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Rationale: The in‐sample calibration curve (ISCC) approach of quantification utilizes the response of isotopologue ions from spiked‐in stable isotope labeled internal standard (SIL‐IS) to build a standard curve. The quantitative analysis of the study sample is achieved based on the response of selected monoisotopic analyte ion against the calibration curve. Although this methodology has been demonstrated to be feasible by unit and high‐resolution mass spectrometers, quantitation on high‐resolution mass spectrometer with product ions has not been tested. We tested the feasibility of this approach using product ions on an high‐resolution mass spectrometer equipped with an Orbitrap detector. Methods: Using a proteomics workflow for sample preparation, two surrogate peptides were quantified from a complex matrix of protein digest from human peripheral blood mononuclear cells (hPBMCs). SIL‐IS was spiked in at different levels to construct calibration curves in a traditional manner. ISCCs were prepared using extracted ion chromatograms from isotopically resolved mass spectra and compared with traditional calibration curves. Results: A linear response was observed with ISCC approach for at least two to three orders of magnitude in MS1 as well as targeted MS2 (tMS2). From protein digests, isobaric interferences were observed for endogenous peptides on the MS1 level; this was circumvented with product‐ion‐based quantitation where for one peptide, %CV for endogenous levels was more than 20% with ISCC but higher with the traditional calibration curve approach. For the second peptide, endogenous levels could not be determined in the traditional approach as calibrant levels did not bracket the lower end, and with the ISCC approach, isotopologues at abundances lower than the endogenous level allowed for quantitative assessments. Conclusions: ISCC demonstrated improved precision across surrogate peptides from endogenous protein digests. In samples where endogenous analyte concentrations were low in abundance, ISCC rescued what would have been a non‐reportable result in a traditional bioanalytical assay as calibrant levels were not prepared at adequately low levels to bracket unknowns. ISCC using high‐resolution mass spectrometer is feasible and ideal compared to unit resolution mass spectrometers. High‐resolution mass spectrometer allows for isotopic resolution for analytes with > + 2 charge state and provides flexibility in quantification using multiple product ions. ISCC using high‐resolution mass spectrometer allows for simultaneous assaying of low abundance isotopologues, the signal acquisition of which is not constrained by limits in data acquisition or calibrant preparation as with other approaches but rather limited by platform sensitivity. In contrast to unit resolution mass spectrometers, these features offered by high‐resolution mass spectrometer could be especially useful for the drug discovery assay support where there is less lead time for assay development than for the assays to support the drug development studies. [ABSTRACT FROM AUTHOR]

In order to improve the quality of welded joints and increase the service life of pipelines, ABAQUS finite element software was used to simulate the temperature field of 18,4 mm thick X80 pipeline steel in multi-layer and multi pass welding. The peak temperature of different passes was compared, and the change trend of temperature field in the welding process was obtained. The results show that the peak temperature of the weld and its adjacent areas is higher, and the peak temperature of the weld center is the highest. Due to the fast welding speed, the heat cannot be transferred to other areas in time, resulting in uneven heating of the entire test panel. [ABSTRACT FROM AUTHOR]

To obtain the exact mechanical properties of TC4 titanium alloy, the compression experiments on TC4 titanium alloy at different strain rates (10-2,10-3,10-4 s-1) were performed at room-temperature on the MTS-810 electrohydraulic servo material testing machine. The data of TC4 titanium alloy compression experiments at different rates were obtained. And furthermore Johnson-Cook constitutive model is established. Due to different conditions, the equation is simplified, the constitutive parameters are obtained by step-by-step estimation method, and the Johnson-Cook (JC) constitutive model of TC4 titanium alloy at room temperature is established. The prediction results of the model were compared with the experimental data, the prediction curve is in good agreement, which verifies the feasibility of the model. [ABSTRACT FROM AUTHOR]