Fermented sour soup is a unique traditional sour food of the Miao and Dong ethnic groups in China.However,due to the commonly used traditional fermentation,the unstable fluctuation of microbial community often leads t...Fermented sour soup is a unique traditional sour food of the Miao and Dong ethnic groups in China.However,due to the commonly used traditional fermentation,the unstable fluctuation of microbial community often leads to some unpleasant inherent off-flavours in rice sour soup.In this study,the microbial composition and volatile flavour components of off-flavour and normal rice sour soup were examined by high-throughput sequencing and headspace solid-phase microextraction coupled with gas chromatography mass spectrometry.Then,based on Pearson correlation coefficients,the correlations between fungi and bacteria and those between core microorganisms and key volatile flavour components were investigated.The dominant fungal genera included Candida,Dekkera,Pichia,Rhizopus,and Issatchenkia,whereas the dominant bacterial genera included Lactobacillus,Pectinatus,Bifidobacterium,Pseudomonas,and Acetobacter.Compared to normal rice sour soup,off-flavoured rice sour soup contained the significantly increased relative abundance of Candida and the significantly decreased relative abundance of Dkkera.In addition,80 volatile flavour compounds detected in off-flavoured rice sour soup,mainly including esters,acids,and alcohols,were different from those detected in normal rice sour soup.Especially,some substances were only detected in off-flavoured rice sour soup,such as 1-hexanol(68-207μg/kg),butyric acid(20-92μg/kg)and heptanoic acid(12-45μg/kg),which might be the main source of off-flavours.These results provide new ideas and strategies of removing or abating odour from fermented rice sour soup.展开更多
While most mammals find highly acidic foods aversive,many bird species have evolved remarkable tolerance for sour fruits-a crucial adaptation that has opened new ecological niches.Wild fruits can contain organic acid ...While most mammals find highly acidic foods aversive,many bird species have evolved remarkable tolerance for sour fruits-a crucial adaptation that has opened new ecological niches.Wild fruits can contain organic acid concentrations dozens of times higher than cultivated varieties,yet species like the redwing(Turdus iliacus)and black grouse(Tetrao tetrix)have evolved to actually prefer these acidic foods as dietary staples.展开更多
The construction and operation of sulfur-containing gas storage are often more difficult than a non-sulfur storage facility due to the need to prevent environmental contamination from H_(2)S leaks,as well as the corro...The construction and operation of sulfur-containing gas storage are often more difficult than a non-sulfur storage facility due to the need to prevent environmental contamination from H_(2)S leaks,as well as the corrosive effects of H_(2)S on production facilities.Rapid elutriation of H_(2)S from the reservoir during the construction of the gas storage is an effective way to avoid these problems.However,the existing H_(2)S elutriation method has low efficiency and high economic cost,which limits the development of reconstructed gas storage of sulfur-containing gas reservoirs.To improve the efficiency of H_(2)S elutriation in sulfur-containing gas reservoirs and enhance the economic benefits,a numerical simulation model of multiphase flow components was established to study the migration law of H_(2)S in the multi-cycle operation of gas storage.Based on the H_(2)S migrate law,the displacement H_(2)S elutriation method was developed,and the elutriation mechanism and elutriation efficiency of the two methods were compared and analyzed.In addition,the main controlling factors affecting the H_(2)S elutriation efficiency were investigated,and the H_(2)S elutriation scheme of H gas storage was optimized.The results indicate that H_(2)S migrates between near-well and far-well regions under pressure differentials.The traditional H_(2)S elutriation method relies on concentration gradient diffusion,whereas the displacement elutriation approach leverages pressure differentials with higher H_(2)S elutriation efficiency.For the displacement elutriation method,higher reservoir permeability enhances the peak-shaving capacity of the gas storage but has a minor impact on H_(2)S elutriation when the formation permeability is between 30 and 100 mD.The elutriation efficiency is significantly higher when wells are drilled in the high structural parts of the reservoir compared to the low structural parts.Longer displacement elutriation time within a cycle improves H_(2)S elutriation efficiency but reduces the working gas volume of the storage.Therefore,the optimal displacement time for H gas storage is 60 days.An optimized H_(2)S elutriation scheme enabled the working gas to meet the national first-class natural gas standard within 10 cycles.This study elucidates H_(2)S migration patterns,H_(2)S elutriation mechanisms,and key influence factors on H_(2)S elutriation efficiency,offering valuable technical insights for sour gas storage operations.展开更多
