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Physical and Chemical Properties of Horns Sheaths Particles for the Manufacture of Composite Materials
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作者 Tawe Laynde Zakari Yaou +2 位作者 Karga Tapsia Lionel Konai Noel Danwe Raidandi 《Journal of Materials Science and Chemical Engineering》 2024年第5期1-9,共9页
Salvaged cow horns from slaughterhouses have been transformed into fine particles for a physical characterization that has led us to determine the humidity rate (2.34% ± 0.054%), the actual density situated betwe... Salvaged cow horns from slaughterhouses have been transformed into fine particles for a physical characterization that has led us to determine the humidity rate (2.34% ± 0.054%), the actual density situated between 0.586 g/cm<sup>3</sup> and 0.732 g/cm<sup>3</sup>, the swelling rate (12%), and one chemical characterization that permitted us to determine the rate of dry matters (97.05%), of mineral matters (2.5%), of protein matters (94.52%). From these weak values, it can easily be seen that cow horn case doesn’t absorb much water and improve the mechanical characteristics of the composite;the high rate of protein shows that keratin which is the structural molecule favors its gripping as reinforcing element in the manufacturing of composite materials. 展开更多
关键词 HORNS Fibers Polymer Loads Physical Properties chemical Composition
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Physico-Chemical and Nutritional Properties of a Food Broth Based on Nere (Parkia biglobosa)
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作者 Lassana Bamba Gervais Melaine M’Boh +5 位作者 N’Gbésso Amos Ekissi Kipré Laurent Séri Gnogbo Alexis Bahi Koffi Pierre Valery Niaba Allico Joseph Djaman Grah Avit Maxwell Beugre 《Food and Nutrition Sciences》 CAS 2024年第5期377-389,共13页
Purpose: Diet and eating habits are major risk factors for the health and the development of disease, such as, for example, metabolic disorder leading to cardiovascular pathology and cancer, decreased immunity exposin... Purpose: Diet and eating habits are major risk factors for the health and the development of disease, such as, for example, metabolic disorder leading to cardiovascular pathology and cancer, decreased immunity exposing to infections. This study of the physico-chemical and nutritional properties of a soumara-based food broth was carried out with the aim of promoting the consumption of organic broth made from nere seeds (soumara). That is to alleviate certain metabolic diseases, which is a matter of food safety, and also to limit the risk for the health about the consumption of some cooking stocks on the market. Methods: Several natural ingredients such as nere seeds (soumara), ginger, black pepper, parsley and garlic were used to create a nere-based stock. All these ingredients were freeze-dried and the powder obtained was used to make the broth, regarding their physical and chemical properties. Results: The broth had a good protein content of 17.41 ± 0.367 g/100g, a lipid content of 16.80 ± 0.08 g/100g and a fiber content of 8.66 ± 0.04 g/100g. In terms of nutritional values, the broth showed good levels of calcium 184.21 ± 0.09 mg/100g, potassium 50.04 ± 1.45 mg/100g and iron and zinc. In terms of antioxidant activity, the broth also showed good antioxidant activity. Conclusion: Regarding the properties of our food broth, whose composition is based on natural ingredients, could be recommended for consumption and, its properties, could play an important role in preventing and combating certain metabolic diseases. 展开更多
关键词 Food Broth Nere Physico-chemical Properties NUTRITION Food Safety
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GIS-Based Assessment of Soil Chemical and Physical Properties as a Basis for Land Reclamation in Toshka Area, Aswan, EGYPT
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作者 Ahmed A. M. Awad Mostafa M. A. Al-Soghir 《Open Journal of Geology》 2023年第7期697-719,共23页
The accurate assessment of soil properties is a crucial factor for composing and implementing reclamation plans. The main objective of this study was to evaluate soil chemical and physical properties and calculate the... The accurate assessment of soil properties is a crucial factor for composing and implementing reclamation plans. The main objective of this study was to evaluate soil chemical and physical properties and calculate the chemical and fertility index for assisting land reclamation in Toshka area. The Toshka area is located between latitudes 31°32'N and 31°36'N and longitudes 32°40'E and 32°60'E. GIS was used to select 16 sites. The results revealed the soil has undesirable characteristics. The soil pH ranged from slightly alkaline to moderately alkaline. Furthermore, it was characterized as saline (with a ECe of 4.65 - 11.45 dS⋅m<sup>−1</sup>) and moderately calcareous soil (with CaCO<sub>3</sub> at 11.85% - 17.20%). The soil had a low soil organic matter content which did not exceed 0.18%. The soil was dominated by a sandy loam texture (62.50%) followed by a sandy clay loam texture (18.75%). The bulk density, total soil porosity and saturated hydraulic conductivity values varied with 1.38 - 1.55 Mg⋅cm<sup>−3</sup>, 41.85% - 48.45% and 1.20 - 3.34 cm⋅h<sup>−1</sup>, respectively. The chemical index ranged from low to moderate quality. The correlations between the parameters osculated between negative and positive. Therefore, the soil may be reclaimed if the soil properties are improved and crop selection is optimized for this soil. 展开更多
