Event detection(ED)is aimed at detecting event occurrences and categorizing them.This task has been previously solved via recognition and classification of event triggers(ETs),which are defined as the phrase or word m...Event detection(ED)is aimed at detecting event occurrences and categorizing them.This task has been previously solved via recognition and classification of event triggers(ETs),which are defined as the phrase or word most clearly expressing event occurrence.Thus,current approaches require both annotated triggers as well as event types in training data.Nevertheless,triggers are non-essential in ED,and it is time-wasting for annotators to identify the“most clearly”word from a sentence,particularly in longer sentences.To decrease manual effort,we evaluate event detectionwithout triggers.We propose a novel framework that combines Type-aware Attention and Graph Convolutional Networks(TA-GCN)for event detection.Specifically,the task is identified as a multi-label classification problem.We first encode the input sentence using a novel type-aware neural network with attention mechanisms.Then,a Graph Convolutional Networks(GCN)-based multilabel classification model is exploited for event detection.Experimental results demonstrate the effectiveness.展开更多
The joint extraction of entities and their relations from certain texts plays a significant role in most natural language processes.For entity and relation extraction in a specific domain,we propose a hybrid neural fr...The joint extraction of entities and their relations from certain texts plays a significant role in most natural language processes.For entity and relation extraction in a specific domain,we propose a hybrid neural framework consisting of two parts:a span-based model and a graph-based model.The span-based model can tackle overlapping problems compared with BILOU methods,whereas the graph-based model treats relation prediction as graph classification.Our main contribution is to incorporate external lexical and syntactic knowledge of a specific domain,such as domain dictionaries and dependency structures from texts,into end-to-end neural models.We conducted extensive experiments on a Chinese military entity and relation extraction corpus.The results show that the proposed framework outperforms the baselines with better performance in terms of entity and relation prediction.The proposed method provides insight into problems with the joint extraction of entities and their relations.展开更多
Uniaxial stress is a powerful tool for tuning exciton emitting wavelength, polarization, fine-structure splitting (FSS), and the symmetry of quantum dots (QDs). Here, we present a technique for applying uniaxial stres...Uniaxial stress is a powerful tool for tuning exciton emitting wavelength, polarization, fine-structure splitting (FSS), and the symmetry of quantum dots (QDs). Here, we present a technique for applying uniaxial stress, which enables us in situ to tune exciton optical properties at low temperature down to 15 K with high tuning precision. The design and operation of the device are described in detail. This technique provides a simple and convenient approach to tune QD structural symmetry, exciton energy and biexciton binding energy. It can be utilized for generating entangled and indistinguishable photons. Moreover, this device can be employed for tuning optical properties of thin film materials at low temperature.展开更多
Luminescent properties of Tm^(3+)-doped GdYTaO_(4) are studied for exploring their potential applications in temperature and pressure sensing.Two main emission peaks from ^(3)H_(4)→^(3)H_(6) transition of Tm^(3+)are ...Luminescent properties of Tm^(3+)-doped GdYTaO_(4) are studied for exploring their potential applications in temperature and pressure sensing.Two main emission peaks from ^(3)H_(4)→^(3)H_(6) transition of Tm^(3+)are investigated.Intensity ratio between the two peaks evolves exponentially with temperature and has a highest sensitivity of 0.014 K^(−1) at 32 K.The energy difference between the two peaks increases linearly with pressure increasing at a rate of 0.38 meV/GPa.Intensity ratio between the two peaks and their emission lifetimes are also analyzed for discussing the pressure-induced variation of the sample structure.Moreover,Raman spectra recorded under high pressures indicate an isostructural phase transition of GdYTaO_(4) occurring at 4.46 GPa.展开更多
