期刊文献+
共找到6,326篇文章
< 1 2 250 >
每页显示 20 50 100
Some of the Chemical and Physical Characteristics of the Graff River in Kut City, Iraq
1
作者 Salih Mahdi Ali Imad Kazem Ali 《Open Journal of Modern Hydrology》 CAS 2024年第1期56-67,共12页
Some of the chemical and physical water qualities of the Graff River in the city of Kut were studied, and for two sites of the river, One was at the Crimea site, the other in the Jihad district, and for the period fro... Some of the chemical and physical water qualities of the Graff River in the city of Kut were studied, and for two sites of the river, One was at the Crimea site, the other in the Jihad district, and for the period from October/2018 to March/2019, Seven variables of river water have been analyzed: temperature PH, electrical conductivity, TDS, turbidity, alkaline, and chloride. The results showed that most of the chemical and physical water properties of the river were in normal proportions and did not rise, except for the turbidity, which was at a very high level, and that the pH values were close to the basal side. The results of the statistical analysis revealed positive significant relationships between the pH and (chloride and TDS). On the other hand, between electrical conductivity and both previous variables as well. And a negative significant connection between temperature and alkaline. 展开更多
关键词 Graff River Kut City Iraq chemical characteristics Physical characteristics
下载PDF
Experimental investigation on coal pore-fracture variation and fractal characteristics synergistically affected by solvents for improving clean gas extraction 被引量:1
2
作者 Feilin Han Sheng Xue +3 位作者 Chunshan Zheng Zhongwei Chen Guofu Li Bingyou Jiang 《International Journal of Mining Science and Technology》 SCIE EI CAS CSCD 2024年第3期413-425,共13页
Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction efficiency.However,pore-fracture variation features of lean coal... Chemical solvents instead of pure water being as hydraulic fracturing fluid could effectively increase permeability and improve clean methane extraction efficiency.However,pore-fracture variation features of lean coal synergistically affected by solvents have not been fully understood.Ultrasonic testing,nuclear magnetic resonance analysis,liquid phase mass spectrometry was adopted to comprehensively analyze pore-fracture change characteristics of lean coal treated by combined solvent(NMP and CS_(2)).Meanwhile,quantitative characterization of above changing properties was conducted using geometric fractal theory.Relationship model between permeability,fractal dimension and porosity were established.Results indicate that the end face fractures of coal are well developed after CS2and combined solvent treatments,of which,end face box-counting fractal dimensions range from 1.1227 to 1.4767.Maximum decreases in ultrasonic longitudinal wave velocity of coal affected by NMP,CS_(2)and combined solvent are 2.700%,20.521%,22.454%,respectively.Solvent treatments could lead to increasing amount of both mesopores and macropores.Decrease ratio of fractal dimension Dsis 0.259%–2.159%,while permeability increases ratio of NMR ranges from 0.1904 to 6.4486.Meanwhile,combined solvent could dissolve coal polar and non-polar small molecules and expand flow space.Results could provide reference for solvent selection and parameter optimization of permeability-enhancement technology. 展开更多
关键词 Clean gas extraction chemical solvent Experimental investigation Fractal characteristics Pore fracture
下载PDF
Functional Optical Fiber Sensors Detecting Imperceptible Physical/Chemical Changes for Smart Batteries
3
作者 Yiding Li Li Wang +3 位作者 Youzhi Song Wenwei Wang Cheng Lin Xiangming He 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第8期268-308,共41页
The battery technology progress has been a contradictory process in which performance improvement and hidden risks coexist.Now the battery is still a“black box”,thus requiring a deep understanding of its internal st... The battery technology progress has been a contradictory process in which performance improvement and hidden risks coexist.Now the battery is still a“black box”,thus requiring a deep understanding of its internal state.The battery should“sense its internal physical/chemical conditions”,which puts strict requirements on embedded sensing parts.This paper summarizes the application of advanced optical fiber sensors in lithium-ion batteries and energy storage technologies that may be mass deployed,focuses on the insights of advanced optical fiber sensors into the processes of one-dimensional nano-micro-level battery material structural phase transition,electrolyte degradation,electrode-electrolyte interface dynamics to three-dimensional macro-safety evolution.The paper contributes to understanding how to use optical fiber sensors to achieve“real”and“embedded”monitoring.Through the inherent advantages of the advanced optical fiber sensor,it helps clarify the battery internal state and reaction mechanism,aiding in the establishment of more detailed models.These advancements can promote the development of smart batteries,with significant importance lying in essentially promoting the improvement of system consistency.Furthermore,with the help of smart batteries in the future,the importance of consistency can be weakened or even eliminated.The application of advanced optical fiber sensors helps comprehensively improve the battery quality,reliability,and life. 展开更多