关键词 Land Reclamation Soil chemical and Physical Properties chemical Quality Index Fertility Quality Index
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Biodiesel Production from Rhynchophorus ferrugineus Larvae Oil: Physichochemical Properties and Acid Composition of Oil as Affected by Oil Extraction Protocol
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作者 Arnaude Folepe Azemo Esther Julius K. Tangka Nsah-ko Tchoumboue 《Journal of Sustainable Bioenergy Systems》 2023年第4期117-130,共14页
Biodiesel, a renewable energy source made from natural oils and fats, can be produced using white raffia larvae as a raw material. These larvae have a high lipid content and a short life cycle, making them suitable fo... Biodiesel, a renewable energy source made from natural oils and fats, can be produced using white raffia larvae as a raw material. These larvae have a high lipid content and a short life cycle, making them suitable for this purpose. One crucial step in biodiesel production is oil extraction, and this study aimed to investigate how the extraction protocol affects the fuel properties of the oil. To study the impact of solvent type, solvent volume, and residence time on oil yield, 200 grams of Rhynchophorus ferrugineus were used in a Soxhlet extractor. The researchers examined the physicochemical properties and fatty acid composition of the crude grease using the European biodiesel standard (EN14214) and gas chromatography methods, respectively. The study found that hexane as a solvent produced the highest oil yield (64.44%) during a four-hour extraction period with a solvent ratio of 300 ml. Furthermore, the hexane-extracted oil had the highest iodine number (3.02 g/100 g) and cetane number (55.69). These values indicate favorable properties for biodiesel production. The Rhynchophorus ferrugineus larvae oil proved to be a rich source of monounsaturated fatty acids (76%), which were found to be significantly affected by the solvent type. Based on quality assessment, Rhynchophorus ferrugineus can be suitable for biodiesel production. In summary, under the given operational conditions, hexane is the most suitable solvent for Rhynchophorus ferrugineus oil extraction for biodiesel production. Further research in optimizing the extraction process can contribute to the efficient utilization of renewable energy sources like white raffia larvae for biodiesel production. 展开更多
关键词 BIODIESEL Extraction Process Fatty Acid Composition Physico-chemical Properties Rhynchophorus ferrugineus Larvae
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Responses of microbial activities and soil physical-chemical properties to the successional process of biological soil crusts in the Gurbantunggut Desert,Xinjiang 被引量:26
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作者 BingChang ZHANG XiaoBing ZHOU YuanMing ZHANG 《Journal of Arid Land》 SCIE CSCD 2015年第1期101-109,共9页
Biological soil crusts (BSCs) are capable of modifying nutrient availability to favor the establishment of biogeochemical cycles. Microbial activities serve as critical roles for both carbon and nutrient transformat... Biological soil crusts (BSCs) are capable of modifying nutrient availability to favor the establishment of biogeochemical cycles. Microbial activities serve as critical roles for both carbon and nutrient transformation in BSCs. However, little is known about microbial activities and physical-chemical properties of BSCs in the Gurbantunggut Desert, Xinjiang, China. In the present research, a sampling line with 1-m wide and 20-m long was set up in each of five typical interdune areas selected randomly in the Gurbantunggut Desert. Within each sampling line, samples of bare sand sheet, algal crusts, lichen crusts and moss crusts were randomly collected at the depth of 0-2 cm. Varia- tions of microalgal biomass, microbial biomass, enzyme activities and soil physical-chemical properties in different succession of BSCs were analyzed. The relationships between microalgal biomass, microbial biomass, enzymatic activities and soil physical-chemical properties were explored by stepwise regression. Our results indicate that micro- algal biomass, microbial biomass and most of enzyme activities increased as the BSCs developed and their highest values occurred in lichen or moss crusts. Except for total K, the contents of most soil nutrients (organic C, total N, total P, available N, available P and available K) were the lowest in the bare sand sheet and significantly increased with the BSCs development, reaching their highest values in moss crusts. However, pH values significantly decreased as the BSCs developed. Significant and positive correlations