The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered species.Broad-leaved Korean pine forests(B...The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered species.Broad-leaved Korean pine forests(BKPFs) are shrinking quickly due to deforestation and rapid urbanization. Thus, scientific protection strategies are urgently needed to change this status. Changbai Mountains contains one of the largest BKPFs and is considered a priority biodiversity conservation area in China. Guided by systematic conservation planning(SCP) methods and procedures, we chose representative species and communities in BKPFs ecosystem as priority conservation objects, and set quantitative conservation target, which is in the light of the biodiversity characteristic of BKPFs. The watershed area is used as planning unit. We used CPlan software to calculate the irreplaceability(Ir)value of each planning unit and the contribution value(Ti) of each conservation object to(1) assess the conservation efficiency;(2) identify the conservation gap of the existing conservation network. Then wecalculated a human disturbance index(HDI) for planning units in the conservation gaps and combine this with the Ir value to design three conservation scenarios to optimize the conservation network.Results show that planning units with high conservation value 14.16% of the total area, with3084.36 km2 were covered by the existing conservation network. 79.28% of planning units with high conservation value have not been protected which were concentrated mainly in the eight gap areas.Only 25.3% of protection objects achieved their conservation target with the existing conservation network. Conservation efficiency is low. Three conservation scenarios are constituted, each prioritizing a different aim:(1) ecological value;(2)species rescue; and(3) economical avoidance. The three conservation schemes potentially enable 93%,88% and 51% of conservation objects, respectively, to achieve identified conservation targets, thereby improving conservation efficiency significantly.展开更多
This study examines the connectedness in high-order moments between cryptocurrency,major stock(U.S.,U.K.,Eurozone,and Japan),and commodity(gold and oil)markets.Using intraday data from 2020 to 2022 and the time and fr...This study examines the connectedness in high-order moments between cryptocurrency,major stock(U.S.,U.K.,Eurozone,and Japan),and commodity(gold and oil)markets.Using intraday data from 2020 to 2022 and the time and frequency connectedness models of Diebold and Yilmaz(Int J Forecast 28(1):57–66,2012)and Barunik and Křehlik(J Financ Econom 16(2):271–296,2018),we investigate spillovers among the markets in realized volatility,the jump component of realized volatility,realized skewness,and realized kurtosis.These higher-order moments allow us to identify the unique characteristics of financial returns,such as asymmetry and fat tails,thereby capturing various market risks such as downside risk and tail risk.Our results show that the cryptocurrency,stock,and commodity markets are highly connected in terms of volatility and in the jump component of volatility,while their connectedness in skewness and kurtosis is smaller.Moreover,jump and volatility connectedness are more persistent than that of skewness and kurtosis connectedness.Our rolling-window analysis of the connectedness models shows that connectedness varies over time across all moments,and tends to increase during periods of high uncertainty.Finally,we show the potential of gold and oil as hedging and safe-haven investments for other markets given that they are the least connected to other markets across all moments and investment horizons.Our findings provide useful information for designing effective portfolio management and cryptocurrency regulations.展开更多
Soil samples for conventional management (CM) and intensive management (IM) practices were taken over a year at 2-month intervals to determine the effect of management practices on soil organic carbon (SOC) and to qua...Soil samples for conventional management (CM) and intensive management (IM) practices were taken over a year at 2-month intervals to determine the effect of management practices on soil organic carbon (SOC) and to quantify seasonal dynamics in SOC for bamboo (Phyllostachys pubescens Mazel ex H. de Lehaie) stands. The results with IM compared to CM showed large decreases in total organic carbon (TOC), microbial biomass carbon (MBC), water-soluble organic carbon (WSOC), and the MBC/TOC ratio in the soils. With all IM plots in the 0-20 cm depth across sampling periods, average decreases compared with CM were: TOC, 12.1%; MBC, 26.1%; WSOC, 29.3%; the MBC/TOC ratio, 16.1%; and the WSOC/TOC ratio, 20.0%. Due to seasonal changes of climate, seasonal variations were observed in MBC and WSOC. Soil MBC in the 0-20 cm depth in September compared to May were 122.9% greater for CM and 57.6% greater for IM. However, due primarily to soil temperature, soil MBC was higher during the July to November period, whereas because of soil moisture, WSOC was lower in July and January. This study revealed that intensive management in bamboo plantations depleted the soil C pool; therefore, soil quality with IM should be improved through application of organic manures.展开更多
