Gas quenching and vacuum quenching process are widely applied to accelerate solvent volatilization to induce nucleation of perovskites in blade-coating method.In this work,we found these two pre-crystallization proces...Gas quenching and vacuum quenching process are widely applied to accelerate solvent volatilization to induce nucleation of perovskites in blade-coating method.In this work,we found these two pre-crystallization processes lead to different order of crystallization dynamics within the perovskite thin film,resulting in the differences of additive distribution.We then tailor-designed an additive molecule named 1,3-bis(4-methoxyphenyl)thiourea to obtain films with fewer defects and holes at the buried interface,and prepared perovskite solar cells with a certified efficiency of 23.75%.Furthermore,this work also demonstrates an efficiency of 20.18%for the large-area perovskite solar module(PSM)with an aperture area of 60.84 cm^(2).The PSM possesses remarkable continuous operation stability for maximum power point tracking of T_(90)>1000 h in ambient air.展开更多
The vast majority of in vitro studies have demonstrated that PINK1 phosphorylates Parkin to work together in mitophagy to protect against neuronal degeneration.However,it remains largely unclear how PINK1 and Parkin a...The vast majority of in vitro studies have demonstrated that PINK1 phosphorylates Parkin to work together in mitophagy to protect against neuronal degeneration.However,it remains largely unclear how PINK1 and Parkin are expressed in mammalian brains.This has been difficult to address because of the intrinsically low levels of PINK1 and undetectable levels of phosphorylated Parkin in small animals.Understanding this issue is critical for elucidating the in vivo roles of PINK1 and Parkin.Recently,we showed that the PINK1 kinase is selectively expressed as a truncated form(PINK1–55)in the primate brain.In the present study,we used multiple antibodies,including our recently developed monoclonal anti-PINK1,to validate the selective expression of PINK1 in the primate brain.We found that PINK1 was stably expressed in the monkey brain at postnatal and adulthood stages,which is consistent with the findings that depleting PINK1 can cause neuronal loss in developing and adult monkey brains.PINK1 was enriched in the membrane-bound fractionations,whereas Parkin was soluble with a distinguishable distribution.Immunofluorescent double staining experiments showed that PINK1 and Parkin did not colocalize under physiological conditions in cultured monkey astrocytes,though they did colocalize on mitochondria when the cells were exposed to mitochondrial stress.These findings suggest that PINK1 and Parkin may have distinct roles beyond their well-known function in mitophagy during mitochondrial damage.展开更多
BACKGROUND Red blood cell distribution width(RDW)is associated with the development and progression of various diseases.AIM To explore the association between pretreatment RDW and short-term outcomes after laparoscopi...BACKGROUND Red blood cell distribution width(RDW)is associated with the development and progression of various diseases.AIM To explore the association between pretreatment RDW and short-term outcomes after laparoscopic pancreatoduodenectomy(LPD).METHODS A total of 804 consecutive patients who underwent LPD at our hospital between March 2017 and November 2021 were retrospectively analyzed.Correlations between pretreatment RDW and clinicopathological characteristics and short-term outcomes were investigated.RESULTS Patients with higher pretreatment RDW were older,had higher Eastern Cooperative Oncology Group scores and were associated with poorer short-term outcomes than those with normal RDW.High pretreatment RDW was an independent risk factor for postoperative complications(POCs)(hazard ratio=2.973,95%confidence interval:2.032-4.350,P<0.001)and severe POCs of grade IIIa or higher(hazard ratio=3.138,95%confidence interval:2.042-4.824,P<0.001)based on the Clavien-Dino classification system.Subgroup analysis showed that high pretreatment RDW was an independent risk factor for Clavien-Dino classi-fication grade IIIb or higher POCs,a comprehensive complication index score≥26.2,severe postoperative pancreatic fistula,severe bile leakage and severe hemorrhage.High pretreatment RDW was positively associated with the neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio and was negatively associated with albumin and the prognostic nutritional index.CONCLUSION Pretreatment RDW was a special parameter for patients who underwent LPD.It was associated with malnutrition,severe inflammatory status and poorer short-term outcomes.RDW could be a surrogate marker for nutritional and inflammatory status in identifying patients who were at high risk of developing POCs after LPD.展开更多
The high proportion of uncertain distributed power sources and the access to large-scale random electric vehicle(EV)charging resources further aggravate the voltage fluctuation of the distribution network,and the exis...The high proportion of uncertain distributed power sources and the access to large-scale random electric vehicle(EV)charging resources further aggravate the voltage fluctuation of the distribution network,and the existing research has not deeply explored the EV active-reactive synergistic regulating characteristics,and failed to realize themulti-timescale synergistic control with other regulatingmeans,For this reason,this paper proposes amultilevel linkage coordinated optimization strategy to reduce the voltage deviation of the distribution network.Firstly,a capacitor bank reactive power compensation voltage control model and a distributed photovoltaic(PV)activereactive power regulationmodel are established.Additionally,an external characteristicmodel of EVactive-reactive power regulation is developed considering the four-quadrant operational characteristics of the EVcharger.Amultiobjective optimization model of the distribution network is then constructed considering the time-series coupling constraints of multiple types of voltage regulators.A multi-timescale control strategy is proposed by considering the impact of voltage regulators on active-reactive EV energy consumption and PV energy consumption.Then,a four-stage voltage control optimization strategy is proposed for various types of voltage regulators with multiple time scales.Themulti-objective optimization is solved with the improvedDrosophila algorithmto realize the power fluctuation control of the distribution network and themulti-stage voltage control optimization.Simulation results validate that the proposed voltage control optimization strategy achieves the coordinated control of decentralized voltage control resources in the distribution network.It effectively reduces the voltage deviation of the distribution network while ensuring the energy demand of EV users and enhancing the stability and economic efficiency of the distribution network.展开更多
