Experimental and modeling studies on continuous liquid removal in horizontal gas wells

The potential risks of liquid-loading can be significantly decreased by precisely calculating the minimum gas flowrate required for continuous liquid removal in gas wells and using suitable deliquification technology beforehand. Due to lack of comparative studies with liquid-loading characteristics, existing prediction models are not very adaptable in the course of the application. So as to investigate the flowing behavior of liquid film under different conditions, visual experiment was conducted. The findings indicate that as the inclined angle increases, the liquid-film-reversal gas velocity increases initially before decreasing. The maximum velocity of liquid-film-reversal is around 55°. The liquid-film-reversing gas velocity increases linearly along with the rise in superficial liquid velocities. The liquid-film-reversal gas velocity likewise increases linearly as the superficial liquid velocities. The analysis findings also indicate that several dynamic liquid-loading symptoms of the gas well are inconsistent with the liquid-film-reversal criterion, meaning that the gas well does not instantly follow the liquid-film-reversal. On the basis of our experimental findings, a new liquid-loading commencement criteria was then developed. As a result, this research suggests a novel model for evaluating liquid-loading in gas wells. The model’s accuracy was found to be as high as 85.7% by looking at 14 gas wells and perform better than other models in the Coleman dataset, which can theoretically enable the prediction of liquid-loading in gas wells

TRIM29 acts as a potential senescence suppressor with epigenetic activation in nasopharyngeal carcinoma.

Epigenetic alterations marked by DNA methylation are frequent events during the early development of nasopharyngeal carcinoma (NPC). We identified that TRIM29 is hypomethylated and overexpressed in NPC cell lines and tissues. TRIM29 silencing not only limited the growth of NPC cells in vitro and in vivo, but also induced cellular senescence, along with reactive oxygen species (ROS) accumulation. Mechanistically, we found that TRIM29 interacted with voltage-dependent anion-selective channel 1 (VDAC1) to activate mitophagy clearing up damaged mitochondria, which are the major source of ROS. In patients with NPC, high levels of TRIM29 expression are associated with an advanced clinical stage. Moreover, we detected hypomethylation of TRIM29 in patient nasopharyngeal swab DNA. Our findings indicate that TRIM29 depends on VDAC1 to induce mitophagy and prevents cellular senescence by decreasing ROS. Detection of aberrantly methylated TRIM29 in the nasopharyngeal swab DNA could be a promising strategy for the early detection of NPC

Towards optimal concolic testing

ACM Distinguished Paper Award</p

Turning Playboys/Playgirls into the Cheerleaders of the National Leadership: Ideological Advocacy via a Recreational Channel in Contemporary China

As China is becoming more autocratic in recent years, the cyberworld, based on the widely popularised access to the Internet, has become the new battlefield for political propaganda. The young adolescents who were previously difficult to target with conventional didactics have become the main objects. The entry of the Central Committee of the Communist Young League to the website: Bilibili, at the beginning of 2017, is a clear sign of the determination of the national leadership in turning the self-entertained ACGN (Animations, Comics, Games and light Novels) fans into the proactive agents of the Party and the State. To figure out the effects of such an action, this research selects 15 most-viewed videos released by three national media on Bilibili for textual and multi-modal discourse analyses. In addition, as danmus (弹幕, also translated as bullet chats) is a unique function of Bilibili, this research also summarises their characteristics and explores the rich discourses with the assistance of the programming language Python. This research finds out that the national leadership is leading the refinement of nationalism on Bilibili. Certain well-developed online grassroots nationalism is selected and incorporated into the official narrative, and the idea of “love the Party” and the dream-chasing struggle of rural grassroots are being included in the umbrella concept of nationalism as new components. With clear acknowledgement of the official natures of the videos, the recipients of such refined nationalism, while keeping their identity as “ACGN fans”, begin to pick up the identity of “little pink”, namely, the advocators of the Party and the Country. Furthermore, the widely-popularised Internet and its communication power have greatly accelerated the interaction between nationalism (the state-led mainstream culture) and ACGN contents (a representative subculture/popular culture). In particular, nationalism is being diffused through subcultural ways recreationally, which further blurs the boundary between mainstream culture and subculture, complying with the overall trend of cultural convergence in the 2020s. This research sets a typical example of investigating the mutual effect between politics and culture in the digital era. The research results may supplement our understanding of the ever-evolving relationship between mainstream culture and subculture in the context of contemporary China, where the political situation is experiencing drastic changes

