Apricot has a long history of cultivation and has many varieties and types. The traditional variety identification methods are timeconsuming and labor-consuming, posing grand challenges to apricot resource management....Apricot has a long history of cultivation and has many varieties and types. The traditional variety identification methods are timeconsuming and labor-consuming, posing grand challenges to apricot resource management. Tool development in this regard will help researchers quickly identify variety information. This study photographed apricot fruits outdoors and indoors and constructed a dataset that can precisely classify the fruits using a U-net model (F-score:99%), which helps to obtain the fruit's size, shape, and color features. Meanwhile, a variety search engine was constructed, which can search and identify variety from the database according to the above features. Besides, a mobile and web application (ApricotView) was developed, and the construction mode can be also applied to other varieties of fruit trees.Additionally, we have collected four difficult-to-identify seed datasets and used the VGG16 model for training, with an accuracy of 97%, which provided an important basis for ApricotView. To address the difficulties in data collection bottlenecking apricot phenomics research, we developed the first apricot database platform of its kind (ApricotDIAP, http://apricotdiap.com/) to accumulate, manage, and publicize scientific data of apricot.展开更多
At present,GNSS-Acoustic(GNSS-A)combined technology is widely used in positioning for seafloor geodetic stations.Based on Sound Velocity Profiles(SVPs)data,the equal gradient acoustic ray-tracing method is applied in ...At present,GNSS-Acoustic(GNSS-A)combined technology is widely used in positioning for seafloor geodetic stations.Based on Sound Velocity Profiles(SVPs)data,the equal gradient acoustic ray-tracing method is applied in high-precision position inversion.However,because of the discreteness of the SVPs used in the forementioned method,it ignores the continuous variation of sound velocity structure in time domain,which worsens the positioning accuracy.In this study,the time-domain variation of Sound Speed Structure(SSS)has been considered,and the cubic B-spline function is applied to characterize the perturbed sound velocity.Based on the ray-tracing theory,an inversion model of“stepwise iteration&progressive corrections”for both positioning and sound speed information is proposed,which conducts the gradual correction of seafloor geodetic station coordinates and disturbed sound velocity.The practical data was used to test the effectiveness of our method.The results show that the Root Mean Square(RMS)errors of the residual values of the traditional methods without sound velocity correction,based on quadratic polynomial correction and based on cubic B-spline function correction are 1.43 ms,0.44 ms and 0.21 ms,respectively.The inversion model with sound velocity correction can effectively eliminate the systematic error caused by the change of SSS,and significantly improve the positioning accuracy of the seafloor geodetic stations.展开更多
With increased exploration in the faulted basins of eastern China,petroleum exploration in this region has been challenged by unclear remaining petroleum resources distribution,complex reservoir and hydrocarbon enrich...With increased exploration in the faulted basins of eastern China,petroleum exploration in this region has been challenged by unclear remaining petroleum resources distribution,complex reservoir and hydrocarbon enrichment patterns,and lacking of suitable exploration techniques.Aiming at resolving these problems,studies on source rocks,reservoirs,hydrocarbon accumulation and geophysical prospection were carried out by laboratory analysis,reservoir anatomy,and seismic analysis.A highlyefficient hydrocarbon generation/expulsion model of source rocks in saline environment was established,which aided in the discovery of a new set of source rocks in the Jiyang Depression.This study also reveals the formation process of high-quality reservoir by alternating acid and alkaline fluids during deposition and diagenesis,and pattern of secondary pores development in deep clastic rocks.Through the fine anatomy of the oil reservoirs,an orderly distribution pattern of the oil reservoirs is established,and the potential exploration targets in the undrilled area are identified.In addition,single-point highdensity seismic acquisition and high-resolution imaging technologies are developed,enabling fine and efficient exploration in areas with high exploration maturity.The research result plays a leading and demonstrative role in the fine and efficient exploration of faulted basins in eastern China.展开更多