关键词 Smart battery Advanced embedded optical fiber sensor Battery internal physical/chemical state Quality-reliability-life characteristic
下载PDF
Assessment of the Variations in Soil Physicochemical Parameters of the Natural Forest and Plantations in Orumba North Local Government Area, Anambra State, Nigeria
4
作者 Maureen Chinwe Odachi Nwabueze Ikenna Igu Ifeanyi Chris Onwuadiochi 《Journal of Geoscience and Environment Protection》 2024年第10期132-151,共20页
Soil physicochemical parameters are the physical and chemical characteristics of soil such as pH, bulk density, organic carbon, nitrogen content, and nutrient levels at different soil depths. These parameters vary fro... Soil physicochemical parameters are the physical and chemical characteristics of soil such as pH, bulk density, organic carbon, nitrogen content, and nutrient levels at different soil depths. These parameters vary from one vegetation to the other and from one soil to the other. The study assessed the variations in soil physicochemical parameters of the natural forest and plantations in Agu Eke (Eke bush) in Etti village, Nanka and Umunnebo village, Ufuma both located in Orumba North Local Government Area, Anambra State. The experimental research design and stratified random sampling methods were used for the study and a total of 12 soil samples were collected at 30 cm depth from the selected locations of natural forest, cashew and palm plantations. The samples were analyzed using laboratory Varian AA240 Atomic Absorption Spectrophotometer, after which the result was subjected to statistical analysis—Analysis of Variance (ANOVA). The study found that there was no significant difference (variation) between the moisture contents of natural forests and the plantations;that is, the moisture contents were the same. It was also found that there was no significant variation between the bulk densities of the natural forest, oil plantation, and cashew plantation, meaning that the bulk densities were significantly the same. However, there were significant variations in nitrogen, potassium and phosphates, with p-values: sig = .000 < .05, sig = .010 < .05 and sig = .000 < .05, respectively. That is, the nitrogen and phosphate contents of the natural forest significantly vary more than those of the oil palm and cashew plantations, which probably means that by reducing natural forest to plantation, the nitrogen and phosphate contents of the natural forest reduced from what it used to be when the lands were mere forests. This shows that plantations do not have the same function of maintaining or improving soil quality as natural forests. The study recommended adopting a sustainable plantation agricultural system, such as using diverse nutrient sources (manure and compost), in order to maintain the desired soil quality. 展开更多
关键词 ECOSYSTEM Land Use Change Soil Quality Physical and chemical characteristics
下载PDF
The Background Features and Formation of Chemical Elements of Groundwater in the Region of the Middle and Lower Reaches of the Yangtze River 被引量:17
5
作者 Zeng Zhaohua Institute of Environmental Geology,Jiangxi Bureau of Geology and Mineral Resources, Nanchang, Jiangxi Shang Ruoyun 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1997年第1期80-89,共10页
The paper deals with the background features, formation and distribution of the chemical el-ements K, Na, Ca, Mg, Si, Fe, Mn, Cr, Ni,V, Co, Ti, Mo, Cu, Pb, Zn, As, Hg, Cd, Be, Li, Sr, B,F, Cl, Br and I in the groundwa... The paper deals with the background features, formation and distribution of the chemical el-ements K, Na, Ca, Mg, Si, Fe, Mn, Cr, Ni,V, Co, Ti, Mo, Cu, Pb, Zn, As, Hg, Cd, Be, Li, Sr, B,F, Cl, Br and I in the groundwater in the region of the middle and lower reaches of the YangtzeRiver and their relations to the composition of the water-bearing media, properties of the overly-ing rocks and soils, redox environment, and groundwater flow condition, mineralization and pHof groundwater. 展开更多
关键词 lower-middle reaches of the Yangtze River GROUNDWATER chemical element background feature
下载PDF
Effects of seven different companion plants on cucumber productivity, soil chemical characteristics and Pseudomonas community 被引量:5
6
作者 CHANG Chun-ling FU Xue-peng +2 位作者 ZHOU Xin-gang GUO Mei-yu WU Feng-zhi 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第10期2206-2214,共9页