J-integral based fracture toughness of 15Cr-5Ni stainless steel during phase transformation

International audienceThis paper proposes a simple effective method to extract the elastoplastic toughness J1C from a simple experiment on a plate. The method is based on a combination of global experimental load displacement measurements, finite element simulation, and digital image correlation which is used to observe the crack propagation initiation as well as to determine the appropriate boundary conditions to be used in numerical simulation. This method is applied to obtain the J1C value of material 15Cr–5Ni stainless steel, which is normally written as 15–5PH after different temperature histories. This paper investigates the influence of the different material state history on the mechanical properties due to the heat treatment and possible phase transformation. Meanwhile, the fractography is also analysed. The result of J1C value shows that the pure martensite 15–5PH has higher fracture toughness at room temperature than at 200 °C. The toughness is also higher than the original material after one cycle heat treatment, which is probably caused by some residual austenite. Meanwhile, pure austenite 15–5PH has a higher fracture toughness than pure martensite 15–5PH at 200 °C. The J1C value of the dual phase 15–5PH during the martensitic transformation also shows that possibly austenite can enhance the ductility of the material as well as fracture toughness.Highlights► This paper gives a new and economic method to evaluate J1C with combination of DIC and FEA. ► It shows that thermal history inducing phase transformation has an effect on fracture toughness. ► J1C toughness values are estimated for 15–5PH stainless steel at different metallurgical states

Investigation into macroscopic and microscopic behaviors of bonded sands using the discrete element method

International audienceThis paper presents an investigation into the inter-particle bonding effects on the mechanical behaviors of structured sands using the distinct element method (DEM) incorporating measured inter-particle mechanical behaviors. The inter-particle mechanical behaviors are first studied by testing on idealized bonded granules under designed loading paths, which demonstrates a linear pre-failure force–displacement relationship and normal force-dependent shear strength of bonded particles. Then a modified contact model is proposed by employing different force–displacement laws for pre-failure and post-failure bonded particles, in which a failure criterion is introduced to describe the inter-particle debonding. The third part deals with the DEM numerical simulation of isotropic and biaxial compression tests to investigate the bonding effects on the mechanical behaviors of bonded sands, where the proposed model has been verified capable of capturing the main mechanical behaviors of bonded sands. In addition, the investigation into the microscopic responses quantitatively figures out the effects of inter-particle cementation on the mechanical behaviors and the loss of soil structure

Capacity assessment of joint reconnaissance &amp; warning system based on wargame

The capability assessment of the joint reconnaissance and early warning system provides the fundamental information for the joint combat commanders to execute combat planning and command and control. According to the urgent needs of the joint operations commander to analyze and evaluate the capability of the joint reconnaissance and early warning system, based on the basic scenarios and real-time deduction data of the joint combat wargame, this paper evaluates the joint reconnaissance and early warning system by combining the static capability boundary evaluation and the real-time combat effectiveness evaluation. According to the evaluation requirements, fifteen specific evaluation indicators from two categories of basic combat capability evaluation and real-time combat effectiveness evaluation are designed and constructed. And the connotation, extension and calculation method of each evaluation index are elaborated. Finally, based on the basic scenario data of the joint combat wargame system and the output data of the game model, this paper constructs the capability evaluation software tool for the joint reconnaissance and early warning system, which provides new ideas and new methods for the capability evaluation of the joint reconnaissance and early warning system to solve the key information requirements of the commander in the wargame

Poly(Propylene Carbonate)-Based Biodegradable and Environment-Friendly Materials for Biomedical Applications

Poly(propylene carbonate) (PPC) is an emerging “carbon fixation” polymer that holds the potential to become a “biomaterial of choice” in healthcare owing to its good biocompatibility, tunable biodegradability and safe degradation products. However, the commercialization and wide application of PPC as a biomedical material are still hindered by its narrow processing temperature range, poor mechanical properties and hydrophobic nature. Over recent decades, several physical, chemical and biological modifications of PPC have been achieved by introducing biocompatible polymers, inorganic ions or small molecules, which can endow PPC with better cytocompatibility and desirable biodegradability, and thus enable various applications. Indeed, a variety of PPC-based degradable materials have been used in medical applications including medical masks, surgical gowns, drug carriers, wound dressings, implants and scaffolds. In this review, the molecular structure, catalysts for synthesis, properties and modifications of PPC are discussed. Recent biomedical applications of PPC-based biomaterials are highlighted and summarized