Hericium erinaceus is a nutritious edible and medicinal fungi,rich in a variety of functional active ingredients,with various physiological functions such as antioxidation,anticancer,and enhancing immunity.It is also ...Hericium erinaceus is a nutritious edible and medicinal fungi,rich in a variety of functional active ingredients,with various physiological functions such as antioxidation,anticancer,and enhancing immunity.It is also effective in protecting the digestive system and preventing neurodegenerative diseases.In this review paper,we summarize the sources,structures and efficacies of the main active components in H.erinaceus fruiting body,mycelium,and culture media,and update the latest research progress on their biological activities and the related molecular mechanisms.Based on this information,we provide detailed challenges in current research,industrialization and information on the active ingredients of H.erinaceus.Perspectives for future studies and new applications of H.erinaceus are proposed.展开更多
With the continuous development of science and technology, digital signal processing is more and more widely used in various fields. Among them, the analog-to-digital converter (ADC) is one of the key components to co...With the continuous development of science and technology, digital signal processing is more and more widely used in various fields. Among them, the analog-to-digital converter (ADC) is one of the key components to convert analog signals to digital signals. As a common type of ADC, 12-bit sequential approximation analog-to-digital converter (SAR ADC) has attracted extensive attention for its performance and application. This paper aims to conduct in-depth research and analysis of 12-bit SAR ADC to meet the growing demands of digital signal processing. This article designs a 12-bit, successive approximation analog-to-digital converter (SAR ADC) with a sampling rate of 5 MS/s. The overall circuit adopts a fully differential structure, with key modules including DAC capacitor array, comparator, and control logic. According to the DAC circuit in this paper, a fully differential capacitor DAC array structure is proposed to reduce the area of layout DAC. The comparator uses a digital dynamic comparator to improve the ADC conversion speed. The chip is designed based on the SMIC180 nm CMOS process. The simulation results show that when the sampling rate is 5 MS/s, the effective bit of SAR ADC is 11.92 bit, the SNR is 74.62 dB, and the SFDR is 89.24 dB.展开更多
Global climate changes significantly impact the water condition of big rivers in glacierized high mountains. However,there is a lack of studies on hydrological changes within river basins caused by climate changes ove...Global climate changes significantly impact the water condition of big rivers in glacierized high mountains. However,there is a lack of studies on hydrological changes within river basins caused by climate changes over a geological timescale due to the impossibility of direct observations. In this study, we examine the hydro-climatic variation of the Yarlung Zangbo River Basin in the Tibet Plateau since the Last Glacial Maximum(LGM) by combining δ18 O proxy records in Indian and Omani caves with the simulated Indian summer monsoon, surface temperature, precipitation, evapotranspiration and runoff via the Community Climate System Model and the reconstructed glacier coverage via the Parallel Ice Sheet Model. The mean river runoff was kept at a low level of 145 billion cubic meters per year until an abrupt increase at a rate of 8.7 million cubic meters per year in the B?lling-Aller?d interval(BA). The annual runoff reached a maximum of 250 billion cubic meters in the early Holocene and then reduced to the current value of 180 billion cubic meters at a rate of 6.4 million cubic meters per year. The low runoff in the LGM and Heinrich Stadial 1(HS1) is likely attributed to such a small contribution of precipitation to runoff and the large glacier cover. The percentage of precipitation to runoff was only 20%during the LGM and HS1. Comparison of glacier area among different periods indicates that the fastest deglaciation occurred during the late HS1, when nearly 60% of glacier area disappeared in the middle reach, 50% in the upper reach,and 30% in the lower reach. The rapid deglaciation and increasing runoff between the late HS1 and BA may have accelerated widespread ice-dam breaches and led to extreme outburst flood events. Combining local geological proxy records and regional simulations could be a useful approach for the study of paleo-hydrologic variations in big river basins.展开更多
[Objective]The paper was to study the relationship between rice leaf roller,rice planthopper and spider and their ecological regulation ability in the field.[Method]The population dynamics of rice leaf roller,rice pla...[Objective]The paper was to study the relationship between rice leaf roller,rice planthopper and spider and their ecological regulation ability in the field.[Method]The population dynamics of rice leaf roller,rice planthopper and spider at three different sowing and transplanting periods of single cropping hybrid rice in the treatment area with combination of 3 drug formulations and untreated area were monitored.[Result]There were significant or extremely significant positive correlations among rice leaf roller,rice planthopper and spider in single cropping hybrid rice.However,with the delay of planting and transplanting period,the population fluctuation crest of rice leaf roller and rice planthopper decreased,but the intensity increased with the advance of time,and the natural ecological regulation ability was relatively improved.[Conclusion]The sowing period of single cropping hybrid rice is delayed 5-10 d compared with conventional rice,that is,sowing in late May and early June.The seedling age of 20-30 d is beneficial not only to reduce the initial population quantity of rice leaf roller and rice planthopper in the field,but also to increase the population quantity of spiders.展开更多