Lead dissolved in water must be removed in order not to cause diseases, especially from high pH aqueous solution. Various oxides having high specific surface area are often applied to remove lead in water media. To im...Lead dissolved in water must be removed in order not to cause diseases, especially from high pH aqueous solution. Various oxides having high specific surface area are often applied to remove lead in water media. To improve removal ability for lead species, it is necessary to understand the adsorbed structure of lead species on oxides. At first, the adsorption behavior of lead from high pH solution in the presence of Ca<sup>2+</sup> and Na+ was compared. Lead and calcium species were adsorbed up to the monolayer, and the adsorption isotherm was analyzed as Langmuir-type adsorption. In the presence of Ca<sup>2+</sup>, the amount of removed lead was reduced. To clarify this influence of Ca<sup>2+</sup>, X-ray absorption spectroscopy was adopted. It was for the first time revealed that lead species at pH > 12 and pH < 10.5 differed, and that lead species adsorbed on various oxides had a similar structure.展开更多
Objective:This study aims to evaluate the natural history of patients with chronic lymphocytic leukemia(CLL)and a 17p deletion(17p-)and identify the predictive factors within this subgroup.Methods:The sample of patien...Objective:This study aims to evaluate the natural history of patients with chronic lymphocytic leukemia(CLL)and a 17p deletion(17p-)and identify the predictive factors within this subgroup.Methods:The sample of patients with CLL were analyzed by fluorescence in situ hybridization for deletions in chromosome bands 11q22,13q14 and 17p13;trisomy of bands 12q13;and translocation involving band 14q32.The data from 456 patients with or without a 17p-were retrospectively collected and analyzed.Results:The overall response rate(ORR)in patients with a 17p-was 56.9%,and patients with a high percentage of 17p-(defined as more than 25%of cells harbouring a 17p-)had a lower ORR.The median overall survival(OS)in patients with a 17p-was 78.0 months,which was significantly shorter than the OS in patients without this genetic abnormality(median 162.0 months,P<0.001).Within the subgroup with a 17p-,the progression-free survival was significantly shorter in patients at Binet stage B-C and patients with elevated lactate dehydrogenase(LDH),B symptoms,unmutated IGHV and a high percentage of 17p-.Conclusions:These results indicated that patients with a 17p-CLL have a variable prognosis that might be predicted using simple clinical and laboratory characteristics.展开更多
Continuous homogenous azeotropic distillation(CHAD) and pressure-swing distillation(PSD) are explored to separate a minimum-boiling azeotropic system of ethyl acetate and n-hexane. The CHAD process with acetone as the...Continuous homogenous azeotropic distillation(CHAD) and pressure-swing distillation(PSD) are explored to separate a minimum-boiling azeotropic system of ethyl acetate and n-hexane. The CHAD process with acetone as the entrainer and the PSD process with the pressures of 0.1 MPa and 0.6 MPa in two columns are designed and simulated by Aspen Plus. The operating conditions of the two processes are optimized via a sequential modular approach to obtain the minimum total annual cost(TAC). The computational results show that the partially heat integrated pressure-swing distillation(HIPSD) has reduced in the energy cost and TAC by 40.79% and 35.94%, respectively, than the conventional PSD, and has more greatly reduced the energy cost and TAC by 62.61% and 49.26% respectively compared with the CHAD process. The comparison of CHAD process and partially HIPSD process illustrates that the partially HIPSD has more advantages in averting the product pollution, energy saving, and economy.展开更多