were observed between chlorophyll a and microbial biomass C. Total P and N were positively associated with chlorophyll a and microbial biomass C, whereas there was a significant and negative correlation between microbial biomass and available P. The growth of cyanobacteria and microorganism contributed C and N in the soil, which offered substrates for enzyme activities thus increasing enzyme activities. Probably, improvement in enzyme activities increased soil fertility and promoted the growth of cyanobacteria, eukary- otic algae and heterotrophic microorganism, with the accelerating succession of BSCs. The present research found that microalgal-microbial biomass and enzyme activities played important roles on the contents of nutrients in the successional stages of BSCs and helped us to understand developmental mechanism in the succession of BSCs. 展开更多
关键词 chlorophyll a microbial biomass C soil enzyme physical-chemical properties biological soil crusts
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QSPR between Physical-Chemical Properties and Molecule Parameters of Alkanes
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作者 XU Qing-qing LI Liang-chao HU Li-ya 《Wuhan University Journal of Natural Sciences》 EI CAS 2005年第5期897-903,共7页
A set of molecule parameters, namely, N, N′, p, q, n, were used to express the structures of alkanes. A correlative model was established between certain physical-chemical properties and molecular parameters of alkan... A set of molecule parameters, namely, N, N′, p, q, n, were used to express the structures of alkanes. A correlative model was established between certain physical-chemical properties and molecular parameters of alkanes by regression method. Eight physical-chemical properties, such as evaporation heat (△vHm^20), density(D^20 ), capacity (C^20), surface tension (δ^20), boiling point (Tb), critical temperature(Tc), critical pressure(Pc) and critical volume(Vc), of fifty-six C3-C16 alkanes were calculated directly from the model in this paper. The calculated values are in good accordance with the literature ones reported for alkanes, and the correlation coefficients (R) equal or exceed 0.99 . The research results indicate that the principle of the method is simple and clear, the method is practical, the correlativity is excellent, and the predicted data are credible. 展开更多
关键词 ALKANE molecular parameters physical-chemical properties
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Compatible stability study of Xing NaoJing injection based on physical-chemical properties analysis
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作者 Dong-Li Qi Chun-Xia Liang +6 位作者 Yue-Lin Zhang Yan-Quan Gao Yue Xing Hong-Li Yan Bing Zhang Jia-Rong Xie Zhi-Dong Liu 《TMR Modern Herbal Medicine》 2019年第4期173-182,共10页
目的:临床脑部疾病救治紧急,醒脑静注射液常与其他注射剂药物联合用药。由于注射剂之间在体内仍可能发生相互作用,因而导致粒径、渗透压、pH值的变化和成分稳定性降低,这是引发各种不良反应的重要因素之一。基于上述情况,本研究考察醒... 目的:临床脑部疾病救治紧急,醒脑静注射液常与其他注射剂药物联合用药。由于注射剂之间在体内仍可能发生相互作用,因而导致粒径、渗透压、pH值的变化和成分稳定性降低,这是引发各种不良反应的重要因素之一。基于上述情况,本研究考察醒脑静注射液与配液溶媒、临床13种常联用注射剂的体外配伍溶液的性质和成分变化,从体外配伍的稳定性角度推测各种药物之间在体内可能发生的相互作用,排查引起不良反应的安全隐患,以指导醒脑静注射液的安全合理用药。方法:根据临床应用和药品说明书,将醒脑静注射液分别与临床常用13种注射剂按比例加入250mL5%葡萄糖注射液中,于室温下放置6小时,分别在0、1、2、4和6小时检测配伍溶液的澄清度、粒径、pH、渗透摩尔浓度以及樟脑、右旋龙脑和麝香酮的含量。结果:研究结果显示,醒脑静注射液分别与前列地尔注射液、丹红注射液配合时,配伍溶液的粒径发生变化,其中麝香酮含量降低,表明一些注射剂配伍后理化性质确实存在一些问题,应引起重视。结论:该研究建议在静脉给药期间,醒脑静注射液与其他注射剂联合配液时应谨慎进行。 展开更多
关键词 醒脑静注射液 药液配伍 理化性质分析 不良反应 麝香酮 右旋龙脑
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Estimating heat capacities of liquid organic compounds based on elements and chemical bonds contribution 被引量:1
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作者 Li Xia Yule Pan +4 位作者 Tingting Zhao Xiaoyan Sun Shaohui Tao Yushi Chen Shuguang Xiang 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2023年第5期30-38,共9页
Molecular property depends on the property, the number of the elements, and the interaction between elements(such as chemical bonds). Based on the above-mentioned idea, two methods to estimate the isobaric heat capaci... Molecular property depends on the property, the number of the elements, and the interaction between elements(such as chemical bonds). Based on the above-mentioned idea, two methods to estimate the isobaric heat capacity of liquids organic compounds were developed. Ten elements groups and 32 chemical bond groups were defined by considering the structure of organic compounds. The group contribution values and correlation parameters were regressed by the ridge regression method with the experiment data of 1137 compounds. The heat capacity can be calculated by summating the contributions of the elements and chemical bond groups. The two methods were compared with existing group contribution methods, such as Chickos, Zabransky-Ruzicka, and Zdenka Kolska. The results show that those new estimation methods' overall average relative deviations were 5.81% and 5.71%, which were lower than the other three methods. Those methods were more straightforward in compound splitting.Those new methods can be used to estimate the liquid heat capacity of silicon-containing compounds,which the other three methods cannot estimate. The new methods are more accessible, broader, and more accurate. Therefore, this research has important scientific significance and vast application prospects. 展开更多
