[Objective] This study aimed to study the effects of different picking time and storage environment on fruit quality of a pear cultivar Xinlin No.7 and the relationship between storage environment and fruit quality, s...[Objective] This study aimed to study the effects of different picking time and storage environment on fruit quality of a pear cultivar Xinlin No.7 and the relationship between storage environment and fruit quality, so as to provide a theoretical basis for storage and preservation of Xinli No.7. [Method] The fruits of Xinli NO.7 were picked up in August (optimal) and September respectively and then stored in room, cellar and freezer, respectively. The dynamics in temperature, humidity, CO2 concentration, fruit weight loss rate, pericarp chlorophyll content and fruit interior quality were determined. [Result] The environment differed significantly among different storage methods. In room and cellar, the temperature showed a downward trend, and the humidity decreased after early-mid October. The CO2 concentration changed steadily, and increased rapidly in cellar after December. In freezer, the temperature and humidity changed steadily, and the CO2 concentration increased after October. The changes in quality of the fruits harvested in August and September were similar. There was a certain correlation between storage environment and fruit quality of Xinli No.7. In room and cellar, the variation trends of tem- perature and humidity were consistent with those of chlorophyll content, fruit hardness and titratable acid content with positive correlations, but were opposite from those of fruit weight loss rate, soluble solids content and soluble sugar content with negative correlations. In freezer, the CO2 concentration was closely related to the changes in fruit quality. Its variation trend was consistent with those of fruit weight loss rate and soluble solids content, but was opposite from those of pericarp chlorophyll content, fruit firmness, soluble sugar content and titratable acid content. The differences in some of the traits reached significant levels (P〈0.05, P〈0.01). [Conclusion] With the extension of storage time, the temperature, humidity and CO2 concentration changed according to different patterns among different storage methods. The changes in fruit quality of Xinli NO.7 were related to the storage environment, especially to the temperature, to a certain extent.展开更多
The relative permeability curve has been measured with simulation oil (refined oil) and gas (nitrogen or air) at room temperature and a lowpressure, both of which are very important parameters for depicting the flow ...The relative permeability curve has been measured with simulation oil (refined oil) and gas (nitrogen or air) at room temperature and a lowpressure, both of which are very important parameters for depicting the flow of fluid through porous media in a hydrocarbon reservoir. This basic measurement is often applied in exploitation evaluation, but the underground conditions with high temperature and pressure, and the phase equilibrium of oil and gas, are not taken into consideration when the relative permeability curve is tested. There is an important theoretical and practical sense in testing the diphase relative permeability curve of the equilibrium of oil and gas under the conditions of high temperature and pressure. The test method for the relative permeability curve is proposed in this paper. The relative permeability of the equilibrium of oil and gas and the standard one are tested in two fluids, and the differences between these two methods are stated. The research results can be applied to the simulation and prediction of CVD in long cores and then the phenomenon can better explain that the recovery of condensate gas rich in condensate oil is higher than that of CVD test in PVT. Meanwhile, the research shows that the relative permeability curve of equilibrium oil and gas is sensitive to the rate of exploitation, and the viewpoint proves that an improved gas recovery rate can properly increase the recovery of condensate oil.展开更多
Two reagents including salicylhydroxamic acid(SHA) and tributyl phosphate(TBP) were tested as collectors either separately or together for electro-flotation of fine cassiterite(<10 μm).Subsequently,the flotation m...Two reagents including salicylhydroxamic acid(SHA) and tributyl phosphate(TBP) were tested as collectors either separately or together for electro-flotation of fine cassiterite(<10 μm).Subsequently,the flotation mechanism of the fine cassiterite was investigated by adsorbance determination,electrophoretic mobility measurements and Fourier transform infra-red(FT-IR) spectrum checking.Results of the flotation experiments show that with SHA as a collector,the collecting performance is remarkably impacted by the pulp pH value as the floatability of cassiterite varies sharply when the pH changes,and flotation with SHA gives distinct maximum at about pH 6.5.Additionally,the floatability of cassiterite is determined by using SHA and TBP as collectors.The range of pulp pH for good floatability is broadened in the presence of TBP as auxiliary collector,and the utilization of TBP improves the recovery of cassiterite modestly.Moreover,the optimum pH value for cassiterite flotation is associated with adsorbance.The results of FT-IR spectrum and the electrophoretic mobility measurements indicate that the adsorption interaction between the collectors and the cassiterite is dominantly a kind of chemical bonding in the form of one or two cycle chelate rings due to the coordination of carbonyl group,hydroxamate and P=O group to the metal tin atoms,where the oxygen atoms contained in carbonyl group,hydroxamate and P=O group of the polar groups have the stereo conditions to form five-membered rings.In addition,the adsorption interactions of SHA and TBP on the surfaces of cassiterite are also dominated by means of hydrogen bonds.展开更多