Designing the low cost, active, durable, and alcohol-tolerant cathode catalysts towards the oxygen reduction reaction(ORR) is significant for the large-scale commercialization of direct alcohol fuel cells.Recently, Pd...Designing the low cost, active, durable, and alcohol-tolerant cathode catalysts towards the oxygen reduction reaction(ORR) is significant for the large-scale commercialization of direct alcohol fuel cells.Recently, Pd-based nanocrystals have attracted attention as Pt-alternative cathode catalysts towards the ORR in the alkaline electrolyte. Unfortunately, the pristine Pd-based nanocrystals lack the selectivity towards the ORR due to their inherent activity for the alcohol molecule oxidation reaction in the alkaline electrolyte. In this work, polyethyleneimine(PEI) modified Au Pd alloy nanocrystals with Au-rich Au Pd alloy cores and Pd-rich Pd Au alloy shells(AuPd@PdAu-PEI) are successfully synthesized using a traditional chemical reduction method in presence of PEI. The rotating disk electrode(RDE) technique is applied to evaluate the ORR performance of AuPd@PdAu-PEI nanocrystals. Compared with commercial Pd black,AuPd@PdAu-PEI nanocrystals show significantly enhanced activity and durability towards the ORR, and simultaneously exhibit particular alcohol tolerance towards the ORR in the alkaline electrolyte.展开更多
Objective:To discuss and compare the plasma pharmacokinetics after three oral Panax notoginseng saponin(PNS)administrations in beagle dogs.PNS is the main active ingredient of the traditional Chinese medicine(TCM)Pana...Objective:To discuss and compare the plasma pharmacokinetics after three oral Panax notoginseng saponin(PNS)administrations in beagle dogs.PNS is the main active ingredient of the traditional Chinese medicine(TCM)Panax notoginseng.Although its outstanding therapeutic efficacy has been demonstrated by various researchers,its broader application is restricted by the low bioavailability of PNS.Methods:An ultra-high performance liquid chromatographyetandem mass spectrometry(UPLC-MS/MS)method for the simultaneous quantification of notoginsenoside R1,ginsenoside Rg1,ginsenoside Rb1,ginsenoside Rd,and ginsenoside Re in beagle dog plasma was developed and validated.The plasma samples were subjected to liquideliquid extraction with acetone and methanol,and separated on an ACQUITY C18 column(100×2.1 mm ID,1.7 mm)using acetonitrile and water as the mobile phase with a run time of 4.5 min.Results:The analytes were detected without interference in Selected Reaction Monitoring mode with positive electrospray ionization.The validated method was successfully used in comparative pharmacokinetic studies of the five saponins in beagle dogs after oral administration of three PNS preparations.Blood samples were collected up to 192 h after administration and pharmacokinetic parameters were calculated using DAS 3.20 and SPSS 17.0.The AUC_(0-t)values of Re and R1 were significantly higher in soft capsules than in hard capsules.However,the AUC_(0-t)values between hard and soft capsules were not significantly different for the other three componentsdRb1,Rd and Rg1.Conclusion:Our intuitive analysis suggests that the bioavailability of PNS in soft capsules is greater than in hard capsules.展开更多
Ammonia synthesis by electrocatalytic nitrogen reduction reaction(NRR)is considered as a promising alternative to the Haber−Bosch process.However,due to the extremely low ammonia yield and easily accessible extraneous...Ammonia synthesis by electrocatalytic nitrogen reduction reaction(NRR)is considered as a promising alternative to the Haber−Bosch process.However,due to the extremely low ammonia yield and easily accessible extraneous contamination in the laboratory,NRR study always suffers from fluctuation and variability.Finding and eliminating all kinds of possible extraneous contamination is crucial to evaluate the performance of electrocatalytic ammonia synthesis accurately.In this work,we systematically explored two factors that affect NRR results but are easy to be ignored:the selection of membrane for NRR and the unconscious N-source in NRR catalysts.After series of experiments,we proposed a low-cost and almost pollution-free Celgard 3501 membrane as the separator for NRR to avoid the adsorption and release of ammonia by the membrane.In addition,we proposed a pre-reduction strategy to remove residual or adsorbed NOx contaminants in catalysts.These two solutions will help the community to evaluate the NRR activity more accurately.展开更多
Encephalomyocarditis virus (EMCV) and porcine circovirus type 2 (PCV2) are common causative agents with high infection rate in pig farms, thus a combined vaccine against both EMCV and PCV2 is highly desirable. In the ...Encephalomyocarditis virus (EMCV) and porcine circovirus type 2 (PCV2) are common causative agents with high infection rate in pig farms, thus a combined vaccine against both EMCV and PCV2 is highly desirable. In the present study, we developed an oil-adjuvant combination vaccine candidate comprising of inactivated EMCV and PCV2, and evaluated the safety and immunogenicity in mice and swine. The combination vaccine was found to elicit serum antibodies and had strong neutralization activity, more importantly, passive immunization with the combined vaccine protected swine against either EMCV or PCV2 lethal infections, whereas the monovalent vaccine only prevent the one of two virus challenge. Our results demonstrated the combined vaccine was safe and induced protective immune response in mice and swine as evident from sero-conservation as well as challenge studies in swine, indicating that component vaccines did not interfere with the immunogenicity of each other.展开更多