Companion cropping can influence cucumber productivity by altering soil chemical characteristics and microbial communities. However, how these alterations affect the growth of cucumber is still unknown. In this study,... Companion cropping can influence cucumber productivity by altering soil chemical characteristics and microbial communities. However, how these alterations affect the growth of cucumber is still unknown. In this study, seven different plant species were selected as companion plants for testing their effects on cucumber productivity. The effects of different companion plants on changes in soil chemical properties such as electrical conductivity (EC) and contents of essential nutrients as well as the structure and abundance of the soil Pseudomonas community were evaluated. The results showed a higher cucumber yield in the wheat/cucumber companion system than that in the cucumber monocultured and other companion cropping systems. The lowest phosphorus (P) and potassium (K) contents in the soil were found in the cucumber monocultured system, and the highest NO3+-N and NH4*-N contents were observed in the rye/cucumber companion system. PCR-denaturing gradient gel electrophoresis (DGGE) and real-time PCR analysis showed that the trifolium/cucumber companion system increased the diversity of the soil Pseudomonas community, while the chrysanthemum/cucumber companion system increased its abundance. Interestingly, plant-soil feedback trials revealed that inoculating the soil of the wheat/cucumber companion system increased the growth of cucumber seedlings. In conclusion, the effects of different companion plants on cucumber productivity, soil chemical characteristics and the soil Pseudomonas community were different, and wheat was a more suitable companion plant for increasing cucumber productivity. In addition, the altered microbial community caused by companion cropping with wheat contributed to increased cucumber productivity. 展开更多
关键词 CUCUMBER companion plants soil chemical characteristics Pseudomonas community
下载PDF
Analysis on the Chemical Characteristics of Shallow Groundwater and Causes of Formation in the Area around Poyang Lake 被引量:5
7
作者 YANG Tao WANG Shi-jie 《Meteorological and Environmental Research》 CAS 2011年第9期77-80,共4页
[Objective] The study aimed at analysing the chemical characteristics of shallow groundwater and causes of formation around Poyang Lake area. [Method] The quality of shallow groundwater under seven counties or cities ... [Objective] The study aimed at analysing the chemical characteristics of shallow groundwater and causes of formation around Poyang Lake area. [Method] The quality of shallow groundwater under seven counties or cities around Poyang Lake was investigated in 2010, and compared different regions from salinity, hardness, conductivity, hydrochemistry types and so forth, so as to reveal the status quo, change characteristics and reasons of shallow groundwater. [Result] Except for pH, other water quality indicators of shallow groundwater around Poyang Lake were better, attaining Class I water quality standards. Among these regions, the salinity, hardness, conductivity, Na+, K+, Ca2+, Mg2+, Cl- and HCO-3 concentration of shallow groundwater in Nanchang city were up to the maximum values, while pH and SO2-4 concentration were the highest in Duchang County; Mg2+ concentration and pH were the lowest in Poyang County, and hardness, K+, Ca2+, SO2-4 and Cl- concentration in Yongxiu County reached the minimum values, while Na+ concentration, salinity and conductivity were the lowest in Jinxian County. In addition, the better quality of groundwater around Poyang Lake was closely related to the low level of economic development in Jiangxi Province. Meanwhile, many water quality indices in Nanchang City reached the maximum values, and even tended to Class Ⅱ water quality standards, which resulted from the high level of economic development and decisive role of human activities. [Conclusion] The research could provide references for the establishment of management strategies for regional shallow groundwater. 展开更多
关键词 Poyang Lake Shallow groundwater chemical characteristics China
下载PDF
Electrokinetic chemical characteristics of humic and dannic acids effecting on the natural water and its coagulation 被引量:1
8
作者 Qu Jiuhui Research Center for Eco-Environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 1997年第1期71-79,共9页
Taking streaming current(SC)as the electrokinetic parameter,this paper demon- strated the electrokinetic chemical characteristics of humic and dannic acids(HA and DA)in sus- pensions including turbid water,coagulated ... Taking streaming current(SC)as the electrokinetic parameter,this paper demon- strated the electrokinetic chemical characteristics of humic and dannic acids(HA and DA)in sus- pensions including turbid water,coagulated water and HA or DA contained water.Accordingly, the studies were carried out for determining the relationship between streaming current and zeta po- tential ζ(expressed by eleetrophoretie mobility EM)in above water conditions.In addition,the mechanisms of HA effecting on streaming current within or after coagulant addition and the elec- trokinetic detection principles for HA or DA were also investigated on experiments and theoretical analysis.The results indicated that the change of SC like ζ presented meaningful information con- cerning the degree for destabilization of a particulate suspension,and HA or DA in water could re- markably decrease the effect of inorganic coagulant upon streaming current,which is in accordance with their influence on coagulation. 展开更多
关键词 electrokinetic chemical characteristics humic acid dannic acid natural water.
