In order to solve the drifting away of thermal fog droplets during thermal spraying and the incompatibility between fog droplet carrier and conventional com- mercial agro-chemicals, the fog droplet carrier, surfactant...In order to solve the drifting away of thermal fog droplets during thermal spraying and the incompatibility between fog droplet carrier and conventional com- mercial agro-chemicals, the fog droplet carrier, surfactant, condensation nucleus ma- terial and antifreeze, dispersant, thickener and defoamer were screened and assem- bled to develop a thermal fog sedimentation stabilizer in this study, thereby provid- ing technical support for application and promotion of thermal spraying technology in pest and disease control in crops.展开更多
AIM： To explore whether cyclooxygenase 2 （COX-2） -765G〉C polymorphism is associated with susceptibility of colorectal cancer （CRC） and to evaluate the risk of colorectal cancer in relation to environmental expos...AIM： To explore whether cyclooxygenase 2 （COX-2） -765G〉C polymorphism is associated with susceptibility of colorectal cancer （CRC） and to evaluate the risk of colorectal cancer in relation to environmental exposures and polymorphism. METHODS： We conducted a case-control study of 137 patients with colorectal cancer and 199 cancerfree controls in northeast China. Multivariate logistic regression analysis was performed to calculate the adjusted odds ratio （OR） and 95% confidence interval （95% CI）. RESULTS： The -765G〉C polymorphism was not independently associated with CRC risk. However, risk associated with the polymorphism differed by smoking and body mass index （BMI）. Smoking and BMI associated risks were stronger among those with -765GG genotype, showing that smokers had a 2.682-fold greater risk of CRC than nonsmokers （51/43 vs 68/126, P = 0.006）. Compared to those with a normal body mass index （BMI 18.5-22.9）, those with overweight （BMI 23-24.9） had a 3.909-fold higher risk of CRC （OR = 3.909, 95% CI = 2.081-7.344; P 〈 0.001）, while those with obesity （BMI 〉 25） had a 2.031- fold higher risk of CRC （OR = 1.107, 95% CI = 1.107-3.726; P = 0.022）. is not associated with an increased risk of CRC, -765GG genotype appears to be related to an increased risk in the presence of smoking and higher BMI.展开更多
This paper examines the effect of equalizing ignition delay in a compression ignition engine.Two sets of tests were conducted,i.e.a set of constant injection timing tests with start of fuel injection at 10°crank ...This paper examines the effect of equalizing ignition delay in a compression ignition engine.Two sets of tests were conducted,i.e.a set of constant injection timing tests with start of fuel injection at 10°crank angle degree(CAD)before top dead center(BTDC)and a set of constant ignition timing tests while also keeping the 10℃AD BTDC injection and adding ignition improver(2-ethylhexylnitrate-,2-EHN)to the fuel mixtures.Soot particles were characterized using DMS-500 instrument in terms of mass,size,and number.The experimental results showed that adding 2-EHN to the model fuel blends reduced the soot surface area,soot mass concentration and soot mean size.Replacing 20 vol%of a C 7-heptane with 20 vol%methyl-decanoate(an oxygenated C 11 molecule)did not affect the ignition delay or rate of fuel air premixing,the peak in-cylinder pressure or heat release rates.Toluene addition(0−22.5 vol%)to heptane increased the mean size of the soot particles generated by only 3%while also resulted in a slight increase in the peak cylinder pressure and peak heat release rates.Blending toluene and methyl-decanoate into heptane without adding 2-EHN increased the premix phase fraction by at least 13%.However,by adding 2-EHN(4×10^(−4)−1.5×10^(−3)),the premixed phase fraction decreased by at least 11%.展开更多
The soot surface growth plays significant role on the soot mass accumulation,which starts with H(hydrogen)atom abstraction forming activated soot surface sites,and is followed by the acetylene addition process.In this...The soot surface growth plays significant role on the soot mass accumulation,which starts with H(hydrogen)atom abstraction forming activated soot surface sites,and is followed by the acetylene addition process.In this study,the effect of the mixture inhomogeneity and combustion temperature on the soot surface activity and soot formation was investigated by developing a new multi-step phenomenological(MSP)soot model of diesel engines.A new detailed soot surface growth mechanism was proposed by correlation analysis of combustion parameters with soot formation.The inhomogeneity coefficient of soot surface activityαCH and the specific rate of soot surface growth R CH were derived to highlight the effect of inhomogeneity of mixture and combustion temperature on soot formation.The predicted diesel engine-out soot agreed well with experimental findings in wide ranges of combustion conditions.In the case of lower engine load with single fuel injection and higher EGR(exhaust gas recirculation)rate,it had quiet homogeneous mixtures before ignition when the combustion temperature dominated the soot surface activity.At medium engine load with multi-pulse fuel injections,it got mixture slightly stratified before ignition and revealed that the mixture inhomogeneity became more dominated on soot surface activity than the combustion temperature.An increased soot surface activity led to increased soot emission.Under the full engine loads with single fuel injection but quite high boost pressure over 0.4 MPa,it led to the combustion conditions of higher mixture density and higher mixture heat capacity,which benefits the mixture homogeneity.The decay rate of soot surface activity became lower due to the decreased combustion temperature and the soot surface activity decreased due to improved mixture homogeneity.In addition,the lowered intake oxygen concentration due to usage of EGR played a role to lower the specific rate of soot surface growth R CH,but to increase the soot surface activityαCH.展开更多
基金Supported by Anhui Agricultural Science and Technology Innovation Fund(16A1132)Science and Technology Major Project of Anhui Province(15CZZ03132)Special Fund for Talent Development in Anhui Province(13C1109)~~
文摘In order to solve the drifting away of thermal fog droplets during thermal spraying and the incompatibility between fog droplet carrier and conventional com- mercial agro-chemicals, the fog droplet carrier, surfactant, condensation nucleus ma- terial and antifreeze, dispersant, thickener and defoamer were screened and assem- bled to develop a thermal fog sedimentation stabilizer in this study, thereby provid- ing technical support for application and promotion of thermal spraying technology in pest and disease control in crops.