[Objective] The paper was to explore the occurrence and damage regularity of Spodoptera litura in broccoli,and to reveal the annual movement regularity and seasonal fluctuation regularity of S.litura population.[Metho...[Objective] The paper was to explore the occurrence and damage regularity of Spodoptera litura in broccoli,and to reveal the annual movement regularity and seasonal fluctuation regularity of S.litura population.[Method] The monitoring data of sexual attractants at fixed points for 11 consecutive years were summarized and analyzed.[Result] The large occurrence frequency of S.litura in Taizhou was 36.4%;the annual movement showed a downward-opening parabolic form,and the movement trajectory was N =-18.416 t^(2)+182.51 t +179.71,t ={1,2,3,…,n}(n =11;r =0.691 7*).The seasonal fluctuation showed a trend of peak oscillation attenuation curve,and the total moth quantity gradually decreased from sowing to heading stage.The functional model of average daily quantity was m=0.000 2 d^(2)-0.067 5 d+6.797 3,d={1,2,3,…,n}(n =186,r=0.955 2**).Air temperature was the main external factor affecting the seasonal variation of quantity,and there was a significant correlation be-tween the number of ten-day moth trapping quantity and ten-day average temperature:M =0.243 T^(2)-6.935 1 T +46.681(n =108,r =0.560 2**)or M=2.734 4 T-35.446(n=108,r=0.500 3**).Therefore,the moth quantity in the field increased with the increase of ten-day average temperature,and the period from July to September with high temperature and less rainfall was the peak occurrence period of S.litura.[Conclusion] These models can be used to improve the prediction and early warning levels of S.litura in broccoli,and has good guiding significance for decision-making and prevention.展开更多
Superamphiphobic surfaces have great potential applications in flame resistance,anti-icing,self-cleaning,anti-adhesion,micro-flow control and so on.However,the surface durability is poor owing to the limitation of des...Superamphiphobic surfaces have great potential applications in flame resistance,anti-icing,self-cleaning,anti-adhesion,micro-flow control and so on.However,the surface durability is poor owing to the limitation of design principles.In recent years,a lot of efforts have been carried out on the morphology,structure,and stability of superamphiphobic surfaces,resulting in significant improvement in their surface superwetting properties.In this review,we present a brief classification of the morphological types of superamphiphobic surfaces and summary of the recent progress of researches on the stability of superamphiphobic surfaces.Several testing methods of mechanical and chemical stability are listed in the article,together with the characteristic results,to provide a better and more detailed understanding of the current research status on superamphiphobic surface stability,which will be of considerable importance as a reference guide for our future researches.Of course,there are still some issues that need to be addressed for the application of superamphiphobic surfaces at large scale,and this is where our future researches will be directed.Finally,we discuss the challenges as well as the prospects in the study of superamphiphobic surfaces.展开更多
Graphene nanoribbons(GNRs)are regarded as an ideal candidate for beyond-silicon electronics.However,synthesis of aligned GNR arrays on insulating substrates with high efficiency is challenging.In this work,we develop ...Graphene nanoribbons(GNRs)are regarded as an ideal candidate for beyond-silicon electronics.However,synthesis of aligned GNR arrays on insulating substrates with high efficiency is challenging.In this work,we develop a facile strategy,involving KOH pre-treatment and high-temperature annealing,to construct parallel steps on the two-fold symmetry a-plane sapphire substrate.Horizontal GNRs as narrow as 15.1 nm with global alignment across a region of 20 mm^(2)are then grown on the step edgeenriched substrate through plasma enhanced chemical vapor deposition(PECVD)method.GNRs align well along the atomic steps on sapphire([■]direction)with their widths and densities swiftly adjustable by step morphology modification on substrate surface.A step-edge confined growth mechanism is proposed,attributing the constraint on the nanoribbon broadening to a relatively low growth temperature in PECVD,which restrains the activation energy to suppress GNRs across step edges on sapphire and prevents detrimental nanoribbon widening.The results provide a new perspective for scalable synthesizing well aligned nanoribbons of other two-dimensional materials.展开更多
Converting solar energy by to other forms of energy has attracted a lot of interest from academy to industry.However,the overall utilization efficiency of solar energy is inferior due to the limited effective solar sp...Converting solar energy by to other forms of energy has attracted a lot of interest from academy to industry.However,the overall utilization efficiency of solar energy is inferior due to the limited effective solar spectrum range.Here,in order to utilize the broadband solar spectrum more efficiently,a novel hybrid absorber structure was proposed,which consists of a four-layer planar nanofilm with dual functions of heat absorption and photocatalysis.The average absorption in the visible range is larger than 0.95,and in the near-infrared spectral region,the average absorption is still larger than 0.85.The overall absorption of the absorber is over 0.86,while the thermal emittance is lower than 0.04,which can lead to remarkable thermal utilization efficiency.Moreover,the full range of the solar irradiance can be utilized by incorporating the photocatalytic TiO_(2) layer into the absorber,which is active in the ultraviolet spectral range.In addition to the broadband spectral usage,the virtues of inexpensiveness and environmental friendliness make it a facile alternative to be applied in solar energy transformation.展开更多