关键词 Thermodynamic Properties MODEL PREDICTION Elements and chemical Bonds
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Effect of fire severity on physical and biochemical soil properties in Zagros oak(Quercus brantii Lindl.)forests in Iran 被引量:15
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作者 M.Heydari A.Rostamy +1 位作者 F.Najafi D.C.Dey 《Journal of Forestry Research》 SCIE CAS CSCD 2017年第1期95-104,共10页
Fire affects the physical and chemical properties and soil biological activity of natural ecosystems. This study was conducted in the Miyan Tang region, Ilam Province in western Iran. The study site was 110 hectares, ... Fire affects the physical and chemical properties and soil biological activity of natural ecosystems. This study was conducted in the Miyan Tang region, Ilam Province in western Iran. The study site was 110 hectares, where we sampled soils in areas that were classified by fire severity: low (LS), high (HS) and medium severity (MS), and unburned (UB), which served as the control. In each severity class, 25 transect points were randomly selected for measurement. Around each transect plot center, 3 soil samples were selected randomly and soils collected from the 0 to 20 cm depth were combined into a composite sample that was used in laboratory analysis to represent conditions at that point. Plots in the UB and LS fire classes had similar soil conditions and had higher values of factors such as saturated moisture, organic carbon, carbon dioxide, and silt and clay content. In contrast, plots in the HS and MS fire severity classes were clustered in the positive direction along the first axis that represented gradients in soil acidity, electrical conductivity, cation exchange capacity, accessible phosphorus, accessible potassium, bulk density, and sand. Soil attributes were similar in areas of HS and MS fire severity classes, whereas soil conditions in the LS class and UB controls were most similar. Fire in the LS areas either did not significantly alter the physicalchemical soil properties and microbial basal respiration, or soils were able to recover quickly after being burned. 展开更多
关键词 Fire severity OAK Soil respiration Physical and chemical soil properties
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Spatial heterogeneity of soil chemical properties between Haloxylon persicum and Haloxylon ammodendron populations 被引量:11
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作者 Li, CongJuan Li, Yan +2 位作者 Ma, Jian Fan, LianLian Wang, QinXue 《Journal of Arid Land》 SCIE 2010年第4期257-265,共9页
Spatial heterogeneity is a ubiquitous feature in natural ecosystems, especially in arid regions. Different species and their discontinuous distribution, accompanied by varied topographic characteristics, result in soi... Spatial heterogeneity is a ubiquitous feature in natural ecosystems, especially in arid regions. Different species and their discontinuous distribution, accompanied by varied topographic characteristics, result in soil resources distributed differently in different locations, and present significant spatial heterogeneity in desert ecosystems. In this study, conventional and geostatistical methods were used to identify the heterogeneity of soil chemical properties in two desert populations, Haloxylon persicum Bunge ex Boss., which dominates on the slopes and tops of sand dunes and Haloxylon ammodendron (C. A. Mey.) Bunge, which inhabits interdunes in the Gurbantunggut Desert of Xinjiang, China. The results showed that soil pH, electrical conductivity (EC), soil organic carbon (SOC), available nitrogen (AN) and available phosphorus (AP) were significantly higher in H. ammodendron populations than that in H. persicum. The coefficient of variation (CV) indicated that (1) most parameters presented a moderate degree of variability (10% 【 CV 【 100%) except pH in both plots, (2) the variability of soil pH, EC and AP in H. ammodendron populations was higher than that in H. persicum populations, and (3) SOC and AN in H. ammodendron populations were lower than that in H. persicum populations. Geostatistical analysis revealed a strong spatial dependence (C0/(C0+C) 【 25%) within the distance of ranges for all tested parameters in both plots. The Kriging-interpolated figures showed that the soil spatial distribution was correlated with the vegetation distribution, individual size of plants, and the topographic features, especially with the plants nearest to sampling points and the topographic features. In each plot, soil EC, SOC, AN and AP presented similar distributions, and fertile islands and salt islands occurred in both plots but did not affect every individual plant, since the sampling distance was larger than the size of such fertile islands. The results of topographic effects on soil heterogeneity suggested significant differences between the interdunes and dune-tops. Different topographic characteristics (physical factors) between plots result in the differences in SOC, AN and AP, while the heterogeneity of soil pH and EC arise from plant species and their distribution (biotic factor). Such biotic and physical factors did not occur in isolation, but worked together on soil heterogeneity, and played important parts in improving the soil properties. Hence these factors were ecologically valuable in the highly resource-stressed arid study area. 展开更多
