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The productivity and pressure response of the tight sand gas wells are influenced by multiple flow mechanisms, such as threshold pressure gradient, phase-change phenomena, and stress sensitivity. Understanding the sensitivity of these factors is crucial for the effective development of tight sand gas reservoirs. This study aims to clarify the sensitivity of various factors affecting the productivity and pressure response of tight sand gas wells. Based on the percolation theory of tight sand gas reservoirs, we considered stress sensitivity, threshold pressure gradient, and phase-change phenomena to derive an unsteady mathematical model of a fractured well with an infinite boundary, and a point source solution was obtained. The proposed model was solved using series function properties, variable substitution, perturbation technique, Poisson superposition formula, Laplace transform, and numerical inversion. The influence of several important parameters on pressure response and productivity is discussed in detail. The results show that the threshold pressure gradient, stress sensitivity, and skin factor significantly impact gas well production and pressure response, while the wellbore storage effect and phase-change effect primarily affect the initial production and pressure response, having little effect on the cumulative gas production. The proposed model can estimate the influence of the threshold pressure gradient and stress sensitivity on productivity and pressure, providing a guide for the development of technical measures for fractured wells in tight sand gas reservoirs. [ABSTRACT FROM AUTHOR]

In this study, (Gd0.9Yb0.1)2Zr2O7 (GYbZ)/yttria-stabilized zirconia (YSZ) double-ceramic-layer (DCL) thermal barrier coatings (TBCs) were prepared by plasma spray-physical vapor deposition (PS-PVD). The microstructure, mechanical performance, and thermal shock behavior of coatings prepared with spraying distances of 600, 800, and 1000 mm were investigated. The GYbZ coating prepared with a spraying distance of 600 mm showed a closely packed columnar structure. However, the GYbZ coatings prepared with spraying distances of 800 and 1000 mm showed a quasi-columnar structure. The GYbZ coating prepared with a spraying distance of 800 mm had the thickest columnar crystals with obvious inter-columnar gaps. In addition, this coating exhibited excellent mechanical performance and the best thermal shock resistance. The primary failure patterns appearing during thermal shocking on the surface of TBCs can be classified into the following five types: caves, exfoliation, delamination cracks, spalled areas, and radiate cracks. Furthermore, the failure behavior of these coatings in water-quenching tests is clarified. [ABSTRACT FROM AUTHOR]

The Pacific/North American pattern (PNA) and North Atlantic Oscillation (NAO) are two of the most important atmospheric low-frequency variability modes modulating interannual anomalies of snowpacks in North America. However, the quantitative degree to which the PNA and NAO affect the annual maximum snow water equivalent (SWEmax), a quantity directly relevant to the ground snow load calculation in National Building Code of Canada, remains unknown. This study explores the relationship of the winter PNA and NAO to the Canadian SWEmax anomalies and potential changes associated with atmospheric circulation patterns. Significant correlations are identified in eastern and western Canada, where climatological mean values are largest due to the high frequency of snow storm occurrence. The regions in Canada where SWEmax anomalies are influenced by the PNA and NAO experienced a significant change from pre-1998 to post-1998. This change is consistent with the observed changes in annual maximum snow depth and the winter atmospheric circulations during 1979-2009. Copyright © 2012 Royal Meteorological Society [ABSTRACT FROM AUTHOR]

This study examines intercontinental linkages between late spring and early summer Eurasian snow cover extent (SCEss) anomalies and the following winter temperature anomalies over Canada for the 1972-2006 period. The structure of the second interannual mode of Canadian winter temperatures variability captures the SCEss related modulation. The North Atlantic winter atmospheric circulation changes associated with the SCEss, resembling the negative phase of the North Atlantic Oscillation (NAO), suggest a possible pathway for the SCEss influences on the Canadian winter temperatures. Regression and composite analyses show that the SCEss relate robustly to the Canadian winter climate. Larger-than-normal SCEss is associated with below normal winter temperatures in south-central Canada and above normal temperatures over northeastern Canada. Predictive skill of Canadian winter temperatures based on a cross-validated regression model shows that the SCEss offers the predictive potential over regions of Canada where El Niño-Southern Oscillation (ENSO) related skill is weak or nonexistent. Analysis of winter extreme minimum temperatures, by a non-stationary generalized extreme value model, with the SCEss as a covariate, exhibits statistically significant changes over Canada resembling a pattern similar to that of winter mean temperatures. Wavelet analysis shows significant coherence between the SCEss and the second mode of winter temperature variability in the 8-12-year band. Copyright © 2011 Crown in the right of Canada. Published by John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

Objective: To explore the potential mechanism of electroacupuncture (EA) for vascular dementia (VD) using tandem mass tag (TMT) quantitative proteomics technology., Methods: Among 80 male SPF SD rats, 78 rats which met the selection criteria through the Morris water maze test were selected and randomly divided into a sham surgery group (18 rats) and a surgery group (60 rats). VD model was established by four-vessel occlusion (4-VO) method in the surgery group, and 36 rats with successful modeling were randomly assigned to a model group (18 rats) and an EA group (18 rats). Each group was further divided into three subgroups based on intervention duration, with each subgroup containing 6 rats. Seven days after model establishment, the EA group received EA intervention at left and right "Sishencong" (EX-HN 1) and bilateral "Fengchi" (GB 20), with continuous wave at a frequency of 2 Hz and current intensity of 1 mA, daily for 30 min, with subgroups receiving EA for 7, 14, or 21 d respectively. Cognitive function before and after interventions was assessed using Morris water maze. Proteomic analysis was conducted on the optimal EA subgroup and corresponding sham surgery and model subgroups, identifying differentially expressed proteins and analyzing them through bioinformatics. Differentially expressed target proteins was performed using parallel reaction monitoring (PRM) and Western blot techniques., Results: Compared to the sham surgery group, the model group exhibited prolonged escape latency and reduced number of platform crossings ( P <0.01); compared with model group, the EA group showed reductions in escape latency and increased platform crossings after 7, 14, and 21 days of intervention ( P <0.01, P <0.05). Compared to the 7 and 14-day intervention, the rats in the EA group of 21-day intervention showed the most significant improvements in reductions of escape latency and increased platform crossings ( P <0.01, P <0.05), and was selected for further proteomic, PRM analyses, and Western blot validation. Compared to the sham surgery group, the model group displayed 71 differentially expressed proteins, with 50 up-regulated and 21 down-regulated proteins; compared to the model group, the EA group had 54 differentially expressed proteins, with 30 up-regulated and 24 down-regulated proteins. Functional enrichment and clustering analyses indicated that these proteins were primarily associated with cellular processes, metabolic processes, phagocytosis recognition, immune response, and regulation of extracellular matrix, etc. Enrichment was observed in the mammalian target of rapamycin (mTOR) signaling pathway and neurotrophic factors signaling pathways, involving glycogen synthase kinase 3β (GSK3β) and mitogen-activated protein kinase kinase 2 (Map2k2), with PRM and Western blot findings consistent with the proteomic results. Which meant that compared with the model group, the protein expression of GSK3β and Map2k2 of hippocampus was increased in the EA group ( P <0.01, P <0.05)., Conclusion: EA at "Sishencong" (EX-HN 1) and "Fengchi" (GB 20) could improve cognitive function in VD rats, with the mechanism involving multiple targets and pathways, potentially related to GSK3β, Map2k2 proteins, and the mTOR and neurotrophic factor signaling pathways.