Benthic macroinvertebrate communities in Spartina alterniflora zones in the Yangtze Estuary, in China, were investigated seasonally in 2005, and their structure and biodiversity were analyzed. Twenty-one species were ...Benthic macroinvertebrate communities in Spartina alterniflora zones in the Yangtze Estuary, in China, were investigated seasonally in 2005, and their structure and biodiversity were analyzed. Twenty-one species were identified, across four Classes; 10 species of Crustacea, five species of Polychaeta, five species of Gastropoda, and one species of Lamellibranchia. Dominant species included： Assiminea sp., Notomastus latericeus, Cerithidea largillierl, Gtauconome chinensi and Gammaridae sp. Functional groups were comprised of a phytophagous group and a detritivorous group. The average density of all benthic macroinvertebrates was 650.5 ±719.2 inds/m^2 in the survey area. The high value of the standard deviation of the average density was a result of abundant Assiminea sp. at Beihu tidal flats. The average density of macroinvertebrates from Beihu tidal flat, Chongming Dongtan to Jinshanwei tidal flat decreased gradually. There was significant difference between compositions and abundance of macroinvertebrates along the estuary gradient （P 〈 0.05）. The density and biodiversity were highest in summer and lowest in winter. The mean biomass of macroinvertebrates was 20.8 ± 6.1 g/m^2. Biomass changed seasonally in the same way as density, with the change in biomass being： summer （Aug.） 〉autumn （Oct.） 〉spring （Apr.） 〉 winter （Dec.）. A BIO-ENV analysis showed that the mean grain size of sediment, height of Spartina and salinity were the ma- jor factors which affected the structure of the macroinvertebrate community. Variations in the community structure were probably caused by the population dynamics of S. alterniflora along with the variation in sampling time and location.展开更多
This study aimed to investigate the effects of reducing application amount of base fertilizer and increasing application time of leaf fertilizer on corn yield so as to find out the most economical fertilization way fo...This study aimed to investigate the effects of reducing application amount of base fertilizer and increasing application time of leaf fertilizer on corn yield so as to find out the most economical fertilization way for corn. On the basis of protecting environment, the economic benefits will be also increased. The results showed that the corn yield was increased with the increase of application amount of base fertilizer, and was also increased with the increase of application time of leaf fertilizer.For each time of spaying of leaf fertilizer, the corn yield was increased 258-592.5kg/hm^2 with increase amplitude ranging from 2.3%-5.6%.展开更多
This study consolidates the efficacy of a non-starch polysaccharide （NSP）ase enzyme-concept in corn and wheat-based broiler diets. The NSP building blocks of corn, wheat and soybean meal （SBM, 44% protein） were st...This study consolidates the efficacy of a non-starch polysaccharide （NSP）ase enzyme-concept in corn and wheat-based broiler diets. The NSP building blocks of corn, wheat and soybean meal （SBM, 44% protein） were studied first. Cereal NSP primarily consists of arabinose, xylose and glucose molecules that form arabinoxylan, β-glucan and cellulose polysaccharides. In soybean meal （SBM）, glucose （cellulose） predominates, next to galactose and uronic acids that form “pectins”. Broiler performance progress using in-feed NSPase enzymes depends on the concentration, complexity and solubility of the substrate and the genetic potential of the animal, mainly. A dual NSPase enzyme-concept for cereal and SBM NSP, predominantly being arabinoxylan, β-glucan and cellulose, was developed. Methods for measuring enzyme activities （endo-1,4-β-xylanase （EC 3.2.1.8） and endo-1,3（4）-β-glucanase （EC 3.2.1.6）） were developed （AVEVE Biochem UNITS） and preparations thereof （XG） standardized to meet requirements for most challenging NSP （corn, barely soluble）. Feed intake （FI）, bodyweight gain （BWG） and feed：gain ratio （F：G） were assessed in three zootechnical studies, each using 160 Ross 308 broilers split in two feeding groups with 80 birds/group （10 replicates of eight） for 42 d （starter/grower period）. Respective corn-SBM, wheat-SBM and corn/wheat-SBM diets were used as negative control （NC） or added with the enzyme-concept （XG）. In the total period, XG ameliorated BWG and F：G compared to NC in each study, where BWG increased best in diets with corn and F：G lowered most in diets with wheat. The dual NSPase enzyme-concept offers ingredient flexibility in present setting by enhancing the nutritional content of corn, wheat and SBM, expectedly from cleaving major NSP target molecules. Thereby, broiler professionals increase feed formulation liberty and safety and production result simultaneously.展开更多