关键词 fertile island GEOSTATISTICS plant population soil chemical properties spatial heterogeneity
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Effects of reclaimed water irrigation and nitrogen fertilization on the chemical properties and microbial community of soil 被引量:10
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作者 GUO Wei Mathias N Andersen +4 位作者 QI Xue-bin LI Ping LI Zhong-yang FAN Xiang-yang ZHOU Yuan 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第3期679-690,共12页
The ecological effect of reclaimed water irrigation and fertilizer application on the soil environment is receiving more attention.Soil microbial activity and nitrogen(N)levels are important indicators of the effect... The ecological effect of reclaimed water irrigation and fertilizer application on the soil environment is receiving more attention.Soil microbial activity and nitrogen(N)levels are important indicators of the effect of reclaimed water irrigation on environment.This study evaluated soil physicochemical properties and microbial community structure in soils irrigated with reclaimed water and receiving varied amounts of N fertilizer.The results indicated that the reclaimed water irrigation increased soil electrical conductivity(EC)and soil water content(SWC).The N treatment has highly significant effect on the ACE,Chao,Shannon(H)and Coverage indices.Based on a 16S ribosomal RNA(16S rRNA)sequence analysis,the Proteobacteria,Gemmatimonadetes and Bacteroidetes were more abundant in soil irrigated with reclaimed water than in soil irrigated with clean water.Stronger clustering of microbial communities using either clean or reclaimed water for irrigation indicated that the type of irrigation water may have a greater influence on the structure of soil microbial community than N fertilizer treatment.Based on a canonical correspondence analysis(CCA)between the species of soil microbes and the chemical properties of the soil,which indicated that nitrate N(NO3-–-N)and total phosphorus(TP)had significant impact on abundance of Verrucomicrobia and Gemmatimonadetes,meanwhile the p H and organic matter(OM)had impact on abundance of Firmicutes and Actinobacteria significantly.It was beneficial to the improvement of soil bacterial activity and fertility under 120 mg kg^-1 N with reclaimed water irrigation. 展开更多
关键词 reclaimed water NITROGEN soil chemical properties 16S rRNA sequence soil microbe community
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Surface chemical properties and pore structure of the activated coke and their effects on the denitrification activity of selective catalytic reduction 被引量:8
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作者 Wei Xie Daming Liang +2 位作者 Lanting Li Sijian Qu Wu Tao 《International Journal of Coal Science & Technology》 EI 2019年第4期595-602,共8页
In order to study the mechanism of selective catalytic reduction of activated coke to remove NO in low-temperature flue gas and provide some theoretical basis for the development of related technologies.The pore sized... In order to study the mechanism of selective catalytic reduction of activated coke to remove NO in low-temperature flue gas and provide some theoretical basis for the development of related technologies.The pore sizedistribution and BET specific surface area of AC were obtain by data analyzing of N2 adsorption/desorption isotherm at -196 ℃ and carbon matrix and surface chemistry of virgin activated coke samples were characterized by acid-base titration and XPS.The process of selective catalytic reduction of activated coke (AC) samples with NH3 as reducing agent was studied in a fixed bed reactor at 150 ℃.The result shows that pore size distribution or BET specific surface of activated cokes have not correlation with denitrification activity for SCR.The NO reduction activities of the activated cokes are apparent to increase with their surface oxygen element content and total amount of acidic sites.Obviously there is good linear relationship between the NH3 adsorption capacity and activity for SCR with linear correlation coefficient 0.943.It has been presented that adsorption of NH3 on acidic functional groups in the edge of large polycyclic aromatic ring of activated coke is key rate controlling step in the SCR heterogeneous catalytic reaction. 展开更多
关键词 ACTIVATED COKE SCR PORE structure Surface chemical properties DENITRIFICATION
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Effects of bioleaching on the mechanical and chemical properties of waste rocks 被引量:2
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作者 Sheng-hua Yin Ai-xiang Wu +1 位作者 Shao-yong Wang Chun-ming Ai 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2012年第1期1-8,共8页