The mechanical behavior of cemented gangue backfill materials(CGBMs)is closely related to particle size distribution(PSD)of aggregates and properties of cementitious materials.Consequently,the true triaxial compressio...The mechanical behavior of cemented gangue backfill materials(CGBMs)is closely related to particle size distribution(PSD)of aggregates and properties of cementitious materials.Consequently,the true triaxial compression tests,CT scanning,SEM,and EDS tests were conducted on cemented gangue backfill samples(CGBSs)with various carbon nanotube concentrations(P_(CNT))that satisfied fractal theory for the PSD of aggregates.The mechanical properties,energy dissipations,and failure mechanisms of the CGBSs under true triaxial compression were systematically analyzed.The results indicate that appropriate carbon nanotubes(CNTs)effectively enhance the mechanical properties and energy dissipations of CGBSs through micropore filling and microcrack bridging,and the optimal effect appears at P_(CNT)of 0.08wt%.Taking PSD fractal dimension(D)of 2.500 as an example,compared to that of CGBS without CNT,the peak strength(σ_(p)),axial peak strain(ε_(1,p)),elastic strain energy(Ue),and dissipated energy(U_(d))increased by 12.76%,29.60%,19.05%,and90.39%,respectively.However,excessive CNTs can reduce the mechanical properties of CGBSs due to CNT agglomeration,manifesting a decrease inρ_(p),ε_(1,p),and the volumetric strain increment(Δε_(v))when P_(CNT)increases from 0.08wt%to 0.12wt%.Moreover,the addition of CNTs improved the integrity of CGBS after macroscopic failure,and crack extension in CGBSs appeared in two modes:detour and pass through the aggregates.Theσ_(p)and U_(d)firstly increase and then decrease with increasing D,and porosity shows the opposite trend.Theε_(1,p)andΔε_(v)are negatively correlated with D,and CGBS with D=2.150 has the maximum deformation parameters(ε_(1,p)=0.05079,Δε_(v)=0.01990)due to the frictional slip effect caused by coarse aggregates.With increasing D,the failure modes of CGBSs are sequentially manifested as oblique shear failure,"Y-shaped"shear failure,and conjugate shear failure.展开更多
This paper examines the changing regional distribution of grain production in China. Based on the analysis of data from county statistics for the period 2000-2003, major differences in the main grain-output regions in...This paper examines the changing regional distribution of grain production in China. Based on the analysis of data from county statistics for the period 2000-2003, major differences in the main grain-output regions in China can be observed. The main grain-producing areas have shifted from the south to the north of China. New grain production regions have been also added to westem China since the late 1990s. The per capita grain consumption in one third of China's main grain-producing counties has fallen below 400 kg; most of these areas are located in southern China. In the new millennium, Northeast China, the central-south North China, and the add and semi-arid regions of Northwest China produced three quarters of the surplus grains. Most of these areas are located in regions susceptible to environmental change. The amount of grain production in these regions shows high fluctuations. It is argued here that fi.trther studies of recent environmental changes as well as a risk assessment of China's food security in main grain-output regions are needed.展开更多
Objective: Morphine concentration measured in postmortem tissues may or may not reflect antemortem concentration. We measured levels of morphine in autopsied tissues to determine whether morphine distribution in morph...Objective: Morphine concentration measured in postmortem tissues may or may not reflect antemortem concentration. We measured levels of morphine in autopsied tissues to determine whether morphine distribution in morphine-dependent rats is altered after death. Methods: Solid-phase extraction was used to extract morphine from the samples, and morphine levels were measured at 0-96 h postmortem using gas chromatography. Results: The study of the morphine dependent rats showed a significant (P<0.05) increase of morphine concentration in postmortem cardiac blood, liver tissues and kidneys tissues. A significant increase was also observed at 72 h and 96 h postmortem in the brain, while morphine levels in cardiac tissues only increased at 24 h and 96 h postmortem. These changes were associated with an observed pH rapid decrease: pH of cardiac blood dropped from 7.36±0.15 to 6.86±0.09 (P<0.01), pH of liver tissues from 6.98±0.04 to 6.34±0.03 (P<0.05). Conclusion: The postmortem regional distribution of morphine occurs in dependent rats, but different from the change that occurs in acute poisoning rats. The morphine concentration in cardiac blood and tissues tends to increase during the period of 0-96 h postmortem in dependent rats. Morphine concentration increases with pH rapid decrease. The antemortem internal amount of morphine affects its postmortem regional distribution. It appears that several mechanisms are accountable for postmortem morphine distribution. The understanding of the mechanisms and patterns may eventually lead to better choices of samples which may better represent antemortem drug levels.展开更多
The fiber quality status is very important for super quality cotton production and diverse requirements of textile industry in China.In this study,the quality of cotton fiber samples which are collected from 13 major ...The fiber quality status is very important for super quality cotton production and diverse requirements of textile industry in China.In this study,the quality of cotton fiber samples which are collected from 13 major cotton production provinces between 2001 to 2005 were analyzed.Eight quality展开更多
For the 2008 Olympic Games, drastic control measures were implemented on industrial and urban emissions of sulfur dioxide (SO2), nitrogen oxides (NOx) and other pollutants to address the issues of poor air quality...For the 2008 Olympic Games, drastic control measures were implemented on industrial and urban emissions of sulfur dioxide (SO2), nitrogen oxides (NOx) and other pollutants to address the issues of poor air quality in Beijing. To investigate the effects of SO2 and NOx reductions on the particulate sulfate and nitrate concentrations as well as their size distributions, size-segregated aerosol samples were collected using micro-orifice uniform deposit impactors (MOUDIs) at urban and downwind rural sites in Beijing before and after full-scale controls. During the sampling period, the mass concentrations of fine particles (PMI.s) at the urban and rural sites were 94.0 and 85.9 p.g m-3, respectively. More than 90% of the sulfates and 60% of nitrates formed as fine particles. Benefiting from the advantageous meteorological conditions and the source controls, sulfates were observed in rather low concentrations and primarily in condensation mode during the Olympics. The effects of the control measures were separately analyzed for the northerly and the southerly air-mass-dominated days to account for any bias. After the control measures were implemented, PM, sulfates, and nitrates were significantly reduced when the northerly air masses prevailed, with a higher percentage of reduction in larger particles. The droplet mode particles, which dominated the sulfates and nitrates before the controls were implemented, were remarkably reduced in mass concentration after the control measures were implemented. Nevertheless, when the polluted southerly air masses prevailed, the local source control measures in Beijing did not effectively reduce the ambient sulfate concentration due to the enormous regional contribution from the North China Plain.展开更多
China was formed by amalgamation of several small continental blocks (cratons), micro, blocks and orogenic belts in different paleoclimatic settings. It may be correlated with other continental blocks but has its ow...China was formed by amalgamation of several small continental blocks (cratons), micro, blocks and orogenic belts in different paleoclimatic settings. It may be correlated with other continental blocks but has its own specific characteristics; therefore the tectonic environments of China's marine and continental saline basins and salt, and potash, forming environment have some specific characteristics: multiple phases of salt formation, difference in salt, forming ages, migration and concentration of salt, forming processes and diversity of component materials, as well as small sizes of marine saline basins and great changes of saline basins in the late stage and occurrence of abundant liquid mineral resources. The nature of the tectonic basement exerted a key controlling effect on the formation of potash basins. The stable tectonic region was favorable for potash concentration in a quasi, stable region, and quasi, and the quasi-stable region was favorable for salt concentration and potash formation in a local stable tectonic region. Most China's major ancient saline basins occur in "quasi, cratons (continental block)"; especially all the marine saline basins occur in continental blocks with the Precambrian basement. These regions are the key ones for potash search. Most relatively large, scale soluble salt deposits are developed in relatively stable continental nuclei. According to the characteristics of the tectonic domains where China's salt, forming basins are located, the North China, Yangtze and Tarim, Qaidam salt minerogenetic domains and the northern Qiangtang, western Yunnan salt minerogenetic belt may be distinguished. Their salt and potash prospects will be discussed separately.展开更多
Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheime...Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheimer’s disease affects the entire brain,further research is needed to elucidate alterations in mitochondrial metabolism in the brain as a whole.Here,we investigated the expression of several important mitochondrial biogenesis-related cytokines in multiple brain regions after treatment with neural stem cell-derived exosomes and used a combination of whole brain clearing,immunostaining,and lightsheet imaging to clarify their spatial distribution.Additionally,to clarify whether the sirtuin 1(SIRT1)-related pathway plays a regulatory role in neural stem cell-de rived exosomes interfering with mitochondrial functional changes,we generated a novel nervous system-SIRT1 conditional knoc kout AP P/PS1mouse model.Our findings demonstrate that neural stem cell-de rived exosomes significantly increase SIRT1 levels,enhance the production of mitochondrial biogenesis-related fa ctors,and inhibit astrocyte activation,but do not suppress amyloid-βproduction.Thus,neural stem cell-derived exosomes may be a useful therapeutic strategy for Alzheimer’s disease that activates the SIRT1-PGC1αsignaling pathway and increases NRF1 and COXIV synthesis to improve mitochondrial biogenesis.In addition,we showed that the spatial distribution of mitochondrial biogenesis-related factors is disrupted in Alzheimer’s disease,and that neural stem cell-derived exosome treatment can reverse this effect,indicating that neural stem cell-derived exosomes promote mitochondrial biogenesis.展开更多
This paper summarizes the distribution and production layout of the major mineral resources in China,including coal,iron ore,copper and bauxite,from a national perspective.It also identifies the incompatibility betwee...This paper summarizes the distribution and production layout of the major mineral resources in China,including coal,iron ore,copper and bauxite,from a national perspective.It also identifies the incompatibility between the mineral resources distribution and regional economic development.Significant issues with China's mineral resource industry cause challenges for the sustainable development of both the mining industry and the national socio-economy.The sustainability of regional mineral resources and the environmental pollution by mining in the western China were also analyzed.Results show that the distribution of China's mineral resources is misaligned with its regional layout of economic development.China's mineral resources have been over-exploited,and the mineral resources production in the eastern China is unsustainable.The continuously expanding production of mineral resources in the western China has heavily endangered the ecological environment.We propose strategies to boost the sustainable development of mineral resources,including measures to accelerate economic development and enhance the sustainability of domestic mineral resources.We also offer suggestions for scientifically planning the mineral resource prospecting and exploitation and regional economic layout,as well as for proactively undertaking industry transfer in the eastern China and raising the environmental benchmark requirements for the mineral industry in the central and western China.展开更多
The characteristics of the raindrop size distribution(DSD)during regional freezing rain(FR)events that occur throughout the phase change(from liquid to solid)are poorly understood due to limited observations.We invest...The characteristics of the raindrop size distribution(DSD)during regional freezing rain(FR)events that occur throughout the phase change(from liquid to solid)are poorly understood due to limited observations.We investigate the evolution of microphysical parameters and the key formation mechanisms of regional FR using the DSDs from five disdrometer sites in January 2018 in the Jianghan Plain(JHP)of Central China.FR is identified via the size and velocity distribution measured from a disdrometer,the discrete Fréchet distancemethod,surface temperature,human observations,and sounding data.With the persistence of precipitation,the emergence of graupel or snowflakes significantly reduces the proportion of FR.The enhancement of this regional FR event is mainly dominated by the increase in the number concentration of raindrops but weakly affected by the diameters.To improve the accuracy of quantitative precipitation estimation for the FR event,a modified second-degree polynomial relation between the shapeμand slopeΛof gamma DSDs is derived,and a new Z-R(radar reflectivity to rain rate)relationship is developed.The mean values of mass-weighted mean diameters(D_(m))and generalized intercepts(lgN_(w))in FR are close to the stratiform results in the northern region of China.Both the melting of tiny-rimed graupels and large-dry snowflakes are a response to the formation of this regional FR process in the JHP,dominated by the joint influence of the physical mechanism of warm rain,vapor deposition,and aggregation/riming coupled with the effect of weak convective motion in some periods.展开更多
We have used a nonlinear one-dimensional heat transfer model based on temperature-dependent blood perfusion to predict temperature distribution in dermis and subcutaneous tissues subjected to point heating sources. By...We have used a nonlinear one-dimensional heat transfer model based on temperature-dependent blood perfusion to predict temperature distribution in dermis and subcutaneous tissues subjected to point heating sources. By using Jacobi elliptic functions, we have first found the analytic solution corresponding to the steady-state temperature distribution in the tissue. With the obtained analytic steady-state temperature, the effects of the thermal conductivity, the blood perfusion, the metabolic heat generation, and the coefficient of heat transfer on the temperature distribution in living tissues are numerically analyzed. Our results show that the derived analytic steady-state temperature is useful to easily and accurately study the thermal behavior of the biological system, and can be extended to such applications as parameter measurement, temperature field reconstruction and clinical treatment.展开更多
Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorptio...Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.展开更多
The lamellar structure of tungsten inert gas (T1G) arc is distinct in that it reflects its inhomogeneous energy distribution. In terms of an arc' s physical properties, the lamellar structure may be divided into th...The lamellar structure of tungsten inert gas (T1G) arc is distinct in that it reflects its inhomogeneous energy distribution. In terms of an arc' s physical properties, the lamellar structure may be divided into three regions : the ionization region, the recombination region and gas fringes. A large gradient of electron density exists between regions ; this causes differences in the physical properties of an arc. In this study, the scale of ionizing regions in TIG arc is accurately determined with experimental conditions by a spectroscopic diagnostic method, which is also used to investigate the distribution of the electron density of the arc. More precise dimensions of arc energy distribution are described; the paper also discusses the difference with or without the influence of metal vapor from the weld pool.展开更多