基金Program for New Century Excellent Talents fromUniversity,No.NCET-06-0296
文摘AIM： To explore whether cyclooxygenase 2 （COX-2） -765G〉C polymorphism is associated with susceptibility of colorectal cancer （CRC） and to evaluate the risk of colorectal cancer in relation to environmental exposures and polymorphism. METHODS： We conducted a case-control study of 137 patients with colorectal cancer and 199 cancerfree controls in northeast China. Multivariate logistic regression analysis was performed to calculate the adjusted odds ratio （OR） and 95% confidence interval （95% CI）. RESULTS： The -765G〉C polymorphism was not independently associated with CRC risk. However, risk associated with the polymorphism differed by smoking and body mass index （BMI）. Smoking and BMI associated risks were stronger among those with -765GG genotype, showing that smokers had a 2.682-fold greater risk of CRC than nonsmokers （51/43 vs 68/126, P = 0.006）. Compared to those with a normal body mass index （BMI 18.5-22.9）, those with overweight （BMI 23-24.9） had a 3.909-fold higher risk of CRC （OR = 3.909, 95% CI = 2.081-7.344; P 〈 0.001）, while those with obesity （BMI 〉 25） had a 2.031- fold higher risk of CRC （OR = 1.107, 95% CI = 1.107-3.726; P = 0.022）. is not associated with an increased risk of CRC, -765GG genotype appears to be related to an increased risk in the presence of smoking and higher BMI.
文摘This paper examines the effect of equalizing ignition delay in a compression ignition engine.Two sets of tests were conducted,i.e.a set of constant injection timing tests with start of fuel injection at 10°crank angle degree(CAD)before top dead center(BTDC)and a set of constant ignition timing tests while also keeping the 10℃AD BTDC injection and adding ignition improver(2-ethylhexylnitrate-,2-EHN)to the fuel mixtures.Soot particles were characterized using DMS-500 instrument in terms of mass,size,and number.The experimental results showed that adding 2-EHN to the model fuel blends reduced the soot surface area,soot mass concentration and soot mean size.Replacing 20 vol%of a C 7-heptane with 20 vol%methyl-decanoate(an oxygenated C 11 molecule)did not affect the ignition delay or rate of fuel air premixing,the peak in-cylinder pressure or heat release rates.Toluene addition(0−22.5 vol%)to heptane increased the mean size of the soot particles generated by only 3%while also resulted in a slight increase in the peak cylinder pressure and peak heat release rates.Blending toluene and methyl-decanoate into heptane without adding 2-EHN increased the premix phase fraction by at least 13%.However,by adding 2-EHN(4×10^(−4)−1.5×10^(−3)),the premixed phase fraction decreased by at least 11%.
基金supported by the National Natural Science Foundation of China through its key project funding CNFS(Grant No.51236005)the Ministry of Science and Technology through its 973 National Key Project(Grant No.2013CB228401)
文摘The soot surface growth plays significant role on the soot mass accumulation,which starts with H(hydrogen)atom abstraction forming activated soot surface sites,and is followed by the acetylene addition process.In this study,the effect of the mixture inhomogeneity and combustion temperature on the soot surface activity and soot formation was investigated by developing a new multi-step phenomenological(MSP)soot model of diesel engines.A new detailed soot surface growth mechanism was proposed by correlation analysis of combustion parameters with soot formation.The inhomogeneity coefficient of soot surface activityαCH and the specific rate of soot surface growth R CH were derived to highlight the effect of inhomogeneity of mixture and combustion temperature on soot formation.The predicted diesel engine-out soot agreed well with experimental findings in wide ranges of combustion conditions.In the case of lower engine load with single fuel injection and higher EGR(exhaust gas recirculation)rate,it had quiet homogeneous mixtures before ignition when the combustion temperature dominated the soot surface activity.At medium engine load with multi-pulse fuel injections,it got mixture slightly stratified before ignition and revealed that the mixture inhomogeneity became more dominated on soot surface activity than the combustion temperature.An increased soot surface activity led to increased soot emission.Under the full engine loads with single fuel injection but quite high boost pressure over 0.4 MPa,it led to the combustion conditions of higher mixture density and higher mixture heat capacity,which benefits the mixture homogeneity.The decay rate of soot surface activity became lower due to the decreased combustion temperature and the soot surface activity decreased due to improved mixture homogeneity.In addition,the lowered intake oxygen concentration due to usage of EGR played a role to lower the specific rate of soot surface growth R CH,but to increase the soot surface activityαCH.