In this study, a combined experimental, numerical and theoretical investigation is conducted on the penetration of semi-infinite 4340 steel targets by a homogeneous 93 W rod and two types of jacketed rods with strikin...In this study, a combined experimental, numerical and theoretical investigation is conducted on the penetration of semi-infinite 4340 steel targets by a homogeneous 93 W rod and two types of jacketed rods with striking velocities of 0.9-3.3 km/s. The results show that the jacketed rods produced typical“co-erosion” damage at all test velocities, except for the 93 W/1060 Al jacketed rod, which switched from an early “bi-erosion” damage to later “co-erosion” damage at a striking velocity of 936 m/s. However, the homogeneous 93 W rod always forms a large mushroom head during the penetration process. The damage mechanisms of these two types of jacketed rods differ for striking velocities of 0.9-2.0 km/s, but this difference gradually decreases with increased striking velocity. For velocities of 2.0-3.3 km/s, all three types of projectiles exhibit typical hydrodynamic penetration characteristics, and the damage mechanisms of the two types of jacketed rods are almost identical. For the same initial kinetic energy, the penetration performance of the jacketed rods is distinctly superior to that of the homogeneous 93 W rods.Compared with jacket density, jacket strength shows a more significant influence on the damage mechanism and penetration performance of the jacketed rod. Finally, an existing theoretical prediction model of the penetration depth of jacketed rods on semi-infinite targets in the co-erosion mode is modified. It transpires that-in terms of penetration depth-the modified theoretical model is in good agreement with the experimental and numerical observations for 93 W/TC4 and 93 W/1060 Al jacketed rods penetrating semi-infinite 4340 steel targets.展开更多
Phellodendron amurense has been used for many years as a medical plant in traditional Chinese medicine and has shown great prospect in recent clinical trials for future applications. Berberine is an essential active c...Phellodendron amurense has been used for many years as a medical plant in traditional Chinese medicine and has shown great prospect in recent clinical trials for future applications. Berberine is an essential active compound contained in P. amurense. Our objective in this study was to quantify the content of berberine in P.amurense from sites at different elevations on Changbai Mountain. We collected samples of P. amurense from five different elevations on Changbai Mountain. Berberine in samples was extracted by ultrahigh pressure extraction(UPE). And the quantity was measured by high performance liquid chromatography(HPLC). First, the optimal HPLC conditions for berberine were identified with satisfactory precision(relative standard deviation, R SD/5.6 %), good accuracy(relative error, R E/ 3.6 %) and good linear relation(R2= 0.9998) in the range of 6.576–328.8 mg L-1. Second, the combination of UPE and HPLC methods in quantitative analysis of berberine showed high repeatability(R SD= 3.28 %), reproducibility(R SD= 4.72 %),stability(R SD/ 1.27 %) and good recovery(99.54 %) for real plant materials. Samples from Heilongjiang Province at the lowest elevation contained the highest amount of berberine.Similarly, the lowest amount of berberine was recorded in samples from Changbai Forest Bureau of Jilin Province collected at the highest elevation in this paper. The proposed UPE–HPLC method is simple, reliable and low-cost for quantitative analysis of berberine. Content of berberine in P.amurense varied significantly by site on Changbai Mountain.展开更多
Agarwood is studied as the resinous secondary metabolites produced by the natural microbial infection. The current study investigated the range of microbial infection in agarwood trees collected from various parts of ...Agarwood is studied as the resinous secondary metabolites produced by the natural microbial infection. The current study investigated the range of microbial infection in agarwood trees collected from various parts of India. A total of 17 isolates were collected and identified based on the morphological and molecular studies. The study revealed that the agarwood was naturally infected with Aspergillus, Lasiodiploidia, Chaetomium, Fusarium and Penicillium species. Further studies on enzyme activities involved in the pathogenesis process showed the higher cellulase, ligninolytic and laccase activities in Aspergillus isolate AR13 when compared to other isolates. The current study has offered a potential opportunity to further strengthen the research on possible development of microbial strains for artificial inoculation in agar trees to induce agarwood formation.展开更多
Both tillage erosion and water erosion are severe erosional forms that occur widely on sloping agricultural land.However,previous studies have rarely considered the process of landform change due to continuous simulat...Both tillage erosion and water erosion are severe erosional forms that occur widely on sloping agricultural land.However,previous studies have rarely considered the process of landform change due to continuous simulation experiments of alternating tillage erosion and water erosion.To identify such changes,we applied a scouring experiment(at a 60 L min-1 water discharge rate based on precipitation data from the local meteorological station and the catchment area in the Yuanmou County,Yunnan Province,China)and a series of simulated tillage experiments where plots were consecutively tilled 5,10,and 15 times in rotation(representing 5 yr,10 yr,and 15 yr of tillage)at slope gradients of 5°,10°,and 20°.Close-range photogrammetry(CRP)employing an unmanned aerial vehicle(UAV)and a real-time kinematic global positioning system(RTK-GPS)was used to measure landform changes,and highresolution digital elevation models(DEMs)were generated to calculate net soil loss volumes.Additionally,the