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建立了一种快速、高效、准确的同时测定蔬菜中恩诺沙星、环丙沙星、氧氟沙星、培氟沙星、诺氟沙星、洛美沙星、氟甲喹、恶喹酸、马波沙星、沙拉沙星、达氟沙星、双氟沙星、氟罗沙星、西诺沙星、伊诺沙星、萘啶酸、奥比沙星与吡哌酸等17种喹诺酮类药物残留的分散固相萃取-高效液相色谱-串联质谱方法(dSPE-HPLC-MS/MS)。采用自制的纳米TiO2修饰COFs材料为dSPE吸附剂,一步实现样品净化;目标分析物在Shim-pack XR-ODS II (150 mm×2.0 mm i.d., 2.2μm)色谱柱上以乙腈和含有0.1%甲酸的水溶液为流动相进行分离,在电喷雾离子源(ESI)正离子多反应监测(MRM)模式下进行检测。17种喹诺酮类药物在0.2μg/kg~100μg/kg范围内具有良好的线性(r2>0.9990),检出限为0.033μg/kg~0.23μg/kg,最低定量限为0.11μg/kg~0.76μg/kg, RSDs为2.6%~7.3%,加标回收率为76.9%~118%。本法可用于蔬菜中17种喹诺酮类药物残留的快速筛查与确证分析。 相似文献
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建立了同位素稀释-气相色谱-串联质谱(GC-MS/MS)法同时测定化妆品中10种合成麝香(SMs),并对方法前处理和仪器条件进行了优化。样品加入氘代同位素内标后,以饱和氯化钠-正己烷溶液体系超声提取,提取液经氮吹浓缩定容后,采用极性毛细管柱VF-WAXms(30 m×0.25 mm×0.25 μm)分离,以多反应监测模式(MRM)测定,内标校正标准曲线法定量。结果表明:10种合成麝香的线性范围为1.0~100.0 μg/L,相关系数均大于0.99,定量限为1.0~8.0 μg/kg。加标回收率在92.5%~102.0%之间,相对标准偏差(RSD)均小于5%。本方法简便、准确、快速、灵敏,可同时检测化妆品中10种合成麝香成分。 相似文献
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勃农兴达机械有限公司生产的2BJD-2型电子数字监测精密播种机与11.03~17.64kW(15~24hp)四轮拖拉机配套,适用于大豆、玉米等作物的垄上播种与平播作业。一次播两行。该机既能一次完成深施化肥、播种、开沟、覆土、镇压等项作业(各种作物的株距均可调)。又能在播种过程中准确计算出播种量,可监控播种时种子的流动情况,对漏播、断条、堵塞等现象及时发出声光报警。卸掉播种装置可装成三铧犁,又能用于垄作农田的起垄、中耕、松土等作业。增加一组播种部件可以进行小垄密植和平播作业。购置并更换相应排种轮还可进行高梁、甜菜、白瓜籽、花生、向日葵等作物穴播。 相似文献
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本文采用高温灰化植物样品,超声雾化器进样,ICP光谱仪进行了5种稀土元素最优测定条件的选择、制定了工作曲线、确定了BEC值和检出限,为蔬菜中镧(La)、铈(Ce)、镨(Pr)、钕(Nd)、钆(Gd)这5种稀土元素的测定提供了一种简便、快速、准确的方法。 相似文献
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TruSpec CN元素分析仪测定土壤中碳氮方法研究 总被引:6,自引:0,他引:6
采用美国Leco公司TruSpec CN元素分析仪对土壤中碳氮含量进行测定并对土壤的分析方法进行优化,确定了最佳取样装置、最小分析时间、燃烧时间和最佳称样量。实验结果表明,碳氮的线性范围分别为0.632~24.647mg(R〉0.999)和0.0601~5.754mg(R〉0.999),检出限(3S/N)分别为0.0022和0.0032mg。土壤样品碳氮的回收率分别为99.2%~100.9%和98.2%~99.2%,测得5种土壤碳氮的相对标准偏差(RSD)为0.997%~2.143%和0.214%~3.115%。该方法操作简便快速、灵敏度高,具有较好的精密度和准确度,可准确可靠地用于土壤碳氮含量的测定。 相似文献
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流动注射 - 氢化物发生原子吸收光谱法测定涂料中的 As、 Sb、 Se和 Hg 总被引:8,自引:0,他引:8
将流动注射、氢化物发生技术与原子吸收分光光度法有机结合起来,建立了一种测定涂料中微量As、Sb、Se、Hg总含量的方法,还在模仿人胃酸(0.07mol/L盐酸溶液)的条件下建立了一种测定这些元素可溶量的方法。方法用于实际样品测定具有快速、高效和灵敏的特点,对As、Sb、Se、Hg检测的相对标准差(n=10)分别为4.22%、2.02%、3.72%和2.98%,试样加标回收率分别为98.9%~101.6%,99.0%~102.6%,99.2%~101.4%和99.1%~101.3%。 相似文献
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于静 《国外分析仪器技术与应用》2001,(3):50-52
以电荷耦合器件(CID)为检测器的ICP-AES光谱仪测定原油中的铁、铜、钒、钙、镁六种金属元素,试样用HNO3进行分解,选择适当的波长和背景样正进行分析,测定回收率在94%~104%之间,相对标准偏差均小于7%。方法快速准确,精密度好。 相似文献
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A new laser induction hybrid cladding technique on cylinder work piece is presented. Based on a series of laser induction hybrid experiments by off-axial powder feeding, the predicting models of individual clad geometric formation and powder catchment were developed in terms of powder feeding rate, laser special energy and induction energy density using multiple regression analysis. In addition, confirmation tests were performed to make a comparison between the predicting results and measured ones. Via the experiments and analysis, the conclusions can be lead to that the process parameters have crucial influence on the clad geometric formation and powder catchment, and that the predicting model reflects well the relationship between the clad geometric formation and process parameters in laser induction hybrid cladding. 相似文献
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KHANDAKAR ABU MD MOSTAFIZAR RAHMAN ABDUL SHUKOR JURAIMI MD. REZWAN MOLLA MUHAMMAD ASYRAF MD HATTA ZULKEFLY BIN SULAIMAN SHAMIMA SULTANA AHMED GABER BENUKAR BISWAS AKBAR HOSSAIN 《Biocell》2023,47(1):227-237
Every breeding program that aims to create new and improved cultivars with desired traits mostly relies on
information related to genetic diversity. Therefore, molecular characterization of germplasms is important to obtain target
cultivars with desirable traits. Sweet potato [Ipomoea batatas (L.) Lam] is widely considered the world’s most important crop,
with great diversity in morphological and phenotypic traits. The genetic diversity of 20 sweet potato germplasms originating
from Bangladesh, CIP, Philippines, Taiwan, and Malaysia were compared, which was accomplished by genetic diversity
analysis by exploring 20 microsatellite DNA markers for germplasm characterization and utilization. This information was
effective in differentiating or clustering the sweet potato genotypes. A total of 64 alleles were generated using the 20 primers
