A morphologically structured model is proposed to describe the batch fermentation of lovastatin according to the growth kinetics of filamentous microorganisms. Three kinds of hyphae are considered in the model: active...A morphologically structured model is proposed to describe the batch fermentation of lovastatin according to the growth kinetics of filamentous microorganisms. Three kinds of hyphae are considered in the model: actively growing hyphae, non-growing hyphae and deactivated hyphae. Furthermore, actively growing hyphae consist of three morphological compartments: apical compartment which gives rise to hyphal tip extension; subapical compartment which is related to hyphal branching; and hyphal compartment which is only responsible for secondary metabolite formation. The kinetics of mycelial growth mechanism is summarized and applied in modeling lovastatin fermentation. A Michaelis-Menten kinetic model with substrate inhibition is proposed for product formation. As expected, the model simulations fit well with experimental data obtained either from a laboratory scale 10L fer-menter or from a pilot-plant scale fermenter.展开更多
Leaf-color mutations are a widely-observed class of mutations, playing an important role in the study of chlorophyll biosynthesis and plant chloroplast structure, function, genetics and development. A naturally-occurr...Leaf-color mutations are a widely-observed class of mutations, playing an important role in the study of chlorophyll biosynthesis and plant chloroplast structure, function, genetics and development. A naturally-occurring leaf-color rice mutant, Baihuaidao 7, was analyzed. Mutant plants typically exhibited a green-white-green leaf-color progression, but this phenotype was only expressed in the presence of a stress signal induced by mechanical scarification such as transplantation. Prior to the appearance of white ~eaves, mutant plant growth, leaf color, chlorophyll content, and chloroplast ultrastructure appeared to be identical to those of the wild type. After the changeover to white leaf color, an examination of the mutated leaves revealed a decrease in total chlorophyll, chlorophyll a, chlorophyll b, and carotenoid content, a reduction in the number of chloroplast grana lamella and grana, and a gradual degradation of the thylakoid lamellas. At maturity, the mutant plant was etiolated and dwarfed compared with wild-type plants. Genetic analysis indicated that the leaf mutant character is controlled by a recessive nuclear gene. Genetic mapping of the mutant gene was performed using an F2 population derived from a Baihuaidao 7 ~ Jiangxi 1587 cross. The mutant gene was mapped to rice chromosome 11, positioned between InDel markers L59.2-7 and L64.8-11, which are separated by approximately 740.5 kb. The mutant gene is believed to be a new leaf-color mutant gene in rice, and is tentatively designated as gwgl.展开更多
The effect of pan-milling on morphological structure,processability and properties of PVC was studied throughSEM,FTIR,granulometer,GPC and mechanical properties test in the hope of gaining ease in operation,needless o...The effect of pan-milling on morphological structure,processability and properties of PVC was studied throughSEM,FTIR,granulometer,GPC and mechanical properties test in the hope of gaining ease in operation,needless ofplasticizers,a clean and efficient route for improving the processability of PVC through stress-induced reactions,fulfilling the idea of“plasticizing PVC by itself”.The experimental results show that during pan-milling at ambienttemperature,within 2-3 min,the microcrystalline structure of PVC becomes indistinct,the grain size of PVC is reducedfrom 130-160 μm to 1-50 μm the molecular weight of PVC is slightly decreased,the variation of molecular weightdistribution is indistinct,the plasticizing time and torque at balance drop a great deal from 71-132 s to 31-33 s and from18.2-22.1 Nm to 14.7-18.4 Nm,respectively,the processability of PVC is markedly improved,and the mechanicalproperties get enhanced too.展开更多
Fascinating with high specific capacity and moderate lithiation potential,SnO_(x)-based materials have been intensively investigated as one of the most promising anodes for lithium-ion batteries.However,due to poor cy...Fascinating with high specific capacity and moderate lithiation potential,SnO_(x)-based materials have been intensively investigated as one of the most promising anodes for lithium-ion batteries.However,due to poor cycling stability,sluggish reaction kinetics,and limited electrochemical reaction reversibility,the development of SnO_(x)-based anodes has been hindered.And the current preparation and modification routes for SnO_(x)-based anodes lack direct and specific illustration.Herein,modification routes for SnO_(x)-based anodes have been emphasized.Firstly,to provide more direct instructions,the tuning routes of morphological structure for SnO_(x)-based electrodes(including slurry-based and self-supported)have been thoroughly discussed from the preparation perspective.Secondly,according to the properties of SnO_(x)-based anodes,the phase structure design ideas have also been properly classified and organized for addressing chemical reaction kinetics or thermodynamic issues.Finally,for future-oriented studies,new insights into the development and commercialization prospects of SnO_(x)-based anodes are also provided.This review,with comprehensive information on SnO_(x)-based anodes,aims to bring more specific guidance and valuable inspiration for peer researchers who are promoting the application of SnO_(x)-based materials for energy conversion and storage devices.展开更多