下载PDF
Anatomical and Chemical Characteristics of a Rolling Leaf Mutant of Rice and Its Ecophysiological Properties 被引量:1
9
作者 BAI Lei DUAN Zhuang-qin +3 位作者 WANG Jun-min AN Li-zhe ZHAO Zhi-guang CHEN Kun-ming 《Rice science》 SCIE 2008年第3期201-208,共8页
The anatomical and chemical characteristics of a rolling leaf mutant (rlm) of rice (Oryza sativa L.) and its ecophysiological properties in photosynthesis and apoplastic transport were investigated. Compared with ... The anatomical and chemical characteristics of a rolling leaf mutant (rlm) of rice (Oryza sativa L.) and its ecophysiological properties in photosynthesis and apoplastic transport were investigated. Compared with the wild type (WT), the areas of whole vascular bundles and xylem as well as the ratios of xylem area/whole vascular bundles area and xylem area/phloem area were higher in rim, whereas the area and the width of foliar bulliform cell were lower. The Fourier transform infrared (FTIR) microspectroscopy spectra of foliar cell walls differed greatly between rim and WT. The rim exhibited lower protein and polysaccharide contents of foliar cell walls. An obvious reduction of pectin content was also found in rim by biochemical measurements. Moreover, the rate of photosynthesis was depressed while the conductance of stoma and the intercellular CO2 concentration were enhanced in rim. The PTS fluorescence, which represents the ability of apoplastic transport, was 11% higher in rim than in WT. These results suggest that the changes in anatomical and chemical characteristics of foliar vascular bundles, such as the reduction of proteins, pectins, and other polysaccharides of foliar cell walls, participate in the leaf rolling mutation, and consequently lead to the reduced photosynthetic dynamics and apoplastic transport ability in the mutant. 展开更多
关键词 RICE rolling leaf mutant anatomical characteristics chemical characteristics apoplastic transport ecophysiological property Fourier transform infrared microspectroscopy
下载PDF
Chemical Reactivity Properties, Drug-Likeness Features and Bioactivity Scores of the Cholecystokinin Peptide Hormone 被引量:2
10
作者 Norma Flores-Holguín Juan Frau Daniel Glossman-Mitnik 《Computational Molecular Bioscience》 2019年第2期41-47,共7页
Five density functionals, CAM-B3LYP, LC-ωPBE, MN12SX, N12SX and ωB97XD, in connection with the Def2TZVP basis set were assessed together with the SMD solvation model for the calculation of the molecular and chemical... Five density functionals, CAM-B3LYP, LC-ωPBE, MN12SX, N12SX and ωB97XD, in connection with the Def2TZVP basis set were assessed together with the SMD solvation model for the calculation of the molecular and chemical reactivity properties of the Cholecystokinin peptide hormone (CCK-8) in the presence of water. All the chemical reactivity descriptors for the systems were calculated via Conceptual Density Functional Theory (CDFT). The potential bioavailability and druggability as well as the bioactivity scoresfor CCK-8 were predicted through different methodologies already reported in the literature which have been previously validated during the study of different peptidic systems. The conclusion was that the CCK-8 peptide will be moderately bioactive regarding all the interactions. 展开更多
关键词 CHOLECYSTOKININ Peptide HORMONE (CCK-8) Conceptual DFT chemical Reactivity DRUG-LIKENESS featureS Bioactivity SCORES
下载PDF
Vibration-based feature extraction of determining dynamic characteristic for engine block low vibration design 被引量:2
11
作者 杜宪峰 李志军 +3 位作者 毕凤荣 张俊红 王霞 邵康 《Journal of Central South University》 SCIE EI CAS 2012年第8期2238-2246,共9页
In order to maintain vibration performances within the limits of the design, a vibration-based feature extraction method for dynamic characteristic using empirical mode decomposition (EMD) and wavelet analysis was p... In order to maintain vibration performances within the limits of the design, a vibration-based feature extraction method for dynamic characteristic using empirical mode decomposition (EMD) and wavelet analysis was proposed. The proposed method was verified experimentally and numerically by implementing the scheme on engine block. In the implementation process, the following steps were identified to be important: 1) EMD technique in order to solve the feature extraction of vibration signals; 2) Vibration measurement for the purpose of confirming the structural weak regions of engine block in experiment; 3) Finite element modeling for the purpose of determining dynamic characteristic in time region and frequency region to affirm the comparability of response character corresponding to improvement schemes; 4) Adopting a feature index oflMF for structural improvement based on EMD and wavelet analysis. The obtained results show that IMF of signal is more sensitive to response character corresponding to improvement schemes. Finally, examination of the results confirms that the proposed vibration-based feature extraction method is very robust, and focuses on the relative merits of modification and full-scale structural optimization of engine, together with the creation of new low-vibration designs. 展开更多