CRP was determined to be accurate and applicable through the use of erosion pins.The average tillage erosion rates were 69.85,131.45,and 155.34 t·hm-2·tillage pass-1,and the average water erosion rates were 1892.52,2961.76,and 4405.93 t·hm-2·h-1 for the 5°,10°,and 20°sloping farmland plots,respectively.The water erosion rates increased as tillage intensity increased,indicating that tillage erosion accelerates water erosion.Following these intensive tillage treatments,slope gradients gradually decreased,while the trend in slope gradients increased in runoff plots at the conclusion of the scouring experiment.Compared to the original plots(prior to our experiments),interactions between tillage and water erosion caused no obvious change in the landform structure of the runoff plots,while the height of all the runoff plots decreased.Our findings showed that both tillage erosion and water erosion caused a pseudo-steady-state landform evolutionary mechanism and resulted in thin soil layers on cultivated land composed of purple soil in China.展开更多
In terms of investigation terminology,this paper uses the method of comparative study to grasp the specific issues involved in the investigation,and further understand the international environment and overall trend o...In terms of investigation terminology,this paper uses the method of comparative study to grasp the specific issues involved in the investigation,and further understand the international environment and overall trend of legalization of investigation. To classify and compare Sino- US historical investigation terminology,through the analysis of the methods of investigation and investigation system,this paper tries to cover all of the investigation terminology; investigation management system is to ensure the coordination,agility,and effectiveness of investigation. Through the comparison of Sino- US organization system and procedure system of investigation,Sino- US investigation management system is studied; law enforcement standardization of police also reflects a kind of culture,and through comparative of Sino- US terminology of law enforcement standardization,valuable lessons can be drawn from this research.展开更多
In order to deepen the understanding of procedural law of interrogation,this paper analyzes the factors of rules and behaviors of interrogation procedure.China has basically formed the system of rules of interrogation...In order to deepen the understanding of procedural law of interrogation,this paper analyzes the factors of rules and behaviors of interrogation procedure.China has basically formed the system of rules of interrogation procedure,including the rule of the privilege against self- incrimination,the rule of lawyer' s defense,the rule of audio and video recording of interrogation,the rule of time and place of interrogation procedure rules of interrogation and the exclusionary rule of illegally obtained evidence.Procedure behaviors of interrogation,constructed by the above mentioned rules,fulfill the legal behavior pattern,set and adjust the behavior pattern of relevant roles and prompt suspects to truthfully confess through regulating conditions,sequence,methods of corresponding behavior.展开更多
Motivated by recent experimental observations of metallic conduction in the quasi-two-dimensional SrFeO_2, we study the epitaxial strain effect on the formation and electronic structures of oxygen vacancy(Vo) by fir...Motivated by recent experimental observations of metallic conduction in the quasi-two-dimensional SrFeO_2, we study the epitaxial strain effect on the formation and electronic structures of oxygen vacancy(Vo) by first-principles calculations.The bulk SrFeO_2 is found to have the G-type antiferromagnetic ordering(G-AFM) at zero strain, which agrees with the experiment. Under compressive strain the bulk SrFeO_2 keeps the G-AFM and has the trend of Mott insulator-metal transition.Different from most of the previous similar work about the strain effect on Vo, both the tensile strain and the compressive strain enhance the Vo formation. It is found that the competitions between the band energies and the electrostatic interactions are the dominant mechanisms in determining the Vo formation. We confirm that the Vo in SrFeO_2 would induce the n-type conductivity where the donor levels are occupied by the delocalized d_(x^2-y^2) electrons. It is suggested that the vanishing of n-type conductivity observed by the Hall measurement on the strained films are caused by the shift of donor levels into the conduction band. These results would provide insightful information for the realization of metallic conduction in SrFeO_2.展开更多
In this paper,the research advances of ontology and its application are reviewed firstly.With the development of ontology technology,subject-oriented web information retrieval technology combining ontology has been be...In this paper,the research advances of ontology and its application are reviewed firstly.With the development of ontology technology,subject-oriented web information retrieval technology combining ontology has been becoming one of the hot scientific issues.The innovative method of the semantic web technology combined with the traditional information retrieval technology is put forward,and the related algorithm based on ontology for judging the relevancy with different topics is also represented,and has proved to be effective in given experiments.展开更多