The depletion of petroleum resources and the intensification of environmental problems have necessitated the development of renewable products from bio-based chemicals instead of petroleum resources.Herein,a new kind ...The depletion of petroleum resources and the intensification of environmental problems have necessitated the development of renewable products from bio-based chemicals instead of petroleum resources.Herein,a new kind of ester lubricating oil,isooctyl furan dicarboxylate(isooctyl-FD),was prepared from bio-based 2,5-furandicarboxylic acid.The structure of isooctyl-FD was evaluated using nuclear magnetic resonance imaging and high-resolution mass spectroscopy.Its physicochemical and tribological properties including thermal and oxidation stabilities,flash point and pour point,viscosity and viscosity index,and friction-reducing and anti-wear properties were systematically evaluated.The results show that isooctyl-FD has comparable thermal and oxidation stability to the synthetic ester lubricating oil,isooctyl sebacate(isooctyl-S).Its friction-reducing and anti-wear properties are superior to isooctyl-S;however,its viscosity-temperature and low-temperature properties are inferior to isooctyl-S.展开更多
The large tunability in the band structure is ubiquitous in two-dimensional(2D)materials,and PtSe_(2) is not an exception,which has attracted considerable attention in electronic and optoelectronic applications due to...The large tunability in the band structure is ubiquitous in two-dimensional(2D)materials,and PtSe_(2) is not an exception,which has attracted considerable attention in electronic and optoelectronic applications due to its high carrier mobility and long-term airstability.Such dimensional dependent properties are closely related to the evolution of electronic band structures.Critical points(CPs),the extrema or saddle points of electronic bands,are the cornerstone of condensed-matter physics and fundamentally determine the optical and transport phenomena of the layered PtSe_(2).Here,we have experimentally revealed the detailed electronic structures in layered PtSe_(2),including the CPs in the Brillouin zones(BZs),by means of reflection contrast spectroscopy and spectroscopic ellipsometry(SE).There are three critical points in the BZs attributed to the excitonic transition,quasi-particle band gap,and the band nesting effect related transition,respectively.Three CPs show red-shifting trends with increasing layer number under the mechanism of strong interlayer coupling.We have further revealed the electron–phonon(e–ph)interaction in such layered material,utilizing temperature-dependent absorbance spectroscopy.The strength of e–ph interaction and the average phonon energy also decline with the increasement of layer number.Our findings give a deep understanding to the physics of the layer-dependent evolution of the electronic structure of PtSe_(2),potentially leading to applications in optoelectronics and electronic devices.展开更多
Reduced graphene oxide-supported tungsten carbide composite(WC/RGO)was prepared by program-con-trolled reduction-carburization technique.Scanning electron microscope(SEM)and transmission electron micro-scope(TEM)show ...Reduced graphene oxide-supported tungsten carbide composite(WC/RGO)was prepared by program-con-trolled reduction-carburization technique.Scanning electron microscope(SEM)and transmission electron micro-scope(TEM)show that WC nanoparticles with a narrow distribution(10-20 nm)are highly dispersed both on the edge and between the layers of RGO.And then it was used as a support to load different low contents(no more than 0.4 wt%)of Pt via sacrificial Cu adlayers.The morphology and the electrocatalytic activity of the prepared catalysts were characterized by TEM and cyclic voltammograms(CV),respectively.The results indicate that a small amount of isolated Pt atoms show low or even no activity for methanol oxidation.With the increasing deposition cycles,the content of Pt and the ensembles of neighboring Pt atoms are increased,which makes the onset potential shift nega-tively and mass current density increase.The results demonstrate that controllable amount of Pt can be deposited on WC/RGO by galvanic displacement with Cu,and the extent and domain of Pt loading affect the electrochemical performance.Meanwhile,this research also provides another route to prepare a catalyst with ultra low noble metal on WC/RGO for solving the problem of high cost of the catalyst.展开更多
Based on distribution of formation pressure by indirect estimation and formation testing,this study investigates origin of abnormal high pressure in the Dina 2 Gas Field in the Kuqa Depression in combination with the ...Based on distribution of formation pressure by indirect estimation and formation testing,this study investigates origin of abnormal high pressure in the Dina 2 Gas Field in the Kuqa Depression in combination with the latest research findings.Contribution of major overpressure mechanisms to this gas field is estimated,and generation of the abnormal high pressure as well as its relationship with natural gas accumulation is explored.Disequilibrium compaction,tectonic stress,and overpressure transfer are the major overpressure mechanisms.Overpressure transfer resulted from vertical opening of faults and folding is the most important cause for the overpressure.Gas accumulation and abnormal high pressure generation in the reservoirs of the Dina 2 Gas Field show synchroneity.During the early oil-gas charge in the Kangcun stage,the reservoirs were generally normal pressure systems.In the Kuqa deposition stage,rapid deposition caused disequilibrium compaction and led to generation of excess pressure(approximately 5-10 MPa)in the reservoirs.During the Kuqa Formation denudation stage to the Quaternary,reservoir overpressure was greatly increased to approximately 40-50 MPa as a result of vertical pressure transfer by episodic fault activation,lateral overpressure transfer by folding and horizontal tectonic stress due to intense tectonic compression.The last stage was the major period of ultra-high pressure generation and gas accumulation in the Dina 2 Gas Field.展开更多