This study investigated the effects of salt(3%and 6%,m/m)and rice flour(10%and 20%,m/m)addition in sour meat,a traditional Chinese fermented meat.It was found that salt has greater effect than rice flour addition in s...This study investigated the effects of salt(3%and 6%,m/m)and rice flour(10%and 20%,m/m)addition in sour meat,a traditional Chinese fermented meat.It was found that salt has greater effect than rice flour addition in spontaneous fermentation.Low-salt groups had lower pH and higher titratable total acid.In the low-salt groups,the dominant genera were Lactobacillus and Lactococcus,whereas Staphylococcus,Weissella,and Tetragenococcus were dominant in the high-salt groups.Higher total free amino acids and essential amino acids,organic acids,hexanoic acid ethyl ester and octanoic acid ethyl ester were found in the low-salt groups.The RDA analysis revealed that Lactococcus was closely related to product quality,with the S3F10(3%salt and 10%rice f lour)group outperforming the others in the sensory evaluation.Therefore,3%salt and 10%rice flour were considered more appropriate for the production of healthy and tasty fermented sour meats.展开更多
CO2 capture by hydrate formation is a novel gas separation technology, by which CO2 is selectively engaged in the cages of hydrate and is separated with other gases, based on the differences of phase equilibrium for C...CO2 capture by hydrate formation is a novel gas separation technology, by which CO2 is selectively engaged in the cages of hydrate and is separated with other gases, based on the differences of phase equilibrium for CO2 and other gases. However. rigorous temperature and pressure, high energy cost and industrialized hydration separator dragged the development of the hydrate based CO2 capture. In this paper, the key problems in CO2 capture from the different sources such as shifted synthesis gas, flue gas and sour natural gas or biogas were analyzed. For shifted synthesis gas and flue gas, its high energy consumption is the barrier, and for the sour natural gas or biogas （CO2/CH4 system）, the bottleneck is how to enhance the selectivity of CO2 hydration. For these gases, scale-up is the main difficulty. Also, this paper explored the possibility of separating different gases by selective hydrate formation and reviewed the progress of CO2 separation from shifted synthesis gas, flue gas and sour natural gas or biogas.展开更多
Sulfur deposition in the formation, induced by a reduction in the solubility of the sulfur in the gas phase, may significantly reduce the inflow performance of sour gas wells and some wells in sour gas reservoirs have...Sulfur deposition in the formation, induced by a reduction in the solubility of the sulfur in the gas phase, may significantly reduce the inflow performance of sour gas wells and some wells in sour gas reservoirs have even become completely plugged with deposited sulfur within several months. Accurate prediction and effective management of sulfur deposition are crucial to the economic viability of sour gas reservoirs. In this paper, a dynamic flow experiment was carried out to investigate formation damage resulting from sulfur deposition using an improved experimental method. The core sample was extracted from the producing interval of the LG2 well, LG gas field in the Sichuan Basin. The experimental temperature was 26 °C and the initial pressure was 19 MPa. The displacement pressure continuously decreased from 19 to 10 MPa, and the depletion process lasted 15 days. Then the core was removed and dried. The core mass and core permeability were measured before and after experiments. Experimental results indicated that the core mass increased from 48.372 g before experiment to 48.386 g afterwards, while the core permeability reduced from 0.726 to 0.608 md during the experiment. Then the core was analyzed with a scanning electron microscope (SEM) and energy-dispersive X-ray mapping. The deposition pattern and micro-distribution of elemental sulfur was observed and the deposited elemental sulfur distributed as a film around the pore surface.展开更多
The removal of NO from oxy-fuel combustion is typically incorporated in sour gas compression purification process. This process involves the oxidation of NO to NO2 at a high pressure of 1–3 MPa, followed by absorptio...The removal of NO from oxy-fuel combustion is typically incorporated in sour gas compression purification process. This process involves the oxidation of NO to NO2 at a high pressure of 1–3 MPa, followed by absorption of NO2 by water. In this pressure range, the NO conversion rates calculated using the existing kinetic constants are often higher than those obtained experimentally. This study aimed to achieve the regression of kinetic parameters of NO oxidation based on the existing experimental results and theoretical models.Based on three existing NO oxidation mechanisms, first, the expressions for NO conversion against residence time were derived. By minimizing the mean-square errors of NO conversion ratio, the optimum kinetic rate constants were obtained. Without considering the reverse reaction for NO oxidation, similar mean-square errors for NO conversion ratio were calculated. Considering the reverse reaction for NO oxidation based on the termolecular reaction mechanism, the minimum mean-square error for NO conversion ratio was obtained. Thus, the optimum NO oxidation rate in the pressure range 0.1–3 MPa can be expressed as follows:-d[NO]/dt=d[NO2]/dt=0.0026[NO]2[O2]-0.0034[NO2]2 Detailed elementary reactions for N2/NO/NO2/O2 system were established to simulate the NO oxidation rate. A sensitivity analysis showed that the critical elementary reaction is 2 NO + O2? 2 NO2. However, the simulated NO conversions at a high pressure of 10–30 bar are still higher than the experimental values and similar to those obtained from the models without considering the reverse reaction for NO oxidation.展开更多
