation in summer shows significant downward trend,while a significant upward trend in autumn.The annual streamflow demonstrates a general downward trend with a decreasing rate of 0.405 m3/s per decade.The streamflow shows significant downward and upward trends in summer and in autumn,respectively.The decreasing rate of streamflow in summer reaches 1.97 m 3 /s per decade,which contributes primarily to the decrease of streamflow.The results of this work would be of great benifit to the design of economic and social development planning in the study area. | ZHANG Lei LU Wenxi YANG Qingchun AN Yongkai LI Di GONG Lei | 2012 | Chinese Geographical Science2012，22，5： | 3 |
| 12 | Pore structure and its impact on CH 4 adsorption capacity and flow capability of bituminous and subbituminous coals from Northeast China显示文摘 | Yidong Cai Dameng Liu Zhejun Pan Yanbin Yao Junqian Li Yongkai Qiu | 2013 | Fuel2013，，： | 2 |
| 13 | Enantioselective Resolution of (±)-l-Phenylethyl Acetate by Using the Whole Cells of Deep-sea Bacterium Bacillus sp. DL-2显示文摘Bacillus sp. DL-2 was isolated from the deep sea of the Western Pacific and further utilized as novel biocatalysts to efficiently asymmetrically hydrolyze (±)-1-phenylethyl acetate. After the optimization of hydrolytic reactions, chiral chemicals (R)1-phenylethanol and (S)-l-phenylethyl acetate were obtained with high optical purities (96% and 99.8%, respectively). Our research is about the asymmeric hydrolysis of (±)-1-phenylethyl acetate using whole-cell biocatalysts. In addition, the optical purity of (S)-l-phenylethyl acetate generated through the kinetic resolution of (±)-1-phenylethyl acetate using the whole-cells of Bacillus sp. DL-2 was the highest report so far. Using the whole cells of deep sea bacterium Bacillus sp. DL-2 as the biocatalysts is an enviromnentally friendly method and will play critical roles in industrial asymmetric synthesis. | DONG Lu XU Yongkai ZHANG Yun SUN Aijun HU Yunfeng | 2019 | Chemical Research in Chinese Universities2019，35，5： | 2 |
| 14 | Utilization of One Novel Microbial Esterase WDEst9 in the Kinetic Resolution of (5)-Methyl 2-chloropropionate and (5)-Ethyl 2-chloropropionate显示文摘One novel microbial esterase WDEst9 from Dactylosporangium aurantiacum subsp. Hamdenensis NRRL 18085 was functionally characterized and the results demonstrated that the enantio-preference of WDEst9 was opposite to that of three other microbial esterases(BSE01701, PHE14 and Bae02030) in the kinetic resolution of racemic methyl lactate. We further investigated the potential of esterase WDEst9 in the kinetic resolution of both (±)-methyl 2-chloropropionate and (±)-ethyl 2-chioropropionate. The enantio-preference of WDEst9 was also interestingly opposite to that of esterases EST 12-7 and EstC10, and generated (S)-methyl 2-chloropropionate and (S)-ethyl 2-chloropropionate with high enantiomeric excess(both e.e.>98%) and high yield after many iterations of process optimization. Through genome mining, microbial esterase WDEst9 was characterized to be a novel esterase which may provide valuable complementary enantio-selectivity and possesses very good potential in the kinetic resolution of high value-added chiral chemicals. | WANG Yilong XU Yongkai ZHANG Yun SUN Aijun HU Yunfeng | 2019 | Chemical Research in Chinese Universities2019，35，5： | 2 |
| 15 | Yield and quality properties of silage maize and their influencing factors in China显示文摘Silage maize(Zea mays L.) is one of the most important forages in the world, and its yield and quality properties are critical parameters for livestock production and assessment of forage values. However, relationships between its yield and quality properties and the controlling factors are not well documented. In this study, we collected 5,663 observations from 196 publications across the country to identify the relationships between yield and quality properties of silage maize and to assess the impact of management practices and climatic factors on its yield and quality in China. The average dry matter yield of silage maize was(19.98±6.93) Mg ha^(-1), and the average value of crude protein, ether extract, crude ash, crude fiber, acid detergent fiber, neutral detergent fiber, nitrogen-free extract, and relative feed value was 7.86%±1.71%, 2.53%±1.01%, 5.05%±1.66%,23.97%±6.34%, 27.62%±7.12%, 51.60%±9.85%, 59.68%±7.72%, and 131.17±31.49, respectively. In general, its nutritive value decreased as its yield increased. Increasing planting density could increase the yield but inhibit the nutritive values, while increasing fertilization could benefit the nutritive values. Geographically, the yield increased and the nutritive value decreased from warm(south) to cold(north) regions. The length of growth duration was a major controlling factor for the patterns of these properties. Our findings provide insights for police-makers to make strategy for achieving high yield and good quality of silage maize and help local people to implement better management practices. | Mengying Zhao Yinping Feng Yue Shi Haihua Shen Huifeng Hu Yongkai Luo Longchao Xu Jie Kang Aijun Xing Shaopeng Wang Jingyun Fang | 2022 | Science China(Life Sciences)2022，65，8： | 2 |