Permafrost is a potential mercury(Hg)pool released by thawing,which can raise the risk of Hg pollution under global warming.Tree rings are useful archives of environment-specific Hg exposure over long periods.We deter...Permafrost is a potential mercury(Hg)pool released by thawing,which can raise the risk of Hg pollution under global warming.Tree rings are useful archives of environment-specific Hg exposure over long periods.We determined Hg concentrations in tree rings of two dominant tree species(Larix gmelinii Rupr.and Pinus sylvestris var.mongolica)at permafrost sites in northeastern China.The biweighted mean Hg concentrations ranged from 0.36 to 3.96 ng g^(-1) from 1840 to 2014.The tree-ring width had no significant influence on the Hg concentration.Larch Hg increased slightly before the 1970 s and peaked in the 1990 s.However,the pine Hg concentration increased continuously until the 1930 s,decreased rapidly until the 1970 s,then rose to a peak in the late 1980 s.The change of Hg concentrations in larch and pine revealed a time offset of 4 to 5 years,which implied possibly high mobility of Hg in pine tree rings.Higher Hg concentrations from 1920 to 1960 and subsequent decreases in isolated permafrost forests revealed the local geographical Hg cycling history.Lower Hg concentrations and faster increases in larch suggest the role of additional winter Hg loading for the evergreen pine and species-specific differences in root absorption in response to melting permafrost.Our results highlight possible geographical impacts on tree-ring Hg records,improve understanding of Hg cycles in permafrost forest,and suggest a need to sample additional species in a range of permafrost environments.展开更多
The genus Limonia Meigen,1803 is globally distributed with 216 known species/subspecies,of which 30 are recorded from China.In this study,we firstly use DNA barcodes(mt COI)to identify specimens of Limonia from China,...The genus Limonia Meigen,1803 is globally distributed with 216 known species/subspecies,of which 30 are recorded from China.In this study,we firstly use DNA barcodes(mt COI)to identify specimens of Limonia from China,result in a discovery of three species.Considering the morphological data,these species were identified as L.albiterminalis Lü,Ren&Zhang,sp.nov.,L.juvenca Alexander,1935(new record in China),and L.macrostigma(Schummel,1829),respectively.Six COI sequences of the three species were provided,analyzed with other 24 COI sequences from Limonia species.The result indicates that intraspecific distances in the genus are generally less than 2.2%,interspecific distances range from 7.9%to 17.2%,and there is no overlap between intra-and interspecific distances.Redescription and illustrations of L.juvenca and illustration of male hypopygium of L.macrostigma,as well as the key to the Chinese Limonia crane flies,are all provided.展开更多
In this work,a neural network(NN)method is developed for pulse duration inferring for an erbium-doped fiber laser at 1550 nm.Experime nt ally,the interferometric autocorrelation trace is observed clearly with the use ...In this work,a neural network(NN)method is developed for pulse duration inferring for an erbium-doped fiber laser at 1550 nm.Experime nt ally,the interferometric autocorrelation trace is observed clearly with the use of the two-photon absorption(TPA)effect in a GaAs photodiode.The intensity autocorrelation function is curvefitted by the NN with an appropriate performance,and the measuring accuracy is consistent with a commercial autocorrelator.Compared with the Levenberg-Marquardt curve-fitting method,the NN can retrieve the intensity autocorrelation function more stably and has a certain noise reduction ability,simplifying the signal processing for a TPA photodiode-based autocorrelator.展开更多
Face hallucination via patch-pairs leaning based methods has been wildly used in the past several years. Some position-patch based face hallucination methods have been proposed to improve the representation power of i...Face hallucination via patch-pairs leaning based methods has been wildly used in the past several years. Some position-patch based face hallucination methods have been proposed to improve the representation power of image patch and obtain the optimal regressive weighted vector. The rationale behind the position-patch based face hallucination is the fact that human face is always highly structured and consequently positioned and it plays an increasingly important role in the reconstruction. However, in the existing position-patch based methods,the probe image patch is usually represented as a linear combination of the corresponding patches of some training images, and the reconstruction residual is usually measured using the vector norm such as 1-norm and 2-norm.Since the vector norms neglect two-dimensional structures inside the residual, the final reconstruction performance is not very satisfactory. To cope with this problem, we present a weighted nuclear-norm constrained sparse coding(WNCSC) model for position-patch based face hallucination. In addition, an efficient algorithm for the WNCSC is developed using the alternating direction method of multipliers(ADMM) and the method of augmented Lagrange multipliers(ALM). The advantages of the proposed model are twofold: in order to fully make use of low-rank structure information of the reconstruction residual, the weighted nuclear norm is applied to measure the residual matrix, which is able to alleviate the bias between input patches and training data, and it is more robust than the Euclidean distance(2-norm); the more flexible selection method for rank components can determine the optimal combination weights and adaptively choose the relevant and nearest hallucinated neighbors. Finally, experimental results prove that the proposed method outperforms the related state-of-the-art methods in both quantitative and visual comparisons.展开更多