In this study. we have employed a facile oxalate-assisted hydrothermal approach to tailor the morphology of β-NaYF_4：Er^（3＋）,Yb^（3＋）（NYFEY） powders through the variation of the molar ratio of oxalate ions（O...In this study. we have employed a facile oxalate-assisted hydrothermal approach to tailor the morphology of β-NaYF_4：Er^（3＋）,Yb^（3＋）（NYFEY） powders through the variation of the molar ratio of oxalate ions（Oxa^（2-）） and rare earth ions（RE^（3＋）） in the range of 0.5：1.1：1.2：1, 5：1. and 10：1. The obtained results show that the crystallinity, particle size and upconversion luminescence intensity of the as-synthesized NYFEY particles are gradually decreased as the Oxa^（2-）：RE^（3＋） molar ratio increases from 0.5：1 to 10：1. For the purpose of photoelectrochemical performance evaluation,the as-synthesized NYFEY particles with different morphologies are incorporated into the nanocrystalline TiO2 films to form the multifunctional nano-and sub-micro meter composite photoanodes of dye-sensitized solar cells（DSSCs）. A short-circuit current density（Jsc） of 14.26 mA/cm^2 and power conversion efficiency（PCE） of 7.31% are obtained for DSSCs prepared with hexagonal rod-like NYFEY crystals,evidencing an increase of 29.8% compared with DSSCs prepared with only TiO_2 nanoparticles. The demonstrated synthesis approach for tailoring the morphology and size of NYFEY particles and enhancing the performance of DSSCs can also be applied for other types of solar cells.展开更多
An efficient and reliable automated model that can map physical Soil and Water Conservation（SWC） structures on cultivated land was developed using very high spatial resolution imagery obtained from Google Earth and ...An efficient and reliable automated model that can map physical Soil and Water Conservation（SWC） structures on cultivated land was developed using very high spatial resolution imagery obtained from Google Earth and Arc GIS？ERDAS IMAGINE？and SDC Morphology Toolbox for MATLAB and statistical techniques. The model was developed using the following procedures：（1） a high-pass spatial filter algorithm was applied to detect linear features,（2） morphological processing was used to remove unwanted linear features,（3） the raster format was vectorized,（4） the vectorized linear features were split per hectare（ha） and each line was then classified according to its compass directionand（5） the sum of all vector lengths per class of direction per ha was calculated. Finallythe direction class with the greatest length was selected from each ha to predict the physical SWC structures. The model was calibrated and validated on the Ethiopian Highlands. The model correctly mapped 80% of the existing structures. The developed model was then tested at different sites with different topography. The results show that the developed model is feasible for automated mapping of physical SWC structures. Thereforethe model is useful for predicting and mapping physical SWC structures areas across diverse areas.展开更多
Venus flytrap can sense the very small insects that touch its tactile receptors,known as trigger hairs,and thus capture prey to maintain its nutrient demand.However,there are few studies on the trigger hair and its mo...Venus flytrap can sense the very small insects that touch its tactile receptors,known as trigger hairs,and thus capture prey to maintain its nutrient demand.However,there are few studies on the trigger hair and its morphological structure and material properties are not fully understood.In this study,the trigger hair is systematically characterized with the help of diff erent instruments.Results show that trigger hair is a special cantilever beam structure and it has a large longitudinal diameter ratio.Besides,it is composed of a hair lever and a basal podium,and there is a notch near the hair base.The crosssection of the trigger hair is approximately a honeycomb structure,which is composed of many holes.Methods to measure mechanical properties of trigger hair are introduced in this paper.Based on the mechanical tests,trigger hair proved to be a variable stiff ness structure and shows a high sensitivity to the external force.These features can provide supports for the understanding of the high-sensitivity sensing mechanism of trigger hairs from the perspective of structure and material,and off er inspirations for the development of high-performance tactile sensors.展开更多
Polymer-supported ruthenium complexes ■-Phen-Ru-①,■-Phen-Ru-②,■-Phen-Ru-③,■-Phen-Ru-④, ■-Phen-Ru-⑤,■-Phen-Ru-⑥and ■-Phen-Ru-⑦were prepared using aminomethyl polystyrenes of different morphological struct...Polymer-supported ruthenium complexes ■-Phen-Ru-①,■-Phen-Ru-②,■-Phen-Ru-③,■-Phen-Ru-④, ■-Phen-Ru-⑤,■-Phen-Ru-⑥and ■-Phen-Ru-⑦were prepared using aminomethyl polystyrenes of different morphological structures as supports.A variety of alcohols were oxidized efficiently into the corresponding ketones, carboxylic acids or aldehydes with iodosylbenzene (PhIO) catalyzed by aminomethyl polystyrene-supported ruthenium complexes under mild reaction conditions in acetonitrile.The influences of morphological structure...展开更多
Poly(phenylene sulfide amide) (PPSA) has been synthesized by using sulfur as S source which reacts with dichlorobenzamide (DCBA) and alkali in polar organic solvent at the atmospheric pressure. The polymer structures ...Poly(phenylene sulfide amide) (PPSA) has been synthesized by using sulfur as S source which reacts with dichlorobenzamide (DCBA) and alkali in polar organic solvent at the atmospheric pressure. The polymer structures were determined by elemental analysis, FT-IR and H-1-NMR. It is shown that the yielded polymer has linear structure and its structure unit is -p-C6H4-CONH -p-C6H4-S-. The polymer morphology was studied by X-ray diffraction and polarized microscopy. The results show that PPSA is a crystalline polymer and its spherulites are the aggregation of nontwisting lamella or micro-thread structure. Under shearing force, these crystals are dispersed to form micro-fibrillar structure. The decomposition kinetics of PPSA was also studied at different heating rates. The decomposition energy of PPSA is higher than that of PPS.展开更多
The growth of filamentous microorganism is contributed by tip extension and branching. The microscopic growth of filamentous microorganism means the growth process from one or a few spores. In order to describe the mi...The growth of filamentous microorganism is contributed by tip extension and branching. The microscopic growth of filamentous microorganism means the growth process from one or a few spores. In order to describe the microscopic process, a population morphologically structured model is proposed, in which three morphological compartment and their interactions were considered, and the heterogeneity of hyphal growth was included. The model was applied to describe the microscopic growth of Streptomyces tendae and Geotrichum candidum with good agreement. From model prediction, it is concluded that if the number of hyphae is large enough (macroscopic growth), the specific growth rate of filamentous microorganism and the ratio of morphological forms in hyphae will become constant.展开更多