Mixed dimensional van der Waals(VdW)heterostructures constructed by one-dimensional(1D)and two-dimensional(2D)materials exhibit extra degree of freedom to modulate the electronic and optical properties due to the comb...Mixed dimensional van der Waals(VdW)heterostructures constructed by one-dimensional(1D)and two-dimensional(2D)materials exhibit extra degree of freedom to modulate the electronic and optical properties due to the combination of difterent dimensionalities.The charge transfer at the intertace between 1D and 2D materials plays a crucial role in the optoelectronic properties and performance of the heterostructure-based devices.Here,we stacked single-walled carbon nanotubes(SWNTs)on monolayer WS2 for a mixed dimensional vdW heterostructure,and investigated the local modulation of excitions and trions in WS2 by SWNTs.Different directions of charge transfer between SWNTs and WSz are evidenced by the photoluminescence(PL)spectra of WS2.The PL intensity can be either enhanced or weakened by individual SWNTs.In our work,the PL intensity of WS2 is enhanced and the exciton peak position heterostructure is red-shifted about 3 meV due to the charge transfer from WS2 to an individual SWNT(SWNT#1).The change of PL by another SWNT(SWNT#2)can not be well-resolved in far fild,but scanning near field optical microscope(SNOM)measurements show that the PL intensity of WS2 is weakened by the SWNT.The peak position of exciton is blue-shifted by^1 meV while that of trion is redshifted by^1 meV due to the charge transfer from the SWNT to WS2,These results give insight into the charge transfer at the interface of SWNTWS2 heterostructure,and can be useful for design of optoelectronic devices based on mixed dimensional vdW heterostructures.展开更多
Background:The human brain is the most complex organ in the body,and it is important to have a better understanding of how the protein composition in the brain regions contributes to the pathogenesis of associated neu...Background:The human brain is the most complex organ in the body,and it is important to have a better understanding of how the protein composition in the brain regions contributes to the pathogenesis of associated neurological disorders.Methods:In this study,a comparative analysis of the frontal and temporal cortex proteomes was conducted by isobaric tags of relative and absolute quantification(iTRAQ)labeling and two-dimensional liquid chromatographytandem mass spectrometry(2D LC-MS/MS).Brain protein was taken from relatively normal tissue that could not be avoided of damage during emergent surgery of the TBI(traumatic brain injury)patients admitted in Beijing Tiantan Hospital from 2014 to 2017.Eight cases were included.Four frontal lobes and 4 temporal lobes proteome were analyzed and the proteins were quantitated.Gene Ontology(GO),Ingenuity Pathway Analysis(IPA),and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis were used to analyze the biological function of identified proteins,unchanged proteins,and differentially expressed proteins(DEPs).Results:A total number of 2127 protein groups were identified in the frontal and temporal lobe proteomes.A total of 1709 proteins could be quantitated in both the frontal and temporal cortex.Among 90 DEPs,14 proteins were screened highly expressed in the temporal cortex,including MAPT,SNCG,ATP5IF1,GAP43,HSPE1,STMN1,NDUFS6,LDHB,SNCB,NDUFA7,MRPS36,EPDR1,CISD1,and RALA.In addition,compared to proteins expressed in the frontal cortex,14 proteins including EDC4,NIT2,VWF,ASTN1,TGM2,SSB,CLU,HBA1,STOM,CRP,LRG1,SAA2,S100A4,and VTN were a low expression in the temporal cortex.The biological process enrichment showed that unchanged proteins between the frontal and temporal cortex mainly take part in regulated exocytosis,axon guidance,and vesicle-mediated transport.The KEGG pathway analysis showed that unchanged proteins between the frontal and temporal cortex mainly take part in oxidative phosphorylation,carbon metabolism,Huntington’s disease,and Parkinson’s disease.Conclusions:The majority of proteins are unchanged between the frontal and temporal cortex,and unchanged proteins are closely related to its function.Among DEPs,MATP(tau)is upregulated in the temporal cortex,closely related to Alzheimer’s disease(AD),and is one of the targets for the treatment of AD.CLU is downregulated in the temporal cortex which functions as an extracellular chaperone that prevents aggregation of non-native proteins.It was suggested that the temporal lobe may not be the“functional dumb area”of the traditional view,but could be involved in important neural metabolic circuits.展开更多
To the Editor: Chronic airflow obstruction (CAO) is a characteristic feature of chronic obstructive pulmonary disease (COPD) and occurs due to airway and/or alveolar abnormalities typically associated with exposure to...To the Editor: Chronic airflow obstruction (CAO) is a characteristic feature of chronic obstructive pulmonary disease (COPD) and occurs due to airway and/or alveolar abnormalities typically associated with exposure to noxious particles or gases.[1] The major risk factor for CAO is cigarette smoking, but exposure to solid fuel likely influences CAO development. Studies have found that solid fuel exposure is associated with a high prevalence of CAO, particularly among women.[2] Comparing COPD caused by either solid fuel or tobacco smoke exposure is very significant because about 3 billion people are exposed to solid fuel smoke, and 1.01 billion people smoke tobacco, globally. This study aimed to investigate and compare the clinical and functional characteristics of CAO patients exposed to solid fuel and tobacco smoke using propensity score matching (PSM) in western China.展开更多
We consider the fractional nonlinear Schr?dinger equation in this paper. Applying the finite reduction method, we prove that the equation has positive solutions with peaks on a Clifford torus under some suitable condi...We consider the fractional nonlinear Schr?dinger equation in this paper. Applying the finite reduction method, we prove that the equation has positive solutions with peaks on a Clifford torus under some suitable conditions.展开更多
基金supported by the fund from Natural Science Foundation of Zhejiang Province,China(LY17C200017)。
文摘Hericium erinaceus is a nutritious edible and medicinal fungi,rich in a variety of functional active ingredients,with various physiological functions such as antioxidation,anticancer,and enhancing immunity.It is also effective in protecting the digestive system and preventing neurodegenerative diseases.In this review paper,we summarize the sources,structures and efficacies of the main active components in H.erinaceus fruiting body,mycelium,and culture media,and update the latest research progress on their biological activities and the related molecular mechanisms.Based on this information,we provide detailed challenges in current research,industrialization and information on the active ingredients of H.erinaceus.Perspectives for future studies and new applications of H.erinaceus are proposed.