基金supported by the 12th fiveyear National Science and Technology plan of China (2012BAC01B03)
文摘The broad-leaved Korean pine(Pinus koraiensis) forest is one of the most biodiverse zonal communities in the North Temperate Zone and an important habitat for many endangered species.Broad-leaved Korean pine forests(BKPFs) are shrinking quickly due to deforestation and rapid urbanization. Thus, scientific protection strategies are urgently needed to change this status. Changbai Mountains contains one of the largest BKPFs and is considered a priority biodiversity conservation area in China. Guided by systematic conservation planning(SCP) methods and procedures, we chose representative species and communities in BKPFs ecosystem as priority conservation objects, and set quantitative conservation target, which is in the light of the biodiversity characteristic of BKPFs. The watershed area is used as planning unit. We used CPlan software to calculate the irreplaceability(Ir)value of each planning unit and the contribution value(Ti) of each conservation object to(1) assess the conservation efficiency;(2) identify the conservation gap of the existing conservation network. Then wecalculated a human disturbance index(HDI) for planning units in the conservation gaps and combine this with the Ir value to design three conservation scenarios to optimize the conservation network.Results show that planning units with high conservation value 14.16% of the total area, with3084.36 km2 were covered by the existing conservation network. 79.28% of planning units with high conservation value have not been protected which were concentrated mainly in the eight gap areas.Only 25.3% of protection objects achieved their conservation target with the existing conservation network. Conservation efficiency is low. Three conservation scenarios are constituted, each prioritizing a different aim:(1) ecological value;(2)species rescue; and(3) economical avoidance. The three conservation schemes potentially enable 93%,88% and 51% of conservation objects, respectively, to achieve identified conservation targets, thereby improving conservation efficiency significantly.
基金financial support from Fundacao para a Ciencia e a Tecnologia under the project(Grant UIDB/04007/2020)supported by the Ministry of Education of the Republic of Korea and the National Research Foundation of Korea(NRF-2022S1A5A2A01038422).
文摘This study examines the connectedness in high-order moments between cryptocurrency,major stock(U.S.,U.K.,Eurozone,and Japan),and commodity(gold and oil)markets.Using intraday data from 2020 to 2022 and the time and frequency connectedness models of Diebold and Yilmaz(Int J Forecast 28(1):57–66,2012)and Barunik and Křehlik(J Financ Econom 16(2):271–296,2018),we investigate spillovers among the markets in realized volatility,the jump component of realized volatility,realized skewness,and realized kurtosis.These higher-order moments allow us to identify the unique characteristics of financial returns,such as asymmetry and fat tails,thereby capturing various market risks such as downside risk and tail risk.Our results show that the cryptocurrency,stock,and commodity markets are highly connected in terms of volatility and in the jump component of volatility,while their connectedness in skewness and kurtosis is smaller.Moreover,jump and volatility connectedness are more persistent than that of skewness and kurtosis connectedness.Our rolling-window analysis of the connectedness models shows that connectedness varies over time across all moments,and tends to increase during periods of high uncertainty.Finally,we show the potential of gold and oil as hedging and safe-haven investments for other markets given that they are the least connected to other markets across all moments and investment horizons.Our findings provide useful information for designing effective portfolio management and cryptocurrency regulations.
基金Project supported by the National Natural Science Foundation of China (No. 30271072) and the Zhejiang Provincial Natural Science Foundation of China (No. 301250).
文摘Soil samples for conventional management (CM) and intensive management (IM) practices were taken over a year at 2-month intervals to determine the effect of management practices on soil organic carbon (SOC) and to quantify seasonal dynamics in SOC for bamboo (Phyllostachys pubescens Mazel ex H. de Lehaie) stands. The results with IM compared to CM showed large decreases in total organic carbon (TOC), microbial biomass carbon (MBC), water-soluble organic carbon (WSOC), and the MBC/TOC ratio in the soils. With all IM plots in the 0-20 cm depth across sampling periods, average decreases compared with CM were: TOC, 12.1%; MBC, 26.1%; WSOC, 29.3%; the MBC/TOC ratio, 16.1%; and the WSOC/TOC ratio, 20.0%. Due to seasonal changes of climate, seasonal variations were observed in MBC and WSOC. Soil MBC in the 0-20 cm depth in September compared to May were 122.9% greater for CM and 57.6% greater for IM. However, due primarily to soil temperature, soil MBC was higher during the July to November period, whereas because of soil moisture, WSOC was lower in July and January. This study revealed that intensive management in bamboo plantations depleted the soil C pool; therefore, soil quality with IM should be improved through application of organic manures.
基金supported by the National Natural Science Foundation of China(Grant nos.:11672138,11602113)Foundation of National Key Lab.of Transient Physics(Grant no.:6142604180407,JCKYS2020606004).
