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Nitrogen Mineralization in Soils Along a Vegetation chronosequence in Hong Kong

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Pedosphere 2005年第2期15卷 181-188页

作者： L.M.MARAFA K.c.cHAU centre for Environmental Policy and Resource Management Centre for Environmental Policy and Resource Management Department of Geography and Resource ManagementThe Chinese University of Hong KongShatinNew TerritoriesHong Kong (China)Department of Geography and Resource ManagementThe Chinese University of Hong KongShatinNew TerritoriesHong Kong (China)

This research examined nitrogen mineralization in the top 10 cm of soils along a vegetation gradient in Hong Kong at sites where fire has been absent for 0, 1, 3, 6 and 17 years (at the time of the study), and the relationships between N mineralization and successional development of vegetation in the absence of fire. The sites including a newly burnt area (S1), short grassland (S2), tall grassland (S3), mixed tall grassland and shrubland (S4), and woodland (S5) were selected,and the in situ core incubation method was used to estimate nitrogen mineralization. Throughout the 60-day incubation in four periods, more nitrogen was mineralized at the S3 and S4 sites, the predominantly grassland sites, which contained the highest levels of soil organic matter (SOM) and total Kjeldahl nitrogen (TKN), than the S1 site, while immobilization occurred at the S2 and S5 sites. Leaching loss decreased with successional development of the vegetation, in the order of S1 ＞ S2 ＞ S3 ＞ S4 ＞ S5. The pattern of nitrogen uptake with ecological succession was less conspicuous, being complicated by the immediate effect of fire and possibly the ability of the woodland species to extract nitrogen from the deeper *** the absence of fire for 3 to 6 years, the build-up of SOM and TKN was accompanied by active mineralization, thus paving the way for the invasion of shrub and tree species. A close relationship existed between nitrogen mineralization and ecological succession with this vegetation gradient. Inherent mechanisms to preserve nitrogen in a fire-prone environment including immobilization and uptake and the practical relevance of nitrogen mineralization to reforestation are discussed.

关键词：氮矿化连续发展植被生长序列火灾影响土壤有机氮

Sideband-controllable soliton pulse with bismuth-based erbium-doped fiber

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chinese Optics Letters 2015年第11期13卷 62-64页

作者： S.J.Tan Z.c.Tiu S.W.Harun H.Ahmad School of Engineering KDU University CollegeGlenmarie Campus Department of Electrical Engineering Faculty of EngineeringUniversity of Malaya Photonics Research center University of Malaya

A sideband-controllable soliton mode-locked erbium-doped fiber laser is successfully demonstrated utilizing the nonlinear polarization rotation technique. The sidebands can be produced or suppressed by performing simple polarization light tuning with a polarization controller. It is believed that the elimination of the sidebands is due to the dispersive waves that are filtered out by the polarization-dependent isolator in the resonator. With the elimination of the Kelly sidebands, the obtained 3 d B bandwidth is 10.6 nm and the attainable pulse duration is0.86 ps. In this experiment, it is proven that the existence of Kelly sidebands limits the attainable pulse duration.

关键词： EDFA Sideband-controllable soliton pulse with bismuth-based erbium-doped fiber mode

绝对动脉期超增强能否提高cT对不确定结节中肝细胞癌检测的敏感性

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国际医学放射学杂志 2024年第3期 377-377页

作者： S.Zafar K.Y.Elbanna A.W.M.Todd L.Guimaraes c.O'Brien A.Goel 余翔玲

摘要目的确定在cT上对不确定性结节进行相对（R）和绝对（A）动脉期过度增强（APHE）和廓清（WO）的定量评估，能否提高肝细胞癌（Hcc）检测的总体敏感性。方法回顾

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current Transport in copper Schottky contacts to a−Plane/ c−Plane n-Type MoSe_(2)

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chinese Physics Letters 2011年第8期28卷 254-257页

作者： c.K.Sumesh K.D.Patel V.M.Pathak R.Srivastav Department of Physics Faculty of Technology and EngineeringCharotar University of Science and TechnologyCHANGA 388421GujaratIndia Department of Physics Sardar Patel UniversityVallabh Vidyanagar 388120GujatatIndia

We identically prepared cu-nMoSe_(2)(a−plane)and cu-nMoSe_(2)(c−plane)Schottky barrier diodes(SBDs)on the same n-type MoSe_(2) single *** effective Schottky barrier heights(SBHs)and ideality factors were obtained from the current−voltage-temperature(I–V–T)*** barrier height and ideality factor,estimated from the conventional thermionic emission model by assuming a Gaussian barrier distribution,are highly dependent on temperature.A notable deviation from the theoretical Richardson constant value is also observed in the conventional Richardson *** decrease in the experimental barrier heightΦB0 and an increase in the ideality factor n with a decrease in temperature have been explained on the basis of barrier height inhomogeneities at the metal−semiconductor *** is proven that the presence of a distribution of barrier heights is responsible for the apparent decrease of the zero bias barrier *** voltage dependence of the standard deviation causes the increase of the ideality factor at low *** value of the Richardson constant obtained without considering the inhomogeneous barrier heights is much closer than the theoretical *** cu-nMoSe_(2)(a−plane)Schottky diode shows better results in comparison with the nMoSe_(2)(c-plane)Schottky diode.