A rapid resolution liquid chromatographic (RRLC) method for the determination of eight polyphenols in to-bacco was developed. Polyphenols were extracted from tobacco samples by methanol/ water in an ultrasonic bath, t...A rapid resolution liquid chromatographic (RRLC) method for the determination of eight polyphenols in to-bacco was developed. Polyphenols were extracted from tobacco samples by methanol/ water in an ultrasonic bath, then subjected to clean up by solid phase extraction. The separation was performed on a 50 × 4.6 mm, 1.8 μm ZORBAX Eclipse XDB-C18 column. Compared with conventional HPLC method, the analysis time for eight polyphenols by RRLC method was reduced from 20 to 5 min without sacrificing resolution, and the sensitivity was improved. This method appears simple, accurate and precious. The relative standard devia-tions (RSD) of overall analysis procedure for eight tobacco polyphenols were less than 2% with the recover-ies ranging from 94% to 107%. This method could be applied to the rapid determination of major polyphe-nols in tobacco with satisfactory results.展开更多
Ammonia synthesis by electrocatalytic nitrogen reduction reaction(EC-NRR)has gained momentum in recent years fueled by its potential to operate at ambient conditions,unlike the highly energyintensive yet long-standing...Ammonia synthesis by electrocatalytic nitrogen reduction reaction(EC-NRR)has gained momentum in recent years fueled by its potential to operate at ambient conditions,unlike the highly energyintensive yet long-standing Haber-Bosch process.However,the large disparity of the yields and Faradic efficiencies reported for EC-NRR raises serious concerns about the reliability of the experimental results.In this perspective,we elaborate on the potential sources of error when assessing EC-NRR and update the testing protocols to circumvent them,and more importantly,we pose a general call for consensus on ammonia production analysis and reporting to lay the solid foundations that this burgeoning field requires to thrive.展开更多
Based on artificial forest of Calotropis gigantea (L.) Dryand. area of 20.1 hm2, planted in the base of seed management station in Yuanjiang County, Yunnan Province, according to the average standard wooden method, th...Based on artificial forest of Calotropis gigantea (L.) Dryand. area of 20.1 hm2, planted in the base of seed management station in Yuanjiang County, Yunnan Province, according to the average standard wooden method, the stand biomass was calculated in this paper. Based on the survey data of representative sample trees, the single-tree biomass model was constructed.展开更多
基金supported by the Fundamental Research Funds for the Central Non-profit Research Institution of the Chinese Academy of Forestry (Grant No.CAFYBB2020ZY003)the Key S&T Project of Inner Mongolia (Grant No.2021ZD0041-001-002)the Central Public-interest Scientific Institution Basal Research Fund (Grant No.11024316000202300001)。
文摘Apricot has a long history of cultivation and has many varieties and types. The traditional variety identification methods are timeconsuming and labor-consuming, posing grand challenges to apricot resource management. Tool development in this regard will help researchers quickly identify variety information. This study photographed apricot fruits outdoors and indoors and constructed a dataset that can precisely classify the fruits using a U-net model (F-score:99%), which helps to obtain the fruit's size, shape, and color features. Meanwhile, a variety search engine was constructed, which can search and identify variety from the database according to the above features. Besides, a mobile and web application (ApricotView) was developed, and the construction mode can be also applied to other varieties of fruit trees.Additionally, we have collected four difficult-to-identify seed datasets and used the VGG16 model for training, with an accuracy of 97%, which provided an important basis for ApricotView. To address the difficulties in data collection bottlenecking apricot phenomics research, we developed the first apricot database platform of its kind (ApricotDIAP, http://apricotdiap.com/) to accumulate, manage, and publicize scientific data of apricot.