文摘In this study, a combined experimental, numerical and theoretical investigation is conducted on the penetration of semi-infinite 4340 steel targets by a homogeneous 93 W rod and two types of jacketed rods with striking velocities of 0.9-3.3 km/s. The results show that the jacketed rods produced typical“co-erosion” damage at all test velocities, except for the 93 W/1060 Al jacketed rod, which switched from an early “bi-erosion” damage to later “co-erosion” damage at a striking velocity of 936 m/s. However, the homogeneous 93 W rod always forms a large mushroom head during the penetration process. The damage mechanisms of these two types of jacketed rods differ for striking velocities of 0.9-2.0 km/s, but this difference gradually decreases with increased striking velocity. For velocities of 2.0-3.3 km/s, all three types of projectiles exhibit typical hydrodynamic penetration characteristics, and the damage mechanisms of the two types of jacketed rods are almost identical. For the same initial kinetic energy, the penetration performance of the jacketed rods is distinctly superior to that of the homogeneous 93 W rods.Compared with jacket density, jacket strength shows a more significant influence on the damage mechanism and penetration performance of the jacketed rod. Finally, an existing theoretical prediction model of the penetration depth of jacketed rods on semi-infinite targets in the co-erosion mode is modified. It transpires that-in terms of penetration depth-the modified theoretical model is in good agreement with the experimental and numerical observations for 93 W/TC4 and 93 W/1060 Al jacketed rods penetrating semi-infinite 4340 steel targets.
基金supported by the 12th five-year National Science and Technology plan of China(2012BAC01B03)the 111 Project of China(B13007)
文摘Phellodendron amurense has been used for many years as a medical plant in traditional Chinese medicine and has shown great prospect in recent clinical trials for future applications. Berberine is an essential active compound contained in P. amurense. Our objective in this study was to quantify the content of berberine in P.amurense from sites at different elevations on Changbai Mountain. We collected samples of P. amurense from five different elevations on Changbai Mountain. Berberine in samples was extracted by ultrahigh pressure extraction(UPE). And the quantity was measured by high performance liquid chromatography(HPLC). First, the optimal HPLC conditions for berberine were identified with satisfactory precision(relative standard deviation, R SD/5.6 %), good accuracy(relative error, R E/ 3.6 %) and good linear relation(R2= 0.9998) in the range of 6.576–328.8 mg L-1. Second, the combination of UPE and HPLC methods in quantitative analysis of berberine showed high repeatability(R SD= 3.28 %), reproducibility(R SD= 4.72 %),stability(R SD/ 1.27 %) and good recovery(99.54 %) for real plant materials. Samples from Heilongjiang Province at the lowest elevation contained the highest amount of berberine.Similarly, the lowest amount of berberine was recorded in samples from Changbai Forest Bureau of Jilin Province collected at the highest elevation in this paper. The proposed UPE–HPLC method is simple, reliable and low-cost for quantitative analysis of berberine. Content of berberine in P.amurense varied significantly by site on Changbai Mountain.
文摘Agarwood is studied as the resinous secondary metabolites produced by the natural microbial infection. The current study investigated the range of microbial infection in agarwood trees collected from various parts of India. A total of 17 isolates were collected and identified based on the morphological and molecular studies. The study revealed that the agarwood was naturally infected with Aspergillus, Lasiodiploidia, Chaetomium, Fusarium and Penicillium species. Further studies on enzyme activities involved in the pathogenesis process showed the higher cellulase, ligninolytic and laccase activities in Aspergillus isolate AR13 when compared to other isolates. The current study has offered a potential opportunity to further strengthen the research on possible development of microbial strains for artificial inoculation in agar trees to induce agarwood formation.
基金supported by the National Key Research and Development Program of China(2017YFC0505102)the National Natural Science Foundation of China(No.41401313)+2 种基金the Major Science and Technology Program for Water Pollution Control and Treatment(2017ZX07101001)the Applied Basic Research Program of Sichuan(2018JY0034)the Major Science and Technology Projects in Sichuan Province(2018SZDZX0034)。
文摘Both tillage erosion and water erosion are severe erosional forms that occur widely on sloping agricultural land.However,previous studies have rarely considered the process of landform change due to continuous simulation experiments of alternating tillage erosion and water erosion.To identify such changes,we applied a scouring experiment(at a 60 L min-1 water discharge rate based on precipitation data from the local meteorological station and the catchment area in the Yuanmou County,Yunnan Province,China)and a series of simulated tillage experiments where plots were consecutively tilled 5,10,and 15 times in rotation(representing 5 yr,10 yr,and 15 yr of tillage)at slope gradients of 5°,10°,and 20°.Close-range photogrammetry(CRP)employing an unmanned aerial vehicle(UAV)and a real-time kinematic global positioning system(RTK-GPS)was used to measure landform changes,and highresolution digital elevation models(DEMs)were generated to calculate net soil loss volumes.Additionally,the CRP was determined to be accurate and applicable through the use of erosion pins.The average tillage erosion rates were 69.85,131.45,and 155.34 t·hm-2·tillage pass-1,and the average water erosion rates were 1892.52,2961.76,and 4405.93 t·hm-2·h-1 for the 5°,10°,and 20°sloping farmland plots,respectively.The water erosion rates increased as tillage intensity increased,indicating that tillage erosion accelerates water erosion.Following these intensive tillage treatments,slope gradients gradually decreased,while the trend in slope gradients increased in runoff plots at the conclusion of the scouring experiment.Compared to the original plots(prior to our experiments),interactions between tillage and water erosion caused no obvious change in the landform structure of the runoff plots,while the height of all the runoff plots decreased.Our findings showed that both tillage erosion and water erosion caused a pseudo-steady-state landform evolutionary mechanism and resulted in thin soil layers on cultivated land composed of purple soil in China.