The poly(β-hydroxybutyrate)/poly(d,1-lactide)(PHB/PLA)blend was found to be immiscible,the melting point and the phase crystallinity of PHB were independent of the blend composition.Comparing with plain PHB,the blend...The poly(β-hydroxybutyrate)/poly(d,1-lactide)(PHB/PLA)blend was found to be immiscible,the melting point and the phase crystallinity of PHB were independent of the blend composition.Comparing with plain PHB,the blend exhibited the crystallization change and a certain improvement of the mechanical property.展开更多
This article presents the overall morphological structure of the Brazil nut tree(Bertholletia excelsa)fruit pericarp,from macro to nano scale.The acquired knowledge would be used for the development of new application...This article presents the overall morphological structure of the Brazil nut tree(Bertholletia excelsa)fruit pericarp,from macro to nano scale.The acquired knowledge would be used for the development of new applications,like using the materials as fillers for biocomposites,or as a hierarchical architecture model for biomimetics.This research was performed using stereo and light microscopy and conventional and force field emission scanning electron microscopy.The pericarp presents three layers:the exocarp,a dark gray,brittle and fragile outer layer;the mesocarp,a beige,dry,rigid,impermeable and fibrous intermediate layer;and the endocarp,an inner layer with similar characteristic as the exocarp,but formed next to the seeds.Morphologically,the exocarp and the endocarp presented minor regions of sclereids,fibers and vascular cell bundles,inside major regions of parenchyma cells.The mesocarp presents a structure of fiber cells regions alternating with sclereids and vascular cells regions,arranged in a composite like arrangement,with the fibers cells bundles acting as randomly oriented disperse phases in a sclereid cells matrix.This arrangement was associated with the mesocarp relative superior proprieties,indicating a great material for using as fillers for biocomposites or in biomimetics applications.展开更多
The morphology of shear-oriented films of a thermotropic liquid crystalline polyester containing a triad ester mesogenic unit and a flexible spacer has been investigated in details. The formation conditions and proces...The morphology of shear-oriented films of a thermotropic liquid crystalline polyester containing a triad ester mesogenic unit and a flexible spacer has been investigated in details. The formation conditions and process, the fine structures and the relaxation process of mat structure in the oriented films have been observed and discussed.展开更多
The paper was to explore the effect of cryopreservation on DNA integrity and morphological structure of boar sperm, and to explore the protective effect of trehalose and lactose on frozen boar sperm. The morphology, u...The paper was to explore the effect of cryopreservation on DNA integrity and morphological structure of boar sperm, and to explore the protective effect of trehalose and lactose on frozen boar sperm. The morphology, ultrastructure and DNA integrity of sperms were observed by phase contract microscope, scanning electron microscope （SEM） and acridine orange （AO） staining, respectively. The results showed that the normal morphological rate and DNA integrity rate of fro- zen sperms were significantly lower than that of fresh sperms （95.5% and 94.7%, respectively）, and the difference between two frozen groups was also significant （P 〈 0.05 ）. The normal morphological rates in trehalose group and lactose group were 74.7% and 67.6%, while DNA integrity rates in trehalose group and lactose group were 66.4% and 63.2%, respectively. The common deformations of frozen sperms under SEM were partial or complete fracture between head and neck, swollen neck_ dama=ed aemsome stnJetn~.展开更多
The 0.8 Me V copper ( Cu) ion beam irradiation-induced effects on structural, morphological and optical properties of tin dioxide nanowires (SnO_(2)NWs) are investigated. The samples are irradiated at three different ...The 0.8 Me V copper ( Cu) ion beam irradiation-induced effects on structural, morphological and optical properties of tin dioxide nanowires (SnO_(2)NWs) are investigated. The samples are irradiated at three different doses 5 × 10^12 ions/cm^(2), 1 ×10^(13) ions/cm^(2) and 5 × 10^(13) ions/em^(2) at room temperature. The XRD analysis shows that the tetragonal phase of SnO_(2)NWs remains stable after Cu ion irradiation, but with increasing irradiation dose level the crystal size increases due to ion beam induced coalescence of NWs. The FTIR spectra of pristine SnO_(2)NWs exhibit the chemical composition of SnO_(2)while the Cn-O bond is also observed in the FTIR spectra after Cu ion beam irradiation. The presence of Cu impurity in SnO_(2)is further confirmed by calculating the stopping range of Cu ions by using TRM/SRIM code. Optical properties of SnO_(2)NWs are studied before and after Cu ion irradiation. Band gap analysis reveMs that the band gap of irradiated samples is found to decrease compared with the pristine sample. Therefore, ion beam irradiation is a promising technology for nanoengineering and band gap tailoring.展开更多
Castor is a cash crop with very wide adaptability in China,and its yield is closely related with its morphological structure.With reference to the research on the relationship between the morphological structure and y...Castor is a cash crop with very wide adaptability in China,and its yield is closely related with its morphological structure.With reference to the research on the relationship between the morphological structure and yield of main cash crops such as rice,wheat and maize,this paper made a review of advances in the research of the relationship between castor variety characteristics,habitat conditions,dry matter distribution,cultivation measures.Finally,it present the research direction,content and route of the relationship between the morphological structure and yield of the castor in the future.展开更多