A very long lifetime exciton emission with non-single exponential decay characteristics has been reported for single InA-s/GaAs quantum dot(QD)samples,in which there exists a long-lived metastable state in the wetting...A very long lifetime exciton emission with non-single exponential decay characteristics has been reported for single InA-s/GaAs quantum dot(QD)samples,in which there exists a long-lived metastable state in the wetting layer(WL)through radiative field coupling between the exciton emissions in the WL and the dipole field of metal islands.In this article we have proposed a new three-level model to simulate the exciton emission decay curve.In this model,assuming that the excitons in a metastable state will diffuse and be trapped by QDs,and then emit fluorescence in QDs,a stretchedlike exponential decay formula is derived as I(t)=At^(β−1)e^(−(rt)^(β)),which can describe well the long lifetime decay curve with an analytical expression of average lifetime(τ)=1/rГ(1/β+1),where G is the Gamma function.Furthermore,based on the proposed three-level model,an expression of the second-order auto-correlation function g^(2)(t)which can fit the measured g^(2)(t)curve well,is also obtained.展开更多
The influence of the pressure transmission medium(PTM)on the excitonic interband transitions in monolayer tungsten diselenide(WSe2)is investigated using photoluminescence(PL)spectra under hydrostatic pressure up...The influence of the pressure transmission medium(PTM)on the excitonic interband transitions in monolayer tungsten diselenide(WSe2)is investigated using photoluminescence(PL)spectra under hydrostatic pressure up to 5GPa.Three kinds of PTMs,condensed argon(Ar),1:1 n-pentane and isopentane mixture(PM),and4:1 methanol and ethanol mixture(MEM,a PTM with polarity),are used.It is found that when either Ar or PM is used as the PTM,the PL peak of exciton related to the direct K-K interband transition shows a pressure-induced blue-shift at a rate of 32±4 or 32±1 meV/GPa,while it turns to be 50±9meV/GPa when MEM is used as the PTM.The indirect A-K interband transition presents almost no shift with increasing pressure up to approximatel.y 5 GPa when Ar and PM are used as the PTM,while it shows a red-shift at the rate of-17±7meV/GPa by using MEM as the PTM.These results reveal that the optical interband transitions of monolayer WSe2 are very sensitive to the polarity of the PTM.The anomalous pressure coefficient obtained using the polar PTM of MEM is ascribed to the existence of hydrogen-like bonds between hydroxyl in MEM and Se atoms under hydrostatic pressure.展开更多
We investigate the pressure spectral characteristics and the effective tuning of defect emissions in hexagonal boron nitride(hBN) at low temperatures using a diamond anvil cell(DAC). It is found that the redshift rate...We investigate the pressure spectral characteristics and the effective tuning of defect emissions in hexagonal boron nitride(hBN) at low temperatures using a diamond anvil cell(DAC). It is found that the redshift rate of emission energy is up to 10 meV/GPa, demonstrating a controllable tuning of single photon emitters through pressure.Based on the distribution character of pressure coefficients as a function of wavelength, different kinds of atomic defect states should be responsible for the observed defect emissions.展开更多
With the rapid and large-scale development of renewable energy, the lack of new energy power transportation or consumption, and the shortage of grid peak-shifting ability have become increasingly serious. Aiming to th...With the rapid and large-scale development of renewable energy, the lack of new energy power transportation or consumption, and the shortage of grid peak-shifting ability have become increasingly serious. Aiming to the severe wind power curtailment issue, the characteristics of interactive load are studied upon the traditional day-ahead dispatch model to mitigate the influence of wind power fluctuation. A multi-objective optimal dispatch model with the minimum operating cost and power losses is built. Optimal power flow distribution is available when both generation and demand side participate in the resource allocation. The quantum particle swarm optimization (QPSO) algorithm is applied to convert multi-objective optimization problem into single objective optimization problem. The simulation results of IEEE 30-bus system verify that the proposed method can effectively reduce the operating cost and grid loss simultaneously enhancing the consumption of wind power.展开更多
Cobalt compounds with different phase compositions and microstructure are promising in solving the energy storage and conversion problems.Herein,the graphene-likeα-Co(OH)_2,ultra-layeredα-Co(OH)_2 stacked with hexag...Cobalt compounds with different phase compositions and microstructure are promising in solving the energy storage and conversion problems.Herein,the graphene-likeα-Co(OH)_2,ultra-layeredα-Co(OH)_2 stacked with hexagonal nanosheets,and needle-like Co(CO_3)0.5(OH)·0.11H_2O were hydrothermally synthesized without using surfactant and templates by increasing the reaction temperature or prolonging the展开更多