The objective of this work is to analyze the spatial distribution of biases of nine (9) regional climate models (RCMs) and their ensemble average used under the framework of COordinated Regional climate Downscaling EX...The objective of this work is to analyze the spatial distribution of biases of nine (9) regional climate models (RCMs) and their ensemble average used under the framework of COordinated Regional climate Downscaling EXperiment (CORDEX) project over West Africa during the summer period. We assessed the ability of RCMs to represent adequately West African summer rainfall by analyzing some statistical parameters such as the relative bias, the standard deviation, the root mean square error (RMSE) and the correlation coefficient between observation data (GPCP used as reference) and regional climate models outputs. We first analyzed the relative bias between GPCP climatology and the other available observed data (CRU, CMAP, UDEL, GPCC, TRMM and their ensemble mean). This analysis highlights the big uncertainty on the quality of these observed rainfall data over West Africa which may be largely due to the rarity of?in situ?measurement data over this region. The statistical analysis with respect to GPCP rainfall shows the presence of large relative bias values over most part of West Africa for engaged RCMs. However their ensemble mean outperforms individual RCMs by exhibiting the weakest relative change. The RMSE values are weak over West Africa except over and off the Guinea highlands for RCMs and the Era-interim reanalysis. The spatial distribution of the coefficient of correlation between the observation data and RCMs shows that all models (except HIRHAM) present positive values over the Northern Sahel and the Gulf of Guinea. The model of the DMI exhibits the weakest values of correlation coefficient. This study shows that RCMs simulate West African climate in a satisfactory way despite the fact that they exhibit systematic biases.展开更多
Some 1313 hair samples from about 200 sample sites are collected. These sites cover 103 counties with different types of natural conditions and are far from cities (towns) or polluted areas.The hair As contents are an...Some 1313 hair samples from about 200 sample sites are collected. These sites cover 103 counties with different types of natural conditions and are far from cities (towns) or polluted areas.The hair As contents are analysed by hydro-atomic fluorescence spetrophotometry and the data are calculated by SPSS. The results show that Chinese hair As contents are between 0.004 and 9.999 μu/g.The median is 0.56μg/g. The arithmetic mean is (0.927±1.213) μg/g and the geometric mean is 0.571 μg/g. There are no significant differences between sexes and ages. The results of Pelson X2 and Shapio-Wilk W tests show that the As content in the same physical geographical area has a logarithm normal distribution. Hair As contents in southern China are significantly higher than that in the northern.The geometric means are 0.2~0.4 μg/g in medium-temperate zone and 0.4~0.6 μg/g in warm-temperate zone. In north-subtropical zone the hair As geometric mean increase up to 0.767 μg/g and in medium-subtropical zone, south-subtropical zone and tropical zone, it is higher than 1.00 μg/g. There is no difference between areas in the same physical geographical zone. Hair As content in Qinghai-Tibet Plateau area is also lower (the geometric mean is 0.267 μg/g). The standard level of hair As content for determining chronic Arsenism areas in China is also discussed.展开更多
To study the regional distribution features of aroma characteristics, the regional distribution maps of aroma characteristics of 225 tobacco leaf samples from Henan Province were drawn by Kriging interpolation method ...To study the regional distribution features of aroma characteristics, the regional distribution maps of aroma characteristics of 225 tobacco leaf samples from Henan Province were drawn by Kriging interpolation method in ArcGIS. The results showed that:(1) the aroma quality of flue-cured tobacco from Henan Province tobacco-growing areas ranged from better to slightly better and aroma quantity ranged from just a little to much. The ability of diffusiveness expressed slight to a little strong and the raw green odour, immature odour and ligneous odour were tiny;(2) there were significant differences between the aroma quality and scorched odour and no statistical differences among the aroma quantity, diffusiveness, raw green odour, ligneous odour and immature odour from different counties;(3) there were trends that scale of aroma quality increased from southwest to both north and east, aroma quantity showed a patchy distribution in space, diffusiveness decreased from east to west, scorched odour increased from west to both north and south, ligneous odour increased from north to south and green odour increased from south to north.展开更多
The effect of pore morphology and regional distribution on liquid diffusion directionality in nonwoven fabrics was investigated in this study.Pore orientation angle(POA) and pore aspect ratio(PAR) were proposed to cha...The effect of pore morphology and regional distribution on liquid diffusion directionality in nonwoven fabrics was investigated in this study.Pore orientation angle(POA) and pore aspect ratio(PAR) were proposed to characterize the pore morphology,and α-region,β-region,and αβ-region were used to describe the characteristics of the pore regional distribution.The directional characteristics of macroscopic diffusion of liquid in nonwoven fabrics were characterized by the indicator of primary diffusion orientation angle(PDOA).Ten kinds of spunlaced nonwoven fabrics were selected.Firstly,the data of pore characteristic indices of each sample were obtained through scanning electron microscope(SEM) and the image processing technology as well,and the pore regional distribution map of each sample was further acquired.Then,the PDOA of each sample was obtained through the droplet method and image processing technology.Based on the data and statistical analysis,it was found that the PDOA of a certain volume of liquid in the nonwoven fabrics presented a significant linear relationship with the average POA of the nonwoven fabrics.And the characteristics of pore distribution affected the directionality of liquid diffusion in the nonwoven fabrics.The samples with a large proportion of α-region and good distribution had prominent liquid diffusion along the direction of laying-up,and the difference in liquid diffusion of the samples was more obvious between the directions of laying-up and vertical laying-up.展开更多
基金supported by National Natural Science Foundation of China(62104082)Guangdong Basic and Applied Basic Research Foundation(2022A1515010746,2022A1515011228,and 2022B1515120006)the Science and Technology Program of Guangzhou(202201010458).
文摘Gas quenching and vacuum quenching process are widely applied to accelerate solvent volatilization to induce nucleation of perovskites in blade-coating method.In this work,we found these two pre-crystallization processes lead to different order of crystallization dynamics within the perovskite thin film,resulting in the differences of additive distribution.We then tailor-designed an additive molecule named 1,3-bis(4-methoxyphenyl)thiourea to obtain films with fewer defects and holes at the buried interface,and prepared perovskite solar cells with a certified efficiency of 23.75%.Furthermore,this work also demonstrates an efficiency of 20.18%for the large-area perovskite solar module(PSM)with an aperture area of 60.84 cm^(2).The PSM possesses remarkable continuous operation stability for maximum power point tracking of T_(90)>1000 h in ambient air.