Zinc oxide （ZnO） is one of the most promising and frequently used semiconductor materials. In-doped nanos- tructure ZnO thin films are grown on p-type gallium nitride substrates by employing the simultaneous rf and ...Zinc oxide （ZnO） is one of the most promising and frequently used semiconductor materials. In-doped nanos- tructure ZnO thin films are grown on p-type gallium nitride substrates by employing the simultaneous rf and dc magnetron co-sputtering technique. The effect of In-doping on structural, morphological and electrical properties is studied. The different dopant concentrations are accomplished by varying the direct current power of the In target while keeping the fixed radio frequency power of the ZnO target through the co-sputtering deposition technique by using argon as the sputtering gas at ambient temperature. The structural analysis confirms that all the grown thin films preferentially orientate along the c-axis with the wurtzite hexagonal crystal structure without having any kind of In oxide phases. The presenting Zn, 0 and In elements＇ chemical compositions are identified with EDX mapping analysis of the deposited thin films and the calculated M ratio has been found to decrease with the increasing In power. The surface topographies of the grown thin films are examined with the atomic force microscope technique. The obtained results reveal that the grown film roughness increases with the In power. The Hall measurements ascertain that all the grown films have n-type conductivity and also the other electrical parameters such as resistivity,mobility and carrier concentration are analyzed.展开更多
The research focuses on the study of anatomical and morphological stalk structure ofsoya interspecific hybrids of the third generation （F3） between （Glycine max （L.） Merr.） and G. soja Sieb. et Zucc. in comparis...The research focuses on the study of anatomical and morphological stalk structure ofsoya interspecific hybrids of the third generation （F3） between （Glycine max （L.） Merr.） and G. soja Sieb. et Zucc. in comparison with parent plant species. The parent plant species and interspecific hybrids were sowed and grew under similar conditions. The similarity of the anatomic structure of stalks of cultivated plants and Glycine soja （wild soya） proves the hypothesis the studied species have the same origin. However, the obtained results show the considerable degree of phylogenetic dissociation between the studied soya species. Interspecific hybrids inherit from G. soja the ability to high intensive growth. The G. soja use in practical selective breeding is of great interest.展开更多
Renewable energy-driven water electrolysis is considered as an environmentally friendly hydrogen(H2)production technology.Replacing the oxygen evolution reaction(OER)with the urea oxidation reaction(UOR)is a more effe...Renewable energy-driven water electrolysis is considered as an environmentally friendly hydrogen(H2)production technology.Replacing the oxygen evolution reaction(OER)with the urea oxidation reaction(UOR)is a more effective way to improve the energy efficiency of H2 generation.Herein,a highly effi-cient 2D NiFeMo-based UOR catalyst and 1D NiFeMo-based HER catalyst are prepared by adjusting the concentration of MoO_(4)^(-).The MoO_(4)^(-)can serve as the key regulator to adjust the balance between the electrolytic dissociation(α)of the reactants and the supersaturation(S)to modulate the morphological and electronic structure.The prepared 2D NiFeMo nanosheet UOR catalyst and 1D NiFeMo nanorod HER catalyst can achieve a current density of 100 mA cm^(−2)at a potential of 1.36 and 0.062 V,respectively.In a HER/UOR system,a cell voltage of 1.58 V is needed to achieve a current density of 100 mA cm^(−2).The HER/UOR system operated stably for over 60 h with 3 times the direct water electrolysis current den-sity.Moreover,the in situ Raman characterization coupled with XPS analysis clarifies that the addition of high-valence Mo can lower the transition energy barrier between the low and high oxidation state of Ni,which in turn lowers the overpotential of UOR.This work provides a novel strategy for synthesizing morphology-dependent electrocatalysts for different catalytic systems.展开更多
ZnO single crystal was used as the substrate to study the effect of ZnO crystal plane polarity on the morphology and structure of CH_3NH_3PbI_3（MAPbI_3） perovskite film and carrier transport properties,which is mean...ZnO single crystal was used as the substrate to study the effect of ZnO crystal plane polarity on the morphology and structure of CH_3NH_3PbI_3（MAPbI_3） perovskite film and carrier transport properties,which is meaningful for improving ZnO-based perovskite solar cell. It is found that perovskite thin film has small grain size（about 190 nm） and high coverage rate on the O-face of ZnO single crystal,and the dominant exposed crystal plane of perovskite film is（110） plane. While the MAPbI_3 thin film has large grain size（about 1.03 μm） and low coverage rate on the Zn-face,and the（022） plane is dominantly exposed for the perovskite film. The injection of photogenerated electrons from MAPbI_3 film into the O-face of ZnO single crystal is faster and more effective than that to Zn-face. It is supposed that O-face is more suitable for ZnO single crystal based perovskite cell fabrication than Zn-face.展开更多
文摘A morphologically structured model is proposed to describe the batch fermentation of lovastatin according to the growth kinetics of filamentous microorganisms. Three kinds of hyphae are considered in the model: actively growing hyphae, non-growing hyphae and deactivated hyphae. Furthermore, actively growing hyphae consist of three morphological compartments: apical compartment which gives rise to hyphal tip extension; subapical compartment which is related to hyphal branching; and hyphal compartment which is only responsible for secondary metabolite formation. The kinetics of mycelial growth mechanism is summarized and applied in modeling lovastatin fermentation. A Michaelis-Menten kinetic model with substrate inhibition is proposed for product formation. As expected, the model simulations fit well with experimental data obtained either from a laboratory scale 10L fer-menter or from a pilot-plant scale fermenter.