In order to establish grading standards of evaluation indices for sour flavor of apples, 10 indices of samples from 106 apple cultivars were tested, including： malic acid（Mal）, oxalic acid（Oxa）, citric acid（Cit...In order to establish grading standards of evaluation indices for sour flavor of apples, 10 indices of samples from 106 apple cultivars were tested, including： malic acid（Mal）, oxalic acid（Oxa）, citric acid（Cit）, lactic acid（Lac）, succinic acid（Suc）, fumaric acid（Fum）, total organic acids（To A, the sum of the six organic acids tested）, titratable acid（TiA）, acidity value（AcV）, and pH value. For most of the cultivars studied（85.8%）, the order of the organic acid contents in apples was Mal〉Oxa〉Cit〉Lac〉Suc〉Fum. Mal was the dominant organic acid, on average, accounting for 94.5% of To A. Among the 10 indices, the dispersion of pH value was the smallest with a coefficient of variation of only 8.2%, while the coefficients of variation of the other nine indices were larger, ranging between 31 and 66%. There were significant linear relationships between Mal and two indices（ToA and AcV） as well as between ToA and AcV. There were significant logarithmic relationships between pH value and four indices： Mal, TiA, ToA, and AcV. All the equations had very high fitting accuracy and can be used to accurately predict related indices. According to this study, Mal, ToA, and AcV of apple were normally distributed, TiA was close to normally distributed, whereas pH value had a skewed distribution. Using the fitted normal distribution curves, the grading standards of Mal, TiA, ToA, and AcV were established. The grading node values of pH value were obtained using the logarithmic relationship between pH value and Mal. The grading standards of these five indices can be used to evaluate the sour flavor of apple. This study provides a scientific basis for evaluating apple flavor and selecting apple cultivars.展开更多
Sweet and sour cherries contain several polyphenols that possess antioxidant and anti-inflammatory properties. Aim of this study was to investigate the effect of the maturity stage on phenol content and biological pro...Sweet and sour cherries contain several polyphenols that possess antioxidant and anti-inflammatory properties. Aim of this study was to investigate the effect of the maturity stage on phenol content and biological properties of extract of a local Morello-type of sour cherry (Prunus cerasus?L.), “visciola”. The study of total phenol content and total antioxidant potential was associated with the evaluation of the antioxidant property of extracts using a copper catalyzed human low density lipoproteins (LDL) oxidation as experimental model. Moreover, using albumin glycated by methylglyoxal, we evaluated the anti-glycation effect of fruit extract. The results demonstrated that fully ripened fruits exert higher antioxidant and anti-glycation properties when compared with partially ripened fruits. Information about the health-promoting components of “visciola” could lead to a better understanding and an increased consumption of these, including its use as functional food.展开更多
Sour water contains ammonia,carbon dioxide,and hydrogen sulfides,producing from oil refining,coking,and coal gasification.To reduce the energy consumption in sour water stripping,a novel process is proposed which inte...Sour water contains ammonia,carbon dioxide,and hydrogen sulfides,producing from oil refining,coking,and coal gasification.To reduce the energy consumption in sour water stripping,a novel process is proposed which integrates with the bottom flashing mechanical vapor recompression heat pump(MVRHP)for treating such wastewater.Here,Aspen PlusTM as a powerful set of chemical process simulation software is utilized to investigate the economy and feasibility of the novel process.Comparison of the results of two process simulations,it can be seen that it is possible to reduce the total annual cost by nearly 45%to adopt the novel process,despite the capital investment increase 45%more than the conventional process.Thus,the provided conceptual design will play a guiding role in the industrialization of the process.展开更多
The study was conducted in an organic nursery of sour cherry cultivars ＂Debreceni Botermo＂ and ＂Sabina＂ in the years 2010 and 2011. Cherry trees grafted on Mahaleb （Prunus mahaleb L.） seedlings were grown at a s...The study was conducted in an organic nursery of sour cherry cultivars ＂Debreceni Botermo＂ and ＂Sabina＂ in the years 2010 and 2011. Cherry trees grafted on Mahaleb （Prunus mahaleb L.） seedlings were grown at a spacing of 25 crn × 1.0 m. In the nursery, an assessment was carried out of the effect of various biopreparations on such growth characteristics as the thickness and height of the maidens, the formation of lateral shoots and the total increase in their length. The control trees were not treated at all, but fertilized with an NPK fertilizer only （second control）. To stimulate growth, use was made of granular manure, mycorrhizal fungi in the form of the preparation Micosat, humic preparations or so-called vermicomposts （Humus UP, Humus Active）, extracts of marine algae （BF Quality） and of terrestrial plants （BF Arnin）, a product derived from yeast （Vinassa） and Tytanit. The specific biological effects of the preparations used in the sour cherry nursery for each morphological feature are presented in this paper in graphical form. A beneficial effect on the increase in the number of lateral shoots and the increase in their length was produced by the use of such products as： Micosat, Humus UP, Humus Active ＋ Aktywit PM and Vinassa. The most effective in this respect was BF Amin.展开更多