The chirality-induced spin selectivity(CISS)has been found in the antiferromagnetic and paramagnetic chiral inorganic materials with unpaired electrons,while rarely reported in the spin-paired diamagnetic inorganic ma...The chirality-induced spin selectivity(CISS)has been found in the antiferromagnetic and paramagnetic chiral inorganic materials with unpaired electrons,while rarely reported in the spin-paired diamagnetic inorganic materials with spin-pairing energy.Here,we report the CISS in the spin-paired diamagnetic BiOBr endowed with three levels of chiral mesostructures.Chiral mesostructured BiOBr films(CMBFs)were fabricated through a sugar alcohol-induced hydrothermal route.The antipodal CMBFs exhibited chirality-dependent,magnetic field-independent magnetic circular dichroism(MCD)signals,which indicates the existence of spin selectivity.The spin selectivity of CMBFs was speculated to be the result of the competing effect between the externally applied magnetic field and the effective magnetic field arisen from the spin electron motions in chiral potential.The chirality-induced effective magnetic field acts on the magnetic moment of electrons,potentially overcoming the spin-pairing energy and producing opposite energy changes for spin-down and spin-up electrons.展开更多
The broad operating temperature range is sought for molecular ferroic materials who are expected to be applied to flexible and electronic materials.Hydrogen bonds,an effective force between molecules,are important to ...The broad operating temperature range is sought for molecular ferroic materials who are expected to be applied to flexible and electronic materials.Hydrogen bonds,an effective force between molecules,are important to regulate the molecule structure and their condition,helping a higher temperature range for ferroic materials.Here,we report a molecular perovskite ferroelastic(Me-Hdabco)Rb[BF_(4)]_(3)(Me-Hdabco=N-methyldabconium)which shows high temperature(T_(1)=322.5 K and T_(2)=381K)ferroelastic phase transitions.The ferroelastic phase transition temperature range of(Me-Hdabco)Rb[BF_(4)]_(3) is significantly increased by 71 K compared with[Meda-bco-F]Rb[BF_(4)]_(3)(Medabco-F=1-fluoro-4-methyl-1,4-diazoniabicyclo[2.2.2]octane).Structural analysis and thermal analysis demonstrate the ferroelastic phase transition is mainly attributed to dynamic cations order and disorder transformation.Therefore,new hydrogen bonds generated between cations and the Rb_(8)[BF_(4)]_(12) frame increase their intermolecular force,which is beneficial to improving the phase transition temperature.This finding has an important impact on the utilization of weak interactionforces to design and optimize functional materials.展开更多
Pressure-and temperature-dependent luminescence properties of ^(3)F_(3/2)→^(4)I9/2 transition of Nd^(3+):GdTaO_(4) were studied for potential applications in optical sensing.Two isolated emission lines corresponding ...Pressure-and temperature-dependent luminescence properties of ^(3)F_(3/2)→^(4)I9/2 transition of Nd^(3+):GdTaO_(4) were studied for potential applications in optical sensing.Two isolated emission lines corresponding to^(3)F_(3/2)(R2,1)→^(4)I_(9/2)(Z5)transitions,located at 920 and 927 nm under ambient condition,are very sensitive to pressure with coefficients of-15.6 and-14.5 cm^(-1)/GPa determined in a pressure range up to about 9 GPa.The luminescence intensity ratio between the two emission lines exhibits a large dependence with temperature in a range from 80 to 620 K,the corresponding temperature sensitivity at room temperature is similar to that of Nd^(3+):YAG.These advantages,together with the other observed features of high stable position relationship under pressure and low thermal shifts for the two emission lines indicate that Nd^(3+):GdTaO_(4) is a promising candidate to be used as pressure and temperature sensors in the near-infrared spectral range.展开更多