基金supported by the National Natural Science Foundation of China,Nos.32070534(to WY),32370567(to WY),82371874(to XL),81830032(to XL),82071421(to SL)Key Field Research and Development Program of Guangdong Province,No.2018B030337001(to XL)+2 种基金Guangzhou Key Research Program on Brain Science,No.202007030008(to XL)Department of Science and Technology of Guangdong Province,Nos.2021ZT09Y007,2020B121201006(to XL)Guangdong Basic and Applied Basic Research Foundation,Nos.2022A1515012301(to WY),2023B1515020031(to WY).
文摘The vast majority of in vitro studies have demonstrated that PINK1 phosphorylates Parkin to work together in mitophagy to protect against neuronal degeneration.However,it remains largely unclear how PINK1 and Parkin are expressed in mammalian brains.This has been difficult to address because of the intrinsically low levels of PINK1 and undetectable levels of phosphorylated Parkin in small animals.Understanding this issue is critical for elucidating the in vivo roles of PINK1 and Parkin.Recently,we showed that the PINK1 kinase is selectively expressed as a truncated form(PINK1–55)in the primate brain.In the present study,we used multiple antibodies,including our recently developed monoclonal anti-PINK1,to validate the selective expression of PINK1 in the primate brain.We found that PINK1 was stably expressed in the monkey brain at postnatal and adulthood stages,which is consistent with the findings that depleting PINK1 can cause neuronal loss in developing and adult monkey brains.PINK1 was enriched in the membrane-bound fractionations,whereas Parkin was soluble with a distinguishable distribution.Immunofluorescent double staining experiments showed that PINK1 and Parkin did not colocalize under physiological conditions in cultured monkey astrocytes,though they did colocalize on mitochondria when the cells were exposed to mitochondrial stress.These findings suggest that PINK1 and Parkin may have distinct roles beyond their well-known function in mitophagy during mitochondrial damage.
基金Supported by the National Natural Science Foundation of China,No.81302124.
文摘BACKGROUND Red blood cell distribution width(RDW)is associated with the development and progression of various diseases.AIM To explore the association between pretreatment RDW and short-term outcomes after laparoscopic pancreatoduodenectomy(LPD).METHODS A total of 804 consecutive patients who underwent LPD at our hospital between March 2017 and November 2021 were retrospectively analyzed.Correlations between pretreatment RDW and clinicopathological characteristics and short-term outcomes were investigated.RESULTS Patients with higher pretreatment RDW were older,had higher Eastern Cooperative Oncology Group scores and were associated with poorer short-term outcomes than those with normal RDW.High pretreatment RDW was an independent risk factor for postoperative complications(POCs)(hazard ratio=2.973,95%confidence interval:2.032-4.350,P<0.001)and severe POCs of grade IIIa or higher(hazard ratio=3.138,95%confidence interval:2.042-4.824,P<0.001)based on the Clavien-Dino classification system.Subgroup analysis showed that high pretreatment RDW was an independent risk factor for Clavien-Dino classi-fication grade IIIb or higher POCs,a comprehensive complication index score≥26.2,severe postoperative pancreatic fistula,severe bile leakage and severe hemorrhage.High pretreatment RDW was positively associated with the neutrophil-to-lymphocyte ratio and platelet-to-lymphocyte ratio and was negatively associated with albumin and the prognostic nutritional index.CONCLUSION Pretreatment RDW was a special parameter for patients who underwent LPD.It was associated with malnutrition,severe inflammatory status and poorer short-term outcomes.RDW could be a surrogate marker for nutritional and inflammatory status in identifying patients who were at high risk of developing POCs after LPD.
基金funded by the State Grid Corporation Science and Technology Project(5108-202218280A-2-391-XG).
文摘The high proportion of uncertain distributed power sources and the access to large-scale random electric vehicle(EV)charging resources further aggravate the voltage fluctuation of the distribution network,and the existing research has not deeply explored the EV active-reactive synergistic regulating characteristics,and failed to realize themulti-timescale synergistic control with other regulatingmeans,For this reason,this paper proposes amultilevel linkage coordinated optimization strategy to reduce the voltage deviation of the distribution network.Firstly,a capacitor bank reactive power compensation voltage control model and a distributed photovoltaic(PV)activereactive power regulationmodel are established.Additionally,an external characteristicmodel of EVactive-reactive power regulation is developed considering the four-quadrant operational characteristics of the EVcharger.Amultiobjective optimization model of the distribution network is then constructed considering the time-series coupling constraints of multiple types of voltage regulators.A multi-timescale control strategy is proposed by considering the impact of voltage regulators on active-reactive EV energy consumption and PV energy consumption.Then,a four-stage voltage control optimization strategy is proposed for various types of voltage regulators with multiple time scales.Themulti-objective optimization is solved with the improvedDrosophila algorithmto realize the power fluctuation control of the distribution network and themulti-stage voltage control optimization.Simulation results validate that the proposed voltage control optimization strategy achieves the coordinated control of decentralized voltage control resources in the distribution network.It effectively reduces the voltage deviation of the distribution network while ensuring the energy demand of EV users and enhancing the stability and economic efficiency of the distribution network.