文摘With the continuous development of science and technology, digital signal processing is more and more widely used in various fields. Among them, the analog-to-digital converter (ADC) is one of the key components to convert analog signals to digital signals. As a common type of ADC, 12-bit sequential approximation analog-to-digital converter (SAR ADC) has attracted extensive attention for its performance and application. This paper aims to conduct in-depth research and analysis of 12-bit SAR ADC to meet the growing demands of digital signal processing. This article designs a 12-bit, successive approximation analog-to-digital converter (SAR ADC) with a sampling rate of 5 MS/s. The overall circuit adopts a fully differential structure, with key modules including DAC capacitor array, comparator, and control logic. According to the DAC circuit in this paper, a fully differential capacitor DAC array structure is proposed to reduce the area of layout DAC. The comparator uses a digital dynamic comparator to improve the ADC conversion speed. The chip is designed based on the SMIC180 nm CMOS process. The simulation results show that when the sampling rate is 5 MS/s, the effective bit of SAR ADC is 11.92 bit, the SNR is 74.62 dB, and the SFDR is 89.24 dB.
基金supported by the National Natural Science Foundation of China(Grant No.91747207)the project of CAS“Light of the West”。
文摘Global climate changes significantly impact the water condition of big rivers in glacierized high mountains. However,there is a lack of studies on hydrological changes within river basins caused by climate changes over a geological timescale due to the impossibility of direct observations. In this study, we examine the hydro-climatic variation of the Yarlung Zangbo River Basin in the Tibet Plateau since the Last Glacial Maximum(LGM) by combining δ18 O proxy records in Indian and Omani caves with the simulated Indian summer monsoon, surface temperature, precipitation, evapotranspiration and runoff via the Community Climate System Model and the reconstructed glacier coverage via the Parallel Ice Sheet Model. The mean river runoff was kept at a low level of 145 billion cubic meters per year until an abrupt increase at a rate of 8.7 million cubic meters per year in the B?lling-Aller?d interval(BA). The annual runoff reached a maximum of 250 billion cubic meters in the early Holocene and then reduced to the current value of 180 billion cubic meters at a rate of 6.4 million cubic meters per year. The low runoff in the LGM and Heinrich Stadial 1(HS1) is likely attributed to such a small contribution of precipitation to runoff and the large glacier cover. The percentage of precipitation to runoff was only 20%during the LGM and HS1. Comparison of glacier area among different periods indicates that the fastest deglaciation occurred during the late HS1, when nearly 60% of glacier area disappeared in the middle reach, 50% in the upper reach,and 30% in the lower reach. The rapid deglaciation and increasing runoff between the late HS1 and BA may have accelerated widespread ice-dam breaches and led to extreme outburst flood events. Combining local geological proxy records and regional simulations could be a useful approach for the study of paleo-hydrologic variations in big river basins.
基金Supported by Science and Technology Project of Taizhou City(14NY14)Key Research and De-velopment Program of Zhejiang Province(2016C02050-3-4)
文摘[Objective]The paper was to study the relationship between rice leaf roller,rice planthopper and spider and their ecological regulation ability in the field.[Method]The population dynamics of rice leaf roller,rice planthopper and spider at three different sowing and transplanting periods of single cropping hybrid rice in the treatment area with combination of 3 drug formulations and untreated area were monitored.[Result]There were significant or extremely significant positive correlations among rice leaf roller,rice planthopper and spider in single cropping hybrid rice.However,with the delay of planting and transplanting period,the population fluctuation crest of rice leaf roller and rice planthopper decreased,but the intensity increased with the advance of time,and the natural ecological regulation ability was relatively improved.[Conclusion]The sowing period of single cropping hybrid rice is delayed 5-10 d compared with conventional rice,that is,sowing in late May and early June.The seedling age of 20-30 d is beneficial not only to reduce the initial population quantity of rice leaf roller and rice planthopper in the field,but also to increase the population quantity of spiders.