关键词 feature extraction dynamic characteristic finite element model empirical mode decomposition diesel engine block
下载PDF
Chemical, Nutritional and Organoleptical Characteristics of Orange-Based Formulated Low-Calorie Jams 被引量:1
12
作者 Rafeek M. Abolila Hassan Barakat +1 位作者 Hassan A. El-Tanahy Hamdy A. El-Mansy 《Food and Nutrition Sciences》 2015年第13期1229-1244,共16页
Twelve low-calorie orange-based formulated jams were prepared mainly from orange, pumpkin and papaya, and then sweetened using fructose (F), stevioside (St) and sucralose (Su). The nutritional value of formulated jams... Twelve low-calorie orange-based formulated jams were prepared mainly from orange, pumpkin and papaya, and then sweetened using fructose (F), stevioside (St) and sucralose (Su). The nutritional value of formulated jams was estimated after the approximate chemical composition and total soluble solid have been determined. The effect of storage on total phenolic compounds, antioxidant capacity, carotenoids content and vitamin C was investigated. Organoleptical attributes of prepared low-calorie jams were done as well. Results indicated that the nutritive value [kcal 100 g–1 fw] ranged from 88.10 ± 0.60 to 164.34 ± 0.41;total phenol content (TPC, mg GAE 100 g–1 fw] ranged from 188.52 ± 2.45 to 411.79 ± 3.3;the antioxidant capacity (μmol TE g–1 fw) ranged from 14.57 ± 0.86 to 32.39 ± 1.19;total carotenoids [mg 100 g–1 fw] ranged from 115.20 ± 5.66 to 204.33 ± 4.21;vitamin C [mg 100 g fw] ranged from 8.94 ± 1.07 to 28.77 ± 4.46;total soluble solids [Brix] ranged from 22.53 ± 0.05 to 43.37 ± 0.13. Jams storage for a period of 12 months at room temperature led to a decrease in vitamin C content, TPC, antioxidant capacity, while total soluble solids (TSS) and carotenoids increased during storage. The results of organoleptical attributes showed that the formulas O11, O1 had the highest score of color and odor respectively while O7 recorded maximum score for taste, texture and bitterness respectively. Statistical analysis showed that storage intervals and treatments had a significant (p < 0.05) effect on sensory quality of diet jam. The organoleptical characteristics were affected with the extension of shelf-life. Addition of stevioside and sucralose to formulate the low-calorie jam increased total phenol and antioxidant capacity, improved color, taste and produced targeted low-calorie jams. The use of sweeteners such as fructose, sucralose and stevioside in the manufacture of orange diet jam was shown to be satisfactory, resulting in low-calorie jams, improved the quality and could be produced commercially. 展开更多
关键词 Low-Calorie Jam chemical NUTRITIONAL Organoleptical characteristicS
下载PDF
Potential Use of Selected Sweetpotato (<i>Ipomea batatas</i>Lam) Varieties as Defined by Chemical and Flour Pasting Characteristics 被引量:1
13
作者 Agnes Nabubuya Agnes Namutebi +2 位作者 Yusuf Byaruhanga Judith Narvhus Trude Wicklund 《Food and Nutrition Sciences》 2012年第7期889-896,共8页
Chemical and functional properties of ten sweetpotato varieties were investigated. The sweetpotato were of various flesh colours which included orange, yellow, cream and white with dry matter content ranging from 30.2... Chemical and functional properties of ten sweetpotato varieties were investigated. The sweetpotato were of various flesh colours which included orange, yellow, cream and white with dry matter content ranging from 30.2% - 39.2%. The sweetpotato varieties varied significantly (p < 0.05) in total amylase activity, total starch and amylose content whose value ranges were 0.256 - 0.570 mg/ml/min 68.4% - 73.6%, 16.2% - 23.4% respectively. The pH of flours from the different sweetpotato varieties ranged from 6.01 - 6.64. The pasting behaviours of the sweetpotato flours also showed significant differences (p < 0.05) in the individual parameters (peak time, pasting temperature, peak viscosity, trough viscosity, final viscosity, breakdown and setback) among the different varieties. The results revealed the influence of variety on the chemical composition of sweetpotato and their pasting properties. Correlations were also revealed among different components of the sweetpotatoes which would be a basis in selection of the varieties for processing into different products. 展开更多
关键词 SWEETPOTATO chemical Properties PASTING characteristics
下载PDF