基金One of the achievements of the special funds for the basic scientific research projects of the central universities(RWZD201501)One of the achievements of social science fund project in Jiangsu Province(14YYD004)
文摘In terms of investigation terminology,this paper uses the method of comparative study to grasp the specific issues involved in the investigation,and further understand the international environment and overall trend of legalization of investigation. To classify and compare Sino- US historical investigation terminology,through the analysis of the methods of investigation and investigation system,this paper tries to cover all of the investigation terminology; investigation management system is to ensure the coordination,agility,and effectiveness of investigation. Through the comparison of Sino- US organization system and procedure system of investigation,Sino- US investigation management system is studied; law enforcement standardization of police also reflects a kind of culture,and through comparative of Sino- US terminology of law enforcement standardization,valuable lessons can be drawn from this research.
基金funded by the research of social science fund project of Jiangsu province(No.14YYD004)"the Fundamental Research Fund for the Central Universities"(No.RWZD201501)
文摘In order to deepen the understanding of procedural law of interrogation,this paper analyzes the factors of rules and behaviors of interrogation procedure.China has basically formed the system of rules of interrogation procedure,including the rule of the privilege against self- incrimination,the rule of lawyer' s defense,the rule of audio and video recording of interrogation,the rule of time and place of interrogation procedure rules of interrogation and the exclusionary rule of illegally obtained evidence.Procedure behaviors of interrogation,constructed by the above mentioned rules,fulfill the legal behavior pattern,set and adjust the behavior pattern of relevant roles and prompt suspects to truthfully confess through regulating conditions,sequence,methods of corresponding behavior.
基金Project supported by the Creative Plan Project of Nanjing Forest Police College,China(Grant Nos.201512213045xy and 201512213007x)
文摘Motivated by recent experimental observations of metallic conduction in the quasi-two-dimensional SrFeO_2, we study the epitaxial strain effect on the formation and electronic structures of oxygen vacancy(Vo) by first-principles calculations.The bulk SrFeO_2 is found to have the G-type antiferromagnetic ordering(G-AFM) at zero strain, which agrees with the experiment. Under compressive strain the bulk SrFeO_2 keeps the G-AFM and has the trend of Mott insulator-metal transition.Different from most of the previous similar work about the strain effect on Vo, both the tensile strain and the compressive strain enhance the Vo formation. It is found that the competitions between the band energies and the electrostatic interactions are the dominant mechanisms in determining the Vo formation. We confirm that the Vo in SrFeO_2 would induce the n-type conductivity where the donor levels are occupied by the delocalized d_(x^2-y^2) electrons. It is suggested that the vanishing of n-type conductivity observed by the Hall measurement on the strained films are caused by the shift of donor levels into the conduction band. These results would provide insightful information for the realization of metallic conduction in SrFeO_2.
基金This research was supported by the National Natural Science Foundation of China(NSFC)(Grant No.61772280).
