MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
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2013
·Vol. 432
·期 3
·1980-1988
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IF 5.521
Rodler F.,Kürster M.,Barnes J. R.
With time series spectroscopic observations taken with the Near-Infrared Spectrometer (NIRSPEC) at Keck II, we investigated the atmosphere of the close orbiting transiting extrasolar giant planet, HD 189733b. In particular, we intended to measure the dense absorption line forest around 2.3 μm, which is produced by carbon monoxide (CO). CO is expected to be present in the planetary atmosphere, although no detection of this molecule has been claimed yet. To identify the best-suited data analysis method, we created artificial spectra of planetary atmospheres and analysed them by three approaches found in the literature, the deconvolution method, data modelling via χ2 minimization and cross-correlation. As a result, we found that cross-correlation and χ2 data modelling show systematically a higher sensitivity than the deconvolution method. We analysed the NIRSPEC data with cross-correlation and detect CO absorption in the day-side spectrum of HD 189733b at the known planetary radial velocity semi-amplitude with 3.4σ confidence.
研究领域:
天文学
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行星科学
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2024
·
IF 8
Ziyi Wang,Ruimin Song,Weigen Chen,Jianxin Wang,Pinyi Wang,Zifeng Ming,Zhixian Zhang
In order to improve the limit of detection (LOD) of trace substances, a general signal analysis and processing method based on cross-correlation theory is proposed, including correlation detection methods and multi-channel signal modified methods. In this paper, both methods were validated on Raman and GC-MS detection, trace substance in insulating oil (dibenzyl disulfide) is introduced as an example, and verification test of multi-substances detection is also conducted. More generally, the cross-correlation theory based method can be applied to all detection based on spectral peak areas. After applying this method, the LOD can be considerably improved. The traditional detection method based on linear fitting between characteristic peak area and trace substance concentration is implemented as a benchmark. The LOD of Raman detection in traditional way is 338.51 ppm, The LOD of GC-MS detection in traditional way is 317.26 ppb. The correlation detection results show that the LOD of Raman spectroscopy and GC-MS are respectively increased by 1.90/2.76 times compared with traditional way. And when the multi-channel signal modified method is introduced, the qualitative LOD of Raman detection reaches 9.8 ppm (number of channel is 100), the qualitative LOD of GC-MS detection reaches 39.1 ppb (number of channel is 10). Comparative study with conventional noise reduction methods have also been carried out, and the results show that correlation detection and multi-channel signal modified method are superior to them.
研究领域:
分析化学
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信号处理
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光谱学
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DOI
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2025
·
IF 8.5
Ting Feng,Haoxian Huang,Ying Xu,Xinyu Che,Mingdong Wang,Xiangyu Tao,Yanbin Feng,Song Xue
The evolution of enzymes through multisite combinations is often constrained by the dynamic correlations among residues, resulting in the challenge of achieving additive effects when combining single-site positive mutants. Nevertheless, the incorporation of distal-site residue mutants offers a promising avenue to unlock synergistic interactions, particularly in enzymes with channels that mediate substrate and product transport. While combinatorial mutagenesis typically requires exhaustive screening of extensive mutant libraries to identify superior variants. In this study, a multisite combination strategy using dynamic cross-correlation matrices (DCCM) iterative analysis, coupled with location orthogonal filtration (DCCM/OL) was established based on single-site mutants enhancing enzyme performance by engineering distal residues using the “Structure, SCANEER, and Sequence (3S)” approach. Thirteen beneficial single mutants of oleate hydratase from Staphylococcus aureus (SaOhy), which catalyzes the hydration of linoleic acid, were targeted using the “3S” approach. By employing the DCCM/OL strategy, the number of candidates in the combination mutation library for experimental screening were reduced from 60 to 5. And a triple-site mutant, SaOhy_L151V/I411L/V135A, was ultimately identified, which increased the catalytic efficiencies with linoleic acid and oleic acid by a 4- and 2.3-fold, respectively. The philosophy of multisite mutation based on distal residues using the DCCM/OL strategy effectively achieves an amplification of enzymatic activity with distinct substrates simultaneously. This study offers a promising strategy for the construction of a mutant smart library and multisite combinations to efficiently increase enzymatic performance.