A kind of undercoat for resistor with high temperature and humidity resistance was obtained by modifying epoxy resin with proper nano-SiO2 added at 80℃. The structure, thermal stability, humidity resistance, and morp...A kind of undercoat for resistor with high temperature and humidity resistance was obtained by modifying epoxy resin with proper nano-SiO2 added at 80℃. The structure, thermal stability, humidity resistance, and morphological characteristics of the modified epoxy resin undercoat were studied by electrical tests, infrared spectra （IR） analysis, and scanning electron microscopy （SEM）. The results show that more compact and steady inter-crosslinked network structures are formed in the modified epoxy resin undercoat added with nano-SiO2, which greatly improves the performance of modified epoxy resin undercoat. The undercoat with nano-SiO2 of about 2. 71%, kept for six months at room temperature without flocculating and aggregating, is of good stability, and the surface of painted resistor is uniform, tight and without air holes on it. The varying ratio of resistance with such undercoat painted is less than one in a thousand after high temperature and humidity resistance tests.展开更多
The determination of pesticide residue on agricultural products is increasingly important. Exposure to pesticides can cause severe acute reactions in humans, including aplastic anemia and leukemia. In this work, we de...The determination of pesticide residue on agricultural products is increasingly important. Exposure to pesticides can cause severe acute reactions in humans, including aplastic anemia and leukemia. In this work, we developed a rapid and sensitive method to detect acetamiprid pesticide residue based on surface-enhanced Raman scattering. Silver nanorod （AgNR） arrays were fabricated by oblique angle deposition technology and were used as SERS substrates. Prior to detection, the AgNR arrays were cleaned with nitric acid solution or a mixture of methanol and acetone. Compared to the unwashed AgNR arrays, the AgNR arrays washed with methanol and acetone shows a signal enhancement 1000 times greater than the unwashed AgNR array due to the effective removal of the impurities on its surface. The limit of detection of acetamiprid was determined to be 0.05 mg/L. In addition, the molecular structure of acetamiprid was simulated and the corresponding vibration modes of the characteristic bands of acetamiprid were calculated by density function theory. To demonstrate its practical application, the AgNRs array substrates were applied successfully to the rapid identification of acetamiprid residue on a cucumber＇s surface. These results confirmed possibility of utilizing the AgNRs SERS substrates as a new method for highly sensitive pesticide residue detection.展开更多
Surface-enhanced Raman scattering(SERS)is a powerful technology for obtaining vibrational information from molecules that present in different chemical or biological environments.This paper presents a 3D SERS substrat...Surface-enhanced Raman scattering(SERS)is a powerful technology for obtaining vibrational information from molecules that present in different chemical or biological environments.This paper presents a 3D SERS substrate based on nanocone forests.The substrates are prepared by using plasma treatment technique,which is a simple,fast and high-throughput approach.The SERS substrate based on nanocone forests exhibits high sensitivity.In the experiment,miRNA with a concentration as low as 10-10 M can be achieved.Meanwhile,the proposed SERS substrate shows a high uniformity over a large area.These experimental results demonstrate great potential of the 3D SERS substrate in wide applications.展开更多
Pepsin was assembled on the surface of prepared poly(ethylene terephthalate)(PET-NH3^+) substrates.The composition and structure of the pepsin/PET-NH3^+ assembling films in different condition were characterized by X-...Pepsin was assembled on the surface of prepared poly(ethylene terephthalate)(PET-NH3^+) substrates.The composition and structure of the pepsin/PET-NH3^+ assembling films in different condition were characterized by X-ray photoelectron spectroscopy(XPS) and atomic force microscopy(AFM).展开更多
