The variation of the principal stress of formations with the working and geo-mechanical conditions can trigger wellbore instabilities and adversely affect the well completion.A finite element model,based on the theory...The variation of the principal stress of formations with the working and geo-mechanical conditions can trigger wellbore instabilities and adversely affect the well completion.A finite element model,based on the theory of poro-elasticity and the Mohr-Coulomb rock damage criterion,is used here to analyze such a risk.The changes in wellbore stability before and after reservoir acidification are simulated for different pressure differences.The results indicate that the risk of wellbore instability grows with an increase in the production-pressure difference regardless of whether acidification is completed or not;the same is true for the instability area.After acidizing,the changes in the main geomechanical parameters(i.e.,elastic modulus,Poisson’s ratio,and rock strength)cause the maximum wellbore instability coefficient to increase.展开更多
A well-known hazardous metal and top contaminant in wastewater is hexavalent chromium. The two forms of most commonly found chromium are chromate ( CrO 4 2− ) and dichromate ( Cr 2 O 7 2− ). Leather tanning, cooling t...A well-known hazardous metal and top contaminant in wastewater is hexavalent chromium. The two forms of most commonly found chromium are chromate ( CrO 4 2− ) and dichromate ( Cr 2 O 7 2− ). Leather tanning, cooling tower blow-down, plating, electroplating, rinse water sources, anodizing baths etc. are the main sources of Cr (VI) contamination. The Cr (VI) is not only non-biodegradable in the environment but also carcinogenic to living population. It is still difficult to treat Cr contaminated waste water effectively, safely, eco-friendly, and economically. As a result, many techniques have been used to treat Cr (VI)-polluted wastewater, including adsorption, chemical precipitation, coagulation, ion-exchange, and filtration. Among these practices, the most practical method is adsorption for the removal of Cr (VI) from aqueous solutions, which has gained widespread acceptance due to the ease of use and affordability of the equipment and adsorbent. It has been revealed that Fe-based adsorbents’ oxides and hydroxides have high adsorptive potential to lower Cr (VI) content below the advised threshold. Fe-based adsorbents were also discovered to be relatively cheap and toxic-free in Cr (VI) treatment. Fe-based adsorbents are commonly utilized in industry. It has been discovered that nanoparticles of Fe-, Ti-, and Cu-based adsorbents have a better capacity to remove Cr (VI). Cr (VI) was effectively removed from contaminated water using mixed element-based adsorbents (Fe-Mn, Fe-Ti, Fe-Cu, Fe-Zr, Fe-Cu-Y, Fe-Mg, etc.). Initial findings suggest that Cr (VI) removal from wastewater may be accomplished by using magnesium ferrite nanomaterials as an efficient adsorbent.展开更多
[Objectives]The paper was to explore the effect of K fertilizer on the absorption of mineral elements in greenhouse-grown strawberry fruits.[Methods]A systematic investigation was conducted on the effects of K fertili...[Objectives]The paper was to explore the effect of K fertilizer on the absorption of mineral elements in greenhouse-grown strawberry fruits.[Methods]A systematic investigation was conducted on the effects of K fertilizer dosage levels on the absorption of mineral elements in Fengxiang strawberries,an excellent variety suitable for cultivation in Anhui Province.The investigation was carried out under medium N and P conditions in a greenhouse.[Results]The N content of strawberry fruits increased as the K_(2)O dosage increased within the range of 0-250 kg/hm^(2).Similarly,the P content of strawberry fruits increased gradually with the increase of K_(2)O dosage within the range of 0-125 kg/hm^(2).[Conclusions]This study presents a basis for enhancing the absorption of mineral elements in strawberry fruit by applying K appropriately.展开更多
[Objectives]This study was conducted to screen suitable seed stems of Fritillaria thunbergii Miq.from different provenances and to provide a theoretical basis for the high-yielding and high-efficiency cultivation of F...[Objectives]This study was conducted to screen suitable seed stems of Fritillaria thunbergii Miq.from different provenances and to provide a theoretical basis for the high-yielding and high-efficiency cultivation of F.thunbergii Miq.introduced to different places.[Methods]F.thunbergii Miq.from four different provenances including Zhejiang,Nantong and Chongqing were introduced and cultivated in Wanzhou of Chongqing.The contents of available Zn,Fe,Mn,Cu,Mo,N,P,K,Ca and Mg in rhizosphere soil of F.thunbergii Miq.during five growing stages were determined after selecting different stem sizes for field cultivation.[Results]Small stems of Pan an and Ningbo provenances(SSG3,121-160/kg)and middle stems of Nantong and Fengjie provenances(SSG2,81-120/kg)showed higher soil availability.[Conclusions]In the process of introduction and cultivation of F.thunbergii Miq.,high yield and high efficiency can be achieved by selecting smaller seed stems of F.thunbergii Miq.展开更多