基金Supported by Science and Technology Planning Project of Taizhou City (071TG04)Taizhou Broccoli Breeding,Propagation and Promotion Integrated Innovation Team Project (TRCL[2014]7)。
文摘[Objective] The paper was to explore the occurrence and damage regularity of Spodoptera litura in broccoli,and to reveal the annual movement regularity and seasonal fluctuation regularity of S.litura population.[Method] The monitoring data of sexual attractants at fixed points for 11 consecutive years were summarized and analyzed.[Result] The large occurrence frequency of S.litura in Taizhou was 36.4%;the annual movement showed a downward-opening parabolic form,and the movement trajectory was N =-18.416 t^(2)+182.51 t +179.71,t ={1,2,3,…,n}(n =11;r =0.691 7*).The seasonal fluctuation showed a trend of peak oscillation attenuation curve,and the total moth quantity gradually decreased from sowing to heading stage.The functional model of average daily quantity was m=0.000 2 d^(2)-0.067 5 d+6.797 3,d={1,2,3,…,n}(n =186,r=0.955 2**).Air temperature was the main external factor affecting the seasonal variation of quantity,and there was a significant correlation be-tween the number of ten-day moth trapping quantity and ten-day average temperature:M =0.243 T^(2)-6.935 1 T +46.681(n =108,r =0.560 2**)or M=2.734 4 T-35.446(n=108,r=0.500 3**).Therefore,the moth quantity in the field increased with the increase of ten-day average temperature,and the period from July to September with high temperature and less rainfall was the peak occurrence period of S.litura.[Conclusion] These models can be used to improve the prediction and early warning levels of S.litura in broccoli,and has good guiding significance for decision-making and prevention.
基金supported by the National Nature Science Foundation of China(nos.51735013,51905520 and 52165040)the Gansu Provincial Natural Science Foundation of China(no.21JR7RA350)the Education Department of Gansu Province:Young Doctor Fund Project(no.2021QB-125).
文摘Superamphiphobic surfaces have great potential applications in flame resistance,anti-icing,self-cleaning,anti-adhesion,micro-flow control and so on.However,the surface durability is poor owing to the limitation of design principles.In recent years,a lot of efforts have been carried out on the morphology,structure,and stability of superamphiphobic surfaces,resulting in significant improvement in their surface superwetting properties.In this review,we present a brief classification of the morphological types of superamphiphobic surfaces and summary of the recent progress of researches on the stability of superamphiphobic surfaces.Several testing methods of mechanical and chemical stability are listed in the article,together with the characteristic results,to provide a better and more detailed understanding of the current research status on superamphiphobic surface stability,which will be of considerable importance as a reference guide for our future researches.Of course,there are still some issues that need to be addressed for the application of superamphiphobic surfaces at large scale,and this is where our future researches will be directed.Finally,we discuss the challenges as well as the prospects in the study of superamphiphobic surfaces.
基金This work was financially supported by the Ministry of Science and Technology of China(Nos.2016YFA0200100 and 2018YFA0703502)the National Natural Science Foundation of China(Nos.52021006,51720105003,21790052,and 21974004)+1 种基金the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB36030100)the Beijing National Laboratory for Molecular Sciences(No.BNLMS-CXTD-202001).
文摘Graphene nanoribbons(GNRs)are regarded as an ideal candidate for beyond-silicon electronics.However,synthesis of aligned GNR arrays on insulating substrates with high efficiency is challenging.In this work,we develop a facile strategy,involving KOH pre-treatment and high-temperature annealing,to construct parallel steps on the two-fold symmetry a-plane sapphire substrate.Horizontal GNRs as narrow as 15.1 nm with global alignment across a region of 20 mm^(2)are then grown on the step edgeenriched substrate through plasma enhanced chemical vapor deposition(PECVD)method.GNRs align well along the atomic steps on sapphire([■]direction)with their widths and densities swiftly adjustable by step morphology modification on substrate surface.A step-edge confined growth mechanism is proposed,attributing the constraint on the nanoribbon broadening to a relatively low growth temperature in PECVD,which restrains the activation energy to suppress GNRs across step edges on sapphire and prevents detrimental nanoribbon widening.The results provide a new perspective for scalable synthesizing well aligned nanoribbons of other two-dimensional materials.
基金financially supported by the National Natural Science Foundation of China(Nos.52072354,21673053,and 21975060)Youth Innovation Promotion Association CAS(No.2019039).
文摘Converting solar energy by to other forms of energy has attracted a lot of interest from academy to industry.However,the overall utilization efficiency of solar energy is inferior due to the limited effective solar spectrum range.Here,in order to utilize the broadband solar spectrum more efficiently,a novel hybrid absorber structure was proposed,which consists of a four-layer planar nanofilm with dual functions of heat absorption and photocatalysis.The average absorption in the visible range is larger than 0.95,and in the near-infrared spectral region,the average absorption is still larger than 0.85.The overall absorption of the absorber is over 0.86,while the thermal emittance is lower than 0.04,which can lead to remarkable thermal utilization efficiency.Moreover,the full range of the solar irradiance can be utilized by incorporating the photocatalytic TiO_(2) layer into the absorber,which is active in the ultraviolet spectral range.In addition to the broadband spectral usage,the virtues of inexpensiveness and environmental friendliness make it a facile alternative to be applied in solar energy transformation.
基金National Natural Science Fund(51675006)the project of Science and Technology Department of Shaanxi Province(2016JZ017)the Local Servicing Research Project of the Education Department of Shanxi Province(15JF007).