In this study, SCM （supplementary cementitious materials）, such as nano silica, micro silica, fly ash and bottom ash, have been evaluated for optimal level of replacement as blending material in cement and concrete....In this study, SCM （supplementary cementitious materials）, such as nano silica, micro silica, fly ash and bottom ash, have been evaluated for optimal level of replacement as blending material in cement and concrete. The physical and chemical properties of the above materials were first analyzed. This study focused on compressive strength of concrete with different mixes at different ages. In many cases, products made with fly ash, micro silica, nano silica and bottom ash perform better than products made without them. Test results obtained in this study indicate that up to 5% nano silica, 10% micro silica, 20-30% fly ash and 10% bottom ash could be advantageously blended with cement without adversely affecting the strength. However, optimum levels of these materials are 1-3% nano silica, 3-8% micro silica, 10% fly ash and 5% of bottom ash when we consider the strength of concrete. All percentages are defined by weight unless otherwise mentioned.展开更多
学术休假英文为"Sabbatical Leave""Sabbatical"或"Academic Sabbatical"。国外学者康和米勒(Kang and Miller,1999)指出学术休假的概念具有神话和宗教意义,它的起源可以追溯到希伯来的传说中,"Sabb...学术休假英文为"Sabbatical Leave""Sabbatical"或"Academic Sabbatical"。国外学者康和米勒(Kang and Miller,1999)指出学术休假的概念具有神话和宗教意义,它的起源可以追溯到希伯来的传说中,"Sabbatical"一词来自一个在米底(Media)的古河流的名字,这条河流淌六天,在第七天休息。基于这样的理念,出现了"Sabbath(安息日)",即在一周的第七天,让信徒们休息、做祷告,展开更多
We report a new strategy to prepare gold nanoflowers （AuNFs） using a two-step seed-mediated method. The as-prepared AuNFs were employed as surface-enhance Raman scattering （SERS） substrates, showing strong signal ...We report a new strategy to prepare gold nanoflowers （AuNFs） using a two-step seed-mediated method. The as-prepared AuNFs were employed as surface-enhance Raman scattering （SERS） substrates, showing strong signal enhancement. We further found that iodide ions （I^-） could selectively induce the morphological transformation of AuNFs to spheres, resulting in a blue-shift of the localized surface plasmon resonance （LSPR） bands, a color change of the AuNFs solution from blue to red, and decreased SERS activity. This behavior allows the AuNFs to be used in the determination of I^-.展开更多
An efficient surface-enhanced Raman scattering(SERS) substrate is developed based on silver nanoparticles decorated anodic aluminum oxide(Ag/AAO).The AAO templates were fabricated using a two-step anodization approach...An efficient surface-enhanced Raman scattering(SERS) substrate is developed based on silver nanoparticles decorated anodic aluminum oxide(Ag/AAO).The AAO templates were fabricated using a two-step anodization approach,and silver nanoparticles(Ag NPs) were obtained by thermal decomposition of Ag nitrate in AAO.The structure of Ag/AAO hybrid substrate is characterized by scanning electron microscopy(SEM).The results show that the as-prepared SERS substrates consist of high-density Ag NPs with sizes of tens of nanometers.The Ag NPs are adsorbed on the surface of AAO template in the form of network structure which is called "hot spot".The SERS enhancement ability of the nanostructure is verified using thiram as probing molecules.The limit of detection is as low as 1×10-9 mol/L.The results indicate that the as-prepared substrate possesses excellent SERS sensitivity,high stability and uniformity enhancement.展开更多
We present a study of the electric field effect on electrochemically grown ultrathin, straight platinum nanowires with minimum diameter of 15 nm and length in the micrometer range, synthesized on a silicon oxide subst...We present a study of the electric field effect on electrochemically grown ultrathin, straight platinum nanowires with minimum diameter of 15 nm and length in the micrometer range, synthesized on a silicon oxide substrate between metal electrodes in H2PtC16 solution. The influence of the concentration of the platinum- containing acid and the frequency of the applied voltage on the diameter of the nanowires is discussed with a corresponding theoretical analysis. We demonstrate for the first time that the electric field profile, provided by the specific geometry of the metal electrodes, dramatically influences the growth and morphology of the nanowires. Finally, we provide guidelines for the controlled fabrication and contacting of straight, ultrathin metal wires, eliminating branching and dendritic growth, which is one of the main shortcomings of the current bottom-up nanotechnology. The proposed concept of self-assembly of thin nanowires, influenced by the electric field, potentially represents a new route for guided nanocontacting via smart design of the electrode geometry. The possible applications reach from nanoelectronics to gas sensors and biosensors.展开更多