研究领域:
生物化学
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酶工程
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DOI
PubMed
高影响因子
THERMOCHIMICA ACTA
·
2022
·
IF 3.378
Song Feng,Qincheng Bi,Wenlin Liao
A novel densimeter based on a random temperature signal cross-correlation method was designed and constructed. Liquid densities of n -decane were measured at T = (293.2–493.5) K and p = (0.1–20.0) MPa. The expanded uncertainties in liquid density measurements are 1.16%, with a confidence level of 0.95 ( k = 2). This experimental study provides new n -decane densities to examine Lemmon's equations' accuracy at high temperatures and pressures, where few experimental densities are yet to be reported. The experimental data's average absolute deviation ( AAD ) and maximum absolute deviation ( MAD ) compared to the fitted data from Lemmon's equations are 0.15% and 0.43%, respectively. The liquid densities at high temperatures and pressures were fitted with a Tait-type equation. The physical meaning and temperature behavior of the Tait correlation's parameters were discussed. The average absolute deviation ( AAD ) between the experimental and calculated data from the Tait-type equation is 0.23%.
研究领域:
物理化学
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热力学
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DOI
高影响因子
Journal of Physical Chemistry C
·
2023
·
IF 3.7
Song Jia,Ming Liu,Xinhu Liang,Xiaojuan Li,Xuefei Wang,Zhiyuan Tian
Lanthanide-doped upconversion nanoparticles (Ln-UCNPs) hold great potential in anticounterfeiting applications owing to their salient optical properties. However, a single-mode anticounterfeiting strategy based on common Ln-UCNPs typically confronts challenges in terms of imitation based on alternatives with a similar luminescence feature. Multilevel anticounterfeiting strategies on the basis of the multicolor beaconing luminescence generated upon dual- or multimode excitation are promising for addressing such a challenge and those based on the intrinsic mutual authentication of the dynamic signals generated via distinct manipulating manners are expected to present a higher security level. Herein, we demonstrate that low-concentration Yb/Er/Tm-codoped UCNPs with optimized formulation enable modulation of luminous color by manipulating the power of a continuous-wave 980-nm laser or the pulse parameter of the pulsed laser. The crucial role of acting as the red-emission-associated transient energy trapping center that Tm3+ species plays can be attenuated by Yb3+-mediated laser-power-dependent sensitization processes. The key intermediate states associated with red and green emission states are populated and deplete via different processes with distinct rates, which enables dependence of the emission feature on the pulse parameters of the laser. The unique feature of this type of Ln-UCNPs in terms of dual-mode luminous color modulation and its potential are preliminarily verified in our proof-of-concept cross-correlation experiment, which provides a feasible modality for high-level anticounterfeiting applications in specific scenarios such as high-value marketable securities and bond certificates.
研究领域:
材料科学
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光学
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纳米技术
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安全与密码学
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DOI
高影响因子
Molecular Catalysis
·
2024
·
IF 3.9
Qiang Chen,Zhi-Pu Li,Xiao-Qiong Pei,Yan Liu,M. Qaiser Fatmi,Zhong-Liu Wu
Chiral epoxides are one of the most versatile building blocks in organic synthesis, but the asymmetric epoxidation of unfunctionalized terminal olefins remains a challenge. Na StyA is a styrene monooxygenase from Nocardia altamirensis that functions as an enantioselective epoxygenase for terminal olefins. To improve its robustness, we investigated over 50 mutants designed via evolutionary- and energy-based approaches, and successfully identified 18 beneficial mutations, which then led to a combinatorial mutant of TM18 with drastically enhanced thermostability and solvent tolerance while retaining excellent activity and enantioselectivity. Its turnover frequency and half-life at 50 °C were increased to 5- and 148-fold of the parental. In the epoxidation of terminal olefins, TM18 achieved high product yields of over 4-fold of the parental, and excellent enantiomeric excess of 99 % to >99 % ee. The analysis of trajectory data from molecular dynamics simulations further validated that the mutations in TM18 increased its local rigidity, as inferred by RMSF and PCA analyses and through novel salt bridges formation. Furthermore, TM18 displayed reduced residue cross-correlation motions. The combined effects of these mutations result in an overall improvement in the structural and dynamic thermostability of TM18.
研究领域:
生物技术
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酶工程
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分子生物学
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化学工程
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有机化学
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产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）