Bioleaching processes cause dramatic changes in the mechanical and chemical properties of waste rocks, and play an important role in metal recovery and dump stability. This study focused on the characteristics of wast... Bioleaching processes cause dramatic changes in the mechanical and chemical properties of waste rocks, and play an important role in metal recovery and dump stability. This study focused on the characteristics of waste rocks subjected to bioleaching. A series of ex- periments were conducted to investigate the evolution of rock properties during the bioleaching process. Mechanical behaviors of the leached waste rocks, such as failure patterns, normal stress, shear strength, and cohesion were determined through mechanical tests. The results of SEM imaging show considerable differences in the surface morphology of leached rocks located at different parts of the dump. The minera- logical content of the leached rocks reflects the extent of dissolution and precipitation during bioleaching. The dump porosity and rock size change under the effect of dissolution, precipitation, and clay transportation. The particle size of the leached rocks decreased due to the loss of rock integrity and the conversion of dry precipitation into fine particles. 展开更多
关键词 BIOLEACHING mechanical properties chemical properties waste rocks
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Overview of Physical and Chemical, Operational Properties of Nitrous Oxide Used as a Propellant for Low-thrust Rocket Engines 被引量:2
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作者 A.A.Boryaev 《火炸药学报》 EI CAS CSCD 北大核心 2019年第1期17-31,I0001,共16页
The results of a system analysis of the efficiency of nitrous oxide(N_2O) as a propellant component for small space vehicles(SSV) were presented. A criterion for mass efficiency of the SSV propulsion system(PS) is det... The results of a system analysis of the efficiency of nitrous oxide(N_2O) as a propellant component for small space vehicles(SSV) were presented. A criterion for mass efficiency of the SSV propulsion system(PS) is determined. The current global state-of-the-art of SSV PSs is shown. The application field of nitrous oxide in SSV PSs is calculated and mass efficiency of N_2O application is quantitatively determined. An overview of physical and chemical as well as operational properties of nitrous oxide as a promising, non-toxic component of rocket propellant is provided. Main physical and chemical constants of gaseous and liquid nitrous oxide; chemical properties of N_2O, thermal stability of N_2O, catalytic decomposition of N_2O, a mechanism of decomposition of N_2O, catalysts for decomposition of N_2O, ballast additives to N_2O, application of nitrous oxide, nitrous oxide as a rocket propellant, production of nitrous oxide, toxicity of nitrous oxide, fire hazard of N_2O, requirements to equipment when handling N_2O; storage and transportation of N_2O are considered. It is demonstrated that nitrous oxide is a chemical compound meeting the requirements to rocket propellants, including those related to the environmental friendliness of propellants. With 75 references. 展开更多
关键词 ROCKET PROPELLANT nitrous oxide PHYSICAL and chemical properties
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Deformation fixation, mechanical properties and chemical analysis of compressed Populus cathayana wood pretreated by glycerin 被引量:3
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作者 LI Yan CAO Jin-zhen JIN Xiao-juan 《Forestry Studies in China》 CAS 2010年第4期213-217,共5页
In order to find an effective and environmentally friendly method to fix compressive deformation of wood, we determined or measured the recovery ratio, surface hardness, modulus of elasticity (MOE) and the modulus o... In order to find an effective and environmentally friendly method to fix compressive deformation of wood, we determined or measured the recovery ratio, surface hardness, modulus of elasticity (MOE) and the modulus of rupture (MOR) of poplar (Populus cathayana Rehd.) samples pretreated by 40-60% glycerin solutions and then compressed at 160℃ for 10-120 min. We analyzed the data statistically by using two-factor analysis of variance. The chemical compositions of thermal treated wood were also analyzed and compared with untreated control samples. The results showed that the compressive deformation of wood can be properly fixed by glycerin pretreatment. The recovery ratio of compressed wood decreased with prolonging compression time and increasing concent-ration of the glycerin solution. However, the mechanical properties of compressed wood decreased after a long time of compression. The optimal fixation of compressive deformation is to pretreat the wood by a solution of 50% glycerin and compression at 160℃ for 60 min. The analysis of chemical composition showed that glycerin displayed an accelerating effect on degradation of hemicelluloses and lignin during heat-treatment, which explains the main reason of the effect of acceleration of glycerin on deformation fixation of compressed wood. 展开更多