The interaction mechanism of collector DLZ in the flotation process of chalcopyrite and pyrite was investigated through flotation experiments,zeta potential measurements and infrared spectrum analysis.Flotation test r...The interaction mechanism of collector DLZ in the flotation process of chalcopyrite and pyrite was investigated through flotation experiments,zeta potential measurements and infrared spectrum analysis.Flotation test results indicate that DLZ is the selective collector of chalcopyrite.Especially,the recovery of chalcopyrite is higher than 90% in neutral and weak alkaline systems,while the recovery of pyrite is less than 10%.When using CaO as pH regulator,at pH=7-11,the floatability of pyrite is depressed and the recovery is less than 5%.Zeta potential analysis shows that the zeta potential of chalcopyrite decreases more obviously than that of pyrite after interaction with DLZ,confirming that collector DLZ shows selectivity to chalcopyrite and pyrite.And FTIR results reveal that the flotation selectivity of collector DLZ is due to chemical absorption onto chalcopyrite surface and only physical absorption onto pyrite surface.展开更多
The floatability of diaspore and three kinds of silicate minerals,including kaolinite,illite and pyrophyllite,by a cationic Gemini surfactant as collector and starch as depressant was investigated as function of reage...The floatability of diaspore and three kinds of silicate minerals,including kaolinite,illite and pyrophyllite,by a cationic Gemini surfactant as collector and starch as depressant was investigated as function of reagents concentration and pulp pH.Further studies of artificially mixed minerals and bauxite ore were also detailedly conducted.At last,the pre-desliming reverse flotation separation process was adopted.It can be concluded that the combinational use of a Gemini cationic collector and the starch depressant is effective.The concentrates with Al2O3 to SiO2 mass ratio of 9.66 and the recovery of Al2O3 of 71.73% are obtained from natural bauxite ore(A/S=5.70) at pH value of around 10.展开更多
The flotation of diaspore and kaolinite by one of a series of tertiary amines(DRN,DEN,DPN and DBN) was investigated.The tertiary amines show better floating recovery for kaolinite compared to diaspore.The maximum re...The flotation of diaspore and kaolinite by one of a series of tertiary amines(DRN,DEN,DPN and DBN) was investigated.The tertiary amines show better floating recovery for kaolinite compared to diaspore.The maximum recovery D-value is 45%over a pH range from 3 to 8.FT-IR spectra confirm the presence of hydroxyl groups on the surface of kaolinite and diaspore.Zeta potential measurements show that the mineral surfaces are negatively charged over a wide pH range.Ionization of hydroxyl groups mainly accounts for the surface charging mechanism.The adsorption of tertiary amines onto the mineral surface is due mainly to electrostatic effects and the difference in electrostatic effect between a collector and the two minerals can explain the flotation separation.Inductive electronic and steric effects from the substituent groups result in different collecting powers for the four tertiary amines.展开更多
The flotation separation of scheelite from fluorite and calcite using dodecyltrimethylammonium chloride (DTAC), dodecyldimethylbenzylammonium chloride (DDBAC), or didodecyldimethylammonium chloride (DDDAC) as th...The flotation separation of scheelite from fluorite and calcite using dodecyltrimethylammonium chloride (DTAC), dodecyldimethylbenzylammonium chloride (DDBAC), or didodecyldimethylammonium chloride (DDDAC) as the collector has been investigated. The results show that the selectivity of these collectors for these three calcareous minerals falls in the order: DDDAC 〉 DDBAC 〉 DTAC. A significantly different flotation response of scheelite compared to the other two calcareous minerals was observed over the pH range from 7 to 8 for DDDAC as the collector. A concentrate containing 41.40% W03 could be produced from a feed mixture containing 23.22% WO3 at the DDDAC concentration of 4.0× 10^-4 mol/L. The WO3 recovery was 92.92% under these conditions. The results of zeta potential measurements suggest that electrostatic interactions are the main forces between DDDAC and the minerals. When the concentration of DDDAC is from 2× 10^-4 to 4×10-3 mol/L large differences in adsorption density, and adsorption kinetics, of DDDAC onto scheelite, calcite, and fluorite provide desirable conditions for achieving high selectivity.展开更多
This paper describes the experience of Jilin oilfield trials for Microbial Enhanced Oil Recovery (MEOR). A new technique to identify microbes with DNA for MEOR has been established, and useful microbes selected f...This paper describes the experience of Jilin oilfield trials for Microbial Enhanced Oil Recovery (MEOR). A new technique to identify microbes with DNA for MEOR has been established, and useful microbes selected for use in field trials. Behaviors of bacteria activated in the reservoir, oil recovery and water cut, and the viscosity of crude oil produced through huff & puff testing and flooding with molasses-injection tests, have been investigated in situ. CJF-002, which produces biopolysaccharide, is the best among the microbes used for field trials, as it can use molasses as nutrient and produce a small quantity of CO2 and a mass of water-insoluble biopolymer. The metabolic behavior in the reservoir showed that CJF-002 had a good potentiality for MEOR.展开更多
Glacier variations in the Tibetan Plateau and surrounding mountain ranges in China affect the livelihood of over one billion people who depend on water from the Yellow, Yangtze, Brahmaputra, Ganges and Indus rivers or...Glacier variations in the Tibetan Plateau and surrounding mountain ranges in China affect the livelihood of over one billion people who depend on water from the Yellow, Yangtze, Brahmaputra, Ganges and Indus rivers originating in these areas. Based on the results of the present study and published literature, we found that the glaciers shrank :5.7% in area from 1963 to 20:0 with an annual area change of -0.33%. The shrinkage generally decreased from peripheral mountain ranges to the interior of Tibet. The linear trends of annual air temperature and precipitation at 147 stations were 0.36℃(10a)^-1 and 8.96 mm (10a)^-1 respectively from 1961 to 2010. The shrinkage of glaciers was well correlated with the rising temperature and the spatial patterns of the shrinkage were influenced by other factors superimposed on the rising temperature such as glacier size, type, elevation, debris cover and precipitation.展开更多