基金National Natural Science Foundation of China(Nos.41931076,42174020)Laoshan Laboratory(No.LSKJ202205101)State Key Laboratory of Geo-Information Engineering(No.SKLGIE2020-M-1-1)。
文摘At present,GNSS-Acoustic(GNSS-A)combined technology is widely used in positioning for seafloor geodetic stations.Based on Sound Velocity Profiles(SVPs)data,the equal gradient acoustic ray-tracing method is applied in high-precision position inversion.However,because of the discreteness of the SVPs used in the forementioned method,it ignores the continuous variation of sound velocity structure in time domain,which worsens the positioning accuracy.In this study,the time-domain variation of Sound Speed Structure(SSS)has been considered,and the cubic B-spline function is applied to characterize the perturbed sound velocity.Based on the ray-tracing theory,an inversion model of“stepwise iteration&progressive corrections”for both positioning and sound speed information is proposed,which conducts the gradual correction of seafloor geodetic station coordinates and disturbed sound velocity.The practical data was used to test the effectiveness of our method.The results show that the Root Mean Square(RMS)errors of the residual values of the traditional methods without sound velocity correction,based on quadratic polynomial correction and based on cubic B-spline function correction are 1.43 ms,0.44 ms and 0.21 ms,respectively.The inversion model with sound velocity correction can effectively eliminate the systematic error caused by the change of SSS,and significantly improve the positioning accuracy of the seafloor geodetic stations.
基金This study is funded by the National major science&technology special project entitled Critical Technologies for Fine Exploration in the Bohai Bay Basin(No.2011ZX0500).
文摘With increased exploration in the faulted basins of eastern China,petroleum exploration in this region has been challenged by unclear remaining petroleum resources distribution,complex reservoir and hydrocarbon enrichment patterns,and lacking of suitable exploration techniques.Aiming at resolving these problems,studies on source rocks,reservoirs,hydrocarbon accumulation and geophysical prospection were carried out by laboratory analysis,reservoir anatomy,and seismic analysis.A highlyefficient hydrocarbon generation/expulsion model of source rocks in saline environment was established,which aided in the discovery of a new set of source rocks in the Jiyang Depression.This study also reveals the formation process of high-quality reservoir by alternating acid and alkaline fluids during deposition and diagenesis,and pattern of secondary pores development in deep clastic rocks.Through the fine anatomy of the oil reservoirs,an orderly distribution pattern of the oil reservoirs is established,and the potential exploration targets in the undrilled area are identified.In addition,single-point highdensity seismic acquisition and high-resolution imaging technologies are developed,enabling fine and efficient exploration in areas with high exploration maturity.The research result plays a leading and demonstrative role in the fine and efficient exploration of faulted basins in eastern China.
文摘Lead dissolved in water must be removed in order not to cause diseases, especially from high pH aqueous solution. Various oxides having high specific surface area are often applied to remove lead in water media. To improve removal ability for lead species, it is necessary to understand the adsorbed structure of lead species on oxides. At first, the adsorption behavior of lead from high pH solution in the presence of Ca<sup>2+</sup> and Na+ was compared. Lead and calcium species were adsorbed up to the monolayer, and the adsorption isotherm was analyzed as Langmuir-type adsorption. In the presence of Ca<sup>2+</sup>, the amount of removed lead was reduced. To clarify this influence of Ca<sup>2+</sup>, X-ray absorption spectroscopy was adopted. It was for the first time revealed that lead species at pH > 12 and pH < 10.5 differed, and that lead species adsorbed on various oxides had a similar structure.
基金supported by grants from the National Nature Science Foundation of China (No. 81200395, 81370632)the National Science and Technology supporting Program (No. 2014BAI09B12)+1 种基金the Fundamental Application and Advanced Technology Research Program of Tianjin (No. 15JCYBJC27900)the National Public Health Grand Research Foundation (No. 201202017)
文摘Objective:This study aims to evaluate the natural history of patients with chronic lymphocytic leukemia(CLL)and a 17p deletion(17p-)and identify the predictive factors within this subgroup.Methods:The sample of patients with CLL were analyzed by fluorescence in situ hybridization for deletions in chromosome bands 11q22,13q14 and 17p13;trisomy of bands 12q13;and translocation involving band 14q32.The data from 456 patients with or without a 17p-were retrospectively collected and analyzed.Results:The overall response rate(ORR)in patients with a 17p-was 56.9%,and patients with a high percentage of 17p-(defined as more than 25%of cells harbouring a 17p-)had a lower ORR.The median overall survival(OS)in patients with a 17p-was 78.0 months,which was significantly shorter than the OS in patients without this genetic abnormality(median 162.0 months,P<0.001).Within the subgroup with a 17p-,the progression-free survival was significantly shorter in patients at Binet stage B-C and patients with elevated lactate dehydrogenase(LDH),B symptoms,unmutated IGHV and a high percentage of 17p-.Conclusions:These results indicated that patients with a 17p-CLL have a variable prognosis that might be predicted using simple clinical and laboratory characteristics.
