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This study examines the hot deformation behavior of Mo-14Re alloy at various true strains (15%, 35%, 65%) and strain rates (0.01 s−1, 10 s−1) at a temperature of 1400K. The findings indicate that dynamic recovery (DRV) and dynamic recrystallization (DRX) occur concomitantly as strain increases at a low strain rate of 0.01 s−1, with DRV being the predominant softening mechanism. At a strain of 65%, DRX emerges as the primary softening process. Conversely, under high strain rates of 10 s−1, DRX is inhibited, and the Mo-14Re alloy experiences work hardening due to an increase in dislocation density. Microscopic analysis shows that the high-density dislocations facilitate the continued nucleation and growth of recrystallized grains at low strain rates. At high strain rates, tangled dislocations hinder dislocation motion and recrystallization. Regarding texture evolution, stronger {100}//CD and weaker {111}//CD fiber texture is observed at low strain rates of 0.01 s−1, while stronger {111}//CD and weaker {100}//CD fiber texture forms at high strain rates of 10 s−1, with enhanced texture intensity. Mechanistic analysis confirms the activation of the {110}, {112}, and {123} dislocation slip systems at elevated temperatures, with the {123} system being the most dominant.

This study conducted temporary plugging and diversion fracturing (TPDF) experiments using a true triaxial fracturing simulation system within a laboratory setting that replicated a lab-based horizontal well completion with multi-cluster sand jetting perforation. The effects of temporary plugging agent (TPA) particle size, TPA concentration, single-cluster perforation number and cluster number on plugging pressure, multi-fracture diversion pattern and distribution of TPAs were investigated. A combination of TPAs with small particle sizes within the fracture and large particle sizes within the segment is conducive to increasing the plugging pressure and promoting the diversion of multi-fractures. The addition of fibers can quickly achieve ultra-high pressure, but it may lead to longitudinal fractures extending along the wellbore. The temporary plugging peak pressure increases with an increase in the concentration of the TPA, reaching a peak at a certain concentration, and further increases do not significantly improve the temporary plugging peak pressure. The breaking pressure and temporary plugging peak pressure show a decreasing trend with an increase in single-cluster perforation number. A lower number of single-cluster perforations is beneficial for increasing the breaking pressure and temporary plugging peak pressure, and it has a more significant control on the propagation of multi-cluster fractures. A lower number of clusters is not conducive to increasing the total number and complexity of artificial fractures, while a higher number of clusters makes it difficult to achieve effective plugging. The TPAs within the fracture is mainly concentrated in the complex fracture areas, especially at the intersections of fractures. Meanwhile, the TPAs within the segment are primarily distributed near the perforation cluster apertures which initiated complex fractures.

Key Clinical Message In recent years, it is necessary to Redo‐TAVR for the patients with bioprosthetic valve degeneration. This case report described a unique instance to successfully Redo‐TAVR a patient with bioprosthetic valve degeneration, in addition, with left cerebral infarction and renal insufficiency. Abstract Over time, more and more patients have bioprosthetic valve degeneration either used in SAVR or TAVR. In order to solve the produced problems due to the degenerated bioprosthetic valve, Redo‐TAVR was increasingly popular due to its safe and efficiency especially for the high risk and complicated symptoms patients. In this case, the patient with left cerebral infarction and renal insufficiency has exhibited severe regurgitation and obvious neoplasm around the previous replaced aortic valve. For the patient with complicated symptoms, we did not image for this patient and only used CT to determine the position and angle for the Redo‐TAVR on the base of metal stent for the previous replaced aortic valve. During the Redo‐TAVR process, for fear of the obvious neoplasm slipping from the previous replaced aortic valve to embolism of important organs, before carrying out the Redo‐TAVR, cerebral protection device, temporary pacemaker, and coronary artery protection device were utilized in order to avoid the damage for the important organs from the obvious neoplasm slipping from the previous replaced aortic valve. The surgery was successful and the patient recovered well. The patient's symptoms of chest tightness and suffocation have been greatly reduced.