Common denominator and one of the goals in the "storage" of many, even different, commodities (agricultural, etc.) is their protection against invasion by biological pests; protection of objects of cultural herita...Common denominator and one of the goals in the "storage" of many, even different, commodities (agricultural, etc.) is their protection against invasion by biological pests; protection of objects of cultural heritage deposited in museums, galleries, archives and other institutions of a similar type is one of the specific case. The present article is an overview of basic (potential) biological pests of some "storage" commodities (with emphasis on the protection of objects of cultural heritage) as well as methods used for their detection. In the final section, a modular system of the ongoing assessment of the environmental characteristics of depositaries and exhibitions (including "biological") is briefly presented; its advantage is the possibility of on-line monitoring of the evaluated parameters (temperature, humidity, lighting, etc.) including the detection of presence of crawling and airborne insects.展开更多
Understanding the diversity and taxonomy of Iran's lichens has never been more important than it is today, and this is undoubtedly the most exciting subject to be studying in the cryptogamic flora of the country. The...Understanding the diversity and taxonomy of Iran's lichens has never been more important than it is today, and this is undoubtedly the most exciting subject to be studying in the cryptogamic flora of the country. The present paper is a part of a more extensive lichenological investigation based on collections made since 2004 in the reserved region Darkesh in the Aladagh mountains. Among a collection of lichens from four localities in the site, in Northern Khorasan province, (NE) IRAN, 13 species were identified, of which five were known outside the province. Lecanora umbrina (Ach.) Massal. is first found in this locality.展开更多
The time has come to recognize the extreme importance of the archaeological sites in Jordan. They provide a wealth evidence and precise information regarding ancient civilizations and cultures. The safeguarding of thi...The time has come to recognize the extreme importance of the archaeological sites in Jordan. They provide a wealth evidence and precise information regarding ancient civilizations and cultures. The safeguarding of this cultural heritage is one of the most urgent priorities, that involve the proper conservation and preservation methods of all artifacts and buildings that have an important artistic and historic value. Conservation is a whole field in regarding the care and treatment of valuable artifacts, both movable and immovable. It has two aspects: (1) the control of the environment--to minimize the decay of artifacts and materials and (2) the treatment of these--in order to stop or slow down any deterioration and to stabilize them where possible against further dilapidation. The museum environment is a limited space dedicated not only to exhibition but also to the appropriate conservation of works of art. This article presents an overview of the types of damage and deterioration that air pollution causes to indoor cultural heritage materials and monuments. It identifies the main damaging air pollutants from outdoor sources to be sulphur dioxide, nitrogen dioxide, ozone and sulphide gases.展开更多
On April 18, 2006, a Ru kiln porcelain bottle of the Song Dynasty was sold 160 million RMB at Beijing Spring Auction Fair, setting a record high auction price of the country.
Water alternating gas(WAG)injection is a widely used strategy for enhancing oil recovery(EOR)during gas flooding,and the mechanisms,operating parameters,and influencing factors of which have been extensively studied.H...Water alternating gas(WAG)injection is a widely used strategy for enhancing oil recovery(EOR)during gas flooding,and the mechanisms,operating parameters,and influencing factors of which have been extensively studied.However,with respect to its capacity in expanding macroscopic sweep volume under varying heterogeneities,the related results appear inadequate.In this research,three cores with different heterogeneities were used and flooded by the joint water and CO_(2) WAG,then the effects of heterogeneity on oil recovery were determined.More importantly,the cores after CO_(2) WAG injection were investigated using the nuclear magnetic resonance(NMR)technique for remaining oil distribution research,which could help us to understand the capacity of CO_(2) WAG in enlarging sweep volume at different heterogeneities.The results show that the presence of heterogeneity may largely weaken the effectiveness of water flooding,the more severe the heterogeneity,the worse the water flooding.The WAG injection of CO_(2) performs well in EOR after water flooding for all the cores with different heterogeneities;however,it could barely form a complete or full sweep throughout the low-permeability region,and un-swept bypassed regions remain.The homogeneous core is better developed by the injection of the joint water and CO_(2) WAG than the heterogeneous and fractured cases.展开更多
The purpose of this paper is to evaluate the possibility of implementation of alternative renewable energy micro-generation installations in dairy farm milk collection posts, from the technical, economical and environ...The purpose of this paper is to evaluate the possibility of implementation of alternative renewable energy micro-generation installations in dairy farm milk collection posts, from the technical, economical and environmental perspectives. Work was performed through dairy farm milk collection post energy audits. Weather data was obtained from CLIMAAT and MacSIMAR projects and introduced in a renewable energy solutions calculator (HOMER). Moreover, a system design from the available portfolio of micro-generation devices was defined and a cost benefit analysis of the selected alternatives was performed. From the analyzed solutions, the set of PV (20 kW) and Wind (3 kW) with no batteries revealed to be the best one. The sensitivity analysis indicated that wind micro-turbines should be installed except if the solar radiation is maximum and that in no case the use of batteries is an advantage. For systems requiring a certain degree of energy (in this case with an average of 350 kW/day), the implementation of micro generation systems, like the ones evaluated, will never be economically feasible in terms of Total Economic Value, even with generous feed-in tariff schemes. It is preferable that grid operators make investments in renewable energy production.展开更多