Nutritional, Chemical and Organoleptical Characteristics of Low-Calorie Fruit Nectars Incorporating Stevioside as a Natural Sweetener 被引量:1
14
作者 Hassan Barakat Abdulaziz Al-Furaydi +1 位作者 Abdulelah Al-Harbi Ali Al-Shedookhi 《Food and Nutrition Sciences》 2017年第1期126-140,共15页
The study is aiming at preparation of low-calorie fruit nectars for diabetes and weight maintaining approaches as well as consumer satisfaction. Therefore, twenty low-calorie fruit-based formulated nectars were prepar... The study is aiming at preparation of low-calorie fruit nectars for diabetes and weight maintaining approaches as well as consumer satisfaction. Therefore, twenty low-calorie fruit-based formulated nectars were prepared mainly from orange, pomegranate, guava and mango pulps which sweetened with sucrose or sucrose— replaced at 25%, 50%, 75% and 100% using stevioside. Primitively, the yield of fresh fruits had been calculated. Consequently, nutritional, chemical and organoleptical characteristics of prepared fruit nectars have been determined. Results indicated that total solids content was in range of 5.57% - 13.20%, 9.90% - 14.37%, 8.25% - 13.27% and 8.25% - 16.50% for orange, pomegranate, guava and mango nectars, respectively. Dependently, caloric value resulted 21.57 to 51.08, 38.31 to 55.62, 31.93 to 51.37 and 31.93 to 63.86 kcal 100 g-1 fw for orange, pomegranate, guava and mango nectars, respectively. Total phenols content [TPC, mg GAE 100 g-1 dw] ranged from 665.12 to 747.41, 1180.42 to 1319.47, 742.54 to 848.27 and 418.01 to 472.42 for orange, pomegranate, guava and mango nectars, respectively. The antioxidant capacity by DPPH method [μmol TE g-1 dw] ranged from (20.79 to 26.51), (47.13 to 56.56), (60.68 to 69.25) and (8.39 to 13.32) for orange, pomegranate, guava and mango nectars, respectively. Total carotenoids [mg 100 g-1 dw] were the highest in mango nectars ranged from (102.99 to 110.52) in mango nectar with 100% sugar and mango nectar with 100% stevioside, respectively. Anthocyanins content recorded 6.14 mg 100 g-1 dw in pomegranate nectar with 100% sugar, while increased to be 9.01 mg 00 g-1 dw in pomegranate nectar with 100% stevioside. Ascorbic acid [mg 100 g fw] ranged from 23.41 to 27.53, 15.73 to 18.32, 25.72 to 30.87 and 18.07 to 20.98 for orange, pomegranate, guava and mango nectars, respectively. The results of organoleptical attributes showed no effect of sugar substituting by stevioside on color, odor and mouth feel. The most dramatic effect of sugar substituting had been observed on taste, bitter after taste and the overall acceptability of prepared nectars with high substitution levels. Practically, using stevioside to produce low-calorie nectars was shown to be satisfactory up to 50% - 75% substituting level, resulting low-calorie nectars and could be applied commercially. 展开更多
关键词 Low-Calorie Nectar chemical NUTRITIONAL Organoleptical characteristicS
下载PDF
Physicochemical Characteristics of Calamondin(Citrus microcarpa)from Hainan 被引量:1
15
作者 Yi ZOU Hongjian ZHANG Lianhe ZHENG 《Asian Agricultural Research》 2020年第12期58-62,共5页
Some physicochemical characteristics of calamondin(Citrus microcarpa)from Hainan were determined in this study.The mean length,width,and thickness of calamondin were(2.763±0.262),(2.721±0.189),and(2.684±... Some physicochemical characteristics of calamondin(Citrus microcarpa)from Hainan were determined in this study.The mean length,width,and thickness of calamondin were(2.763±0.262),(2.721±0.189),and(2.684±0.201)cm,respectively.The average values for geometric mean diameter,sphericity,fruit shape index,mass,surface area,volume,true density,bulk density and porosity were(2.721±0.196)cm,(98.79±5.149)%,(101.64±7.609)%,(11.18±2.149)g,(23.36±3.362)cm2,(11.16±2.115)cm3,(1.00±0.060)g/cm3,0.44 g/cm3,and(56.40±0.027)%,respectively.The mean edible part,juice rate,and soluble solids were(85.77±3.53),(48.36±4.20),and(7.86±0.09)%,respectively.The total flavonoids,pectin,limonin,reducing sugar and volatile oil contents of the peel were 1.00,7.14,0.51,5.98,and 4.25%,respectively.The total flavonoids,pectin,limonin and reducing sugar contents of the pulp were 0.02,5.04,0.03 and 4.56%,respectively.The total flavonoids,total acid,reducing sugar and vitamin E contents of the juice were 0.11,6.74,0.37%,and 1.68 mg/kg,respectively,while the content of vitamins A,B1,B2,B3,B6,and D in the juice was very low.The seeds had limonin,reducing sugar and oil contents of 0.46,1.39,and 30.46%,respectively.The vitamin B2,B3,B6 and E contents of the fruit residue were 44.83,19.31,17.55,and 15.72 mg/kg,respectively.The amino acid profile of the residue included aspartic acid,glutamate,cystine,serine,glycine,histidine,arginine,threonine,alanine,proline,tyrosine,valine,methionine,isoleucine,leucine,phenylalanine and lysine,with respective contents of 4.42,1.81,2.10,0.78,0.59,0.20,0.72,0.160.67,3.650.50,0.67,0.59,1.00,0.76,0.57 and 0.91 g/kg. 展开更多