文摘The depletion of petroleum resources and the intensification of environmental problems have necessitated the development of renewable products from bio-based chemicals instead of petroleum resources.Herein,a new kind of ester lubricating oil,isooctyl furan dicarboxylate(isooctyl-FD),was prepared from bio-based 2,5-furandicarboxylic acid.The structure of isooctyl-FD was evaluated using nuclear magnetic resonance imaging and high-resolution mass spectroscopy.Its physicochemical and tribological properties including thermal and oxidation stabilities,flash point and pour point,viscosity and viscosity index,and friction-reducing and anti-wear properties were systematically evaluated.The results show that isooctyl-FD has comparable thermal and oxidation stability to the synthetic ester lubricating oil,isooctyl sebacate(isooctyl-S).Its friction-reducing and anti-wear properties are superior to isooctyl-S;however,its viscosity-temperature and low-temperature properties are inferior to isooctyl-S.
基金supported by the National Key Research and Development Program of China(No.2021YFB2012601)the Fudan University-CIOMP Joint Fund(No.FC2019-006).
文摘The large tunability in the band structure is ubiquitous in two-dimensional(2D)materials,and PtSe_(2) is not an exception,which has attracted considerable attention in electronic and optoelectronic applications due to its high carrier mobility and long-term airstability.Such dimensional dependent properties are closely related to the evolution of electronic band structures.Critical points(CPs),the extrema or saddle points of electronic bands,are the cornerstone of condensed-matter physics and fundamentally determine the optical and transport phenomena of the layered PtSe_(2).Here,we have experimentally revealed the detailed electronic structures in layered PtSe_(2),including the CPs in the Brillouin zones(BZs),by means of reflection contrast spectroscopy and spectroscopic ellipsometry(SE).There are three critical points in the BZs attributed to the excitonic transition,quasi-particle band gap,and the band nesting effect related transition,respectively.Three CPs show red-shifting trends with increasing layer number under the mechanism of strong interlayer coupling.We have further revealed the electron–phonon(e–ph)interaction in such layered material,utilizing temperature-dependent absorbance spectroscopy.The strength of e–ph interaction and the average phonon energy also decline with the increasement of layer number.Our findings give a deep understanding to the physics of the layer-dependent evolution of the electronic structure of PtSe_(2),potentially leading to applications in optoelectronics and electronic devices.
基金This work was supported by International Science&Technology Cooperation Program of China(No.2010DFB63680)the National Natural Science Foundation of China(No.21376220).
文摘Reduced graphene oxide-supported tungsten carbide composite(WC/RGO)was prepared by program-con-trolled reduction-carburization technique.Scanning electron microscope(SEM)and transmission electron micro-scope(TEM)show that WC nanoparticles with a narrow distribution(10-20 nm)are highly dispersed both on the edge and between the layers of RGO.And then it was used as a support to load different low contents(no more than 0.4 wt%)of Pt via sacrificial Cu adlayers.The morphology and the electrocatalytic activity of the prepared catalysts were characterized by TEM and cyclic voltammograms(CV),respectively.The results indicate that a small amount of isolated Pt atoms show low or even no activity for methanol oxidation.With the increasing deposition cycles,the content of Pt and the ensembles of neighboring Pt atoms are increased,which makes the onset potential shift nega-tively and mass current density increase.The results demonstrate that controllable amount of Pt can be deposited on WC/RGO by galvanic displacement with Cu,and the extent and domain of Pt loading affect the electrochemical performance.Meanwhile,this research also provides another route to prepare a catalyst with ultra low noble metal on WC/RGO for solving the problem of high cost of the catalyst.
基金supported by the Ministry of Science and Technology of China (2016YFA0200101 and 2016YFA0200104)the National Natural Science Foundation of China (51432002, 21790052 and 51720105003)+2 种基金Beijing Municipal Science and Technology Planning Project (Z161100002116026)China PostdoctoralScience Foundation (8201400852 and 8201400892)the National Program for Thousand Young Talents of China
基金This work was funded by National Science and Technology Major Project of China(Grant No.2008ZX05003,2011ZX05003001).
文摘Based on distribution of formation pressure by indirect estimation and formation testing,this study investigates origin of abnormal high pressure in the Dina 2 Gas Field in the Kuqa Depression in combination with the latest research findings.Contribution of major overpressure mechanisms to this gas field is estimated,and generation of the abnormal high pressure as well as its relationship with natural gas accumulation is explored.Disequilibrium compaction,tectonic stress,and overpressure transfer are the major overpressure mechanisms.Overpressure transfer resulted from vertical opening of faults and folding is the most important cause for the overpressure.Gas accumulation and abnormal high pressure generation in the reservoirs of the Dina 2 Gas Field show synchroneity.During the early oil-gas charge in the Kangcun stage,the reservoirs were generally normal pressure systems.In the Kuqa deposition stage,rapid deposition caused disequilibrium compaction and led to generation of excess pressure(approximately 5-10 MPa)in the reservoirs.During the Kuqa Formation denudation stage to the Quaternary,reservoir overpressure was greatly increased to approximately 40-50 MPa as a result of vertical pressure transfer by episodic fault activation,lateral overpressure transfer by folding and horizontal tectonic stress due to intense tectonic compression.The last stage was the major period of ultra-high pressure generation and gas accumulation in the Dina 2 Gas Field.
基金the National Basic Research Program of China(Nos.2018YFA0703502 and 2016YFA0200104)the National Natural Science Foundation of China(Nos.51720105003,21790052,21573004 and 21974004).