文摘Benthic macroinvertebrate communities in Spartina alterniflora zones in the Yangtze Estuary, in China, were investigated seasonally in 2005, and their structure and biodiversity were analyzed. Twenty-one species were identified, across four Classes; 10 species of Crustacea, five species of Polychaeta, five species of Gastropoda, and one species of Lamellibranchia. Dominant species included： Assiminea sp., Notomastus latericeus, Cerithidea largillierl, Gtauconome chinensi and Gammaridae sp. Functional groups were comprised of a phytophagous group and a detritivorous group. The average density of all benthic macroinvertebrates was 650.5 ±719.2 inds/m^2 in the survey area. The high value of the standard deviation of the average density was a result of abundant Assiminea sp. at Beihu tidal flats. The average density of macroinvertebrates from Beihu tidal flat, Chongming Dongtan to Jinshanwei tidal flat decreased gradually. There was significant difference between compositions and abundance of macroinvertebrates along the estuary gradient （P 〈 0.05）. The density and biodiversity were highest in summer and lowest in winter. The mean biomass of macroinvertebrates was 20.8 ± 6.1 g/m^2. Biomass changed seasonally in the same way as density, with the change in biomass being： summer （Aug.） 〉autumn （Oct.） 〉spring （Apr.） 〉 winter （Dec.）. A BIO-ENV analysis showed that the mean grain size of sediment, height of Spartina and salinity were the ma- jor factors which affected the structure of the macroinvertebrate community. Variations in the community structure were probably caused by the population dynamics of S. alterniflora along with the variation in sampling time and location.
文摘This study aimed to investigate the effects of reducing application amount of base fertilizer and increasing application time of leaf fertilizer on corn yield so as to find out the most economical fertilization way for corn. On the basis of protecting environment, the economic benefits will be also increased. The results showed that the corn yield was increased with the increase of application amount of base fertilizer, and was also increased with the increase of application time of leaf fertilizer.For each time of spaying of leaf fertilizer, the corn yield was increased 258-592.5kg/hm^2 with increase amplitude ranging from 2.3%-5.6%.
文摘This study consolidates the efficacy of a non-starch polysaccharide （NSP）ase enzyme-concept in corn and wheat-based broiler diets. The NSP building blocks of corn, wheat and soybean meal （SBM, 44% protein） were studied first. Cereal NSP primarily consists of arabinose, xylose and glucose molecules that form arabinoxylan, β-glucan and cellulose polysaccharides. In soybean meal （SBM）, glucose （cellulose） predominates, next to galactose and uronic acids that form “pectins”. Broiler performance progress using in-feed NSPase enzymes depends on the concentration, complexity and solubility of the substrate and the genetic potential of the animal, mainly. A dual NSPase enzyme-concept for cereal and SBM NSP, predominantly being arabinoxylan, β-glucan and cellulose, was developed. Methods for measuring enzyme activities （endo-1,4-β-xylanase （EC 3.2.1.8） and endo-1,3（4）-β-glucanase （EC 3.2.1.6）） were developed （AVEVE Biochem UNITS） and preparations thereof （XG） standardized to meet requirements for most challenging NSP （corn, barely soluble）. Feed intake （FI）, bodyweight gain （BWG） and feed：gain ratio （F：G） were assessed in three zootechnical studies, each using 160 Ross 308 broilers split in two feeding groups with 80 birds/group （10 replicates of eight） for 42 d （starter/grower period）. Respective corn-SBM, wheat-SBM and corn/wheat-SBM diets were used as negative control （NC） or added with the enzyme-concept （XG）. In the total period, XG ameliorated BWG and F：G compared to NC in each study, where BWG increased best in diets with corn and F：G lowered most in diets with wheat. The dual NSPase enzyme-concept offers ingredient flexibility in present setting by enhancing the nutritional content of corn, wheat and SBM, expectedly from cleaving major NSP target molecules. Thereby, broiler professionals increase feed formulation liberty and safety and production result simultaneously.