基金financially supported by the National Natural Science Foundation of China(Nos.52174092,51904290,and 52374147)the Natural Science Foundation of Jiangsu Province,China(No.BK20220157)+2 种基金the Fundamental Research Funds for the Central Universities,China(No.2022YCPY0202)the National Key Research and Development Program of China(No.2023YFC3804204)the Major Program of Xinjiang Uygur Autonomous Region S cience and Technology(No.2023A01002)。
文摘The mechanical behavior of cemented gangue backfill materials(CGBMs)is closely related to particle size distribution(PSD)of aggregates and properties of cementitious materials.Consequently,the true triaxial compression tests,CT scanning,SEM,and EDS tests were conducted on cemented gangue backfill samples(CGBSs)with various carbon nanotube concentrations(P_(CNT))that satisfied fractal theory for the PSD of aggregates.The mechanical properties,energy dissipations,and failure mechanisms of the CGBSs under true triaxial compression were systematically analyzed.The results indicate that appropriate carbon nanotubes(CNTs)effectively enhance the mechanical properties and energy dissipations of CGBSs through micropore filling and microcrack bridging,and the optimal effect appears at P_(CNT)of 0.08wt%.Taking PSD fractal dimension(D)of 2.500 as an example,compared to that of CGBS without CNT,the peak strength(σ_(p)),axial peak strain(ε_(1,p)),elastic strain energy(Ue),and dissipated energy(U_(d))increased by 12.76%,29.60%,19.05%,and90.39%,respectively.However,excessive CNTs can reduce the mechanical properties of CGBSs due to CNT agglomeration,manifesting a decrease inρ_(p),ε_(1,p),and the volumetric strain increment(Δε_(v))when P_(CNT)increases from 0.08wt%to 0.12wt%.Moreover,the addition of CNTs improved the integrity of CGBS after macroscopic failure,and crack extension in CGBSs appeared in two modes:detour and pass through the aggregates.Theσ_(p)and U_(d)firstly increase and then decrease with increasing D,and porosity shows the opposite trend.Theε_(1,p)andΔε_(v)are negatively correlated with D,and CGBS with D=2.150 has the maximum deformation parameters(ε_(1,p)=0.05079,Δε_(v)=0.01990)due to the frictional slip effect caused by coarse aggregates.With increasing D,the failure modes of CGBSs are sequentially manifested as oblique shear failure,"Y-shaped"shear failure,and conjugate shear failure.
基金National Natural Science Foundation of China, No.40571165 No.40271115
文摘This paper examines the changing regional distribution of grain production in China. Based on the analysis of data from county statistics for the period 2000-2003, major differences in the main grain-output regions in China can be observed. The main grain-producing areas have shifted from the south to the north of China. New grain production regions have been also added to westem China since the late 1990s. The per capita grain consumption in one third of China's main grain-producing counties has fallen below 400 kg; most of these areas are located in southern China. In the new millennium, Northeast China, the central-south North China, and the add and semi-arid regions of Northwest China produced three quarters of the surplus grains. Most of these areas are located in regions susceptible to environmental change. The amount of grain production in these regions shows high fluctuations. It is argued here that fi.trther studies of recent environmental changes as well as a risk assessment of China's food security in main grain-output regions are needed.
文摘Objective: Morphine concentration measured in postmortem tissues may or may not reflect antemortem concentration. We measured levels of morphine in autopsied tissues to determine whether morphine distribution in morphine-dependent rats is altered after death. Methods: Solid-phase extraction was used to extract morphine from the samples, and morphine levels were measured at 0-96 h postmortem using gas chromatography. Results: The study of the morphine dependent rats showed a significant (P<0.05) increase of morphine concentration in postmortem cardiac blood, liver tissues and kidneys tissues. A significant increase was also observed at 72 h and 96 h postmortem in the brain, while morphine levels in cardiac tissues only increased at 24 h and 96 h postmortem. These changes were associated with an observed pH rapid decrease: pH of cardiac blood dropped from 7.36±0.15 to 6.86±0.09 (P<0.01), pH of liver tissues from 6.98±0.04 to 6.34±0.03 (P<0.05). Conclusion: The postmortem regional distribution of morphine occurs in dependent rats, but different from the change that occurs in acute poisoning rats. The morphine concentration in cardiac blood and tissues tends to increase during the period of 0-96 h postmortem in dependent rats. Morphine concentration increases with pH rapid decrease. The antemortem internal amount of morphine affects its postmortem regional distribution. It appears that several mechanisms are accountable for postmortem morphine distribution. The understanding of the mechanisms and patterns may eventually lead to better choices of samples which may better represent antemortem drug levels.
文摘The fiber quality status is very important for super quality cotton production and diverse requirements of textile industry in China.In this study,the quality of cotton fiber samples which are collected from 13 major cotton production provinces between 2001 to 2005 were analyzed.Eight quality
基金the National Key Basic Research Program of China (973program),a key project of the Shandong Provincial Environmental Protection Department,the Niche Area Development Scheme of the Hong Kong Polytechnic University,the Hong Kong Research Grants Council,the central level,scientific research institutes for basic R & D special fund business
文摘For the 2008 Olympic Games, drastic control measures were implemented on industrial and urban emissions of sulfur dioxide (SO2), nitrogen oxides (NOx) and other pollutants to address the issues of poor air quality in Beijing. To investigate the effects of SO2 and NOx reductions on the particulate sulfate and nitrate concentrations as well as their size distributions, size-segregated aerosol samples were collected using micro-orifice uniform deposit impactors (MOUDIs) at urban and downwind rural sites in Beijing before and after full-scale controls. During the sampling period, the mass concentrations of fine particles (PMI.s) at the urban and rural sites were 94.0 and 85.9 p.g m-3, respectively. More than 90% of the sulfates and 60% of nitrates formed as fine particles. Benefiting from the advantageous meteorological conditions and the source controls, sulfates were observed in rather low concentrations and primarily in condensation mode during the Olympics. The effects of the control measures were separately analyzed for the northerly and the southerly air-mass-dominated days to account for any bias. After the control measures were implemented, PM, sulfates, and nitrates were significantly reduced when the northerly air masses prevailed, with a higher percentage of reduction in larger particles. The droplet mode particles, which dominated the sulfates and nitrates before the controls were implemented, were remarkably reduced in mass concentration after the control measures were implemented. Nevertheless, when the polluted southerly air masses prevailed, the local source control measures in Beijing did not effectively reduce the ambient sulfate concentration due to the enormous regional contribution from the North China Plain.
基金supported by projects of China Geological Survey(grants 1212010918025 and 1212010011810)National Natural Science Foundation of China and joint foundation(grants 40531002 and U0833601)
文摘China was formed by amalgamation of several small continental blocks (cratons), micro, blocks and orogenic belts in different paleoclimatic settings. It may be correlated with other continental blocks but has its own specific characteristics; therefore the tectonic environments of China's marine and continental saline basins and salt, and potash, forming environment have some specific characteristics: multiple phases of salt formation, difference in salt, forming ages, migration and concentration of salt, forming processes and diversity of component materials, as well as small sizes of marine saline basins and great changes of saline basins in the late stage and occurrence of abundant liquid mineral resources. The nature of the tectonic basement exerted a key controlling effect on the formation of potash basins. The stable tectonic region was favorable for potash concentration in a quasi, stable region, and quasi, and the quasi-stable region was favorable for salt concentration and potash formation in a local stable tectonic region. Most China's major ancient saline basins occur in "quasi, cratons (continental block)"; especially all the marine saline basins occur in continental blocks with the Precambrian basement. These regions are the key ones for potash search. Most relatively large, scale soluble salt deposits are developed in relatively stable continental nuclei. According to the characteristics of the tectonic domains where China's salt, forming basins are located, the North China, Yangtze and Tarim, Qaidam salt minerogenetic domains and the northern Qiangtang, western Yunnan salt minerogenetic belt may be distinguished. Their salt and potash prospects will be discussed separately.