In this paper, the effects of equivalence ratio (0.8–2.0) and temperature (30°C–120°C) on ethanol, acetone, and, ethyl acetate vapors explosion characteristics through experimental and numerical studies were investigated. The explosion overpressure and flame propagation velocity were recorded through the pressure transducer and high-speed camera. The results showed that the flame propagation velocity, peak explosion overpressure, and peak growth rate of explosion overpressure increased first and then decreased with the increase of equivalence ratio. The cracks on the flame surface enhanced with the increase of the equivalence ratio. As the initial temperature increased, peak explosion overpressure, the flame propagation velocity, and peak growth rate of explosion overpressure gradually increased. The sensitivity analysis of laminar burning velocity indicated that with the change of equivalence ratio and initial temperature, the shared elementary reactions that increased the reactivity were H + O2 O + OH, HCO + M H + CO + M, and CO + OH CO2 + H, and the shared elementary reaction that reduced the reactivity was H + OH + M H2O + M. The main factor affecting laminar burning velocity was the mole fraction of H and OH radicals.

The efficient and accurate calculation of neutron flux distribution is essential for evaluating the safety of nuclear facilities and the surrounding environment. While traditional numerical simulation methods such as the discrete ordinates (SN) method and Monte Carlo method have demonstrated excellent performance in terms of accuracy, their complex solving process incurs significant computational costs. This paper explores a data-driven and efficient method for obtaining neutron flux distribution based on deep learning, specifically targeting shielding problems with constant geometry and varying material cross-sections in practical engineering. The proposed method bypasses the intricate numerical transport calculation process of the discrete ordinates method by constructing a surrogate model that captures the correlation between transport characteristics and neutron flux from data characteristics. Simulations were carried out using Kobayashi-1 and Kobayashi-2 geometric models for shielding problems with constant geometry and varying material cross-sections. A series of validations have proved that the data-driven surrogate model demonstrates high generalization ability and reliability, while reducing the time required to obtain neutron flux distribution to 0.1 s without compromising on calculation accuracy compared to the discrete ordinates method.

Hydraulic fracturing plays a crucial role in the development of unconventional resources, and assessing fracture geometry is a fundamental aspect of hydraulic fracturing analysis. Among the various technologies for evaluating fracture geometry, the water percussion signal-based method has gained popularity due to its cost-effectiveness, convenience, and real-time capabilities. In this study, we present a methodology for analyzing fracture data that utilizes the water percussion effect. By leveraging the impact of fractures on water percussion pressure attenuation, we propose an inverse calculation approach to determine fracture geometry. Firstly, we introduce the RCI (Reservoir-Completion-Interaction) circuit model, which effectively addresses the bottom hole fracture boundary and simulates the variation of water percussion pressure in the wellbore. Secondly, the simulation results are utilized in an iterative process to determine the RCI values, which are then utilized for the inversion calculation of fracture geometry. Finally, we apply this method to a field case and compare the simulation results with microseismic monitoring data. A larger resistance (R) value indicates a smaller fracture volume, while the (C) value can be used to monitor any poorly performing stages of the fracturing simulation process. The (I) value primarily affects the parameter calculation of the fracture size, especially the fracture width. The results of the field application show that the accuracy rate exceeding 80%, validating the reliability of the model and providing a valuable reference for field fracturing data analysis.

Abstract Background Interferon regulatory factor 1 (IRF1) is an important transcription factor that activates the type I interferon (IFN-I) response and plays a vital role in the antiviral immune response. Although IRF1 has been identified in several mammals, little information related to its function in canines has been described. Results In this study, canine IRF1 (CaIRF1) was cloned. After a series of bioinformatics analyses, we found that the CaIRF1 protein structure was similar to that of other animal IRF1 proteins, including a conserved DNA-binding domain (DBD), an IRF-association domain 2 (IAD2) domain and two nuclear localization signals (NLSs). An indirect immunofluorescence assay (IFA) revealed that CaIRF1 was mainly distributed in the nucleus. Overexpression of CaIRF1 in Madin-Darby canine kidney cells (MDCK) induced high levels of interferon β (IFNβ) and IFN-stimulated response element (ISRE) promoter activation and induced interferon-stimulated gene (ISG) expression. Subsequently, we assayed the antiviral activity of CaIRF1 against vesicular stomatitis virus (VSV) and canine parvovirus type-2 (CPV-2) in MDCK cells. Overexpression of CaIRF1 effectively inhibited the viral yields of VSV and CPV-2, while knocking down of CaIRF1 expression mildly increased viral gene copies. Conclusions CaIRF1 is involved in the cellular IFN-I signaling pathway and plays an important role in the antiviral response.