关键词： Schottky temperature ideality

Gender Role,But Not Sex,Shapes Humans’Susceptibility to Emotion

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Neuroscience Bulletin 2021年第2期37卷 201-216页

作者： Jiajin Yuan Hong Li Quanshan Long Jiemin Yang Tatia M.c.Lee Dandan Zhang The Laboratory for Affect cognition and Regulation Institute of Brain and Psychological SciencesSichuan Normal UniversityChengdu 610068China college of Psychology Shenzhen UniversityShenzhen 518060China Faculty of Psychology Southwest UniversityChongqing 400715China Department of Psychology The University of Hong KongHong Kong 999077China Shenzhen-Hong Kong Institute of Brain Science Shenzhen 518060China Shenzhen Institute of Neuroscience Shenzhen 518060China

It is unknown whether the famous sex-related difference in emotion processing is accounted for by biological sex,gender role,or their *** clarify the issue,in Study 1 we recorded event-related potentials in response to negative and positive images of diverse intensities when 47 masculine(26 males)and 47 feminine(22 males)subjects performed a non-emotional *** occipital P1 and N1 amplitudes were larger in women than in men,while feminine subjects showed larger N1 amplitudes than masculine subjects,regardless of ***,feminine subjects showed enhanced frontocentral N2(210–270 ms)amplitudes for highly and mildly negative than for neutral stimuli,while masculine subjects showed an emotion effect only for highly negative *** feminine-specific effect for mildly negative stimuli was positively correlated to the feminine score,and this correlation was located to the anterior cingulate and the superior and medial frontal ***,feminine but not masculine subjects showed enhanced parietal P3(330–560 ms)amplitudes for highly and mildly positive than for neutral stimuli,an effect positively related to the feminine score and localized to the precuneus,posterior cingulate,and superior temporal *** learning analyses verified that single-trial N2 and P3 amplitudes of feminine subjects reliably discriminated the intensity of negative and positive stimuli,*** ecological considerations,in Study 2 we used an observational approach(n=300)and confirmed that feminine gender role,rather than biological sex,predicted individual differences in daily experience of emotion-related psychopathological *** findings provide solid evidence for the critical impact of gender role rather than sex on emotional susceptibility.

关键词： Sex difference Gender role Emotional susceptibility Event-related potential Machine learning

Mechanical Properties and Defective Effects of 316LN Stainless Steel by First-Principles Simulations

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Journal of Materials Science & Technology 2011年第11期27卷 1029-1033页

作者： X.Q. Li J.J. Zhao J.c. Xu X. Liu Key Laboratory of Materials Modification by Laser Ion and Electron Beams Ministry of Education Dalian University of Technology Dalian 116024 China college of Advanced Science and Technology Dalian University of Technology Dalian 116024 China School of chemical Engineering Dalian University of Technology Dalian 116024 China

In current International Thermonuclear Experimental Reactor （ITER） design, the 316LN austenitic stainless steel （316LN SS） is used for first-wall/blanket structures. Thus, it is necessary to study the fundamental mechanical properties and irradiation effect of 316LN SS. A random solid solution model of Fe-cr-Ni-Mn- Mo-Si alloy is used for describing 310LN S$. Using first-principles approaches, the elastic constants and ideal strength of the alloy were calculated. Such alloy exhibits good ductile behavior according to the theoretical values of cauchy pressure and ratio of bulk modulus and shear modulus. Within the 256-atom supercell, inclusion of single vacancy defect further enhances the ductility of the alloy, and the existence of interstitial （Fe, H, He） atoms enhances the Young＇s modulus.

关键词： Stainless steel Mechanical properties Vacancy Interstitial

Behavioural and energetic consequences of competition among three overwintering swan(cygnus spp.)species

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Avian Research 2021年第4期12卷 707-721页

作者： Kevin A.Wood Julia L.Newth Geoff M.Hilton Eileen c.Rees Wildfowl&Wetlands Trust SlimbridgeGloucestershire GL27BTUnited Kingdom centre for Ecology and conservation/Environment and Sustainabil-ity Institute College of Life and Environmental SciencesUniversity of ExeterExeter TR109EZUnited Kingdom Department of Zoology University of CambridgeDowning StreetCambridge CB23EJUnited Kingdom