Covering the grapevine rows to delay maturity and thus the harvest date becomes a widespread practice at Sultana seedless vineyards. The research work was carried out with different covers to examine their effects on ...Covering the grapevine rows to delay maturity and thus the harvest date becomes a widespread practice at Sultana seedless vineyards. The research work was carried out with different covers to examine their effects on grape quality and storage life in 2009 and 2010. Grapevines were covered with three different densities (shading ratios: 35%, 55%, 75%) at the veraison period. Unshaded (0%) control grapevines and grapevines shaded under different ratios were covered with polypropylene cross-stitch just before harvest maturity. Grapes under cover were harvested nearly one month after than those maturing under open conditions. Grape clusters were packed in PE bags and pre-cooled after harvest and then SO2-generating pads has been put on top, bags were sealed. In the second year at the 120th day of the storage, decay development has been observed in all applications. Total soluble solids content, maturity index and a* colour value were found lower in 55% and 75% shaded grapes compared to unshaded grapevines. Still, berry removal force and hue angle value in 55% and 75% of shaded grapes were higher than unshaded grapes. Effects of shading ratios on these parameters decrease or disappear at the end of storage.展开更多
The Bakken formation has become a prominent oil resource for south-east Saskatchewan, especially with the advent of horizontal well technology and new hydraulic fracturing methods. As more wells are drilled, there is ...The Bakken formation has become a prominent oil resource for south-east Saskatchewan, especially with the advent of horizontal well technology and new hydraulic fracturing methods. As more wells are drilled, there is a desire to determine whether there is potential for improved oil recovery and to evaluate the economic feasibility. This paper evaluates the benefit of implementing waterflooding, CO2 injection or WAG (water-alternating-gas) recovery methods for improved oil recovery of the Bakken formation. A simulation model resembling the study area was built using CMG-GEM (computer modeling group-generalized equation of state model) reservoir simulation package and a history match of the primary recovery data available was performed. Based on the simulation results, it was concluded that waterflooding had a significant influence on the oil recovery factor, although COz provided the highest increase in crude oil recovery, The capital expenditure for surface facilities and cost of injected fluid was the most economically viable for implementation of waterflooding. The WAG injection simulation results were similar to CO2 injection, except that reservoir pressure was able to be better maintained. Given that high-quality source water is available, waterflooding is the most economically feasible choice according to the simulation results obtained from this study.展开更多
This study was designed to evaluate the sensory quality indices, freshness assessment and safety of eating Nile tilapia fed recycled food waste materials [food industry waste (FIW) and soy sauce waste (SSW)] for 3...This study was designed to evaluate the sensory quality indices, freshness assessment and safety of eating Nile tilapia fed recycled food waste materials [food industry waste (FIW) and soy sauce waste (SSW)] for 32 weeks using K values, IMP content and microbial viable cell count. Five experimental diets were formulated at 0% and 20%-22% inclusion level of recycled food wastes. The diets were designated as D 1: 0% of recycled food waste, D2: 20% inclusion of FIW, D3: 20% inclusion of FIW and SSW, D4: 20% inclusion of FIW and tryptophan, and D5: 22% inclusion of SSW. The result from the body composition shows that D I had higher carcass protein, while D3 had the highest lipid content and there was no significant difference in the carcass moisture and ash contents among all treatments. The results of microbial viable cell counts showed that no significant differences were observed among the dietary treatments and all the fish fed experimental diets still remained fresh four days after refrigerated storage at 5 ~C. In addition, no significant differences were noted among the K value concentrations of all the fish fed the experimental diets. From the result of this study, we concluded that using 20% inclusion of recycled food waste materials (FIW and SSW) in the diet of tilapia had no negative effect on the flesh of the fish; hence, recycled food waste could be a good alternative ingredient to aquaculture.展开更多
A simple approach is described to estimate the wave power absorption potential of submerged devices known to cause wave focusing and flow enhancement. In particular, the presence of a flow-through power take-off (PTO...A simple approach is described to estimate the wave power absorption potential of submerged devices known to cause wave focusing and flow enhancement. In particular, the presence of a flow-through power take-off (PTO) system, such as low-head turbines, can be accounted for. The wave radiation characteristics of an appropriately selected Lagrangian element (LE) in the fluid domain are first determined. In the limit of a vanishing mass, the LE reduces to a patch of distributed normal dipoles. The hydrodynamic coefficients of this virtual object are then input in a standard equation of motion where the effect of the PTO can be represented, for example, as a dashpot damping term. The process is illustrated for a class of devices recently proposed by Carter and Ertekin (2011), although in a simplified form. Favorable wave power absorption is shown for large ratios of the LE wave radiation coefficient over the LE added mass coefficient. Under optimal conditions, the relative flow reduction from the PTO theoretically lies between 0.50 and 1 2 ≈ 0.71, with lower values corresponding to better configurations. Wave power capture widths, the sensitivity of results to PTO damping and sample spectral calculations at a typical site in Hawaiian waters are proposed to further illustrate the versatility of the method.展开更多