基金supported by the National Natural Science Foundation of China,Nos.82171194 and 81974155(both to JL)the Shanghai Municipal Science and Technology Commission Medical Guide Project,No.16411969200(to WZ)Shanghai Municipal Science and Technology Commission Biomedical Science and Technology Project,No.22S31902600(to JL)。
文摘Mitochondrial dysfunction is a hallmark of Alzheimer’s disease.We previously showed that neural stem cell-derived extracellular vesicles improved mitochondrial function in the cortex of AP P/PS1 mice.Because Alzheimer’s disease affects the entire brain,further research is needed to elucidate alterations in mitochondrial metabolism in the brain as a whole.Here,we investigated the expression of several important mitochondrial biogenesis-related cytokines in multiple brain regions after treatment with neural stem cell-derived exosomes and used a combination of whole brain clearing,immunostaining,and lightsheet imaging to clarify their spatial distribution.Additionally,to clarify whether the sirtuin 1(SIRT1)-related pathway plays a regulatory role in neural stem cell-de rived exosomes interfering with mitochondrial functional changes,we generated a novel nervous system-SIRT1 conditional knoc kout AP P/PS1mouse model.Our findings demonstrate that neural stem cell-de rived exosomes significantly increase SIRT1 levels,enhance the production of mitochondrial biogenesis-related fa ctors,and inhibit astrocyte activation,but do not suppress amyloid-βproduction.Thus,neural stem cell-derived exosomes may be a useful therapeutic strategy for Alzheimer’s disease that activates the SIRT1-PGC1αsignaling pathway and increases NRF1 and COXIV synthesis to improve mitochondrial biogenesis.In addition,we showed that the spatial distribution of mitochondrial biogenesis-related factors is disrupted in Alzheimer’s disease,and that neural stem cell-derived exosome treatment can reverse this effect,indicating that neural stem cell-derived exosomes promote mitochondrial biogenesis.
文摘This paper summarizes the distribution and production layout of the major mineral resources in China,including coal,iron ore,copper and bauxite,from a national perspective.It also identifies the incompatibility between the mineral resources distribution and regional economic development.Significant issues with China's mineral resource industry cause challenges for the sustainable development of both the mining industry and the national socio-economy.The sustainability of regional mineral resources and the environmental pollution by mining in the western China were also analyzed.Results show that the distribution of China's mineral resources is misaligned with its regional layout of economic development.China's mineral resources have been over-exploited,and the mineral resources production in the eastern China is unsustainable.The continuously expanding production of mineral resources in the western China has heavily endangered the ecological environment.We propose strategies to boost the sustainable development of mineral resources,including measures to accelerate economic development and enhance the sustainability of domestic mineral resources.We also offer suggestions for scientifically planning the mineral resource prospecting and exploitation and regional economic layout,as well as for proactively undertaking industry transfer in the eastern China and raising the environmental benchmark requirements for the mineral industry in the central and western China.
基金supported by the National Natural Science Foundation of China(Grant Nos.41875170 and 41675136)the National Key Research and Development Program of China(2018YFC1507201 and 2018YFC1507905)the Guangxi Key Research and Development Program(AB20159013)。
文摘The characteristics of the raindrop size distribution(DSD)during regional freezing rain(FR)events that occur throughout the phase change(from liquid to solid)are poorly understood due to limited observations.We investigate the evolution of microphysical parameters and the key formation mechanisms of regional FR using the DSDs from five disdrometer sites in January 2018 in the Jianghan Plain(JHP)of Central China.FR is identified via the size and velocity distribution measured from a disdrometer,the discrete Fréchet distancemethod,surface temperature,human observations,and sounding data.With the persistence of precipitation,the emergence of graupel or snowflakes significantly reduces the proportion of FR.The enhancement of this regional FR event is mainly dominated by the increase in the number concentration of raindrops but weakly affected by the diameters.To improve the accuracy of quantitative precipitation estimation for the FR event,a modified second-degree polynomial relation between the shapeμand slopeΛof gamma DSDs is derived,and a new Z-R(radar reflectivity to rain rate)relationship is developed.The mean values of mass-weighted mean diameters(D_(m))and generalized intercepts(lgN_(w))in FR are close to the stratiform results in the northern region of China.Both the melting of tiny-rimed graupels and large-dry snowflakes are a response to the formation of this regional FR process in the JHP,dominated by the joint influence of the physical mechanism of warm rain,vapor deposition,and aggregation/riming coupled with the effect of weak convective motion in some periods.
文摘We have used a nonlinear one-dimensional heat transfer model based on temperature-dependent blood perfusion to predict temperature distribution in dermis and subcutaneous tissues subjected to point heating sources. By using Jacobi elliptic functions, we have first found the analytic solution corresponding to the steady-state temperature distribution in the tissue. With the obtained analytic steady-state temperature, the effects of the thermal conductivity, the blood perfusion, the metabolic heat generation, and the coefficient of heat transfer on the temperature distribution in living tissues are numerically analyzed. Our results show that the derived analytic steady-state temperature is useful to easily and accurately study the thermal behavior of the biological system, and can be extended to such applications as parameter measurement, temperature field reconstruction and clinical treatment.
基金supported by the National Natural Science Foundation of China(Nos.61805257,41905130)in part by the China Postdoctoral Science Foundation(Nos.2020M671383,2020M681517)in part by the Science and Technology Development Plan Foundation of Suzhou(No.SS202148).