基金supported by the Natural ScienceFoundation of Jiangsu Province of China (Grant No.SBK2010294)an Open Project Program of Jiangsu Key Laboratory of the Ministry of Education for Plant Functional Genomics (Grant No. K10001)
文摘Leaf-color mutations are a widely-observed class of mutations, playing an important role in the study of chlorophyll biosynthesis and plant chloroplast structure, function, genetics and development. A naturally-occurring leaf-color rice mutant, Baihuaidao 7, was analyzed. Mutant plants typically exhibited a green-white-green leaf-color progression, but this phenotype was only expressed in the presence of a stress signal induced by mechanical scarification such as transplantation. Prior to the appearance of white ~eaves, mutant plant growth, leaf color, chlorophyll content, and chloroplast ultrastructure appeared to be identical to those of the wild type. After the changeover to white leaf color, an examination of the mutated leaves revealed a decrease in total chlorophyll, chlorophyll a, chlorophyll b, and carotenoid content, a reduction in the number of chloroplast grana lamella and grana, and a gradual degradation of the thylakoid lamellas. At maturity, the mutant plant was etiolated and dwarfed compared with wild-type plants. Genetic analysis indicated that the leaf mutant character is controlled by a recessive nuclear gene. Genetic mapping of the mutant gene was performed using an F2 population derived from a Baihuaidao 7 ~ Jiangxi 1587 cross. The mutant gene was mapped to rice chromosome 11, positioned between InDel markers L59.2-7 and L64.8-11, which are separated by approximately 740.5 kb. The mutant gene is believed to be a new leaf-color mutant gene in rice, and is tentatively designated as gwgl.
基金Subsidized by the Special Funds for Major State Basic Research Projects of China(Contract/grant number:199064809)
文摘The effect of pan-milling on morphological structure,processability and properties of PVC was studied throughSEM,FTIR,granulometer,GPC and mechanical properties test in the hope of gaining ease in operation,needless ofplasticizers,a clean and efficient route for improving the processability of PVC through stress-induced reactions,fulfilling the idea of“plasticizing PVC by itself”.The experimental results show that during pan-milling at ambienttemperature,within 2-3 min,the microcrystalline structure of PVC becomes indistinct,the grain size of PVC is reducedfrom 130-160 μm to 1-50 μm the molecular weight of PVC is slightly decreased,the variation of molecular weightdistribution is indistinct,the plasticizing time and torque at balance drop a great deal from 71-132 s to 31-33 s and from18.2-22.1 Nm to 14.7-18.4 Nm,respectively,the processability of PVC is markedly improved,and the mechanicalproperties get enhanced too.
基金financially supported by the National Natural Science Foundation of China(Nos.52071144,51831009 and 51621001)Guangzhou key research and development program(No.202103040001)。
文摘Fascinating with high specific capacity and moderate lithiation potential,SnO_(x)-based materials have been intensively investigated as one of the most promising anodes for lithium-ion batteries.However,due to poor cycling stability,sluggish reaction kinetics,and limited electrochemical reaction reversibility,the development of SnO_(x)-based anodes has been hindered.And the current preparation and modification routes for SnO_(x)-based anodes lack direct and specific illustration.Herein,modification routes for SnO_(x)-based anodes have been emphasized.Firstly,to provide more direct instructions,the tuning routes of morphological structure for SnO_(x)-based electrodes(including slurry-based and self-supported)have been thoroughly discussed from the preparation perspective.Secondly,according to the properties of SnO_(x)-based anodes,the phase structure design ideas have also been properly classified and organized for addressing chemical reaction kinetics or thermodynamic issues.Finally,for future-oriented studies,new insights into the development and commercialization prospects of SnO_(x)-based anodes are also provided.This review,with comprehensive information on SnO_(x)-based anodes,aims to bring more specific guidance and valuable inspiration for peer researchers who are promoting the application of SnO_(x)-based materials for energy conversion and storage devices.