文摘[Objective] This study aimed to study the effects of different picking time and storage environment on fruit quality of a pear cultivar Xinlin No.7 and the relationship between storage environment and fruit quality, so as to provide a theoretical basis for storage and preservation of Xinli No.7. [Method] The fruits of Xinli NO.7 were picked up in August (optimal) and September respectively and then stored in room, cellar and freezer, respectively. The dynamics in temperature, humidity, CO2 concentration, fruit weight loss rate, pericarp chlorophyll content and fruit interior quality were determined. [Result] The environment differed significantly among different storage methods. In room and cellar, the temperature showed a downward trend, and the humidity decreased after early-mid October. The CO2 concentration changed steadily, and increased rapidly in cellar after December. In freezer, the temperature and humidity changed steadily, and the CO2 concentration increased after October. The changes in quality of the fruits harvested in August and September were similar. There was a certain correlation between storage environment and fruit quality of Xinli No.7. In room and cellar, the variation trends of tem- perature and humidity were consistent with those of chlorophyll content, fruit hardness and titratable acid content with positive correlations, but were opposite from those of fruit weight loss rate, soluble solids content and soluble sugar content with negative correlations. In freezer, the CO2 concentration was closely related to the changes in fruit quality. Its variation trend was consistent with those of fruit weight loss rate and soluble solids content, but was opposite from those of pericarp chlorophyll content, fruit firmness, soluble sugar content and titratable acid content. The differences in some of the traits reached significant levels (P〈0.05, P〈0.01). [Conclusion] With the extension of storage time, the temperature, humidity and CO2 concentration changed according to different patterns among different storage methods. The changes in fruit quality of Xinli NO.7 were related to the storage environment, especially to the temperature, to a certain extent.
基金This paper was subsidized by the 15th National key Sci-Tech Project (NO.2001BA605A02-04-01)
文摘The relative permeability curve has been measured with simulation oil (refined oil) and gas (nitrogen or air) at room temperature and a lowpressure, both of which are very important parameters for depicting the flow of fluid through porous media in a hydrocarbon reservoir. This basic measurement is often applied in exploitation evaluation, but the underground conditions with high temperature and pressure, and the phase equilibrium of oil and gas, are not taken into consideration when the relative permeability curve is tested. There is an important theoretical and practical sense in testing the diphase relative permeability curve of the equilibrium of oil and gas under the conditions of high temperature and pressure. The test method for the relative permeability curve is proposed in this paper. The relative permeability of the equilibrium of oil and gas and the standard one are tested in two fluids, and the differences between these two methods are stated. The research results can be applied to the simulation and prediction of CVD in long cores and then the phenomenon can better explain that the recovery of condensate gas rich in condensate oil is higher than that of CVD test in PVT. Meanwhile, the research shows that the relative permeability curve of equilibrium oil and gas is sensitive to the rate of exploitation, and the viewpoint proves that an improved gas recovery rate can properly increase the recovery of condensate oil.
基金Project(50774094) supported by the National Natural Science Foundation of ChinaProject(2010CB630905) supported by the National Basic Research Program of China
文摘Two reagents including salicylhydroxamic acid(SHA) and tributyl phosphate(TBP) were tested as collectors either separately or together for electro-flotation of fine cassiterite(<10 μm).Subsequently,the flotation mechanism of the fine cassiterite was investigated by adsorbance determination,electrophoretic mobility measurements and Fourier transform infra-red(FT-IR) spectrum checking.Results of the flotation experiments show that with SHA as a collector,the collecting performance is remarkably impacted by the pulp pH value as the floatability of cassiterite varies sharply when the pH changes,and flotation with SHA gives distinct maximum at about pH 6.5.Additionally,the floatability of cassiterite is determined by using SHA and TBP as collectors.The range of pulp pH for good floatability is broadened in the presence of TBP as auxiliary collector,and the utilization of TBP improves the recovery of cassiterite modestly.Moreover,the optimum pH value for cassiterite flotation is associated with adsorbance.The results of FT-IR spectrum and the electrophoretic mobility measurements indicate that the adsorption interaction between the collectors and the cassiterite is dominantly a kind of chemical bonding in the form of one or two cycle chelate rings due to the coordination of carbonyl group,hydroxamate and P=O group to the metal tin atoms,where the oxygen atoms contained in carbonyl group,hydroxamate and P=O group of the polar groups have the stereo conditions to form five-membered rings.In addition,the adsorption interactions of SHA and TBP on the surfaces of cassiterite are also dominated by means of hydrogen bonds.