To determine whether the functional stability of nitrification was correlated to a stable community structure of ammonia oxidizing bacteria(AOB)in a fullscale wastewater treatment plant,the AOB community dynamics in a...To determine whether the functional stability of nitrification was correlated to a stable community structure of ammonia oxidizing bacteria(AOB)in a fullscale wastewater treatment plant,the AOB community dynamics in a wastewater treatment system was monitored over one year.The community dynamics were investigated using specific PCR followed by terminal restriction fragment length polymorphism(T-RFLP)analysis of the amoA gene.The T-RFLP results indicated that during the period of nitrification stability,the AOB community structure in the full-scale wastewater treatment system was relatively stable,and the average change rate every 15 d of the system was 6.6%±5.8%.The phylogenetic analysis of the cloned amoA gene showed clearly that the dominant AOB in the system was Nitrosomonas spp.The results of this study indicated that throughout the study period,the AOB community structure was relatively stable in the full-scale wastewater treatment system with functional stability of nitrification.展开更多
Phosphor-converted light-emitting diodes (pc- LEDs), which employ blue LEDs with yellow phosphors to generate white light illumination, is a widely used solid- state lighting source. In order to conduct a phosphor l...Phosphor-converted light-emitting diodes (pc- LEDs), which employ blue LEDs with yellow phosphors to generate white light illumination, is a widely used solid- state lighting source. In order to conduct a phosphor layer coating with high quality on LED chip, a self-adaptive coating technology is introduced in this paper. A slurry coating technique combined with selfexposure method is applied and developed to demonstrate the benefits of selfadaptive coating layer. For self-exposure, the slurry coating is exposed to the blue emission of LED itself other than to ultraviolet (UV) light outside to make photoresist crosslinking. Results of measurement indicate that white LEDs with self-adaptive coating have shown self-adaptability to the angular distribution of intensity of blue light and performed higher spatial color uniformity than those with conventional coating and other conformal coating.展开更多
基金supported by the Hunan Provincial Natural Science Foundation of China(Grant No.2020JJ4624)the National Social Science Fund of China(Grant No.20&ZD047)+1 种基金the Scientific Research Fund of Hunan Provincial Education Department(Grant No.19A020)the National University of Defense Technology Research Project ZK20-46 and the Young Elite Scientists Sponsorship Program 2021-JCJQ-QT-050.
文摘Event detection(ED)is aimed at detecting event occurrences and categorizing them.This task has been previously solved via recognition and classification of event triggers(ETs),which are defined as the phrase or word most clearly expressing event occurrence.Thus,current approaches require both annotated triggers as well as event types in training data.Nevertheless,triggers are non-essential in ED,and it is time-wasting for annotators to identify the“most clearly”word from a sentence,particularly in longer sentences.To decrease manual effort,we evaluate event detectionwithout triggers.We propose a novel framework that combines Type-aware Attention and Graph Convolutional Networks(TA-GCN)for event detection.Specifically,the task is identified as a multi-label classification problem.We first encode the input sentence using a novel type-aware neural network with attention mechanisms.Then,a Graph Convolutional Networks(GCN)-based multilabel classification model is exploited for event detection.Experimental results demonstrate the effectiveness.
基金supported by the Jiangsu Province“333”project BRA2020418the NSFC under Grant Number 71901215+2 种基金the National University of Defense Technology Research Project ZK20-46the Outstanding Young Talents Program of National University of Defense Technologythe National University of Defense Technology Youth Innovation Project。
文摘The joint extraction of entities and their relations from certain texts plays a significant role in most natural language processes.For entity and relation extraction in a specific domain,we propose a hybrid neural framework consisting of two parts:a span-based model and a graph-based model.The span-based model can tackle overlapping problems compared with BILOU methods,whereas the graph-based model treats relation prediction as graph classification.Our main contribution is to incorporate external lexical and syntactic knowledge of a specific domain,such as domain dictionaries and dependency structures from texts,into end-to-end neural models.We conducted extensive experiments on a Chinese military entity and relation extraction corpus.The results show that the proposed framework outperforms the baselines with better performance in terms of entity and relation prediction.The proposed method provides insight into problems with the joint extraction of entities and their relations.