基金Supported by the Education Foundation of Chongqing(KJ1712307)the Application Technology Research and Developments Foundation of Fuling Technology Board(FLKJ,2016ABA1026)the Young Foundation of Yangtze Normal University(2015XJXM03)
文摘Continuous homogenous azeotropic distillation(CHAD) and pressure-swing distillation(PSD) are explored to separate a minimum-boiling azeotropic system of ethyl acetate and n-hexane. The CHAD process with acetone as the entrainer and the PSD process with the pressures of 0.1 MPa and 0.6 MPa in two columns are designed and simulated by Aspen Plus. The operating conditions of the two processes are optimized via a sequential modular approach to obtain the minimum total annual cost(TAC). The computational results show that the partially heat integrated pressure-swing distillation(HIPSD) has reduced in the energy cost and TAC by 40.79% and 35.94%, respectively, than the conventional PSD, and has more greatly reduced the energy cost and TAC by 62.61% and 49.26% respectively compared with the CHAD process. The comparison of CHAD process and partially HIPSD process illustrates that the partially HIPSD has more advantages in averting the product pollution, energy saving, and economy.
基金sponsored by the National Natural Science Foundation of China(21473111)Fundamental Research Funds for the Central Universities(GK201602002 and GK201701007)
文摘Designing the low cost, active, durable, and alcohol-tolerant cathode catalysts towards the oxygen reduction reaction(ORR) is significant for the large-scale commercialization of direct alcohol fuel cells.Recently, Pd-based nanocrystals have attracted attention as Pt-alternative cathode catalysts towards the ORR in the alkaline electrolyte. Unfortunately, the pristine Pd-based nanocrystals lack the selectivity towards the ORR due to their inherent activity for the alcohol molecule oxidation reaction in the alkaline electrolyte. In this work, polyethyleneimine(PEI) modified Au Pd alloy nanocrystals with Au-rich Au Pd alloy cores and Pd-rich Pd Au alloy shells(AuPd@PdAu-PEI) are successfully synthesized using a traditional chemical reduction method in presence of PEI. The rotating disk electrode(RDE) technique is applied to evaluate the ORR performance of AuPd@PdAu-PEI nanocrystals. Compared with commercial Pd black,AuPd@PdAu-PEI nanocrystals show significantly enhanced activity and durability towards the ORR, and simultaneously exhibit particular alcohol tolerance towards the ORR in the alkaline electrolyte.
基金This workwas financially supported by the National Science and Technology Major Project for Essential Drug Research and Development(No.2014ZX09301306-009)the National Science and Technology Major Project for Essential Drug Research and Development(No.2014ZX09301306-008).
文摘Objective:To discuss and compare the plasma pharmacokinetics after three oral Panax notoginseng saponin(PNS)administrations in beagle dogs.PNS is the main active ingredient of the traditional Chinese medicine(TCM)Panax notoginseng.Although its outstanding therapeutic efficacy has been demonstrated by various researchers,its broader application is restricted by the low bioavailability of PNS.Methods:An ultra-high performance liquid chromatographyetandem mass spectrometry(UPLC-MS/MS)method for the simultaneous quantification of notoginsenoside R1,ginsenoside Rg1,ginsenoside Rb1,ginsenoside Rd,and ginsenoside Re in beagle dog plasma was developed and validated.The plasma samples were subjected to liquideliquid extraction with acetone and methanol,and separated on an ACQUITY C18 column(100×2.1 mm ID,1.7 mm)using acetonitrile and water as the mobile phase with a run time of 4.5 min.Results:The analytes were detected without interference in Selected Reaction Monitoring mode with positive electrospray ionization.The validated method was successfully used in comparative pharmacokinetic studies of the five saponins in beagle dogs after oral administration of three PNS preparations.Blood samples were collected up to 192 h after administration and pharmacokinetic parameters were calculated using DAS 3.20 and SPSS 17.0.The AUC_(0-t)values of Re and R1 were significantly higher in soft capsules than in hard capsules.However,the AUC_(0-t)values between hard and soft capsules were not significantly different for the other three componentsdRb1,Rd and Rg1.Conclusion:Our intuitive analysis suggests that the bioavailability of PNS in soft capsules is greater than in hard capsules.