文摘A kind of undercoat for resistor with high temperature and humidity resistance was obtained by modifying epoxy resin with proper nano-SiO2 added at 80℃. The structure, thermal stability, humidity resistance, and morphological characteristics of the modified epoxy resin undercoat were studied by electrical tests, infrared spectra （IR） analysis, and scanning electron microscopy （SEM）. The results show that more compact and steady inter-crosslinked network structures are formed in the modified epoxy resin undercoat added with nano-SiO2, which greatly improves the performance of modified epoxy resin undercoat. The undercoat with nano-SiO2 of about 2. 71%, kept for six months at room temperature without flocculating and aggregating, is of good stability, and the surface of painted resistor is uniform, tight and without air holes on it. The varying ratio of resistance with such undercoat painted is less than one in a thousand after high temperature and humidity resistance tests.
基金supported by the National Natural Science Foundation of China (No.61575087, No.21505057, and No.61771227)the Natural Science Foundation ofJiangsu Province (No.BK20151164, No.BK20150227, and No.BK20170229)+2 种基金the Innovation Project of Jiangsu Province(No.KYLX16_1322)the Natural Science Foundation of the Jiangsu Higher Education Institutions (No.17KJB140007)Foundation of Xuzhou City (No.KC15MS030)
文摘The determination of pesticide residue on agricultural products is increasingly important. Exposure to pesticides can cause severe acute reactions in humans, including aplastic anemia and leukemia. In this work, we developed a rapid and sensitive method to detect acetamiprid pesticide residue based on surface-enhanced Raman scattering. Silver nanorod （AgNR） arrays were fabricated by oblique angle deposition technology and were used as SERS substrates. Prior to detection, the AgNR arrays were cleaned with nitric acid solution or a mixture of methanol and acetone. Compared to the unwashed AgNR arrays, the AgNR arrays washed with methanol and acetone shows a signal enhancement 1000 times greater than the unwashed AgNR array due to the effective removal of the impurities on its surface. The limit of detection of acetamiprid was determined to be 0.05 mg/L. In addition, the molecular structure of acetamiprid was simulated and the corresponding vibration modes of the characteristic bands of acetamiprid were calculated by density function theory. To demonstrate its practical application, the AgNRs array substrates were applied successfully to the rapid identification of acetamiprid residue on a cucumber＇s surface. These results confirmed possibility of utilizing the AgNRs SERS substrates as a new method for highly sensitive pesticide residue detection.
文摘Surface-enhanced Raman scattering(SERS)is a powerful technology for obtaining vibrational information from molecules that present in different chemical or biological environments.This paper presents a 3D SERS substrate based on nanocone forests.The substrates are prepared by using plasma treatment technique,which is a simple,fast and high-throughput approach.The SERS substrate based on nanocone forests exhibits high sensitivity.In the experiment,miRNA with a concentration as low as 10-10 M can be achieved.Meanwhile,the proposed SERS substrate shows a high uniformity over a large area.These experimental results demonstrate great potential of the 3D SERS substrate in wide applications.
文摘Pepsin was assembled on the surface of prepared poly(ethylene terephthalate)(PET-NH3^+) substrates.The composition and structure of the pepsin/PET-NH3^+ assembling films in different condition were characterized by X-ray photoelectron spectroscopy(XPS) and atomic force microscopy(AFM).