基金supported by the National Key Research and Development Program of China(Grant No.2016YFA0301202)the National Natural Science Foundation of China(Grant No.61674135)
文摘Uniaxial stress is a powerful tool for tuning exciton emitting wavelength, polarization, fine-structure splitting (FSS), and the symmetry of quantum dots (QDs). Here, we present a technique for applying uniaxial stress, which enables us in situ to tune exciton optical properties at low temperature down to 15 K with high tuning precision. The design and operation of the device are described in detail. This technique provides a simple and convenient approach to tune QD structural symmetry, exciton energy and biexciton binding energy. It can be utilized for generating entangled and indistinguishable photons. Moreover, this device can be employed for tuning optical properties of thin film materials at low temperature.
基金the National Natural Science Foundation of China(Grant No.11804047)the Science and Technology Development Program of Jilin City,China(Grant No.201831733).
文摘Luminescent properties of Tm^(3+)-doped GdYTaO_(4) are studied for exploring their potential applications in temperature and pressure sensing.Two main emission peaks from ^(3)H_(4)→^(3)H_(6) transition of Tm^(3+)are investigated.Intensity ratio between the two peaks evolves exponentially with temperature and has a highest sensitivity of 0.014 K^(−1) at 32 K.The energy difference between the two peaks increases linearly with pressure increasing at a rate of 0.38 meV/GPa.Intensity ratio between the two peaks and their emission lifetimes are also analyzed for discussing the pressure-induced variation of the sample structure.Moreover,Raman spectra recorded under high pressures indicate an isostructural phase transition of GdYTaO_(4) occurring at 4.46 GPa.
基金Project supported by the National Key Research and Development Program of China(Grant No.2016YFA0301202)the National Natural Science Foundation of China(Grant Nos.61827823 and 11974342).
文摘A very long lifetime exciton emission with non-single exponential decay characteristics has been reported for single InA-s/GaAs quantum dot(QD)samples,in which there exists a long-lived metastable state in the wetting layer(WL)through radiative field coupling between the exciton emissions in the WL and the dipole field of metal islands.In this article we have proposed a new three-level model to simulate the exciton emission decay curve.In this model,assuming that the excitons in a metastable state will diffuse and be trapped by QDs,and then emit fluorescence in QDs,a stretchedlike exponential decay formula is derived as I(t)=At^(β−1)e^(−(rt)^(β)),which can describe well the long lifetime decay curve with an analytical expression of average lifetime(τ)=1/rГ(1/β+1),where G is the Gamma function.Furthermore,based on the proposed three-level model,an expression of the second-order auto-correlation function g^(2)(t)which can fit the measured g^(2)(t)curve well,is also obtained.
基金Supported by the National Key Research and Development Program of China under Grant No 2016YFA0301202the National Natural Science Foundation of China under Grant Nos 11474275,61674135 and 91536101+1 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No XDPB0603the China Postdoctoral Science Foundation under Grant No 2017M622400
文摘The influence of the pressure transmission medium(PTM)on the excitonic interband transitions in monolayer tungsten diselenide(WSe2)is investigated using photoluminescence(PL)spectra under hydrostatic pressure up to 5GPa.Three kinds of PTMs,condensed argon(Ar),1:1 n-pentane and isopentane mixture(PM),and4:1 methanol and ethanol mixture(MEM,a PTM with polarity),are used.It is found that when either Ar or PM is used as the PTM,the PL peak of exciton related to the direct K-K interband transition shows a pressure-induced blue-shift at a rate of 32±4 or 32±1 meV/GPa,while it turns to be 50±9meV/GPa when MEM is used as the PTM.The indirect A-K interband transition presents almost no shift with increasing pressure up to approximatel.y 5 GPa when Ar and PM are used as the PTM,while it shows a red-shift at the rate of-17±7meV/GPa by using MEM as the PTM.These results reveal that the optical interband transitions of monolayer WSe2 are very sensitive to the polarity of the PTM.The anomalous pressure coefficient obtained using the polar PTM of MEM is ascribed to the existence of hydrogen-like bonds between hydroxyl in MEM and Se atoms under hydrostatic pressure.