关键词 Hainan calamondin Physical characteristic chemical characteristic Nutrient content
下载PDF
Chemical and physical characteristics of quartz from gold deposits in the North China platform: relationship to gold mineralization 被引量:1
16
作者 Jianzhao Yin Yang Liu Hongyun Shi 《Acta Geochimica》 EI CAS CSCD 2021年第6期998-1022,共25页
This paper seeks to identify macroscopic metallogenic mechanisms of various mineral deposits by studying microscopic typomorphic characteristics of typical minerals associated with the deposits and to reveal the mecha... This paper seeks to identify macroscopic metallogenic mechanisms of various mineral deposits by studying microscopic typomorphic characteristics of typical minerals associated with the deposits and to reveal the mechanism of lattice gold in detail by studying both physical and chemical characteristics of quartz from representative gold deposits in the North China Platform.As part of their extensive research,the authors examine the relationship between trace elements with wall rock,the ore-forming media,and gold immigration of various types of gold deposits,including their salinity,type,temperature.These are key factors to revealing the mineralization mechanism,and indicators for mineral prospecting,exploration,mining,and metallurgical technology.In order to address the questions posed,the following methods were used:field investigations of geology and sampling of the representative gold deposits,physical study and chemical analysis of quartz including,but not limited to,fluid inclusions as well as their compositions and trace elements in quartz,the unit cell parameters,electron paramagnetic resonance spectrum(EPR),and infrared spectroscopic analysis(ISA).As a result of this study,the authors observe the following key findings:unit cell parameters of quartz vary with their contents of foreign elements including gold,paragenetic stage,wall rock type,and other factors;the higher the forming temperature and the lower the gold content in quartz,the smaller the unit cell parameters,and vice versa.Additionally,the EPR absorption lines resulted from the O–Al defect center.The density of these types of hole centers increases and the EPR signal strengthens when the temperature decreases.Based on the findings,the authors conclude that lattice gold exists in quartz.Gold,in the form of Au^(+)and/or Au^(3+),entering quartz and producing an electron–hole center,namely,the O-Au hole center,makes the center produce spin resonance absorption and results in the EPR absorption peak#I.Both unit cell parameters and EPR of quartz can potentially be used in mineral prospecting,relative ore-forming temperature determination,and grade control during mining. 展开更多
关键词 Physical and chemical characteristics QUARTZ Gold mineralization Unit cell parameter Electron paramagnetic resonance spectrum Infrared spectrum
下载PDF
Study of aquatic chemical characteristic in some bays along the coastal region of Zhejiang Province 被引量:2
17
作者 Wang Yuheng,Dong Henglin and Jiang Guochang The Second Institute of Oceanography,State Oceanic Administration ,Hangzhou,China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1990年第4期547-554,共8页
In this paper,the aquatic chemical characteristics in the Hangzhou Bay,Xiangshan Bay and Leqing Bay along the coastal region of Zhejiang Province are discussed . Results show that the seasonal variations of chemical e... In this paper,the aquatic chemical characteristics in the Hangzhou Bay,Xiangshan Bay and Leqing Bay along the coastal region of Zhejiang Province are discussed . Results show that the seasonal variations of chemical elements are obvious. The distribution of silicate in Hangzhou Bay and contents of dissolved oxygen and nutrient in the Xiangshan Bay are found to be unusual in winter. Correlations among the elements are complex. The content of nutrient in the Hangzhou Bay is higher than that in Xiangshan Bay and the content of nutrient in the Xiangshan Bay is higher than that in the Leqing Bay . The variation of the ratio of N/P is obvious. This reflects the aquatic chemical characteristics in the bay. Finally, this paper also discusses the reason why the aquatic chemical characteristics in the bays are unusual. 展开更多
关键词 Study of aquatic chemical characteristic in some bays along the coastal region of Zhejiang Province BAY
下载PDF
Effect of Garlic Straw on Physical and Chemical Characteristics of Continuous Cropping Soil and Root Activity of Tomato in Solar Greenhouse 被引量:1
18
作者 刘素慧 徐金强 +2 位作者 尉辉 刘庆涛 徐峥 《Agricultural Science & Technology》 CAS 2016年第6期1349-1354,共6页
