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91.
Bowfield A Barrett DA Alexander MR Ortori CA Rutten FM Salter TL Gilmore IS Bradley JW 《The Review of scientific instruments》2012,83(6):063503
The authors report on a modified micro-plasma assisted desorption/ionisation (PADI) device which creates plasma through the breakdown of ambient air rather than utilising an independent noble gas flow. This new micro-PADI device is used as an ion source for ambient mass spectrometry to analyse species released from the surfaces of polytetrafluoroethylene, and generic ibuprofen and paracetamol tablets through remote activation of the surface by the plasma. The mass spectra from these surfaces compare favourably to those produced by a PADI device constructed using an earlier design and confirm that the new ion source is an effective device which can be used to achieve ambient mass spectrometry with improved spatial resolution. 相似文献
92.
A strip-based biosensor using the enzyme-linked immunosorbent assay technique was fabricated to detect Escherichia coli O157:H7. Two types of antibody specified to E. coli O157:H7 were used to form sandwich-binding complexes. To fabricate an immuno-strip, capture antibody (monoclonal antibody) was immobilized onto signal generation pad and polyclonal antibody conjugated with horseradish peroxidase (HRP) was utilized as detection antibody. Four different functional membranes have been used to fabricate immuno-chromatographic assay strip. A sample application pad was a glass fiber membrane pre-treated with polyvinyl alcohol. A conjugate release pad was fabricated using a glass membrane. A signal generation pad was made on nitrocellulose membrane. Finally, a cellulose membrane was used as an absorption pad. Under optimal conditions of analysis, a color signal in proportion to the E. coli O157:H7 concentration was measured using a detector. The measurement range was 1.8x10(3)-1.8x10(8)CFU/mL. 相似文献
93.
We describe the first Hadamard transform time-of-flight mass spectrometer (HT-TOFMS) that incorporates an electron (impact) ionization source. This implementation was realized in an existent TOF instrument using commercially available components and simple modifications to the ion source. In the present apparatus, a Hadamard mask is expressed by modulating the ion generation process within the ion source; thus, the present approach differs from previous designs that use external electrostatic devices to modulate a continuous ion stream. The present implementation may be operated in conventional TOF mode at 12.5 kHz and in HT-TOF mode at 20-40 MHz. In Hadamard mode the design can operate using any circulant simplex code, allowing the operator much flexibility for optimizing resolution and mass range and for eliminating nonstochastic fluctuations, e.g., encoding errors and signal hum. We demonstrate typical performance of the HT-TOFMS in standard and reflectron geometries using sequences of three constructions and of varied length, generating HT-TOF mass spectra of molecules that match conventional reference spectra. The auxiliary material includes an electrical schematic for the floating high-speed encoding amplifier, which is also of use in other high-speed electrostatic optics applications, and a list of 537 validated vectors comprising the first row of each circulant simplex sequence (S(n)=3-8219) derived using maximal shift register (n=2(m)-1), quadratic residue (n=4m-3), and twin prime constructions [n=p(p+2)]. 相似文献
94.
中秋节后,凉意日渐袭来,身体逐渐觉得干燥,家里老的老、小的小,都觉得身体不是那么舒服,这时候就需要有针对性地为家人做一些养生汤水来改善一下身体的亚健康状况。可是作为年轻妈妈,来自职场的压力也很大,幸好我有九阳豆浆机作后盾,方便又省时间,既能照顾好家人又不耽误工作。对了,在我们家,豆浆机也是专人专用的呢。 相似文献
95.
贝太厨房:您在担任《舌尖上的中国》美食顾问时怀揣着怎样一份情怀?这么多不同地域的传统美食您希望带给观众怎样的理念? 相似文献
96.
98.
The effects of magnetic field intensity, roasting temperature and roasting time on digestion rate and settling performance of bauxite with different iron contents were investigated systematically. The results indicate that such magnetic treatment can profoundly change the microstructure and digestion performance of bauxite. For the two samples carrying different iron contents, phase transformation of the aluminum oxide phase proceeds faster in the high iron bauxite than the low one. The optimal pretreatment conditions of low iron bauxite are roasting temperature 550 ℃ and magnetic field intensity 6 T, while for high iron bauxite are 500 ℃ and 9 T. The digestion rate of alumina can reach 95% and 92% at digestion temperature of 190 ℃ and 250 ℃. The settling performances of roasted ore by intense magnetic field after digestion are enhanced through pretreatment. 相似文献
99.
100.
本文提出利用光学成像干涉技术主动遥感探测可燃冰的温度、压强、浓度物理量。通过光纤将海面上波长为1.65μm的激光传输到海底,激发海底可燃冰,将CH4发射的1.65μm附近相距很近的10条谱线用光纤收集传回到海面上,经过成像干涉系统,在CCD相机上得到5条成像干涉条纹,选择两条相邻干涉条纹的灰度值,利用"转动谱线测温法"和洛伦兹线型即可获得海底可燃冰CH4的温度、压强、浓度等参量。实验得出CH4的正演成像干涉图,并得到CCD上的电子计数1.68×105远远大于拟用CCD噪声400e,系统的最大信噪比为291,窄带干涉滤光片可在16°视场内区分CH4的10条目标谱线,CH4的温度和浓度探测精度分别为1K和3%。研究表明,该成像干涉系统可用于遥感探测海底可燃冰。 相似文献