throughout the 20 germplasm samples, with locus IBS97 having the highest number of alleles (5), whereas locus IbU33 had
the fewest alleles (2). The alleles varied in size from 105 (IbU31) to 213 base pairs (IBS34). The Polymorphism Information
Content (PIC) values for the loci IbL46 and IBS97 varied from 0.445 to 0.730. IBS97 has the highest number of effective
alleles (3.704), compared to an average of 2.520. The average Shannon’s diversity index (H) was 1.003, ranging from 0.673 in
IbU3 to 1.432 in IBS97. The value of gene flow (Nm) varied between 0.000 and 0.005, with an average of 0.003, whereas
genetic differentiation (FST-values) ranged between 0.901 and 1.000. The sweet potato germplasm included in this study had
a broad genetic base. SP1 vs. SP9 and SP12 vs. SP18 germplasm pairings had the greatest genetic distance (GD = 0.965),
while SP1 vs. SP2 germplasm couples had the least genetic diversity (GD = 0.093). Twenty genotypes were classified into two
groups in the UPGMA dendrogram, with 16 genotypes classified as group “A” and the remaining four genotypes, SP10,
SP18, SP19, and SP20, classified as group “B.” According to cluster analysis, the anticipated heterozygosity (gene diversity) of
Nei (1973) was 0.591 on average. In summary, SSR markers successfully evaluated the genetic relationships among the sweet
potato accessions used and generated a high level of polymorphism. The results of the present study will be useful for the
management of germplasm, improvement of the current breeding strategies, and the release of new cultivars as varieties. 相似文献
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Ductile fracture of metal often occurs in the plastic forming process of parts.The establishment of ductile fracture cri-terion can effectively guide the selection of process parameters and avoid ductile fracture of parts during machining.The 3D ductile fracture envelope of AA6063-T6 was developed to predict and prevent its fracture.Smooth round bar tension tests were performed to characterize the flow stress,and a series of experiments were conducted to charac-terize the ductile fracture firstly,such as notched round bar tension tests,compression tests and torsion tests.These tests cover a wide range of stress triaxiality(ST)and Lode parameter(LP)to calibrate the ductile fracture criterion.Plas-ticity modeling was performed,and the predicted results were compared with corresponding experimental data to verify the plasticity model after these experiments.Then the relationship between ductile fracture strain and ST with LP was constructed using the modified Mohr-Coulomb(MMC)model and Bai-Wierzbicki(BW)model to develop the 3D ductile fracture envelope.Finally,two ductile damage models were proposed based on the 3D fracture envelope of AA6063.Through the comparison of the two models,it was found that BW model had better fitting effect,and the sum of squares of residual error of BW model was 0.9901.The two models had relatively large errors in predicting the fracture strain of SRB tensile test and torsion test,but both of the predicting error of both two models were within the acceptable range of 15%.In the process of finite element simulation,the evolution process of ductile fracture can be well simulated by the two models.However,BW model can predict the location of fracture more accurately than MMC model. 相似文献
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Ching-Kao Chang H.S. Lu 《The International Journal of Advanced Manufacturing Technology》2006,29(9-10):867-878
The paper presents a feasibility study on prediction of surface roughness in side milling operations using the different polynomial networks. A series of experiments using S45C steel plates is conducted to study the effects of the various cutting parameters on surface roughness. The different polynomial networks for predicting surface roughness are developed using the abductive modeling technique and based on the F-ratio to select their input variables. The results show that the developed models achieve high predicting capability on surface roughness, especially for the case of smaller flank wear of peripheral cutting edge. Hence, it can be concluded that the developed polynomial-network models posses promising potential in the application of predicting surface roughness in side milling operations. 相似文献