关键词 compressed wood GLYCERIN recovery ratio mechanical properties chemical composition
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Effects of Chlorination on Soil Chemical Properties and Nitrogen Uptake for Tomato Drip Irrigated with Secondary Sewage Effluent 被引量:2
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作者 LI Yan-feng LI Jiu-sheng ZHANG Hang 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第9期2049-2060,共12页
Chlorination is usually an economical method for treating clogging in drip emitters during sewage application. Appropriate assessment of the responses of soil and crop is essential for determining an optimal chlorinat... Chlorination is usually an economical method for treating clogging in drip emitters during sewage application. Appropriate assessment of the responses of soil and crop is essential for determining an optimal chlorination scheme. During 2008 to 2009, field experiments were conducted in a solar-heated greenhouse for tomato drip irrigated with secondary sewage effluent, to investigate the influences of chlorine injection intervals and levels on soil chemical properties and nitrogen uptake. Injection intervals ranging from two to eight weeks and injection concentrations ranging from 2 to 50 mg L-1 were used. A salinity factor and a nutrient factor were extracted from the pool of the nine soil chemical constituents using factor analysis method. The results demonstrated that chlorination practices increased the residual Cl in the soil, resulting in an increased salinity factor, especially for the frequent chlorination at a high injection concentration. Chlorination weakened the accumulation of nutrients factor in the upper soil layer. Nitrogen uptake of the tomato plants also was inhibited by the increased salinity in the upper soil layer caused by high chlorination levels. In order to reduce the unfavorable effect on soil chemical properties and nitrogen uptake, chlorination scheme with concentrations of lower than 20 mg L-1 was recommended. 展开更多
关键词 CHLORINATION drip irrigation soil chemical properties nitrogen uptake sewage effluent
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Effect of land-use changes on chemical and physical properties of soil in western Iran(Zagros oak forests) 被引量:4
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作者 Kyumars Mohmmadi Samani Narges Pordel +1 位作者 Vahid Hosseini Zahed Shakeri 《Journal of Forestry Research》 SCIE CAS CSCD 2020年第2期637-647,共11页
The consequence of land-use change from forest to agriculture and other uses has become one of the world’s greatest concerns.The soil,one of the most important components of forests and containing all the required pl... The consequence of land-use change from forest to agriculture and other uses has become one of the world’s greatest concerns.The soil,one of the most important components of forests and containing all the required plant nutrients as soluble ions,is highly impacted by these changes.Because vast areas of the Zagros forests in western Iran have changed in use during the last few decades,the present study investigated the effects of landuse changes of forest area to agriculture,orchard,and agroforestry on soil chemical and physical properties.Soil was sampled at four land-use areas:less-disturbed forest areas(control)and agricultural,orchard,and agroforestry areas.Among each of the two forest-use areas(agroforestry and orchard),we selected five trees with similar-sized crowns and sampled under each tree crown at 0-15 and>15-30 cm depths.Five soil samples also were taken in agriculture area at each depth.The findings indicated that during land-use changes,soil sand particles decreased,and clay and silt particles of soil increased,resulting in a fine soil texture.Moreover,the amount of nitrogen(N),phosphorus(P),organic carbon(OC),and electrical conductivity(EC)of soil decreased at both depths due to the decrease in organic matter.Soil pH and magnesium(Mg)level rose during land-use change at both depths except at agricultural sites.Soil potassium(K)content decreased during agricultural use due to the elimination of tree cover.The level of K decreased only at the depth of 0-15 cm because of K dependency on parent materials.Generally,most soil nutrients were affected by plant removal in the conversion.Forest and agricultural soil are distinguishable by their properties,while land-uses such as agroforestry-orchard separated from the others.Soil nutrients were severely affected by the decrease and elimination of tree cover,plowing,and continuous harvesting,resulting in a decline in soil quality and fertility. 展开更多
关键词 chemical soil properties Land-use change AGROFORESTRY AGRICULTURE Zagros Oak forest
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Preparation and Electrochemical Properties of 3-Pyridinyl-6-aryl-1,2,4-triazolo [3,4-b][1, 3,4]thiadiazoles 被引量:3
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作者 TaiXIAO HuiXueLI +1 位作者 ChunXiaTAN MiaoCHEN 《Chinese Chemical Letters》 SCIE CAS CSCD 2005年第3期335-337,共3页
关键词 PREPARATION 3-pyridinyl-6-aryl-1 2 4-triazolo[3 4-b][1. 3 4]thiadiazoles electro- chemical properties.