| 16 | A new approach of proration-injection allocation for water-flooding mature oilfields显示文摘This paper presents a new method of injection-production allocation estimation for water-flooding mature oilfields.The suggested approach is based on logistic growth rate functions and several type-curve matching methods.Using the relationship between these equations,oil production and water injection rate as well as injection-production ratio can be easily forecasted.The calculation procedure developed and outlined in this paper requires very few production data and is easily implemented.Furthermore,an oilfield case has been analyzed.The synthetic and field cases validate the calculation procedure,so it can be accurately used in forecasting production data,and it is important to optimize the whole injection-production system. | Shuyong Hu Yongkai Li Ziwei Wang Guoqiang Hu | 2015 | Petroleum2015，1，1： | 2 |
| 17 | 2,000,000 fps 2D and 3D imaging of periodic or reproducible scenes with single-pixel detectors显示文摘Single-pixel imaging(SPI)can capture 2D images of the target with only a nonpixelated detector,showing promising application potential in nonvisible spectral imaging,low-photon imaging,lidar,and other extreme imaging fields.However,the imaging mechanism of traditional SPI makes it difficult to achieve high imaging speed,which is a primary barrier for its widespread application.To address this issue,in this work,we propose and demonstrate a novel high-speed 2D and 3D imaging scheme based on traditional SPI,termed time-resolved single-pixel imaging(TRSPI).Previous SPI works mainly utilize correlation between a stable target and iterative illumination masks to reconstruct a single image.In TRSPI,by further exploiting correlation information between a dynamic scene and every static mask,we can reconstruct a series of time-varying images of the dynamic scene,given the dynamic scene is repetitive or reproducible.Experimentally,we conducted 2D and 3D imaging on a rotating chopper with a speed of 4800 revolutions per minute(rpm),and imaging speeds up to 2,000,000 fps.It is believed that this technology not only opens up a novel application direction for SPI,but also will provide a powerful solution for high-speed imaging. | WENJIE JIANG YONGKAI YIN JUNPENG JIAO XIAN ZHAO BAOQING SUN | 2022 | Photonics Research2022，10，9： | 2 |
| 18 | Pre-sodiation strategy for superior sodium storage batteries显示文摘The irreversible consumption of sodium in the initial several cycles greatly led to the attenuation of capacity,which caused the low initial coulombic efficiency(ICE)and obvious poor cycle stability.Presodiation can effectively improve the electrochemical performance by compensating the capacity loss in the initial cycle.Here,carbon-coated sodium-pretreated iron disulfide(NaFeS_(2)@C)has been synthesized through conventional chemical method and used in sodium metal battery as a cathode material.The calculated density of states(DOS)of NaFeS2@C is higher,which implies enhanced electron mobility and improved cycle reversibility.Because of the highly reversible conversion reaction and the compensation of irreversible capacity loss during the initial cycle,the Na/NaFeS_(2)@C battery achieves ultrahigh initial coulombic efficiency(96.7%)and remarkable capacity(751 mA·h·g^(-1) at 0.1 A·g^(-1)).In addition,highly reversible electrochemical reactions and ultra-thin NaF-rich solid electrolyte interphase(SEI)also benefit for the electrochemical performance,even at high current density of 100 A·g^(-1),it still exhibits a reversible capacity of 136 mA·h·g^(-1),and 343 mA·h·g^(-1) after 2500 cycles at 5.0 A·g^(-1).This work aims to bring up new insights to improve the ICE and stability of sodium metal batteries. | Yongkai Xu Haozheng Sun Cunshuang Ma Jingjing Gai Yanhua Wan Weihua Chen | 2021 | Chinese Journal of Chemical Engineering2021，34，11： | 2 |
| 19 | Resorption efficiency of leaf nutrients in woody plants on Mt. Dongling of Beijing, North China显示文摘Aims To explore resorption efficiency of nitrogen(NrE)and phosphorus(PrE)of woody plants in relation to soil nutrient availability,climate and evolutionary history,in North China.Methods We measured concentrations of nitrogen([N])and phosphorus([P])in both full expanded mature green and senescent leaves of the same individuals for 88 woody species from 10 sites of mt.Dongling,beijing,China.We built a phylogenetic tree for all these species and compared NrE and PrE among life forms(trees,shrubs and woody lianas)and between functional groups(N-fixers and non-N-fixers).We then explored patterns of NrE and PrE along gradients of mean annual temperature(MAT),soil inorganic N and available P,and phylogeny using a general linear model.Important Findingsmass-based NrE(NrEm)and PrE(PrEm)averaged 57.4 and 61.4%,respectively,with no significant difference among life forms or functional groups.Neither NrEm nor PrEm exhibited significant phylogenetic signals,indicating that NrEm and PrEm were not phylogenetically conserved.NrEm was not related to[N]in green leaves;PrEm was positively correlated with[P]in green leaves;however,this relationship disappeared for different groups.NrEm decreased with[N]in senescent leaves,PrEm decreased with[P]in senescent leaves,for all species combined and for trees and shrubs.NrEm decreased with soil inorganic N for all species and for shrubs;PrEm did not exhibit a significant trend with soil available P for all species or for different plant groups.Neither NrEm nor PrEm was significantly related to MAT for overall species and for species of different groups. | Jianhua Zhang Zhiyao Tang Yongkai Luo Xiulian Chi Yahan Chen Jingyun Fang Haihua Shen | 2015 | Journal of Plant Ecology2015，8，5： | 2 |
| 20 | The Impact of Land Policy on the Relation between Housing and Land Prices:Evidence from China显示文摘 | Hongyan Du Yongkai Ma Yunbi An | | 0，，01： | 1 |
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