Purpose:To analyze the application path of the integration of clinical medicine integrated courses with the elements of ideology and politics under the theory of“Sanquan Education,”and to provide references for the ...Purpose:To analyze the application path of the integration of clinical medicine integrated courses with the elements of ideology and politics under the theory of“Sanquan Education,”and to provide references for the promotion of educational reform in medical schools.Methods:60 clinical medicine undergraduates at Jiamusi University in 2018 and 2019 were randomly selected as research subjects.On the basis of the analysis of students’characteristics and pre-study content,the students were divided into the integration group and the traditional group,each with 30 students.Students in the integration group carried out clinical medicine integrated class with the integration of ideological and political elements.Students in the traditional group carried out the traditional clinical medicine integrated class.Classroom evaluation scales,anonymous questionnaires,and interviews were used to conduct research,collect data,and compare and observe the application effects.Results:After carrying out different modes of clinical medicine integrated courses,the undergraduates of the Excellent Physician Class in the integration group were higher than those in the traditional group in terms of teaching satisfaction,comprehensive quality,basic knowledge test,and case analysis scores through questionnaire analysis(P<0.05).In the evaluation of the effect of ideological education,the undergraduates of the Excellent Physician Class of the integration group were higher than the traditional group in terms of the acceptance of doctor-patient communication,the correct rate of mastering the history of the discipline,and the correct rate of mastering the frontiers and policies(P<0.05).Conclusion:Through the integration of clinical medicine integrated course and ideological and political elements,we can help students establish correct values while teaching them professional knowledge,improve the implementation of moral education in medical schools,cultivate excellent medical workers with high morality and firm beliefs for the society,and realize the fundamental educational task of establishing morality and educating people in medical schools in the context of“Sanquan Education.”展开更多
基金This work is financially sponsored by Tarim Oilfield“Study on Adaptability Evaluation and Parameter Optimization of Completion Technology in Bozi Block,Tarim Oilfield”(Item Number:201021113436).
文摘The variation of the principal stress of formations with the working and geo-mechanical conditions can trigger wellbore instabilities and adversely affect the well completion.A finite element model,based on the theory of poro-elasticity and the Mohr-Coulomb rock damage criterion,is used here to analyze such a risk.The changes in wellbore stability before and after reservoir acidification are simulated for different pressure differences.The results indicate that the risk of wellbore instability grows with an increase in the production-pressure difference regardless of whether acidification is completed or not;the same is true for the instability area.After acidizing,the changes in the main geomechanical parameters(i.e.,elastic modulus,Poisson’s ratio,and rock strength)cause the maximum wellbore instability coefficient to increase.
文摘A well-known hazardous metal and top contaminant in wastewater is hexavalent chromium. The two forms of most commonly found chromium are chromate ( CrO 4 2− ) and dichromate ( Cr 2 O 7 2− ). Leather tanning, cooling tower blow-down, plating, electroplating, rinse water sources, anodizing baths etc. are the main sources of Cr (VI) contamination. The Cr (VI) is not only non-biodegradable in the environment but also carcinogenic to living population. It is still difficult to treat Cr contaminated waste water effectively, safely, eco-friendly, and economically. As a result, many techniques have been used to treat Cr (VI)-polluted wastewater, including adsorption, chemical precipitation, coagulation, ion-exchange, and filtration. Among these practices, the most practical method is adsorption for the removal of Cr (VI) from aqueous solutions, which has gained widespread acceptance due to the ease of use and affordability of the equipment and adsorbent. It has been revealed that Fe-based adsorbents’ oxides and hydroxides have high adsorptive potential to lower Cr (VI) content below the advised threshold. Fe-based adsorbents were also discovered to be relatively cheap and toxic-free in Cr (VI) treatment. Fe-based adsorbents are commonly utilized in industry. It has been discovered that nanoparticles of Fe-, Ti-, and Cu-based adsorbents have a better capacity to remove Cr (VI). Cr (VI) was effectively removed from contaminated water using mixed element-based adsorbents (Fe-Mn, Fe-Ti, Fe-Cu, Fe-Zr, Fe-Cu-Y, Fe-Mg, etc.). Initial findings suggest that Cr (VI) removal from wastewater may be accomplished by using magnesium ferrite nanomaterials as an efficient adsorbent.