文摘Mixed dimensional van der Waals(VdW)heterostructures constructed by one-dimensional(1D)and two-dimensional(2D)materials exhibit extra degree of freedom to modulate the electronic and optical properties due to the combination of difterent dimensionalities.The charge transfer at the intertace between 1D and 2D materials plays a crucial role in the optoelectronic properties and performance of the heterostructure-based devices.Here,we stacked single-walled carbon nanotubes(SWNTs)on monolayer WS2 for a mixed dimensional vdW heterostructure,and investigated the local modulation of excitions and trions in WS2 by SWNTs.Different directions of charge transfer between SWNTs and WSz are evidenced by the photoluminescence(PL)spectra of WS2.The PL intensity can be either enhanced or weakened by individual SWNTs.In our work,the PL intensity of WS2 is enhanced and the exciton peak position heterostructure is red-shifted about 3 meV due to the charge transfer from WS2 to an individual SWNT(SWNT#1).The change of PL by another SWNT(SWNT#2)can not be well-resolved in far fild,but scanning near field optical microscope(SNOM)measurements show that the PL intensity of WS2 is weakened by the SWNT.The peak position of exciton is blue-shifted by^1 meV while that of trion is redshifted by^1 meV due to the charge transfer from the SWNT to WS2,These results give insight into the charge transfer at the interface of SWNTWS2 heterostructure,and can be useful for design of optoelectronic devices based on mixed dimensional vdW heterostructures.
基金Ministry of Science and Technology of China grant(2012CB825505)。
文摘Background:The human brain is the most complex organ in the body,and it is important to have a better understanding of how the protein composition in the brain regions contributes to the pathogenesis of associated neurological disorders.Methods:In this study,a comparative analysis of the frontal and temporal cortex proteomes was conducted by isobaric tags of relative and absolute quantification(iTRAQ)labeling and two-dimensional liquid chromatographytandem mass spectrometry(2D LC-MS/MS).Brain protein was taken from relatively normal tissue that could not be avoided of damage during emergent surgery of the TBI(traumatic brain injury)patients admitted in Beijing Tiantan Hospital from 2014 to 2017.Eight cases were included.Four frontal lobes and 4 temporal lobes proteome were analyzed and the proteins were quantitated.Gene Ontology(GO),Ingenuity Pathway Analysis(IPA),and Kyoto Encyclopedia of Genes and Genomes(KEGG)pathway analysis were used to analyze the biological function of identified proteins,unchanged proteins,and differentially expressed proteins(DEPs).Results:A total number of 2127 protein groups were identified in the frontal and temporal lobe proteomes.A total of 1709 proteins could be quantitated in both the frontal and temporal cortex.Among 90 DEPs,14 proteins were screened highly expressed in the temporal cortex,including MAPT,SNCG,ATP5IF1,GAP43,HSPE1,STMN1,NDUFS6,LDHB,SNCB,NDUFA7,MRPS36,EPDR1,CISD1,and RALA.In addition,compared to proteins expressed in the frontal cortex,14 proteins including EDC4,NIT2,VWF,ASTN1,TGM2,SSB,CLU,HBA1,STOM,CRP,LRG1,SAA2,S100A4,and VTN were a low expression in the temporal cortex.The biological process enrichment showed that unchanged proteins between the frontal and temporal cortex mainly take part in regulated exocytosis,axon guidance,and vesicle-mediated transport.The KEGG pathway analysis showed that unchanged proteins between the frontal and temporal cortex mainly take part in oxidative phosphorylation,carbon metabolism,Huntington’s disease,and Parkinson’s disease.Conclusions:The majority of proteins are unchanged between the frontal and temporal cortex,and unchanged proteins are closely related to its function.Among DEPs,MATP(tau)is upregulated in the temporal cortex,closely related to Alzheimer’s disease(AD),and is one of the targets for the treatment of AD.CLU is downregulated in the temporal cortex which functions as an extracellular chaperone that prevents aggregation of non-native proteins.It was suggested that the temporal lobe may not be the“functional dumb area”of the traditional view,but could be involved in important neural metabolic circuits.
基金Beijing Hospital Clinical Research 121 Project(No.BJ-2018-199)National Science and Technology Major Project(No.2018YFC1315101)。
文摘To the Editor: Chronic airflow obstruction (CAO) is a characteristic feature of chronic obstructive pulmonary disease (COPD) and occurs due to airway and/or alveolar abnormalities typically associated with exposure to noxious particles or gases.[1] The major risk factor for CAO is cigarette smoking, but exposure to solid fuel likely influences CAO development. Studies have found that solid fuel exposure is associated with a high prevalence of CAO, particularly among women.[2] Comparing COPD caused by either solid fuel or tobacco smoke exposure is very significant because about 3 billion people are exposed to solid fuel smoke, and 1.01 billion people smoke tobacco, globally. This study aimed to investigate and compare the clinical and functional characteristics of CAO patients exposed to solid fuel and tobacco smoke using propensity score matching (PSM) in western China.
基金supported by National Natural Science Foundation of China(Grant No.11601139)
文摘We consider the fractional nonlinear Schr?dinger equation in this paper. Applying the finite reduction method, we prove that the equation has positive solutions with peaks on a Clifford torus under some suitable conditions.