共查询到20条相似文献,搜索用时 15 毫秒
1.
An improved accuracy is researched in flat and silicon based nano-calorimeters related to fluid reaction via drop-to-drop
'reaction' or via a steady state in continuous injection of two reactants inside a working chamber. Two types of the experimental
aspects of the sensitivity changes, related to 3-D effects, are described: drop effects and volume rate effects. To increase
the accuracy, well-controlled joule measurements are dissipated in the manufacturer resistance and in several resistances
in carefully controlled experiments. The shape factor (SF) values reduce the manufacturer's joule sensitivity up to fifty per cent. a working methodology is proposed: the results
are compared with the standard TRIS reaction. The results suggest that the systematic error can be reduced to ±5%.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
2.
C. Auguet J. L. Seguin F. Martorell F. Moll V. Torra J. Lerchner 《Journal of Thermal Analysis and Calorimetry》2006,86(2):521-529
Micro-calorimetric
devices using Si-based sensors are very useful for the study of gas–solid
reactions, in which very low mass of reactants are necessary. But in fact
the consequence of using flat detectors is an increase of the uncertainty
in the measured energy. In this work a calorimetric gas sensor based on Xensor
chip is analysed studying the local x–y
contributions of dissipation to the sensitivity related to the value in the
centre. We study also the effects of the gas-flow on the sensitivity, comparing
the results obtained with two Xensor type chips. Finally we carry out a deeper
analysis of the x–y effects on the
calorimetric detector for dissipations in the reactant shell extremely close
to the detector surface to visualize the link between the power density distribution
and the output signal. 相似文献
3.
R. Kirchner M. Rodriguez de Rivera J. Seidel V. Torra 《Journal of Thermal Analysis and Calorimetry》2005,82(1):179-184
Summary Using an RC model, the behavior of a TAM high-performance calorimeter (Thermometric AB, Sweden) equipped with a flow-mixing
insertion vessel using independent pumps for each reactant is studied. The model shows a reliable sensitivity behavior for
mixtures realized inside the cell. The model behavior is compared with experimental measurements.</o:p> 相似文献
4.
Auguet C. Lerchner J. Marinelli P. Martorell F. Rodriguez de Rivera M. Torra V. Wolf G. 《Journal of Thermal Analysis and Calorimetry》2003,71(3):951-966
The experimental analysis of conventional conduction calorimeters shows excellent reproducibility and relevant systematic
errors in comparison with thermodynamic values established via adiabatic calorimeters. Two examples: a DSC and a liquid flow
device are schematically analyzed. When an increased accuracy will be obtained the positional effects on the experimental
set-up and on the measurement process need to be modelled. From experimental measurements realized on the Xensor liquid nano-calorimeter
representative models can be built. To evaluate the reliability of measurement routines, established from experimental basis,
several different dissipation structures inside the working space can be simulated. Two experimental configurations related
to drop to drop reaction and to continuous mixing are modelled via RC approach. The RC formalism is extended to evaluate the
carried energy effect produced by the continuous inflow/outflow of reactants in the mixing enthalpy chamber.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
5.
Torra V. Auguet C. Lerchner J. Marinelli P. Tachoire H. 《Journal of Thermal Analysis and Calorimetry》2001,66(1):255-264
The miniaturization of the calorimetric devices to ‘nano-sized’ scale reduces progressively the available surface of the heat
flux detectors with an increase in systematic uncertainty. By means of several Joule and laser signals, the positional effects
in ‘liquid microcalorimeter’ micro-sized chip are evaluated. This allows the introduction of a 3-D coefficient, modifying
the standard Joule sensitivity. The shape factor includes the surface and the volume effects.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
6.
A. Krauss 《Thermochimica Acta》2006,445(2):126-132
A transportable water calorimeter for the determination of the quantity of absorbed dose to water in radiotherapy beams has been developed at the PTB and is presented in detail in this investigation. Heat conduction effects occurring in the calorimeter are studied for different lateral sizes of high-energy photon beams, for different depth dose distributions of electron beams and for a scanned-beam irradiation with a heavy ion beam. The corresponding correction factors are calculated and arguments are given under which conditions these can adequately be applied. 相似文献
7.
对合成的莫达非尼试验品用液相色谱(HPLC)鉴定其纯度后,同时进行元素(EMA)、红外光谱(IR)、紫外光谱(UV)、质谱(MS)、差热()DTA)、核磁共振(NMR)氢谱及碳谱分析,根据分析的结果进行解析,确证了其化学结构为莫达非尼。 相似文献
8.
Shin-ichi Ishiguro Bojana G. Jeliazkova Hitoshi Ohtaki 《Journal of solution chemistry》1987,16(1):1-10
Complex formation of copper(II) with N,N-dimethylformamide(DMF) has been investigated calorimetrically in acetonitrile at 25°C. Calorimetric titration curves obtained are explained in terms of formation of [Cu(dmf)
n
]2+ (n=1–4, 6) and their formation constants, enthalpies and entropies were determined. Formation of [Cu(dmf)5]2+ is uncertain. The stepwise enthalpies S
3
0
and entropies S
n
0
at each consecutive step are all negative except for S
3
0
. The overall enthalpies of formation of [Cu(dmf)6]2+ is –(77.8±5.4) kJ-mol–1, which is compared with the enthalpy of transfer of copper(II) ion, H
t
o
=–79.7 kJ-mol–1, from acetonitrile to DMF. 相似文献
9.