基金Project partially supported by the National Natural Science Foundation of China(51202179)the National Science and Technology Research Key Project of the Ministry of Education(212174)+1 种基金the Natural Science Foundation of Shaanxi Province(2013KJXX-57)the Science Foundation of Shaanxi Provincial Department of Education(12JS060,13JS053,14JS047,14JS048,16JS058)
文摘In this study. we have employed a facile oxalate-assisted hydrothermal approach to tailor the morphology of β-NaYF_4：Er^（3＋）,Yb^（3＋）（NYFEY） powders through the variation of the molar ratio of oxalate ions（Oxa^（2-）） and rare earth ions（RE^（3＋）） in the range of 0.5：1.1：1.2：1, 5：1. and 10：1. The obtained results show that the crystallinity, particle size and upconversion luminescence intensity of the as-synthesized NYFEY particles are gradually decreased as the Oxa^（2-）：RE^（3＋） molar ratio increases from 0.5：1 to 10：1. For the purpose of photoelectrochemical performance evaluation,the as-synthesized NYFEY particles with different morphologies are incorporated into the nanocrystalline TiO2 films to form the multifunctional nano-and sub-micro meter composite photoanodes of dye-sensitized solar cells（DSSCs）. A short-circuit current density（Jsc） of 14.26 mA/cm^2 and power conversion efficiency（PCE） of 7.31% are obtained for DSSCs prepared with hexagonal rod-like NYFEY crystals,evidencing an increase of 29.8% compared with DSSCs prepared with only TiO_2 nanoparticles. The demonstrated synthesis approach for tailoring the morphology and size of NYFEY particles and enhancing the performance of DSSCs can also be applied for other types of solar cells.
基金covered by the Swiss National Centre of Competence in Research North-South (NCCR North-South) program
文摘An efficient and reliable automated model that can map physical Soil and Water Conservation（SWC） structures on cultivated land was developed using very high spatial resolution imagery obtained from Google Earth and Arc GIS？ERDAS IMAGINE？and SDC Morphology Toolbox for MATLAB and statistical techniques. The model was developed using the following procedures：（1） a high-pass spatial filter algorithm was applied to detect linear features,（2） morphological processing was used to remove unwanted linear features,（3） the raster format was vectorized,（4） the vectorized linear features were split per hectare（ha） and each line was then classified according to its compass directionand（5） the sum of all vector lengths per class of direction per ha was calculated. Finallythe direction class with the greatest length was selected from each ha to predict the physical SWC structures. The model was calibrated and validated on the Ethiopian Highlands. The model correctly mapped 80% of the existing structures. The developed model was then tested at different sites with different topography. The results show that the developed model is feasible for automated mapping of physical SWC structures. Thereforethe model is useful for predicting and mapping physical SWC structures areas across diverse areas.
基金supported by the National Natural Science Foundation of China[Grant no.52005355]Postdoctoral Science Foundation of China[Grant no.2020M671575]+2 种基金Opening Project of the Key Laboratory of Bionic Engineering(Ministry of Education),Jilin University[Grant no.KF20200004]Opening Project of the Key Laboratory of Advanced Robotics of Jiangsu Provience[Grant no.JAR201901]Natural Natural Science Research Project of Higher Education of Jiangsu Province[Grant no.20KJB460007].
文摘Venus flytrap can sense the very small insects that touch its tactile receptors,known as trigger hairs,and thus capture prey to maintain its nutrient demand.However,there are few studies on the trigger hair and its morphological structure and material properties are not fully understood.In this study,the trigger hair is systematically characterized with the help of diff erent instruments.Results show that trigger hair is a special cantilever beam structure and it has a large longitudinal diameter ratio.Besides,it is composed of a hair lever and a basal podium,and there is a notch near the hair base.The crosssection of the trigger hair is approximately a honeycomb structure,which is composed of many holes.Methods to measure mechanical properties of trigger hair are introduced in this paper.Based on the mechanical tests,trigger hair proved to be a variable stiff ness structure and shows a high sensitivity to the external force.These features can provide supports for the understanding of the high-sensitivity sensing mechanism of trigger hairs from the perspective of structure and material,and off er inspirations for the development of high-performance tactile sensors.
基金supported by the National Natural Science Foundation of China (Nos.20174031 and 20674063)Specialized Research Fund for the Doctoral Program of Higher Education (No.20050736001).+1 种基金the Key Laboratory of Eco-Environment-Related Polymer Materials (Northwest Normal University)Ministry of Education,for financial support.
文摘Polymer-supported ruthenium complexes ■-Phen-Ru-①,■-Phen-Ru-②,■-Phen-Ru-③,■-Phen-Ru-④, ■-Phen-Ru-⑤,■-Phen-Ru-⑥and ■-Phen-Ru-⑦were prepared using aminomethyl polystyrenes of different morphological structures as supports.A variety of alcohols were oxidized efficiently into the corresponding ketones, carboxylic acids or aldehydes with iodosylbenzene (PhIO) catalyzed by aminomethyl polystyrene-supported ruthenium complexes under mild reaction conditions in acetonitrile.The influences of morphological structure...
