Suppression of cross-interference in the absorption spectra of gas mixtures.

In the quantitative analysis of mixed gases by tunable diode laser absorption spectroscopy, the overlapping of absorption spectra and mutual interference of multi-component gases can lead to problems of large measurement errors and low analysis accuracy. In this paper, an improved firefly algorithm is proposed and applied to the support vector machine regression model to solve this problem. The specific method includes introducing an adaptive step size to balance the local and global searches and using the gradient descent method to accelerate the parameter optimization process so as to improve the model's generalization ability and prediction accuracy.

Highly sensitive and reliable optical fiber TDLAS gas detection system for methane in situ monitoring in near space.

A highly sensitive and reliable tunable diode laser absorption spectroscopy gas detection system with a temperature-pressure compensation algorithm is demonstrated for detecting concentrations in near space. Near space generally refers to the airspace 20-100 km away from the ground, where temperature and pressure changes are complex. Since the gas absorption spectrum is easily affected by temperature and pressure, a temperature-pressure compensation algorithm is proposed and used in the sensor to improve the detection accuracy of the sensor.

Ultra-Stable Temperature Controller-Based Laser Wavelength Locking for Improvement in WMS Methane Detection.

In the wavelength modulation spectroscopy (WMS) gas detection system, the laser diode is usually stabilized at a constant temperature and driven by current injection. So, a high-precision temperature controller is indispensable in every WMS system. To eliminate wavelength drift influence and improve detection sensitivity and response speed, laser wavelength sometimes needs to be locked at the gas absorption center.

CH/CH dual gas sensing system using a single mid-infrared laser.

Methane (CH) and ethane (CH) dual gas sensor with low system complexity and strong stability is proposed. The correction method based on absorbance spectrum is applied, and the cross-interference of CH to CH is eliminated. In the single gas concentration measurement, linear fitting is performed between the absorbance and concentration of CH and CH, and the correlation coefficients of R = 0.

Feature Domain Transform Filter for the Removal of Inherent Noise Bound to the Absorption Signal.

We propose to replace the traditional time-frequency domain filtering with feature domain filtering to realize an innovation of filtering algorithm. A feature domain transform filter (FDTF) is composed of the feature domain transform layer based on principal component analysis (PCA) algorithm, the feature domain information extractor based on deep learning and the time domain transform layer. It is established to filter out the noise with the same frequency and phase as the signal and is verified on methane gas.

Systematic Identification of Survival-Associated Alternative Splicing Events in Kidney Renal Clear Cell Carcinoma.

There is growing evidence that aberrant alternative splicing (AS) is highly correlated with driving tumorigenesis, but its function in kidney renal clear cell carcinoma (KIRC) remains to be discovered. In this study, we obtained the level-3 RNA sequencing and clinical data of KIRC from The Cancer Genome Atlas (TGCA). Combining with the splicing event detail information from TGCA SpliceSeq database, we established the independent prognosis signatures for KIRC with the univariate and multivariate Cox regression analyses.

A Robust Optical Sensor for Remote Multi-Species Detection Combining Frequency-Division Multiplexing and Normalized Wavelength Modulation Spectroscopy.

By combining frequency-division multiplexing and normalized wavelength modulation spectroscopy, a robust remote multi-species sensor was developed and demonstrated for practical hydrocarbon monitoring. Independently modulated laser beams are combined to simultaneously interrogate different gas samples using an open-ended centimeter-size multipass cell. Gas species of interest are demodulated with the second harmonics to enhance sensitivity, and high immunity to laser power variation is achieved by normalizing to the corresponding first harmonics.

Extent of lymph node dissection improves overall survival in pT3N0 non-metastatic renal cell carcinoma patients treated with radical nephrectomy: a propensity score-based analysis.

Background: To assess the impact of lymph node dissection (LND) extent on overall survival (OS) and cancer-specific survival (CSS) in patients with pN0M0 renal cell carcinoma (RCC) treated with radical nephrectomy (RN).

Materials And Methods: Data queried for this study include RCC (2010-2014) from the Surveillance, Epidemiology, and End Results (SEER) program. Kaplan-Meier analyses and multivariate Cox regression models tested the effect of number of removed lymph node (NRN) ≥ 50th percentile on OS and CSS.

Demodulation algorithm used in single-beam system immune to light power drift.

A demodulation algorithm based on the head-tail technique is proposed for single-beam water vapor detection under rough environmental conditions, which is immune to fluctuations of light power. In the head-tail technique, collected data are processed by adding the head and tail data together and gradually approaching the center. The majority of photocurrent attenuation caused by optical loss can be effectively compensated by combining an optical intensity normalization coefficient in the method.

[Application in methane extraction of fiber methane monitoring system based on spectral absorption].

An optical fiber distributed multi-point methane real-time monitoring system based on the methane spectral absorption characteristic is researched, and it's application in methane extraction is presented. An 1665 nm distributed feedback (DFB) laser is used as the light source by taking the triangular signal to modulate the light frequency of the DFB laser. Using the combination of single-chip computer C8051F410, A/D transform circuit, communication circuit, display circuit, etc, the concentration of methane can be monitored and displayed on the screen.