文摘In this study, SCM （supplementary cementitious materials）, such as nano silica, micro silica, fly ash and bottom ash, have been evaluated for optimal level of replacement as blending material in cement and concrete. The physical and chemical properties of the above materials were first analyzed. This study focused on compressive strength of concrete with different mixes at different ages. In many cases, products made with fly ash, micro silica, nano silica and bottom ash perform better than products made without them. Test results obtained in this study indicate that up to 5% nano silica, 10% micro silica, 20-30% fly ash and 10% bottom ash could be advantageously blended with cement without adversely affecting the strength. However, optimum levels of these materials are 1-3% nano silica, 3-8% micro silica, 10% fly ash and 5% of bottom ash when we consider the strength of concrete. All percentages are defined by weight unless otherwise mentioned.
文摘学术休假英文为"Sabbatical Leave""Sabbatical"或"Academic Sabbatical"。国外学者康和米勒(Kang and Miller,1999)指出学术休假的概念具有神话和宗教意义,它的起源可以追溯到希伯来的传说中,"Sabbatical"一词来自一个在米底(Media)的古河流的名字,这条河流淌六天,在第七天休息。基于这样的理念,出现了"Sabbath(安息日)",即在一周的第七天,让信徒们休息、做祷告,
基金supported by the National Natural Science Foundation of China (21305113)the Chongqing Fundamental and Advanced Research Project (cstc2013jcyjA50008)+2 种基金the Fundamental Research Funds for the Central Universities (XDJK2015B029)the fund of State Key Laboratory of Electroanalytical Chemistry (Changchun Institute of Applied Chemistry, Chinese Academy of Sciences) (SKLEAC201312)the Research Fund for the Doctor Program of Southwest University (swu111077)
文摘We report a new strategy to prepare gold nanoflowers （AuNFs） using a two-step seed-mediated method. The as-prepared AuNFs were employed as surface-enhance Raman scattering （SERS） substrates, showing strong signal enhancement. We further found that iodide ions （I^-） could selectively induce the morphological transformation of AuNFs to spheres, resulting in a blue-shift of the localized surface plasmon resonance （LSPR） bands, a color change of the AuNFs solution from blue to red, and decreased SERS activity. This behavior allows the AuNFs to be used in the determination of I^-.
基金supported by the Scientific Research Project of Beijing Educational Committee(No.KM201410017005)the BIPT Breeding Project of Outstanding Young Teachers and Management Backbone 2013+2 种基金the Beijing University Academic Research Training Project(No.2014J00032)the Importation and Development of High-Caliber Talents Project of Beijing Municipal Institutions(No.CIT&TCD201304099)BIPT-BPOAL-2013
文摘An efficient surface-enhanced Raman scattering(SERS) substrate is developed based on silver nanoparticles decorated anodic aluminum oxide(Ag/AAO).The AAO templates were fabricated using a two-step anodization approach,and silver nanoparticles(Ag NPs) were obtained by thermal decomposition of Ag nitrate in AAO.The structure of Ag/AAO hybrid substrate is characterized by scanning electron microscopy(SEM).The results show that the as-prepared SERS substrates consist of high-density Ag NPs with sizes of tens of nanometers.The Ag NPs are adsorbed on the surface of AAO template in the form of network structure which is called "hot spot".The SERS enhancement ability of the nanostructure is verified using thiram as probing molecules.The limit of detection is as low as 1×10-9 mol/L.The results indicate that the as-prepared substrate possesses excellent SERS sensitivity,high stability and uniformity enhancement.
文摘We present a study of the electric field effect on electrochemically grown ultrathin, straight platinum nanowires with minimum diameter of 15 nm and length in the micrometer range, synthesized on a silicon oxide substrate between metal electrodes in H2PtC16 solution. The influence of the concentration of the platinum- containing acid and the frequency of the applied voltage on the diameter of the nanowires is discussed with a corresponding theoretical analysis. We demonstrate for the first time that the electric field profile, provided by the specific geometry of the metal electrodes, dramatically influences the growth and morphology of the nanowires. Finally, we provide guidelines for the controlled fabrication and contacting of straight, ultrathin metal wires, eliminating branching and dendritic growth, which is one of the main shortcomings of the current bottom-up nanotechnology. The proposed concept of self-assembly of thin nanowires, influenced by the electric field, potentially represents a new route for guided nanocontacting via smart design of the electrode geometry. The possible applications reach from nanoelectronics to gas sensors and biosensors.