文摘In this paper,the research advances of ontology and its application are reviewed firstly.With the development of ontology technology,subject-oriented web information retrieval technology combining ontology has been becoming one of the hot scientific issues.The innovative method of the semantic web technology combined with the traditional information retrieval technology is put forward,and the related algorithm based on ontology for judging the relevancy with different topics is also represented,and has proved to be effective in given experiments.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDA20040501)the National Natural Science Foundation of China(Grant Nos.41971104 and 41571196)+2 种基金the Fundamental Research Funds for the Central Universities(Grant No.GK202107009)the State Key Laboratory of Cryospheric Science(Grant No.SKLCS2020-09)Northwest Institute of Eco-Environment and Resources,Chinese Academy of Sciences。
文摘Permafrost is a potential mercury(Hg)pool released by thawing,which can raise the risk of Hg pollution under global warming.Tree rings are useful archives of environment-specific Hg exposure over long periods.We determined Hg concentrations in tree rings of two dominant tree species(Larix gmelinii Rupr.and Pinus sylvestris var.mongolica)at permafrost sites in northeastern China.The biweighted mean Hg concentrations ranged from 0.36 to 3.96 ng g^(-1) from 1840 to 2014.The tree-ring width had no significant influence on the Hg concentration.Larch Hg increased slightly before the 1970 s and peaked in the 1990 s.However,the pine Hg concentration increased continuously until the 1930 s,decreased rapidly until the 1970 s,then rose to a peak in the late 1980 s.The change of Hg concentrations in larch and pine revealed a time offset of 4 to 5 years,which implied possibly high mobility of Hg in pine tree rings.Higher Hg concentrations from 1920 to 1960 and subsequent decreases in isolated permafrost forests revealed the local geographical Hg cycling history.Lower Hg concentrations and faster increases in larch suggest the role of additional winter Hg loading for the evergreen pine and species-specific differences in root absorption in response to melting permafrost.Our results highlight possible geographical impacts on tree-ring Hg records,improve understanding of Hg cycles in permafrost forest,and suggest a need to sample additional species in a range of permafrost environments.
基金funded by the National Natural Science Foundation of China(32100356)the National Science&Technology Fundamental Resources Investigation Program of China(2019FY100400)the National Key R&D Program of China(2022YFD1401102)。
文摘The genus Limonia Meigen,1803 is globally distributed with 216 known species/subspecies,of which 30 are recorded from China.In this study,we firstly use DNA barcodes(mt COI)to identify specimens of Limonia from China,result in a discovery of three species.Considering the morphological data,these species were identified as L.albiterminalis Lü,Ren&Zhang,sp.nov.,L.juvenca Alexander,1935(new record in China),and L.macrostigma(Schummel,1829),respectively.Six COI sequences of the three species were provided,analyzed with other 24 COI sequences from Limonia species.The result indicates that intraspecific distances in the genus are generally less than 2.2%,interspecific distances range from 7.9%to 17.2%,and there is no overlap between intra-and interspecific distances.Redescription and illustrations of L.juvenca and illustration of male hypopygium of L.macrostigma,as well as the key to the Chinese Limonia crane flies,are all provided.
基金the Public Security Theory and Soft Science Research Project(No.2020LLYJSL JY040)the Fundamental Research Funds for the Central Universities(No.LGYB202003).
文摘In this work,a neural network(NN)method is developed for pulse duration inferring for an erbium-doped fiber laser at 1550 nm.Experime nt ally,the interferometric autocorrelation trace is observed clearly with the use of the two-photon absorption(TPA)effect in a GaAs photodiode.The intensity autocorrelation function is curvefitted by the NN with an appropriate performance,and the measuring accuracy is consistent with a commercial autocorrelator.Compared with the Levenberg-Marquardt curve-fitting method,the NN can retrieve the intensity autocorrelation function more stably and has a certain noise reduction ability,simplifying the signal processing for a TPA photodiode-based autocorrelator.
基金the National Natural Science Foundation of China(Nos.61702269,61171165,11431015 and 61571230)the Natural Science Foundation of Jiangsu Province(No.BK20171074)+1 种基金the Natural Science Foundation of Guangxi Province(No.2014GXNSFAA118360)the National Scientific Equipment Developing Project of China(No.2012YQ050250)
文摘Face hallucination via patch-pairs leaning based methods has been wildly used in the past several years. Some position-patch based face hallucination methods have been proposed to improve the representation power of image patch and obtain the optimal regressive weighted vector. The rationale behind the position-patch based face hallucination is the fact that human face is always highly structured and consequently positioned and it plays an increasingly important role in the reconstruction. However, in the existing position-patch based methods,the probe image patch is usually represented as a linear combination of the corresponding patches of some training images, and the reconstruction residual is usually measured using the vector norm such as 1-norm and 2-norm.Since the vector norms neglect two-dimensional structures inside the residual, the final reconstruction performance is not very satisfactory. To cope with this problem, we present a weighted nuclear-norm constrained sparse coding(WNCSC) model for position-patch based face hallucination. In addition, an efficient algorithm for the WNCSC is developed using the alternating direction method of multipliers(ADMM) and the method of augmented Lagrange multipliers(ALM). The advantages of the proposed model are twofold: in order to fully make use of low-rank structure information of the reconstruction residual, the weighted nuclear norm is applied to measure the residual matrix, which is able to alleviate the bias between input patches and training data, and it is more robust than the Euclidean distance(2-norm); the more flexible selection method for rank components can determine the optimal combination weights and adaptively choose the relevant and nearest hallucinated neighbors. Finally, experimental results prove that the proposed method outperforms the related state-of-the-art methods in both quantitative and visual comparisons.