文摘[Objectives]The paper was to explore the effect of K fertilizer on the absorption of mineral elements in greenhouse-grown strawberry fruits.[Methods]A systematic investigation was conducted on the effects of K fertilizer dosage levels on the absorption of mineral elements in Fengxiang strawberries,an excellent variety suitable for cultivation in Anhui Province.The investigation was carried out under medium N and P conditions in a greenhouse.[Results]The N content of strawberry fruits increased as the K_(2)O dosage increased within the range of 0-250 kg/hm^(2).Similarly,the P content of strawberry fruits increased gradually with the increase of K_(2)O dosage within the range of 0-125 kg/hm^(2).[Conclusions]This study presents a basis for enhancing the absorption of mineral elements in strawberry fruit by applying K appropriately.
基金Supported by Technological Innovation and Application Demonstration Project of Chongqing City(cstc2018jscx-msybX0367).
文摘[Objectives]This study was conducted to screen suitable seed stems of Fritillaria thunbergii Miq.from different provenances and to provide a theoretical basis for the high-yielding and high-efficiency cultivation of F.thunbergii Miq.introduced to different places.[Methods]F.thunbergii Miq.from four different provenances including Zhejiang,Nantong and Chongqing were introduced and cultivated in Wanzhou of Chongqing.The contents of available Zn,Fe,Mn,Cu,Mo,N,P,K,Ca and Mg in rhizosphere soil of F.thunbergii Miq.during five growing stages were determined after selecting different stem sizes for field cultivation.[Results]Small stems of Pan an and Ningbo provenances(SSG3,121-160/kg)and middle stems of Nantong and Fengjie provenances(SSG2,81-120/kg)showed higher soil availability.[Conclusions]In the process of introduction and cultivation of F.thunbergii Miq.,high yield and high efficiency can be achieved by selecting smaller seed stems of F.thunbergii Miq.
基金Heilongjiang Province Education Science Planning Key Project(Project number:GJB1423157)。
文摘Purpose:To analyze the application path of the integration of clinical medicine integrated courses with the elements of ideology and politics under the theory of“Sanquan Education,”and to provide references for the promotion of educational reform in medical schools.Methods:60 clinical medicine undergraduates at Jiamusi University in 2018 and 2019 were randomly selected as research subjects.On the basis of the analysis of students’characteristics and pre-study content,the students were divided into the integration group and the traditional group,each with 30 students.Students in the integration group carried out clinical medicine integrated class with the integration of ideological and political elements.Students in the traditional group carried out the traditional clinical medicine integrated class.Classroom evaluation scales,anonymous questionnaires,and interviews were used to conduct research,collect data,and compare and observe the application effects.Results:After carrying out different modes of clinical medicine integrated courses,the undergraduates of the Excellent Physician Class in the integration group were higher than those in the traditional group in terms of teaching satisfaction,comprehensive quality,basic knowledge test,and case analysis scores through questionnaire analysis(P<0.05).In the evaluation of the effect of ideological education,the undergraduates of the Excellent Physician Class of the integration group were higher than the traditional group in terms of the acceptance of doctor-patient communication,the correct rate of mastering the history of the discipline,and the correct rate of mastering the frontiers and policies(P<0.05).Conclusion:Through the integration of clinical medicine integrated course and ideological and political elements,we can help students establish correct values while teaching them professional knowledge,improve the implementation of moral education in medical schools,cultivate excellent medical workers with high morality and firm beliefs for the society,and realize the fundamental educational task of establishing morality and educating people in medical schools in the context of“Sanquan Education.”
基金Natural Science Foundation of China(No.51871244)Hunan Provincial Innovation Foundation for Postgraduate,China(No.CX20200172)Fundamental Research Funds for the Central Universities of Central South University,China(No.1053320190103)。