基金Project(50674102) supported by the National Natural Science Foundation of China
文摘The interaction mechanism of collector DLZ in the flotation process of chalcopyrite and pyrite was investigated through flotation experiments,zeta potential measurements and infrared spectrum analysis.Flotation test results indicate that DLZ is the selective collector of chalcopyrite.Especially,the recovery of chalcopyrite is higher than 90% in neutral and weak alkaline systems,while the recovery of pyrite is less than 10%.When using CaO as pH regulator,at pH=7-11,the floatability of pyrite is depressed and the recovery is less than 5%.Zeta potential analysis shows that the zeta potential of chalcopyrite decreases more obviously than that of pyrite after interaction with DLZ,confirming that collector DLZ shows selectivity to chalcopyrite and pyrite.And FTIR results reveal that the flotation selectivity of collector DLZ is due to chemical absorption onto chalcopyrite surface and only physical absorption onto pyrite surface.
基金Project(50874118) supported by the National Natural Science Foundation of ChinaProject(2007B52) supported by the Foundation for the Author of National Excellent Doctoral Dissertation of ChinaProject(2005CB623701) supported by the National Basic Research Program of China
文摘The floatability of diaspore and three kinds of silicate minerals,including kaolinite,illite and pyrophyllite,by a cationic Gemini surfactant as collector and starch as depressant was investigated as function of reagents concentration and pulp pH.Further studies of artificially mixed minerals and bauxite ore were also detailedly conducted.At last,the pre-desliming reverse flotation separation process was adopted.It can be concluded that the combinational use of a Gemini cationic collector and the starch depressant is effective.The concentrates with Al2O3 to SiO2 mass ratio of 9.66 and the recovery of Al2O3 of 71.73% are obtained from natural bauxite ore(A/S=5.70) at pH value of around 10.
基金supported by the National Key Fundamental Research and Development Program(No.2005CB623701)the National Department Public Benefit Research Foundation from Ministry of Land and Resources(No.201011031 )the Foundation for the Author of Zhengzhou Institute of Multipurpose Utilization of Mineral Resources CAGS(No.2935)
文摘The flotation of diaspore and kaolinite by one of a series of tertiary amines(DRN,DEN,DPN and DBN) was investigated.The tertiary amines show better floating recovery for kaolinite compared to diaspore.The maximum recovery D-value is 45%over a pH range from 3 to 8.FT-IR spectra confirm the presence of hydroxyl groups on the surface of kaolinite and diaspore.Zeta potential measurements show that the mineral surfaces are negatively charged over a wide pH range.Ionization of hydroxyl groups mainly accounts for the surface charging mechanism.The adsorption of tertiary amines onto the mineral surface is due mainly to electrostatic effects and the difference in electrostatic effect between a collector and the two minerals can explain the flotation separation.Inductive electronic and steric effects from the substituent groups result in different collecting powers for the four tertiary amines.
基金supported by the State Key Program of National Natural Science Foundation of China (No. 50834006)
文摘The flotation separation of scheelite from fluorite and calcite using dodecyltrimethylammonium chloride (DTAC), dodecyldimethylbenzylammonium chloride (DDBAC), or didodecyldimethylammonium chloride (DDDAC) as the collector has been investigated. The results show that the selectivity of these collectors for these three calcareous minerals falls in the order: DDDAC 〉 DDBAC 〉 DTAC. A significantly different flotation response of scheelite compared to the other two calcareous minerals was observed over the pH range from 7 to 8 for DDDAC as the collector. A concentrate containing 41.40% W03 could be produced from a feed mixture containing 23.22% WO3 at the DDDAC concentration of 4.0× 10^-4 mol/L. The WO3 recovery was 92.92% under these conditions. The results of zeta potential measurements suggest that electrostatic interactions are the main forces between DDDAC and the minerals. When the concentration of DDDAC is from 2× 10^-4 to 4×10-3 mol/L large differences in adsorption density, and adsorption kinetics, of DDDAC onto scheelite, calcite, and fluorite provide desirable conditions for achieving high selectivity.
文摘This paper describes the experience of Jilin oilfield trials for Microbial Enhanced Oil Recovery (MEOR). A new technique to identify microbes with DNA for MEOR has been established, and useful microbes selected for use in field trials. Behaviors of bacteria activated in the reservoir, oil recovery and water cut, and the viscosity of crude oil produced through huff & puff testing and flooding with molasses-injection tests, have been investigated in situ. CJF-002, which produces biopolysaccharide, is the best among the microbes used for field trials, as it can use molasses as nutrient and produce a small quantity of CO2 and a mass of water-insoluble biopolymer. The metabolic behavior in the reservoir showed that CJF-002 had a good potentiality for MEOR.