Background:Winter numbers of the northwest European population of Bewick's Swans(cygnus columbianus bewickii)declined recently by c.40%.During the same period,numbers of two sympatric and ecologically-similar congeners,the Mute Swan(cygnus olor)and Whooper Swan(cygnus cygnus)showed increases or *** has been suggested that these opposing population trends could have a causal relationship,as Mute and Whooper Swans are larger and competitively dominant to Bewick's Swans in foraging *** so,effects of competition of Mute and Whooper Swans on Bewick's Swans should be detectable as measurable impacts on behaviour and ***:Here,we studied the diurnal behaviour and energetics of 1083 focal adults and first-winter juveniles("cygnets")of the three swan species on their winter grounds in eastern *** analysed video recordings to derive time-activity budgets and these,together with estimates of energy gain and expenditure,were analysed to determine whether individual Bewick's Swans altered the time spent on key behaviours when sharing feeding habitat with other swan species,and any consequences for their energy expenditure and net energy ***:All three swan species spent a small proportion of their total time(0.011)on aggressive interactions,and these were predominantly intraspecific(≥0.714).Mixed-effects models indicated that sharing feeding habitat with higher densities of Mute and Whooper Swans increased the likelihood of engaging in aggression for cygnet Bewick's Swans,but not for *** levels of interspecific competition decreased the time spent by Bewick's Swan cygnets on foraging,whilst adults showed the opposite *** among low densities of conspecifics(c.200 individuals/km^(2)),individual Bewick's Swans spent more time on vigilance in the presence of higher densities of Mute and Whooper Swans,whilst individuals within higher density Bewick's Swan flocks showed the opposite ***,we found no evide

关键词： Avian behaviour Energy expenditure Ethology Interference competition Interspecific interactions Time activity budgets Video observations

Microstructure and Mechanical Properties of Fe-based Amorphous composite coatings Reinforced by Stainless Steel Powders

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Journal of Materials Science & Technology 2015年第1期31卷 43-47页

作者： H.Zhou c.Zhang W.Wang M.Yasir L.Liu School of Materials Science and Engineering State Key Lab for Materials Processing and Die &Mould TechnologyHuazhong University of Science and Technology Huazhong University of Science and Technology Research Institute in Shenzhen

In this study,a few Fe-based amorphous matrix composite coatings reinforced with various portions(4,8 and16 vol.%) of 31 6L stainless steel powders have been successfully produced through high velocity oxy-fuel(HVOF) *** microstructure of the composite coatings was systematically characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM) and transmission electron microscopy(TEM).The main structure of composite coatings remained amorphous while 31 6L stainless steel splats were distributed homogeneously in the amorphous matrix and well connected with surrounding amorphous *** strength of coatings to the substrate was determined by 'pull-off' tensile *** results revealed that the31 6L stainless steel phase effectively improved the bonding strength of amorphous coatings,which is mainly contributed by the strong metallurgical bonding between stainless steel and amorphous *** addition of31 6L stainless steel also enhanced the ductility and fracture resistance of the coatings due to the ductile stainless steel phases,which can arrest crack propagation and increase energy dissipation.

关键词： Thermal spraying Fe-based amorphous coating Stainl

current Soil Nutrient Status of Intensively Managed Greenhouses

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Pedosphere 2012年第6期22卷 825-833页

作者： HU Yun-cai SONG Zhi-Wen LU Wen-Long c. POScHENRIEDER U. ScHMIDHALTER chair of Plant Nutrition Technische Universitat Miinchen D-85350 Freising (Germany) Institute of Information Tianjin Academy of Agricultural Sciences Tianjin (China)

Nine districts covering the main greenhouse vegetable areas in Tianjin Municipality of the North china Plain were selected for the soil investigation in 2010 to survey the current soil nutrient status (soil available N, P and K), acidification and salinization due to excessive input of fertilizers in greenhouses in Tianjin. The study showed that, in particular, soil available P content increased with the age of greenhouses. In contrast, our results did not reveal higher K accumulation and lowered pH in the greenhouse soils compared with cultivation in open fields. Over-fertilization, causing high NO 3 accumulation, most likely resulted in salinity problems in the greenhouses. Ninety percent of the investigated greenhouse soils had electrical conductivity values of saturated paste extracts of 2-10 d S m-1 , which might affect the yields of vegetable crops like green bean, pepper, cabbage, carrot, eggplant, lettuce, spinach, celery, cucumber and tomato. The findings of our survey of the current fertility and salinity problems in greenhouse soils suggest that there is an urgent need to improve the farmers' practices and strategies in fertilization management in greenhouses of china. Because education and the agricultural technical extension services may play a more important role in avoiding overuse of fertilizers, we suggest that current nutrient management practices should be improved in the near future through training of local farmers in farmers' schools and through strengthening the agricultural extension services with practical techniques.

关键词：土壤养分状况温室蔬菜集约型管理农业技术推广土壤盐渍化土壤速效磷含量中国北方温室土壤