基金Supported by the Postdoctoral Science Foundation of China under Grant No.Y8T0111001.
文摘We investigate the pressure spectral characteristics and the effective tuning of defect emissions in hexagonal boron nitride(hBN) at low temperatures using a diamond anvil cell(DAC). It is found that the redshift rate of emission energy is up to 10 meV/GPa, demonstrating a controllable tuning of single photon emitters through pressure.Based on the distribution character of pressure coefficients as a function of wavelength, different kinds of atomic defect states should be responsible for the observed defect emissions.
文摘With the rapid and large-scale development of renewable energy, the lack of new energy power transportation or consumption, and the shortage of grid peak-shifting ability have become increasingly serious. Aiming to the severe wind power curtailment issue, the characteristics of interactive load are studied upon the traditional day-ahead dispatch model to mitigate the influence of wind power fluctuation. A multi-objective optimal dispatch model with the minimum operating cost and power losses is built. Optimal power flow distribution is available when both generation and demand side participate in the resource allocation. The quantum particle swarm optimization (QPSO) algorithm is applied to convert multi-objective optimization problem into single objective optimization problem. The simulation results of IEEE 30-bus system verify that the proposed method can effectively reduce the operating cost and grid loss simultaneously enhancing the consumption of wind power.
文摘Cobalt compounds with different phase compositions and microstructure are promising in solving the energy storage and conversion problems.Herein,the graphene-likeα-Co(OH)_2,ultra-layeredα-Co(OH)_2 stacked with hexagonal nanosheets,and needle-like Co(CO_3)0.5(OH)·0.11H_2O were hydrothermally synthesized without using surfactant and templates by increasing the reaction temperature or prolonging the
基金supported by the National Key R&D Program of China(No.2021YFA1200300)the National Natural Science Foundation of China(Nos.21931008,21975184,21873072,and 21922304)the scientific foundation of the Shanghai Municipal Science and Technology Commission(Nos.19JC1410300).
文摘The chirality-induced spin selectivity(CISS)has been found in the antiferromagnetic and paramagnetic chiral inorganic materials with unpaired electrons,while rarely reported in the spin-paired diamagnetic inorganic materials with spin-pairing energy.Here,we report the CISS in the spin-paired diamagnetic BiOBr endowed with three levels of chiral mesostructures.Chiral mesostructured BiOBr films(CMBFs)were fabricated through a sugar alcohol-induced hydrothermal route.The antipodal CMBFs exhibited chirality-dependent,magnetic field-independent magnetic circular dichroism(MCD)signals,which indicates the existence of spin selectivity.The spin selectivity of CMBFs was speculated to be the result of the competing effect between the externally applied magnetic field and the effective magnetic field arisen from the spin electron motions in chiral potential.The chirality-induced effective magnetic field acts on the magnetic moment of electrons,potentially overcoming the spin-pairing energy and producing opposite energy changes for spin-down and spin-up electrons.