基金supported by the National Science Foundation of China (Grant Nos. 40871057 and 41271024)CAAS Project Innovation (2016-2020)+1 种基金IARRP (2016-637-1)Tianjin Philosophy and Social Science Planning Project (TJGL15-028)
文摘Glacier variations in the Tibetan Plateau and surrounding mountain ranges in China affect the livelihood of over one billion people who depend on water from the Yellow, Yangtze, Brahmaputra, Ganges and Indus rivers originating in these areas. Based on the results of the present study and published literature, we found that the glaciers shrank :5.7% in area from 1963 to 20:0 with an annual area change of -0.33%. The shrinkage generally decreased from peripheral mountain ranges to the interior of Tibet. The linear trends of annual air temperature and precipitation at 147 stations were 0.36℃(10a)^-1 and 8.96 mm (10a)^-1 respectively from 1961 to 2010. The shrinkage of glaciers was well correlated with the rising temperature and the spatial patterns of the shrinkage were influenced by other factors superimposed on the rising temperature such as glacier size, type, elevation, debris cover and precipitation.
文摘Common denominator and one of the goals in the "storage" of many, even different, commodities (agricultural, etc.) is their protection against invasion by biological pests; protection of objects of cultural heritage deposited in museums, galleries, archives and other institutions of a similar type is one of the specific case. The present article is an overview of basic (potential) biological pests of some "storage" commodities (with emphasis on the protection of objects of cultural heritage) as well as methods used for their detection. In the final section, a modular system of the ongoing assessment of the environmental characteristics of depositaries and exhibitions (including "biological") is briefly presented; its advantage is the possibility of on-line monitoring of the evaluated parameters (temperature, humidity, lighting, etc.) including the detection of presence of crawling and airborne insects.
文摘Understanding the diversity and taxonomy of Iran's lichens has never been more important than it is today, and this is undoubtedly the most exciting subject to be studying in the cryptogamic flora of the country. The present paper is a part of a more extensive lichenological investigation based on collections made since 2004 in the reserved region Darkesh in the Aladagh mountains. Among a collection of lichens from four localities in the site, in Northern Khorasan province, (NE) IRAN, 13 species were identified, of which five were known outside the province. Lecanora umbrina (Ach.) Massal. is first found in this locality.
文摘The time has come to recognize the extreme importance of the archaeological sites in Jordan. They provide a wealth evidence and precise information regarding ancient civilizations and cultures. The safeguarding of this cultural heritage is one of the most urgent priorities, that involve the proper conservation and preservation methods of all artifacts and buildings that have an important artistic and historic value. Conservation is a whole field in regarding the care and treatment of valuable artifacts, both movable and immovable. It has two aspects: (1) the control of the environment--to minimize the decay of artifacts and materials and (2) the treatment of these--in order to stop or slow down any deterioration and to stabilize them where possible against further dilapidation. The museum environment is a limited space dedicated not only to exhibition but also to the appropriate conservation of works of art. This article presents an overview of the types of damage and deterioration that air pollution causes to indoor cultural heritage materials and monuments. It identifies the main damaging air pollutants from outdoor sources to be sulphur dioxide, nitrogen dioxide, ozone and sulphide gases.
文摘On April 18, 2006, a Ru kiln porcelain bottle of the Song Dynasty was sold 160 million RMB at Beijing Spring Auction Fair, setting a record high auction price of the country.
基金Project(KFJJ-TZ-2019-3)supported by the Open Project of Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil&Gas Reservoirs,ChinaProjects(51504275,51974344)supported by the National Natural Science Foundation of China。
文摘Water alternating gas(WAG)injection is a widely used strategy for enhancing oil recovery(EOR)during gas flooding,and the mechanisms,operating parameters,and influencing factors of which have been extensively studied.However,with respect to its capacity in expanding macroscopic sweep volume under varying heterogeneities,the related results appear inadequate.In this research,three cores with different heterogeneities were used and flooded by the joint water and CO_(2) WAG,then the effects of heterogeneity on oil recovery were determined.More importantly,the cores after CO_(2) WAG injection were investigated using the nuclear magnetic resonance(NMR)technique for remaining oil distribution research,which could help us to understand the capacity of CO_(2) WAG in enlarging sweep volume at different heterogeneities.The results show that the presence of heterogeneity may largely weaken the effectiveness of water flooding,the more severe the heterogeneity,the worse the water flooding.The WAG injection of CO_(2) performs well in EOR after water flooding for all the cores with different heterogeneities;however,it could barely form a complete or full sweep throughout the low-permeability region,and un-swept bypassed regions remain.The homogeneous core is better developed by the injection of the joint water and CO_(2) WAG than the heterogeneous and fractured cases.
