Shock Waves Generated in the Presence of Barriers in Gas Explosions

This paper examines conditions that generates shock waves in a gas explosion through experiment. The result shows that the presence of barrier and thin film, which is similar to air door and stopping in underground coal mines, is very important for the generation of shock waves in a gas explosion. When there are physical barriers, the speed of transmission would be very fast and shock waves will result in the process; when the film is destroyed in gas explosion, shock waves will also appear which would result in an increase in explosion power. Therefore, in order to weaken the gas explosion and prevent the generation of shock waves, the number of barriers should be reduced, and the air door and stopping in tunnels should be strengthened in coal mines. The result of research is very important to prevent gas explosion and decrease the power of such explosions

FreePSI: an alignment-free approach to estimating exon-inclusion ratios without a reference transcriptome.

Alternative splicing plays an important role in many cellular processes of eukaryotic organisms. The exon-inclusion ratio, also known as percent spliced in, is often regarded as one of the most effective measures of alternative splicing events. The existing methods for estimating exon-inclusion ratios at the genome scale all require the existence of a reference transcriptome. In this paper, we propose an alignment-free method, FreePSI, to perform genome-wide estimation of exon-inclusion ratios from RNA-Seq data without relying on the guidance of a reference transcriptome. It uses a novel probabilistic generative model based on k-mer profiles to quantify the exon-inclusion ratios at the genome scale and an efficient expectation-maximization algorithm based on a divide-and-conquer strategy and ultrafast conjugate gradient projection descent method to solve the model. We compare FreePSI with the existing methods on simulated and real RNA-seq data in terms of both accuracy and efficiency and show that it is able to achieve very good performance even though a reference transcriptome is not provided. Our results suggest that FreePSI may have important applications in performing alternative splicing analysis for organisms that do not have quality reference transcriptomes. FreePSI is implemented in C++ and freely available to the public on GitHub

Attenuated IL-2 muteins leverage the TCR signal to enhance regulatory T cell homeostasis and response in vivo

Interleukin-2 (IL-2), along with T-cell receptor (TCR) signaling, are required to control regulatory T cell (Treg) homeostasis and function in vivo. Due to the heightened sensitivity to IL-2, Tregs retain the ability to respond to low-dose or attenuated forms of IL-2, as currently being developed for clinical use to treat inflammatory diseases. While attenuated IL-2 increases Treg selectivity, the question remains as to whether a weakened IL-2 signal sufficiently enhances Treg suppressive function(s) toward disease modification. To understand this question, we characterized the in vivo activity and transcriptomic profiles of two different attenuated IL-2 muteins in comparison with wildtype (WT) IL-2. Our study showed that, in addition to favoring Tregs, the attenuated muteins induced disproportionately robust effects on Treg activation and conversion to effector Treg (eTreg) phenotype. Our data furthermore suggested that Tregs activated by attenuated IL-2 muteins showed reduced dependence on TCR signal, at least in part due to the enhanced ability of IL-2 muteins to amplify the TCR signal in vivo. These results point to a new paradigm wherein IL-2 influences Tregs’ sensitivity to antigenic signal, and that the combination effect may be leveraged for therapeutic use of attenuated IL-2 muteins

Double-transmitting and Sextuple-receiving Borehole Transient Electromagnetic Method and Experimental Study

With the continuous improvement of precision requirements for borehole geophysical exploration, the application of transient electromagnetic method (from now on referred to as TEM) in a borehole has become a hot spot. The conventional borehole TEM can only determine the longitudinal depth of the geological anomaly, the radial azimuth and depth cannot be resolved. A double-transmitting and sextuple-receiving borehole TEM is proposed, through which the radial anomaly is excited by the electromagnetic field generated by the double-emitting loops, and the azimuth and depth of the anomaly will be identified by the difference characteristics of the six receiving loops signals. In this paper, the response equations of the transmitting-receiving mode of double-transmitting and sextuple-receiving borehole TEM are deduced, and the response characteristics of the induction segment and the attenuation segment of the receiving loops are obtained based on the response equations under ramp function turn-off condition, providing the basis for theoretical analysis. Due to the negative value of the double-transmitting and sextuple-receiving transient electromagnetic response signals, a negative transformation algorithm under the double logarithmic coordinate system is proposed to provide the essential method for the analysis of two kinds of physical simulation experimental data of the radial azimuth and radial depth detection of the anomaly. The results show that the double-transmitting and sextuple-receiving borehole TEM has decent resolution ability in detecting the radial azimuth of the anomaly, and the effective resolution is 30°. The geometric difference among induced voltages of different measuring points can be used to evaluate the radial depth of the anomaly qualitatively. It is expected that the double-transmitting and sextuple-receiving borehole TEM can provide technical guidance for little borehole geophysical exploration in the fields of oil, natural gas, coal and basic engineering construction