文摘Poly(phenylene sulfide amide) (PPSA) has been synthesized by using sulfur as S source which reacts with dichlorobenzamide (DCBA) and alkali in polar organic solvent at the atmospheric pressure. The polymer structures were determined by elemental analysis, FT-IR and H-1-NMR. It is shown that the yielded polymer has linear structure and its structure unit is -p-C6H4-CONH -p-C6H4-S-. The polymer morphology was studied by X-ray diffraction and polarized microscopy. The results show that PPSA is a crystalline polymer and its spherulites are the aggregation of nontwisting lamella or micro-thread structure. Under shearing force, these crystals are dispersed to form micro-fibrillar structure. The decomposition kinetics of PPSA was also studied at different heating rates. The decomposition energy of PPSA is higher than that of PPS.
文摘The growth of filamentous microorganism is contributed by tip extension and branching. The microscopic growth of filamentous microorganism means the growth process from one or a few spores. In order to describe the microscopic process, a population morphologically structured model is proposed, in which three morphological compartment and their interactions were considered, and the heterogeneity of hyphal growth was included. The model was applied to describe the microscopic growth of Streptomyces tendae and Geotrichum candidum with good agreement. From model prediction, it is concluded that if the number of hyphae is large enough (macroscopic growth), the specific growth rate of filamentous microorganism and the ratio of morphological forms in hyphae will become constant.
文摘The poly(β-hydroxybutyrate)/poly(d,1-lactide)(PHB/PLA)blend was found to be immiscible,the melting point and the phase crystallinity of PHB were independent of the blend composition.Comparing with plain PHB,the blend exhibited the crystallization change and a certain improvement of the mechanical property.
文摘This article presents the overall morphological structure of the Brazil nut tree(Bertholletia excelsa)fruit pericarp,from macro to nano scale.The acquired knowledge would be used for the development of new applications,like using the materials as fillers for biocomposites,or as a hierarchical architecture model for biomimetics.This research was performed using stereo and light microscopy and conventional and force field emission scanning electron microscopy.The pericarp presents three layers:the exocarp,a dark gray,brittle and fragile outer layer;the mesocarp,a beige,dry,rigid,impermeable and fibrous intermediate layer;and the endocarp,an inner layer with similar characteristic as the exocarp,but formed next to the seeds.Morphologically,the exocarp and the endocarp presented minor regions of sclereids,fibers and vascular cell bundles,inside major regions of parenchyma cells.The mesocarp presents a structure of fiber cells regions alternating with sclereids and vascular cells regions,arranged in a composite like arrangement,with the fibers cells bundles acting as randomly oriented disperse phases in a sclereid cells matrix.This arrangement was associated with the mesocarp relative superior proprieties,indicating a great material for using as fillers for biocomposites or in biomimetics applications.
文摘The morphology of shear-oriented films of a thermotropic liquid crystalline polyester containing a triad ester mesogenic unit and a flexible spacer has been investigated in details. The formation conditions and process, the fine structures and the relaxation process of mat structure in the oriented films have been observed and discussed.
基金Supported by Natural Science Foundation of Jiangsu Province(BK2008589)
文摘The paper was to explore the effect of cryopreservation on DNA integrity and morphological structure of boar sperm, and to explore the protective effect of trehalose and lactose on frozen boar sperm. The morphology, ultrastructure and DNA integrity of sperms were observed by phase contract microscope, scanning electron microscope （SEM） and acridine orange （AO） staining, respectively. The results showed that the normal morphological rate and DNA integrity rate of fro- zen sperms were significantly lower than that of fresh sperms （95.5% and 94.7%, respectively）, and the difference between two frozen groups was also significant （P 〈 0.05 ）. The normal morphological rates in trehalose group and lactose group were 74.7% and 67.6%, while DNA integrity rates in trehalose group and lactose group were 66.4% and 63.2%, respectively. The common deformations of frozen sperms under SEM were partial or complete fracture between head and neck, swollen neck_ dama=ed aemsome stnJetn~.
基金Supported by the Department of Physics,the University of AJKHigh Tech.Centralized Instrumentation Lab,the University of AJK,Pakistanthe Experimental Physics Division,and the National Center for Physics,Islamabad Pakistan
文摘The 0.8 Me V copper ( Cu) ion beam irradiation-induced effects on structural, morphological and optical properties of tin dioxide nanowires (SnO_(2)NWs) are investigated. The samples are irradiated at three different doses 5 × 10^12 ions/cm^(2), 1 ×10^(13) ions/cm^(2) and 5 × 10^(13) ions/em^(2) at room temperature. The XRD analysis shows that the tetragonal phase of SnO_(2)NWs remains stable after Cu ion irradiation, but with increasing irradiation dose level the crystal size increases due to ion beam induced coalescence of NWs. The FTIR spectra of pristine SnO_(2)NWs exhibit the chemical composition of SnO_(2)while the Cn-O bond is also observed in the FTIR spectra after Cu ion beam irradiation. The presence of Cu impurity in SnO_(2)is further confirmed by calculating the stopping range of Cu ions by using TRM/SRIM code. Optical properties of SnO_(2)NWs are studied before and after Cu ion irradiation. Band gap analysis reveMs that the band gap of irradiated samples is found to decrease compared with the pristine sample. Therefore, ion beam irradiation is a promising technology for nanoengineering and band gap tailoring.