基金the funding support from the National Thousand Talent Program for Young Professionals and the startup funding from Nankai UniversityThe Overseas Expertise Introduction Project for Discipline Innovation of Higher Education of China(Grant no.B16027)is also acknowledged。
文摘Ammonia synthesis by electrocatalytic nitrogen reduction reaction(NRR)is considered as a promising alternative to the Haber−Bosch process.However,due to the extremely low ammonia yield and easily accessible extraneous contamination in the laboratory,NRR study always suffers from fluctuation and variability.Finding and eliminating all kinds of possible extraneous contamination is crucial to evaluate the performance of electrocatalytic ammonia synthesis accurately.In this work,we systematically explored two factors that affect NRR results but are easy to be ignored:the selection of membrane for NRR and the unconscious N-source in NRR catalysts.After series of experiments,we proposed a low-cost and almost pollution-free Celgard 3501 membrane as the separator for NRR to avoid the adsorption and release of ammonia by the membrane.In addition,we proposed a pre-reduction strategy to remove residual or adsorbed NOx contaminants in catalysts.These two solutions will help the community to evaluate the NRR activity more accurately.
文摘Encephalomyocarditis virus (EMCV) and porcine circovirus type 2 (PCV2) are common causative agents with high infection rate in pig farms, thus a combined vaccine against both EMCV and PCV2 is highly desirable. In the present study, we developed an oil-adjuvant combination vaccine candidate comprising of inactivated EMCV and PCV2, and evaluated the safety and immunogenicity in mice and swine. The combination vaccine was found to elicit serum antibodies and had strong neutralization activity, more importantly, passive immunization with the combined vaccine protected swine against either EMCV or PCV2 lethal infections, whereas the monovalent vaccine only prevent the one of two virus challenge. Our results demonstrated the combined vaccine was safe and induced protective immune response in mice and swine as evident from sero-conservation as well as challenge studies in swine, indicating that component vaccines did not interfere with the immunogenicity of each other.
文摘A rapid resolution liquid chromatographic (RRLC) method for the determination of eight polyphenols in to-bacco was developed. Polyphenols were extracted from tobacco samples by methanol/ water in an ultrasonic bath, then subjected to clean up by solid phase extraction. The separation was performed on a 50 × 4.6 mm, 1.8 μm ZORBAX Eclipse XDB-C18 column. Compared with conventional HPLC method, the analysis time for eight polyphenols by RRLC method was reduced from 20 to 5 min without sacrificing resolution, and the sensitivity was improved. This method appears simple, accurate and precious. The relative standard devia-tions (RSD) of overall analysis procedure for eight tobacco polyphenols were less than 2% with the recover-ies ranging from 94% to 107%. This method could be applied to the rapid determination of major polyphe-nols in tobacco with satisfactory results.
基金the Chinese Thousand Talents Program for Young Professionalsthe startup funding from Nankai Universitythe“111”project(Grant No.B16027)。
文摘Ammonia synthesis by electrocatalytic nitrogen reduction reaction(EC-NRR)has gained momentum in recent years fueled by its potential to operate at ambient conditions,unlike the highly energyintensive yet long-standing Haber-Bosch process.However,the large disparity of the yields and Faradic efficiencies reported for EC-NRR raises serious concerns about the reliability of the experimental results.In this perspective,we elaborate on the potential sources of error when assessing EC-NRR and update the testing protocols to circumvent them,and more importantly,we pose a general call for consensus on ammonia production analysis and reporting to lay the solid foundations that this burgeoning field requires to thrive.
文摘Based on artificial forest of Calotropis gigantea (L.) Dryand. area of 20.1 hm2, planted in the base of seed management station in Yuanjiang County, Yunnan Province, according to the average standard wooden method, the stand biomass was calculated in this paper. Based on the survey data of representative sample trees, the single-tree biomass model was constructed.