基金This work was supported by the National Key Research and Development Program of China(Grant No.2017YFA0204800)and Southeast University。
文摘The broad operating temperature range is sought for molecular ferroic materials who are expected to be applied to flexible and electronic materials.Hydrogen bonds,an effective force between molecules,are important to regulate the molecule structure and their condition,helping a higher temperature range for ferroic materials.Here,we report a molecular perovskite ferroelastic(Me-Hdabco)Rb[BF_(4)]_(3)(Me-Hdabco=N-methyldabconium)which shows high temperature(T_(1)=322.5 K and T_(2)=381K)ferroelastic phase transitions.The ferroelastic phase transition temperature range of(Me-Hdabco)Rb[BF_(4)]_(3) is significantly increased by 71 K compared with[Meda-bco-F]Rb[BF_(4)]_(3)(Medabco-F=1-fluoro-4-methyl-1,4-diazoniabicyclo[2.2.2]octane).Structural analysis and thermal analysis demonstrate the ferroelastic phase transition is mainly attributed to dynamic cations order and disorder transformation.Therefore,new hydrogen bonds generated between cations and the Rb_(8)[BF_(4)]_(12) frame increase their intermolecular force,which is beneficial to improving the phase transition temperature.This finding has an important impact on the utilization of weak interactionforces to design and optimize functional materials.
基金Project supported by the National Natural Science Foundation of China(11804047)Science and Technology Development Program of Jilin City(201831733)Development Program of Education Department of Jilin Province(JJKH20180425KJ)。
文摘Pressure-and temperature-dependent luminescence properties of ^(3)F_(3/2)→^(4)I9/2 transition of Nd^(3+):GdTaO_(4) were studied for potential applications in optical sensing.Two isolated emission lines corresponding to^(3)F_(3/2)(R2,1)→^(4)I_(9/2)(Z5)transitions,located at 920 and 927 nm under ambient condition,are very sensitive to pressure with coefficients of-15.6 and-14.5 cm^(-1)/GPa determined in a pressure range up to about 9 GPa.The luminescence intensity ratio between the two emission lines exhibits a large dependence with temperature in a range from 80 to 620 K,the corresponding temperature sensitivity at room temperature is similar to that of Nd^(3+):YAG.These advantages,together with the other observed features of high stable position relationship under pressure and low thermal shifts for the two emission lines indicate that Nd^(3+):GdTaO_(4) is a promising candidate to be used as pressure and temperature sensors in the near-infrared spectral range.
基金This study was supported by the National Natural Science Foundation of China(Grant No.51078207)Mega-projects of Science Research for Water(No.2008ZX07313-3)the Program of Research on Key Technology of Environmental Pollution Control and Quality Improvement(No.2007DFC90170),and Research Fund for the Doctoral Program of Higher Education of China(No.20090002770003).
文摘To determine whether the functional stability of nitrification was correlated to a stable community structure of ammonia oxidizing bacteria(AOB)in a fullscale wastewater treatment plant,the AOB community dynamics in a wastewater treatment system was monitored over one year.The community dynamics were investigated using specific PCR followed by terminal restriction fragment length polymorphism(T-RFLP)analysis of the amoA gene.The T-RFLP results indicated that during the period of nitrification stability,the AOB community structure in the full-scale wastewater treatment system was relatively stable,and the average change rate every 15 d of the system was 6.6%±5.8%.The phylogenetic analysis of the cloned amoA gene showed clearly that the dominant AOB in the system was Nitrosomonas spp.The results of this study indicated that throughout the study period,the AOB community structure was relatively stable in the full-scale wastewater treatment system with functional stability of nitrification.
文摘Phosphor-converted light-emitting diodes (pc- LEDs), which employ blue LEDs with yellow phosphors to generate white light illumination, is a widely used solid- state lighting source. In order to conduct a phosphor layer coating with high quality on LED chip, a self-adaptive coating technology is introduced in this paper. A slurry coating technique combined with selfexposure method is applied and developed to demonstrate the benefits of selfadaptive coating layer. For self-exposure, the slurry coating is exposed to the blue emission of LED itself other than to ultraviolet (UV) light outside to make photoresist crosslinking. Results of measurement indicate that white LEDs with self-adaptive coating have shown self-adaptability to the angular distribution of intensity of blue light and performed higher spatial color uniformity than those with conventional coating and other conformal coating.