Yuyan Li Duqingcuo Li Tianrui Qin Zhan Shi Pengkun Fu Dingqi Xiong Xiuyan Dong 《应用有机金属化学》2023,37(1):e6920
Two new complexes based on 4,4′-[1,3-phenylenebis(oxy)]diphthalic acid (H4L) ligands were synthesized, namely, [Cd2(L)(1,10-phen)2(H2O)]n( 1 ) and [Co2(L)(1,10-phen)2(H2O)]n( 2 ), in which 2D structures transform into 3D supramolecular structures by C H···π interaction. The proton conductivity of complexes 1 and 2 at low temperature is close (σ1 = 3.12 × 10−8 S cm−1 and σ2 = 3.81 × 10−8 S cm−1 at 30°C), but these two complexes show different conduction mechanisms. The Vehicular mechanism in 1 is caused by the O···H/H···O contact in 1 , which is stronger than 2 , and the Grotthuss mechanism in 2 is caused by the N···H/H···N contact in 2 , which is stronger than 1 . At the same time, complex 1 showed excellent antibacterial properties in vitro, mainly reflected in that five kinds of bacteria (Escherichia coli, Bacillus amyloliquefaciens, Pantoea agglomerans, Pseudomonas putida, and Pectobacterium carotovora) could play an obvious inhibitory effect in the concentration range of 20 μg·ml−1. 相似文献
10.
评述了Ge-132定性方法的文献资料。实验证明对于Ge-132的定性方法,除了用荧光酮检测Ge外,羧基的鉴定也是必要的。 相似文献
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Purification and Structure Identification of Hyaluronic Acid 总被引:1,自引:0,他引:1
Shui Sheng HONG Jia CHEN Jian Guo ZHANG Yan Chun TAO Lan YingLIUCollege of Life Science Jilin University Changchun State Key Laboratory of Electroanalytical Chemistry Chinese Academy of Sciences ChangchunInstitute of Applied Chemistry Changchun Key Laboratory of Supermolecular Structure Spectroscopy of Educational Ministry Jilin University Changchun 《中国化学快报》2004,15(7):811-812
Polysaccharide produced by mutated strain of Streptococcus zooepidemicus was purified by the procedures including Savage method, quaternary ammonium compound precipitation, DEAE-cellulose(DE52) chromatography and Sephadex G-75 gel filtration. The structure of the purified polysaccharide has been characterized by means of chemical composition analysis,13C NMR spectrum, infrared spectrum and circular dichroism (CD). All the results showed that the purified polysaccharide was hyaluronic acid (HA). The single helix conformation of the purified HA was determined by Congo red experiment. The molecular weight of the HA was about 1.16×106D, which was measured by viscosity method. 相似文献
15.
V. P. Lukovtsev A. N. Doronin N. V. Lukovtseva V. A. Semenova V. M. Ganshin 《Russian Journal of Electrochemistry》2009,45(7):810-812
The possibility in principle is shown of using the stripping voltammetry method for identification of alkaloids with the help of a test system in the form of an electrolyte solution containing a set of cations of different metals. 相似文献
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We report a method for precisely identifying and locating the pollen of different species in a microscope based on multihyperspectral imaging. Since pollen species are complicated and difficult to identify by one feature, both fluorescence and transmission spectral images of the samples were obtained and used for the identification together with their morphologic features. Three different species of pollens were used as test samples for investigation. The results showed that the accuracy reached 99.5%, which was a significant improvement comparing with the single spectral detection. Because more information was taken into consideration, this method has great potential for the precise identification of biological specimens. 相似文献
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20.
Hua-Qun Zhou Sai-Li Zheng Can-Min Wu Xin-He Ye Wei-Ming Liao Jun He 《Molecules (Basel, Switzerland)》2021,26(16)
A novel Zn(II) metal-organic framework [Zn4O(C30H12F4O4S8)3]n, namely ZnBPD-4F4TS, has been constructed from a fluoro- and thiophenethio-functionalized ligand 2,2′,5,5′-tetrafluoro-3,3′,6,6′-tetrakis(2-thiophenethio)-4,4′-biphenyl dicarboxylic acid (H2BPD-4F4TS). ZnBPD-4F4TS shows a broad green emission around 520 nm in solid state luminescence, with a Commission International De L’Eclairage (CIE) coordinate at x = 0.264, y = 0.403. Since d10-configured Zn(II) is electrochemically inert, its photoluminescence is likely ascribed to ligand-based luminescence which originates from the well-conjugated system of phenyl and thiophenethio moieties. Its luminescent intensities diminish to different extents when exposed to various metal ions, indicating its potential as an optical sensor for detecting metal ion species. Furthermore, ZnBPD-4F4TS and its NH4Br-loaded composite, NH4Br@ZnBPD-4F4TS, were used for proton conduction measurements in different relative humidity (RH) levels and temperatures. Original ZnBPD-4F4TS shows a low proton conductivity of 9.47 × 10−10 S cm−1 while NH4Br@ZnBPD-4F4TS shows a more than 25,000-fold enhanced value of 2.38 × 10−5 S cm−1 at 40 °C and 90% RH. Both of the proton transport processes in ZnBPD-4F4TS and NH4Br@ZnBPD-4F4TS belong to the Grotthuss mechanism with Ea = 0.40 and 0.32 eV, respectively. 相似文献