This study presents a new multiphase flow model with transient heat transfer and pressure coupling to simulate HTHP(high temperature and high pressure)sour gas“kicks”phenomena.The model is intended to support the es...This study presents a new multiphase flow model with transient heat transfer and pressure coupling to simulate HTHP(high temperature and high pressure)sour gas“kicks”phenomena.The model is intended to support the estimation of wellbore temperature and pressure when sour gas kicks occur during drilling operation.The model considers sour gas solubility,phase transition and effects of temperature and pressure on the physical parameters of drilling fluid.Experimental data for a large-diameter pipe flow are used to validate the model.The results indicate that with fluid circulation,the annulus temperature with H2S kicks is the highest,followed by CO_(2),and CH_(4) is the lowest.The phase transition point of H2S is closer to wellhead compared with CO_(2),resulting in a faster expansion rate,which is more imperceptible and dangerous.With fluid circulation,the drilling fluid density and plastic viscosity both first decrease and then increase with the increase in the well depth.The bottom hole pressure when H2S kicks is greater than that for CO_(2) with the same amount of sour gas,and the pressure difference gradually increases with the increase of H2S/CO_(2) content.In addition,a parametric sensitivity analysis has been conducted to evaluate qualitatively and rank the influential factors affecting the bottom hole temperature and pressure.展开更多
Timothy Mo,a famous British writer whose works have won many important prizes,experiences both Chinese culture and English culture since his childhood.Due to this kind of experience,his works are usually concerned wit...Timothy Mo,a famous British writer whose works have won many important prizes,experiences both Chinese culture and English culture since his childhood.Due to this kind of experience,his works are usually concerned with the issue of cultural conflict.Among these works,Sour Sweet is the most well-known one in China,and it has also been filmed as Soursweet in 1988 with the famous actress Zhang Aijia.In Sour Sweet,Timothy Mo tells a story about a Chinese family’s struggle in the UK.After experiencing a serious of cultural conflict,among the three family members Chen,Lily and Mui,only Lily achieves a delicate balance.After defining the process of establishing oneself in a new environment as a kind of human translation,the article applies AndréLefevere’s theory to study the three characters’different responses to the cultural conflict,analyze how different poetic and different strategies adopted to deal with ideology affect their translation,explain why does or doesn’t he/she translates himself/herself successfully,and finally gets the conclusion:because Lily deals well with the dominant ideological and poetical currents,and makes appropriate choice in face of cultural translatability and untranslatability,so only she can translate herself successfully.展开更多
Cenozoic high\|K igneous rocks are widely distributed in eastern Tibet. These rocks are exposed as flows, dykes and small intrusions along a narrow north\|south trending zone, which follows Tertiary fold belts and the...Cenozoic high\|K igneous rocks are widely distributed in eastern Tibet. These rocks are exposed as flows, dykes and small intrusions along a narrow north\|south trending zone, which follows Tertiary fold belts and the Batang—Lijiang and Ailao Shan—Red River strike\|slip systems. Although several models were proposed to interpret their petrogenesis (Deng, 1989; Arnaud et al., 1991; Turner et al., 1996; Yin et al., 1995; Miller et al., 1999), their origin still remains hotly debated. Moreover, the published results were only focused on the high\|K igneous rocks resulted from partial melting of an enriched lithospheric mantle. Here, we present the detailed documents to testify the existence of a new kind of high\|K igneous rocks in eastern Tibet.Our new 39 Ar/ 40 Ar age data (Wang et al., 1999) and published age data for high\|K rocks in eastern Tibet show two distinctive magmatic episodes: one between 42Ma and 24Ma, and the other since ca.16Ma. They correspond to two types of high\|K magmatism in eastern Tibet. We name the older and younger groups as types Ⅰ and Ⅱ, respectively.展开更多
基金funded by National Natural Science Foundation of China(32360568)Science and Technology Plan Project of Guizhou Province(Qian Ke He Chengguo[2023]Zhongda 011)+2 种基金Guizhou Basic Research Program(Natural Science)Mianshang Project(Qiankehe Basic MS[2025]671)Guizhou Provincial Association of Science and Technology Youth Science and Technology Talent Support Project(GASTYESS202407)Guizhou University Natural Science Specialized(Te Gang)Scientific Research Fund(Gui Da Te Gang He Zi(2022)39).