The occurrence of recrystallization will cause catastrophic damage to the structure of metallic single crystal, which can be avoided by choosing crystal orientation reasonably. In this work, the effect of crystal orientation on the recrystallization behavior of single crystal is investigated using multi-scale characterization method. The electron backscattered diffraction analysis shows that in mesoscopic scale, the recrystallization behavior of Mo–3Nb single crystal exhibits a strong orientation dependence, which the new recrystallization grains are produced in the -oriented single crystal, while the single crystal structure is still retained in other orientations. At the micro scale, the elongated dislocation cells with certain misorientations appear in the -oriented single crystal, while only the dislocation walls and parallel dislocation cells distribute on the single crystal with the and orientations, respectively. The length of dislocation lines in deformed single crystal with orientation is calculated using molecular dynamics to be 3491.22 Å, which is much longer than that of the orientation (1133.27 Å) and the orientation (2862.68 Å), suggesting a higher crystal distortion and easier recrystallization in the orientation. In addition to the coalescence mechanism of discontinuous sub-grains, the shear band also plays an important role in promoting recrystallization nucleation. This work provides reference value for the secondary processing of molybdenum single crystal, so as to obtain more excellent products and expand its potential application.

High-entropy alloys (HEAs) attract much attention as possible radiation-resistant materials due to their several unique properties. In this work, the generation and evolution of the radiation damage response of an FeNiCrCoCu HEA and bulk Ni in the early stages were explored using molecular dynamics (MD). The design, concerned with investigating the irradiation tolerance of the FeNiCrCoCu HEA, encompassed the following: (1) The FeNiCrCoCu HEA structure was obtained through a hybrid method that combined Monte Carlo (MC) and MD vs. the random distribution of atoms. (2) Displacement cascades caused by different primary knock-on atom (PKA) energy levels (500 to 5000 eV) of the FeNiCrCoCu HEA vs. bulk Ni were simulated. There was almost no element segregation in bulk FeNiCrCoCu obtained with the MD/MC method by analyzing the Warren–Cowley short-range order (SRO) parameters. In this case, the atom distribution was similar to the random structure that was selected as a substrate to conduct the damage cascade process. A mass of defects (interstitials and vacancies) was generated primarily by PKA departure. The number of adatoms grew, which slightly roughened the surface, and the defects were distributed deeper as the PKA energy increased for both pure Ni and the FeNiCrCoCu HEA. At the time of thermal spike, one fascinating phenomenon occurred where the number of Frenkel pairs for HEA was more than that for pure Ni. However, we obtained the opposite result, that fewer Frenkel pairs survived in the HEA than in pure Ni in the final state of the damage cascade. The number and size of defect clusters grew with increasing PKA energy levels for both materials. Defects were suppressed in the HEA; that is to say, defects were “cowards”, behaving in an introverted manner according to the anthropomorphic rhetorical method.

Pulse injection hydraulic fracturing (HF) can release high-energy peak pressure in a split-second, forming a complex hydraulic fracture network in shale reservoirs. However, the initiation and propagation of multiple fractures in the horizontal well of shale reservoirs under pulse injection HF have been inadequately studied. Hence, in this study, a HF model coupling the fracturing fluid flow along the fracture and the rock deformation was adopted, and the effect of the pulsed injection method on multistage HF of horizontal wells was determined. The results show that the pulsed injection HF can improve the fracturing effect of horizontal wells. However, no matter how the injection displacement and pulse frequency change, the propagation length of cracks at both ends seriously disturbed by stress almost remains unchanged. When the dominant fracture is temporarily shielded, the fluid pressure of the non-dominant fractures at both ends disturbed by stress compression increases, and the non-dominant fractures can be further expanded. Thus, a new composite multistaged HF scheme suitable for horizontal wells with pulse-temporary shielding in shale reservoirs was proposed. The method presented here can be adopted to optimize the fracture growth regime and provide a scientific basis for the fracturing operation of the horizontal well in shale reservoirs.