文摘Aiming at the in situ and mobile observation of urban environmental air pollution,a portable instrument using ultraviolet spectrum retrieval algorithm was developed based on the basis of Differential Optical Absorption Spectroscopy(DOAS)and multiple-pass cell technique.Typical trace gas pollutants,NH3,SO2,and NO2,were explored using their optical spectral characteristics in deep ultraviolet wavelength range from 210 to 215 nm.The gas concentration was retrieved by Lambert-Beer’s law and nonlinear least square method.With an optimized optical alignment,the detection limits of NH3,SO2,NO2 were estimated to be 2.2,2.3,and 36.2 ppb,respectively.The system was used in carrying out some cruise observations in Chengdu,China.During the entire period,the polluted gases showed varied distribution and typical daily average concentrations ofNH3,SO2,NO2 were 23.2,3.5,and 106.0 ppb,respectively.The contributions from different sources were analyzed combined with the HYSPLIT model.Results show that the portable DOAS system is a convenient and effective tool for regional distribution measurement and pollution source monitoring.
基金The work was supported by the National Natural Science Foundation of China (No. 51275009).
文摘The lamellar structure of tungsten inert gas (T1G) arc is distinct in that it reflects its inhomogeneous energy distribution. In terms of an arc' s physical properties, the lamellar structure may be divided into three regions : the ionization region, the recombination region and gas fringes. A large gradient of electron density exists between regions ; this causes differences in the physical properties of an arc. In this study, the scale of ionizing regions in TIG arc is accurately determined with experimental conditions by a spectroscopic diagnostic method, which is also used to investigate the distribution of the electron density of the arc. More precise dimensions of arc energy distribution are described; the paper also discusses the difference with or without the influence of metal vapor from the weld pool.
文摘The objective of this work is to analyze the spatial distribution of biases of nine (9) regional climate models (RCMs) and their ensemble average used under the framework of COordinated Regional climate Downscaling EXperiment (CORDEX) project over West Africa during the summer period. We assessed the ability of RCMs to represent adequately West African summer rainfall by analyzing some statistical parameters such as the relative bias, the standard deviation, the root mean square error (RMSE) and the correlation coefficient between observation data (GPCP used as reference) and regional climate models outputs. We first analyzed the relative bias between GPCP climatology and the other available observed data (CRU, CMAP, UDEL, GPCC, TRMM and their ensemble mean). This analysis highlights the big uncertainty on the quality of these observed rainfall data over West Africa which may be largely due to the rarity of?in situ?measurement data over this region. The statistical analysis with respect to GPCP rainfall shows the presence of large relative bias values over most part of West Africa for engaged RCMs. However their ensemble mean outperforms individual RCMs by exhibiting the weakest relative change. The RMSE values are weak over West Africa except over and off the Guinea highlands for RCMs and the Era-interim reanalysis. The spatial distribution of the coefficient of correlation between the observation data and RCMs shows that all models (except HIRHAM) present positive values over the Northern Sahel and the Gulf of Guinea. The model of the DMI exhibits the weakest values of correlation coefficient. This study shows that RCMs simulate West African climate in a satisfactory way despite the fact that they exhibit systematic biases.
文摘Some 1313 hair samples from about 200 sample sites are collected. These sites cover 103 counties with different types of natural conditions and are far from cities (towns) or polluted areas.The hair As contents are analysed by hydro-atomic fluorescence spetrophotometry and the data are calculated by SPSS. The results show that Chinese hair As contents are between 0.004 and 9.999 μu/g.The median is 0.56μg/g. The arithmetic mean is (0.927±1.213) μg/g and the geometric mean is 0.571 μg/g. There are no significant differences between sexes and ages. The results of Pelson X2 and Shapio-Wilk W tests show that the As content in the same physical geographical area has a logarithm normal distribution. Hair As contents in southern China are significantly higher than that in the northern.The geometric means are 0.2~0.4 μg/g in medium-temperate zone and 0.4~0.6 μg/g in warm-temperate zone. In north-subtropical zone the hair As geometric mean increase up to 0.767 μg/g and in medium-subtropical zone, south-subtropical zone and tropical zone, it is higher than 1.00 μg/g. There is no difference between areas in the same physical geographical zone. Hair As content in Qinghai-Tibet Plateau area is also lower (the geometric mean is 0.267 μg/g). The standard level of hair As content for determining chronic Arsenism areas in China is also discussed.
基金Supported by Major Special Projects of Development of Strong Flavor Characteristic and High Quality Tobacco Leaf by China National Tobacco Corporation(110201101001 TS-01)Pingdingshan Tobacco Company Technology Projects(PDSKJ2017018)Tianchang International Tobacco Company Technology Projects(TCKJ201701)
文摘To study the regional distribution features of aroma characteristics, the regional distribution maps of aroma characteristics of 225 tobacco leaf samples from Henan Province were drawn by Kriging interpolation method in ArcGIS. The results showed that:(1) the aroma quality of flue-cured tobacco from Henan Province tobacco-growing areas ranged from better to slightly better and aroma quantity ranged from just a little to much. The ability of diffusiveness expressed slight to a little strong and the raw green odour, immature odour and ligneous odour were tiny;(2) there were significant differences between the aroma quality and scorched odour and no statistical differences among the aroma quantity, diffusiveness, raw green odour, ligneous odour and immature odour from different counties;(3) there were trends that scale of aroma quality increased from southwest to both north and east, aroma quantity showed a patchy distribution in space, diffusiveness decreased from east to west, scorched odour increased from west to both north and south, ligneous odour increased from north to south and green odour increased from south to north.
基金National Key R&D Program of China (No. 2017YFB0309100)。
文摘The effect of pore morphology and regional distribution on liquid diffusion directionality in nonwoven fabrics was investigated in this study.Pore orientation angle(POA) and pore aspect ratio(PAR) were proposed to characterize the pore morphology,and α-region,β-region,and αβ-region were used to describe the characteristics of the pore regional distribution.The directional characteristics of macroscopic diffusion of liquid in nonwoven fabrics were characterized by the indicator of primary diffusion orientation angle(PDOA).Ten kinds of spunlaced nonwoven fabrics were selected.Firstly,the data of pore characteristic indices of each sample were obtained through scanning electron microscope(SEM) and the image processing technology as well,and the pore regional distribution map of each sample was further acquired.Then,the PDOA of each sample was obtained through the droplet method and image processing technology.Based on the data and statistical analysis,it was found that the PDOA of a certain volume of liquid in the nonwoven fabrics presented a significant linear relationship with the average POA of the nonwoven fabrics.And the characteristics of pore distribution affected the directionality of liquid diffusion in the nonwoven fabrics.The samples with a large proportion of α-region and good distribution had prominent liquid diffusion along the direction of laying-up,and the difference in liquid diffusion of the samples was more obvious between the directions of laying-up and vertical laying-up.