文摘Fermented sour soup is a unique traditional sour food of the Miao and Dong ethnic groups in China.However,due to the commonly used traditional fermentation,the unstable fluctuation of microbial community often leads to some unpleasant inherent off-flavours in rice sour soup.In this study,the microbial composition and volatile flavour components of off-flavour and normal rice sour soup were examined by high-throughput sequencing and headspace solid-phase microextraction coupled with gas chromatography mass spectrometry.Then,based on Pearson correlation coefficients,the correlations between fungi and bacteria and those between core microorganisms and key volatile flavour components were investigated.The dominant fungal genera included Candida,Dekkera,Pichia,Rhizopus,and Issatchenkia,whereas the dominant bacterial genera included Lactobacillus,Pectinatus,Bifidobacterium,Pseudomonas,and Acetobacter.Compared to normal rice sour soup,off-flavoured rice sour soup contained the significantly increased relative abundance of Candida and the significantly decreased relative abundance of Dkkera.In addition,80 volatile flavour compounds detected in off-flavoured rice sour soup,mainly including esters,acids,and alcohols,were different from those detected in normal rice sour soup.Especially,some substances were only detected in off-flavoured rice sour soup,such as 1-hexanol(68-207μg/kg),butyric acid(20-92μg/kg)and heptanoic acid(12-45μg/kg),which might be the main source of off-flavours.These results provide new ideas and strategies of removing or abating odour from fermented rice sour soup.
文摘While most mammals find highly acidic foods aversive,many bird species have evolved remarkable tolerance for sour fruits-a crucial adaptation that has opened new ecological niches.Wild fruits can contain organic acid concentrations dozens of times higher than cultivated varieties,yet species like the redwing(Turdus iliacus)and black grouse(Tetrao tetrix)have evolved to actually prefer these acidic foods as dietary staples.
基金supported by the Science and Technology Research Program of Chongqing Municipal Education Commission(KJQN202401501,KJZD-M202401501).
文摘The construction and operation of sulfur-containing gas storage are often more difficult than a non-sulfur storage facility due to the need to prevent environmental contamination from H_(2)S leaks,as well as the corrosive effects of H_(2)S on production facilities.Rapid elutriation of H_(2)S from the reservoir during the construction of the gas storage is an effective way to avoid these problems.However,the existing H_(2)S elutriation method has low efficiency and high economic cost,which limits the development of reconstructed gas storage of sulfur-containing gas reservoirs.To improve the efficiency of H_(2)S elutriation in sulfur-containing gas reservoirs and enhance the economic benefits,a numerical simulation model of multiphase flow components was established to study the migration law of H_(2)S in the multi-cycle operation of gas storage.Based on the H_(2)S migrate law,the displacement H_(2)S elutriation method was developed,and the elutriation mechanism and elutriation efficiency of the two methods were compared and analyzed.In addition,the main controlling factors affecting the H_(2)S elutriation efficiency were investigated,and the H_(2)S elutriation scheme of H gas storage was optimized.The results indicate that H_(2)S migrates between near-well and far-well regions under pressure differentials.The traditional H_(2)S elutriation method relies on concentration gradient diffusion,whereas the displacement elutriation approach leverages pressure differentials with higher H_(2)S elutriation efficiency.For the displacement elutriation method,higher reservoir permeability enhances the peak-shaving capacity of the gas storage but has a minor impact on H_(2)S elutriation when the formation permeability is between 30 and 100 mD.The elutriation efficiency is significantly higher when wells are drilled in the high structural parts of the reservoir compared to the low structural parts.Longer displacement elutriation time within a cycle improves H_(2)S elutriation efficiency but reduces the working gas volume of the storage.Therefore,the optimal displacement time for H gas storage is 60 days.An optimized H_(2)S elutriation scheme enabled the working gas to meet the national first-class natural gas standard within 10 cycles.This study elucidates H_(2)S migration patterns,H_(2)S elutriation mechanisms,and key influence factors on H_(2)S elutriation efficiency,offering valuable technical insights for sour gas storage operations.