Taking tomato "Kate two" as the experimental material, the effects of different dosage of garlic straw on physical and chemical characteristics of continuous cropping soil and root activity of tomato in solar greenh... Taking tomato "Kate two" as the experimental material, the effects of different dosage of garlic straw on physical and chemical characteristics of continuous cropping soil and root activity of tomato in solar greenhouse were studied. The results showed that after applying with garlic straw, maximal and minimal temperatures in 0-15 cm soil layers were directly proportional to the amount of returned garlic straw, which were 2.39 ℃ and 1℃ higher than that of the control respectively. The unit weight was decreasing upon the amount of applied garlic straws of soils in different depths, but the porosity of soil was increasing. For example, unit weight and porosity changed the most significantly in soils in the depths of 0-10 cm, which went down by 6.71% and 6.18%, respectively. Besides, garlic straw returning to field improved soil pH, reduced soil conductivity and soil acidification and relieved soil secondary salinization, especially in 0-20 cm soil layers. In addition to that, the application of garlic straw increased the root activity of tomato (max 31.45%), and delayed root system senescence in late stage. Therefore, garlic straw returning could improve the physical and chemical characteristics of soil by succession planting and root activity of tomato in solar greenhouse. 展开更多
关键词 Garlic Crop straw TOMATO Physical and chemical characteristics Root activity
下载PDF
Effects of Varieties and Cooking Methods on Physical and Chemical Characteristics of Cooked Rice 被引量:1
19
作者 Merynda Indriyani SYAFUTRI Filli PRATAMA +1 位作者 Friska SYAIFUL Achmad FAIZAL 《Rice science》 SCIE CSCD 2016年第5期282-286,共5页
To analyze the effect of different lowland rice varieties and different cooking methods on physical and chemical characteristics of cooked rice. A factorial randomized block design with two factors was used and each c... To analyze the effect of different lowland rice varieties and different cooking methods on physical and chemical characteristics of cooked rice. A factorial randomized block design with two factors was used and each combination of the factors was repeated three times. The first factor was rice variety(Ciherang and Ciliwung) and the second factor was the cooking method(stovetop, boiling and steaming, and rice cooker). Results showed that Ciherang and Ciliwung varieties were classified into slender grain rice type with yellowred color. The amylose content of Ciherang was classified as moderate, while the amylose content of Ciliwung classified as low. The most abundant amino acid contained in Ciherang and Ciliwung varieties was glutamic acid. Statistical analysis showed that cooking method had significant effects on texture, lightness, chroma, hue and moisture content of cooked rice. Rice cooked with liwet method had the lowest texture value, lowest lightness value, highest chroma value, and highest moisture content. 展开更多
关键词 physical and chemical characteristic cooking method rice variety amino acid
下载PDF
Effects of Microbial Fertilizer on Growth Characteristics of Facility Tomato and Chemical Properties of Acidic soil 被引量:1
20
作者 Peiping ZHANG Zhidian WANG Yao SUN 《Agricultural Biotechnology》 CAS 2018年第2期55-57,70,共4页
[Objectives]This study was conducted to discuss the possibility of applying microbial fertilizer to production of facility tomato,so as to determine rational application rate for facility tomato.[Methods]A field exper... [Objectives]This study was conducted to discuss the possibility of applying microbial fertilizer to production of facility tomato,so as to determine rational application rate for facility tomato.[Methods]A field experiment was carried out to investigate the effects of the application of microbial fertilizer onto acidic soil on yield,quality and soil chemical properties of facility tomato.[Results]Yield of facility tomato was improved after the application of microbial fertilizer.Treatment ABA-2 showed the highest yield,which was higher than the CK by 7.98%.On the basis of conventional fertilization,the combined application with microbial fertilizer could promote growth and development of tomato,and could significantly improve fruit weight,and Vc,soluble solid and lycopene contents.Furthermore,the microbial fertilizer could remarkably improve soil p H,alkali-hydrolyzale nitrogen,available phosphorus and rapidly available potassium contents.[Conclusions]The application of microbial fertilizer at 80 kg/667 m^(2) has better effects on tomato growth and development and soil status. 展开更多
关键词 Microbial fertilizer Facility tomato Growth characteristics Soil chemical propertiesHome
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部