文摘The purpose of this paper is to evaluate the possibility of implementation of alternative renewable energy micro-generation installations in dairy farm milk collection posts, from the technical, economical and environmental perspectives. Work was performed through dairy farm milk collection post energy audits. Weather data was obtained from CLIMAAT and MacSIMAR projects and introduced in a renewable energy solutions calculator (HOMER). Moreover, a system design from the available portfolio of micro-generation devices was defined and a cost benefit analysis of the selected alternatives was performed. From the analyzed solutions, the set of PV (20 kW) and Wind (3 kW) with no batteries revealed to be the best one. The sensitivity analysis indicated that wind micro-turbines should be installed except if the solar radiation is maximum and that in no case the use of batteries is an advantage. For systems requiring a certain degree of energy (in this case with an average of 350 kW/day), the implementation of micro generation systems, like the ones evaluated, will never be economically feasible in terms of Total Economic Value, even with generous feed-in tariff schemes. It is preferable that grid operators make investments in renewable energy production.
文摘Covering the grapevine rows to delay maturity and thus the harvest date becomes a widespread practice at Sultana seedless vineyards. The research work was carried out with different covers to examine their effects on grape quality and storage life in 2009 and 2010. Grapevines were covered with three different densities (shading ratios: 35%, 55%, 75%) at the veraison period. Unshaded (0%) control grapevines and grapevines shaded under different ratios were covered with polypropylene cross-stitch just before harvest maturity. Grapes under cover were harvested nearly one month after than those maturing under open conditions. Grape clusters were packed in PE bags and pre-cooled after harvest and then SO2-generating pads has been put on top, bags were sealed. In the second year at the 120th day of the storage, decay development has been observed in all applications. Total soluble solids content, maturity index and a* colour value were found lower in 55% and 75% shaded grapes compared to unshaded grapevines. Still, berry removal force and hue angle value in 55% and 75% of shaded grapes were higher than unshaded grapes. Effects of shading ratios on these parameters decrease or disappear at the end of storage.
文摘The Bakken formation has become a prominent oil resource for south-east Saskatchewan, especially with the advent of horizontal well technology and new hydraulic fracturing methods. As more wells are drilled, there is a desire to determine whether there is potential for improved oil recovery and to evaluate the economic feasibility. This paper evaluates the benefit of implementing waterflooding, CO2 injection or WAG (water-alternating-gas) recovery methods for improved oil recovery of the Bakken formation. A simulation model resembling the study area was built using CMG-GEM (computer modeling group-generalized equation of state model) reservoir simulation package and a history match of the primary recovery data available was performed. Based on the simulation results, it was concluded that waterflooding had a significant influence on the oil recovery factor, although COz provided the highest increase in crude oil recovery, The capital expenditure for surface facilities and cost of injected fluid was the most economically viable for implementation of waterflooding. The WAG injection simulation results were similar to CO2 injection, except that reservoir pressure was able to be better maintained. Given that high-quality source water is available, waterflooding is the most economically feasible choice according to the simulation results obtained from this study.
文摘This study was designed to evaluate the sensory quality indices, freshness assessment and safety of eating Nile tilapia fed recycled food waste materials [food industry waste (FIW) and soy sauce waste (SSW)] for 32 weeks using K values, IMP content and microbial viable cell count. Five experimental diets were formulated at 0% and 20%-22% inclusion level of recycled food wastes. The diets were designated as D 1: 0% of recycled food waste, D2: 20% inclusion of FIW, D3: 20% inclusion of FIW and SSW, D4: 20% inclusion of FIW and tryptophan, and D5: 22% inclusion of SSW. The result from the body composition shows that D I had higher carcass protein, while D3 had the highest lipid content and there was no significant difference in the carcass moisture and ash contents among all treatments. The results of microbial viable cell counts showed that no significant differences were observed among the dietary treatments and all the fish fed experimental diets still remained fresh four days after refrigerated storage at 5 ~C. In addition, no significant differences were noted among the K value concentrations of all the fish fed the experimental diets. From the result of this study, we concluded that using 20% inclusion of recycled food waste materials (FIW and SSW) in the diet of tilapia had no negative effect on the flesh of the fish; hence, recycled food waste could be a good alternative ingredient to aquaculture.
基金Unsponsored(cost share)contribution to the U.S.Department of Energy through the Hawaii National Marine Renewable Energy Center(Hawaii Natural Energy Institute,University of Hawaii),Account No.6658090
文摘A simple approach is described to estimate the wave power absorption potential of submerged devices known to cause wave focusing and flow enhancement. In particular, the presence of a flow-through power take-off (PTO) system, such as low-head turbines, can be accounted for. The wave radiation characteristics of an appropriately selected Lagrangian element (LE) in the fluid domain are first determined. In the limit of a vanishing mass, the LE reduces to a patch of distributed normal dipoles. The hydrodynamic coefficients of this virtual object are then input in a standard equation of motion where the effect of the PTO can be represented, for example, as a dashpot damping term. The process is illustrated for a class of devices recently proposed by Carter and Ertekin (2011), although in a simplified form. Favorable wave power absorption is shown for large ratios of the LE wave radiation coefficient over the LE added mass coefficient. Under optimal conditions, the relative flow reduction from the PTO theoretically lies between 0.50 and 1 2 ≈ 0.71, with lower values corresponding to better configurations. Wave power capture widths, the sensitivity of results to PTO damping and sample spectral calculations at a typical site in Hawaiian waters are proposed to further illustrate the versatility of the method.