基金supported by the National Key Research and Development Project(2022YFD2100902)National Natural Science Foundation of China(32372363)+1 种基金Dalian High-level Talent Innovation Support Program(2021RQ093)the Basic Research Project of Education Department of Liaoning Province(LJKZ0544).
文摘This study investigated the effects of salt(3%and 6%,m/m)and rice flour(10%and 20%,m/m)addition in sour meat,a traditional Chinese fermented meat.It was found that salt has greater effect than rice flour addition in spontaneous fermentation.Low-salt groups had lower pH and higher titratable total acid.In the low-salt groups,the dominant genera were Lactobacillus and Lactococcus,whereas Staphylococcus,Weissella,and Tetragenococcus were dominant in the high-salt groups.Higher total free amino acids and essential amino acids,organic acids,hexanoic acid ethyl ester and octanoic acid ethyl ester were found in the low-salt groups.The RDA analysis revealed that Lactococcus was closely related to product quality,with the S3F10(3%salt and 10%rice f lour)group outperforming the others in the sensory evaluation.Therefore,3%salt and 10%rice flour were considered more appropriate for the production of healthy and tasty fermented sour meats.
基金the National Natural Science Foundation of China(Grant No.51176051 and 51106054)the National Basic Research Program of China(973 Program,No.2009CB219504-03)
文摘CO2 capture by hydrate formation is a novel gas separation technology, by which CO2 is selectively engaged in the cages of hydrate and is separated with other gases, based on the differences of phase equilibrium for CO2 and other gases. However. rigorous temperature and pressure, high energy cost and industrialized hydration separator dragged the development of the hydrate based CO2 capture. In this paper, the key problems in CO2 capture from the different sources such as shifted synthesis gas, flue gas and sour natural gas or biogas were analyzed. For shifted synthesis gas and flue gas, its high energy consumption is the barrier, and for the sour natural gas or biogas （CO2/CH4 system）, the bottleneck is how to enhance the selectivity of CO2 hydration. For these gases, scale-up is the main difficulty. Also, this paper explored the possibility of separating different gases by selective hydrate formation and reviewed the progress of CO2 separation from shifted synthesis gas, flue gas and sour natural gas or biogas.
基金supported by the National High Technology Research and Development Program of China (863 Program) (No. 2007AA06Z209)the National Natural Science Foundation of China (No. 50974104,50774062 and 50474039)
文摘Sulfur deposition in the formation, induced by a reduction in the solubility of the sulfur in the gas phase, may significantly reduce the inflow performance of sour gas wells and some wells in sour gas reservoirs have even become completely plugged with deposited sulfur within several months. Accurate prediction and effective management of sulfur deposition are crucial to the economic viability of sour gas reservoirs. In this paper, a dynamic flow experiment was carried out to investigate formation damage resulting from sulfur deposition using an improved experimental method. The core sample was extracted from the producing interval of the LG2 well, LG gas field in the Sichuan Basin. The experimental temperature was 26 °C and the initial pressure was 19 MPa. The displacement pressure continuously decreased from 19 to 10 MPa, and the depletion process lasted 15 days. Then the core was removed and dried. The core mass and core permeability were measured before and after experiments. Experimental results indicated that the core mass increased from 48.372 g before experiment to 48.386 g afterwards, while the core permeability reduced from 0.726 to 0.608 md during the experiment. Then the core was analyzed with a scanning electron microscope (SEM) and energy-dispersive X-ray mapping. The deposition pattern and micro-distribution of elemental sulfur was observed and the deposited elemental sulfur distributed as a film around the pore surface.