Double-transmitting and Sextuple-receiving Borehole Transient Electromagnetic Method and Experimental Study

With the continuous improvement of precision requirements for borehole geophysical exploration, the application of transient electromagnetic method (from now on referred to as TEM) in a borehole has become a hot spot. The conventional borehole TEM can only determine the longitudinal depth of the geological anomaly, the radial azimuth and depth cannot be resolved. A double-transmitting and sextuple-receiving borehole TEM is proposed, through which the radial anomaly is excited by the electromagnetic field generated by the double-emitting loops, and the azimuth and depth of the anomaly will be identified by the difference characteristics of the six receiving loops signals. In this paper, the response equations of the transmitting-receiving mode of double-transmitting and sextuple-receiving borehole TEM are deduced, and the response characteristics of the induction segment and the attenuation segment of the receiving loops are obtained based on the response equations under ramp function turn-off condition, providing the basis for theoretical analysis. Due to the negative value of the double-transmitting and sextuple-receiving transient electromagnetic response signals, a negative transformation algorithm under the double logarithmic coordinate system is proposed to provide the essential method for the analysis of two kinds of physical simulation experimental data of the radial azimuth and radial depth detection of the anomaly. The results show that the double-transmitting and sextuple-receiving borehole TEM has decent resolution ability in detecting the radial azimuth of the anomaly, and the effective resolution is 30°. The geometric difference among induced voltages of different measuring points can be used to evaluate the radial depth of the anomaly qualitatively. It is expected that the double-transmitting and sextuple-receiving borehole TEM can provide technical guidance for little borehole geophysical exploration in the fields of oil, natural gas, coal and basic engineering construction.Con la necesidad continua de mejorar la precisión en la exploración de perforaciones geofísicas, la aplicación del Método Electromagnético Transitorio (TEM, del inglés Transient Electromagnetic Method) se ha convertido en un tema de constantes estudios. La aplicación del TEM en perforaciones convencionales solo puede determinar la profundidad longitudinal de las anomalías geológicas, pero no puede resolver el acimut radial y la profundidad. Este estudio propone la aplicación del método TEM con transmisión doble y recepción séxtuple a través de la cual se altera la anomalía radial con el campo electromagnético generado por la doble emisión de ondas, mientras el acimut y la profundidad de las anomalías se identifican por las características de las señales de las seis enlaces de recepción. En este trabajo se dedujo la respuesta de las ecuaciones del modo transmisión-recepción para la transmisión doble y la recepción séxtuple en las perforaciones con el método TEM, y se obtuvieron las respuestas características del segmento de inducción y el segmento de atenuación de las ondas de recepción basados en la solución de las ecuaciones en condición de apagado de la función rampa, lo que proporciona las bases para el análisis teórico. Debido al valor negativo en las señales de respuesta de la transmisión doble y recepción séxtuple del transitorio electromagnéctio, se propone un algoritmo de transformación negativa bajo el sistema de coordenadas doblemente logarítmicas para proveer el método esencial del análisis de dos clases de información de simulación física experimental del acimut radial y la detección de la profundidad radial de la anomalía. Los resultados muestran que el TEM con transmisión doble y recepción séxtuple en perforaciones tiene una buena capacidad de resolución para detectar el acimut radial de la anomalía, con una resolución efectiva de 30 grados. La diferencia geométrica de los voltajes inducidos desde los diferentes puntos de medida se puede utilizar para evaluar cualitativamente la profundidad radial de la anomalía. La expectativa es que el método TEM con transmisión doble y recepción séxtuple en perforaciones puede proveer orientación técnica para pequeñas exploraciones de perforación geofísica en los campos de petróleo, gas natural, carbón y construcciones básicas de ingeniería

Experimental Study on Unconfined Compression Strength of Polypropylene Fiber Reinforced Composite Cemented Clay

The effects of three main factors, including polypropylene fiber content, composite cement content and curing time on the unconfined compressive strength of fiber-reinforced cemented clay were studied through a series of unconfined compressive strength tests. The experimental results show that the incorporation of fibers can increase the compressive strength and residual strength of cement-reinforced clay as well as the corresponding axial strain when the stress peak is reached compared with cement-reinforced clay. The compressive strength of fiber-reinforced cement clay decreases first, then increases with small-composite cement at curing time 14 d and 28 d. However, fiber-reinforced cement clay’s strength increases with the increase of fiber content for heavy-composite cement. The compressive strength of fiber-composite cement-reinforced marine clay increases with the increase of curing time and composite cement content. The growth rate increases with the increase of curing time. The failure mode of composite cement-reinforced clay is brittle failure, while the failure mode of fiber-reinforced cemented clay is plastic failure