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Effect of Carrot and Pumpkin Pulps Adding on Chemical, Rheological, Nutritional and Organoleptic Properties of Ice Cream 被引量:2
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作者 Mohamed F. Y. Hassan Hassan Barakat 《Food and Nutrition Sciences》 2018年第8期969-982,共14页
Ice cream manufactured using a substantial amount of pumpkin pulp (PP) and carrot pulp (CP) has a high organoleptic acceptability. PP and CP were added to typical control ice cream (TC) up to 20%. Through adding PP an... Ice cream manufactured using a substantial amount of pumpkin pulp (PP) and carrot pulp (CP) has a high organoleptic acceptability. PP and CP were added to typical control ice cream (TC) up to 20%. Through adding PP and CP, natural flavor, unique color, and health-promoting constituents were presented. The resultant ice cream was subjected to chemical, rheological, nutritional, and organoleptic properties investigation. Results revealed that dry matter especially SNF in both PPand CP-ice creams were increased significantly. Accordingly, ash, fiber, and available carbohydrates contents were significantly increased whereas opposite result was recorded for crude protein as a result of PP and CP substitution. The ice cream containing high PP and CP contents had higher melting resistance and lower overrun %. Health beneficial phytochemicals such as carotenoids, flavonoids (TF), flavonols (TFL), and vit. C were commonly detected in PP and CP-ice creams, reflecting the attributes of PP and CP ingredients. PP and CP-ice cream had the valuable content of TPC, vit. C and antioxidant capacity. However, only ice cream made with 15% of PP and CP was highly accepted than others. Therefore, it is possible to use a substantial amount from PP and CP to produce ice cream up to 15% with retained much of natural color, unique vit. C, TPC, carotenoids, TF, TFL contents as well as valuable antioxidant capacity. Health beneficial compounds and organoleptic attributes of prepared ice cream formulas were encouragingly the commercial possibility of using PP and CP for scaling up further. 展开更多
关键词 Ice CREAM PUMPKIN CARROT chemical Physical and NUTRITIONAL Properties
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Recycling organic waste in managed tropical forest ecosystems:effects of arboreal litter types on soil chemical properties in Abeokuta, southwestern Nigeria 被引量:1
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作者 J.O.Azeez 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第5期1903-1911,共9页
The aim of this study is to determine the influence of tree litters on soil nutrients in a managed forest in southwestern Nigeria.Mono species tree clusters consisted of indigenous species:Gmelina arborea,Tectona gran... The aim of this study is to determine the influence of tree litters on soil nutrients in a managed forest in southwestern Nigeria.Mono species tree clusters consisted of indigenous species:Gmelina arborea,Tectona grandis,Leucaena leucocephala,Bambusa vulgaris,Treculia africana,Anogeissus leiocarpus were selected and analyzed for their litter and soil chemical properties at 0–5 and 15–30 cm.T.africana and T.grandis litters have the highest nutrients,while L.leucocephala and A.leiocarpus are the lowest.Soils under G.arborea,T.africana,and A.leiocarpus are more acidic due to lower calcium and magnesium contents but have higher manganese and sulphur levels.Tree litters improved soil nitrogen,phosphorous,and micro-nutrients but depleted potassium.Litter lignin and carbon appeared to hinder the release of some nutrients.Nitrogen,potassium and copper are concentrated in the topsoil while others nutrients are not differentiated with soil depth.There is a positive correlation between litter chemistry and soil chemical properties.It was concluded that tree litter chemistry differs according to species but determines soil reaction and nutrient content.The magnitude of the effect on soil properties is related to the quality of the organic litters. 展开更多
关键词 LITTER chemistry NUTRIENT stocks Soil chemical properties TROPICAL trees Biosystems
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