基金Supported by the Shanghai Pujiang Program(16PJ1407900)
文摘The removal of NO from oxy-fuel combustion is typically incorporated in sour gas compression purification process. This process involves the oxidation of NO to NO2 at a high pressure of 1–3 MPa, followed by absorption of NO2 by water. In this pressure range, the NO conversion rates calculated using the existing kinetic constants are often higher than those obtained experimentally. This study aimed to achieve the regression of kinetic parameters of NO oxidation based on the existing experimental results and theoretical models.Based on three existing NO oxidation mechanisms, first, the expressions for NO conversion against residence time were derived. By minimizing the mean-square errors of NO conversion ratio, the optimum kinetic rate constants were obtained. Without considering the reverse reaction for NO oxidation, similar mean-square errors for NO conversion ratio were calculated. Considering the reverse reaction for NO oxidation based on the termolecular reaction mechanism, the minimum mean-square error for NO conversion ratio was obtained. Thus, the optimum NO oxidation rate in the pressure range 0.1–3 MPa can be expressed as follows:-d[NO]/dt=d[NO2]/dt=0.0026[NO]2[O2]-0.0034[NO2]2 Detailed elementary reactions for N2/NO/NO2/O2 system were established to simulate the NO oxidation rate. A sensitivity analysis showed that the critical elementary reaction is 2 NO + O2? 2 NO2. However, the simulated NO conversions at a high pressure of 10–30 bar are still higher than the experimental values and similar to those obtained from the models without considering the reverse reaction for NO oxidation.
基金financially supported by the earmarked fund for the China Agriculture Research System (CARS-27)the National Program for Quality and Safety Risk Assessment of Agricultural Products of China (GJFP2017003)the Scientific and Technological Innovation Project of the Chinese Academy of Agricultural Sciences (CAAS-ASTIP)
文摘In order to establish grading standards of evaluation indices for sour flavor of apples, 10 indices of samples from 106 apple cultivars were tested, including： malic acid（Mal）, oxalic acid（Oxa）, citric acid（Cit）, lactic acid（Lac）, succinic acid（Suc）, fumaric acid（Fum）, total organic acids（To A, the sum of the six organic acids tested）, titratable acid（TiA）, acidity value（AcV）, and pH value. For most of the cultivars studied（85.8%）, the order of the organic acid contents in apples was Mal〉Oxa〉Cit〉Lac〉Suc〉Fum. Mal was the dominant organic acid, on average, accounting for 94.5% of To A. Among the 10 indices, the dispersion of pH value was the smallest with a coefficient of variation of only 8.2%, while the coefficients of variation of the other nine indices were larger, ranging between 31 and 66%. There were significant linear relationships between Mal and two indices（ToA and AcV） as well as between ToA and AcV. There were significant logarithmic relationships between pH value and four indices： Mal, TiA, ToA, and AcV. All the equations had very high fitting accuracy and can be used to accurately predict related indices. According to this study, Mal, ToA, and AcV of apple were normally distributed, TiA was close to normally distributed, whereas pH value had a skewed distribution. Using the fitted normal distribution curves, the grading standards of Mal, TiA, ToA, and AcV were established. The grading node values of pH value were obtained using the logarithmic relationship between pH value and Mal. The grading standards of these five indices can be used to evaluate the sour flavor of apple. This study provides a scientific basis for evaluating apple flavor and selecting apple cultivars.
文摘Sweet and sour cherries contain several polyphenols that possess antioxidant and anti-inflammatory properties. Aim of this study was to investigate the effect of the maturity stage on phenol content and biological properties of extract of a local Morello-type of sour cherry (Prunus cerasus?L.), “visciola”. The study of total phenol content and total antioxidant potential was associated with the evaluation of the antioxidant property of extracts using a copper catalyzed human low density lipoproteins (LDL) oxidation as experimental model. Moreover, using albumin glycated by methylglyoxal, we evaluated the anti-glycation effect of fruit extract. The results demonstrated that fully ripened fruits exert higher antioxidant and anti-glycation properties when compared with partially ripened fruits. Information about the health-promoting components of “visciola” could lead to a better understanding and an increased consumption of these, including its use as functional food.
基金the support provided by the National Key R&D Program of China(No.2017YFB0602804)the National Natural Science Foundation of China(No.21878164)。
文摘Sour water contains ammonia,carbon dioxide,and hydrogen sulfides,producing from oil refining,coking,and coal gasification.To reduce the energy consumption in sour water stripping,a novel process is proposed which integrates with the bottom flashing mechanical vapor recompression heat pump(MVRHP)for treating such wastewater.Here,Aspen PlusTM as a powerful set of chemical process simulation software is utilized to investigate the economy and feasibility of the novel process.Comparison of the results of two process simulations,it can be seen that it is possible to reduce the total annual cost by nearly 45%to adopt the novel process,despite the capital investment increase 45%more than the conventional process.Thus,the provided conceptual design will play a guiding role in the industrialization of the process.