基金Key Research and Development Program of Hunan Province(2017NK2222).
文摘Castor is a cash crop with very wide adaptability in China,and its yield is closely related with its morphological structure.With reference to the research on the relationship between the morphological structure and yield of main cash crops such as rice,wheat and maize,this paper made a review of advances in the research of the relationship between castor variety characteristics,habitat conditions,dry matter distribution,cultivation measures.Finally,it present the research direction,content and route of the relationship between the morphological structure and yield of the castor in the future.
基金Supported by the RU Top-Down under Grant No 1001/CSS/870019
文摘Zinc oxide （ZnO） is one of the most promising and frequently used semiconductor materials. In-doped nanos- tructure ZnO thin films are grown on p-type gallium nitride substrates by employing the simultaneous rf and dc magnetron co-sputtering technique. The effect of In-doping on structural, morphological and electrical properties is studied. The different dopant concentrations are accomplished by varying the direct current power of the In target while keeping the fixed radio frequency power of the ZnO target through the co-sputtering deposition technique by using argon as the sputtering gas at ambient temperature. The structural analysis confirms that all the grown thin films preferentially orientate along the c-axis with the wurtzite hexagonal crystal structure without having any kind of In oxide phases. The presenting Zn, 0 and In elements＇ chemical compositions are identified with EDX mapping analysis of the deposited thin films and the calculated M ratio has been found to decrease with the increasing In power. The surface topographies of the grown thin films are examined with the atomic force microscope technique. The obtained results reveal that the grown film roughness increases with the In power. The Hall measurements ascertain that all the grown films have n-type conductivity and also the other electrical parameters such as resistivity,mobility and carrier concentration are analyzed.
文摘The research focuses on the study of anatomical and morphological stalk structure ofsoya interspecific hybrids of the third generation （F3） between （Glycine max （L.） Merr.） and G. soja Sieb. et Zucc. in comparison with parent plant species. The parent plant species and interspecific hybrids were sowed and grew under similar conditions. The similarity of the anatomic structure of stalks of cultivated plants and Glycine soja （wild soya） proves the hypothesis the studied species have the same origin. However, the obtained results show the considerable degree of phylogenetic dissociation between the studied soya species. Interspecific hybrids inherit from G. soja the ability to high intensive growth. The G. soja use in practical selective breeding is of great interest.
基金supported by the National Natural Science Foundation of China(No.22308322)the Science Foundation of Donghai Laboratory(No.DH-2022ZY0010)the R&D Project of State Grid Corporation of China(No.5108-202218280A-2-439-XG).
文摘Renewable energy-driven water electrolysis is considered as an environmentally friendly hydrogen(H2)production technology.Replacing the oxygen evolution reaction(OER)with the urea oxidation reaction(UOR)is a more effective way to improve the energy efficiency of H2 generation.Herein,a highly effi-cient 2D NiFeMo-based UOR catalyst and 1D NiFeMo-based HER catalyst are prepared by adjusting the concentration of MoO_(4)^(-).The MoO_(4)^(-)can serve as the key regulator to adjust the balance between the electrolytic dissociation(α)of the reactants and the supersaturation(S)to modulate the morphological and electronic structure.The prepared 2D NiFeMo nanosheet UOR catalyst and 1D NiFeMo nanorod HER catalyst can achieve a current density of 100 mA cm^(−2)at a potential of 1.36 and 0.062 V,respectively.In a HER/UOR system,a cell voltage of 1.58 V is needed to achieve a current density of 100 mA cm^(−2).The HER/UOR system operated stably for over 60 h with 3 times the direct water electrolysis current den-sity.Moreover,the in situ Raman characterization coupled with XPS analysis clarifies that the addition of high-valence Mo can lower the transition energy barrier between the low and high oxidation state of Ni,which in turn lowers the overpotential of UOR.This work provides a novel strategy for synthesizing morphology-dependent electrocatalysts for different catalytic systems.
基金supported by the National Natural Science Foundation of China(Nos.91333207,61427901 and U1505252)
文摘ZnO single crystal was used as the substrate to study the effect of ZnO crystal plane polarity on the morphology and structure of CH_3NH_3PbI_3（MAPbI_3） perovskite film and carrier transport properties,which is meaningful for improving ZnO-based perovskite solar cell. It is found that perovskite thin film has small grain size（about 190 nm） and high coverage rate on the O-face of ZnO single crystal,and the dominant exposed crystal plane of perovskite film is（110） plane. While the MAPbI_3 thin film has large grain size（about 1.03 μm） and low coverage rate on the Zn-face,and the（022） plane is dominantly exposed for the perovskite film. The injection of photogenerated electrons from MAPbI_3 film into the O-face of ZnO single crystal is faster and more effective than that to Zn-face. It is supposed that O-face is more suitable for ZnO single crystal based perovskite cell fabrication than Zn-face.