文摘The study was conducted in an organic nursery of sour cherry cultivars ＂Debreceni Botermo＂ and ＂Sabina＂ in the years 2010 and 2011. Cherry trees grafted on Mahaleb （Prunus mahaleb L.） seedlings were grown at a spacing of 25 crn × 1.0 m. In the nursery, an assessment was carried out of the effect of various biopreparations on such growth characteristics as the thickness and height of the maidens, the formation of lateral shoots and the total increase in their length. The control trees were not treated at all, but fertilized with an NPK fertilizer only （second control）. To stimulate growth, use was made of granular manure, mycorrhizal fungi in the form of the preparation Micosat, humic preparations or so-called vermicomposts （Humus UP, Humus Active）, extracts of marine algae （BF Quality） and of terrestrial plants （BF Arnin）, a product derived from yeast （Vinassa） and Tytanit. The specific biological effects of the preparations used in the sour cherry nursery for each morphological feature are presented in this paper in graphical form. A beneficial effect on the increase in the number of lateral shoots and the increase in their length was produced by the use of such products as： Micosat, Humus UP, Humus Active ＋ Aktywit PM and Vinassa. The most effective in this respect was BF Amin.
基金financial supported by the National Natural Science Foundation of China(Contract Nos.51904034,51734010).
文摘This study presents a new multiphase flow model with transient heat transfer and pressure coupling to simulate HTHP(high temperature and high pressure)sour gas“kicks”phenomena.The model is intended to support the estimation of wellbore temperature and pressure when sour gas kicks occur during drilling operation.The model considers sour gas solubility,phase transition and effects of temperature and pressure on the physical parameters of drilling fluid.Experimental data for a large-diameter pipe flow are used to validate the model.The results indicate that with fluid circulation,the annulus temperature with H2S kicks is the highest,followed by CO_(2),and CH_(4) is the lowest.The phase transition point of H2S is closer to wellhead compared with CO_(2),resulting in a faster expansion rate,which is more imperceptible and dangerous.With fluid circulation,the drilling fluid density and plastic viscosity both first decrease and then increase with the increase in the well depth.The bottom hole pressure when H2S kicks is greater than that for CO_(2) with the same amount of sour gas,and the pressure difference gradually increases with the increase of H2S/CO_(2) content.In addition,a parametric sensitivity analysis has been conducted to evaluate qualitatively and rank the influential factors affecting the bottom hole temperature and pressure.
文摘Timothy Mo,a famous British writer whose works have won many important prizes,experiences both Chinese culture and English culture since his childhood.Due to this kind of experience,his works are usually concerned with the issue of cultural conflict.Among these works,Sour Sweet is the most well-known one in China,and it has also been filmed as Soursweet in 1988 with the famous actress Zhang Aijia.In Sour Sweet,Timothy Mo tells a story about a Chinese family’s struggle in the UK.After experiencing a serious of cultural conflict,among the three family members Chen,Lily and Mui,only Lily achieves a delicate balance.After defining the process of establishing oneself in a new environment as a kind of human translation,the article applies AndréLefevere’s theory to study the three characters’different responses to the cultural conflict,analyze how different poetic and different strategies adopted to deal with ideology affect their translation,explain why does or doesn’t he/she translates himself/herself successfully,and finally gets the conclusion:because Lily deals well with the dominant ideological and poetical currents,and makes appropriate choice in face of cultural translatability and untranslatability,so only she can translate herself successfully.
文摘Cenozoic high\|K igneous rocks are widely distributed in eastern Tibet. These rocks are exposed as flows, dykes and small intrusions along a narrow north\|south trending zone, which follows Tertiary fold belts and the Batang—Lijiang and Ailao Shan—Red River strike\|slip systems. Although several models were proposed to interpret their petrogenesis (Deng, 1989; Arnaud et al., 1991; Turner et al., 1996; Yin et al., 1995; Miller et al., 1999), their origin still remains hotly debated. Moreover, the published results were only focused on the high\|K igneous rocks resulted from partial melting of an enriched lithospheric mantle. Here, we present the detailed documents to testify the existence of a new kind of high\|K igneous rocks in eastern Tibet.Our new 39 Ar/ 40 Ar age data (Wang et al., 1999) and published age data for high\|K rocks in eastern Tibet show two distinctive magmatic episodes: one between 42Ma and 24Ma, and the other since ca.16Ma. They correspond to two types of high\|K magmatism in eastern Tibet. We name the older and younger groups as types Ⅰ and Ⅱ, respectively.