This paper demonstrates a high-efficiency modular multilevel resonant DC-DC converter (MMRC) with zero-voltage switching (ZVS) capability. In order to minimize the conduction loss in the converter, optimizing the root-mean-square (RMS) current flowing through switching devices is considered an effective approach. The analysis of circuit configuration and operating principle show that the RMS value of the current flowing through switching devices is closely related to the factors such as the resonant tank parameters, switching frequency, converter output voltage and current, etc. A quantitative analysis that considers all these factors has been performed to evaluate the RMS current of all the components in the circuit. When the circuit parameters are carefully designed, the switch current waveform can be close to the square waveform, which has a low RMS value and results in low conduction loss. And a design example based on the theoretical analysis is presented to show the design procedures of the presented converter. A 600 W 48 V-to-12 V prototype is built with the parameters obtained from the design example section. Simulation and experiments have been performed to verify the high-efficiency feature of the designed converter. The measured converter peak efficiency reaches 99.55% when it operates at 200 kHz. And its power density can be as high as 795 W/in3.

Feline parvovirus often causes a fatal infectious disease and has a serious impact on domestic cats and wild felines. Feline chaphamaparvovirus (FeChPV) is a novel type of feline parvovirus that has been successively identified in Canada, Italy, and Turkey. The prevalence and pathogenicity of FeChPV in other regions is still unknown. In this study, we recorded the detection of FeChPV in a cat shelter in China. A high prevalence (81.08%, 30/37) of FeChPV was detected in cats with symptoms of upper respiratory tract disease (URTD) in this cat shelter. Multiple pathogen testing indicated high coinfection rates of 80% (24/30) with other common viruses in FeChPV-positive cats. Analyses of the necropsy and histopathological findings revealed severe lymphadenitis, encephalitis, and viral DNA in several tissues (including brain) of the deceased cat. Finally, we obtained nearly full-length genomes of four strains with 98.4%~98.6% homology with previously reported genomes. Notably, VP1 proteins showed seven unique amino acid mutations, while NS1 proteins carried eight mutations. In the evolutionary tree based on VP1 and NS1, the sequences clustered in a large branch with Italian and Canadian FeChPV strains. Given the possible association of FeChPV with URTD, further studies are necessary to evaluate the pathogenicity and epidemiological characteristics of this novel feline pathogen.

With the rapid development of shale gas exploration and development in China, casing deformation in shale gas horizontal wells happens frequently, which directly impacts the development efficiency and benefits of shale gas. In order to explore casing deformation prediction, prevention and treatment methods, this paper analyzes the geological and engineering causes of casing deformation in shale-gas horizontal wells through laboratory work, such as the casing resistance to internal pressure alternating test, the ground simulation test and systematical casing deformation characteristic analysis of MIT24 caliper logging, and the large-scale physical simulation test and numerical simulation of casing deformation. Then, combined with the generalized shear activity criterion, a new method for evaluating casing deformation risk points and some technical measures for preventing casing deformation were formulated. And the following research results were obtained. First, the deformation characteristics of 119 casing deformation points in 23 wells interpreted by MIT24 caliper logging are consistent with the mechanical behaviors of shear compression deformation test. Second, the large-scale physical simulation test shows that natural fault-fractures slip obviously under the state of strike-slip stress. Third, numerical simulation shows that the compression stress on casing increases with the increase of fault-fracture slip. When the fault-fracture slip is between 7.5 mm and 9.0 mm, the casing reaches the critical yield strength and begins to undergo plastic deformation. The “temporary fracture plugging + long segment and multi-cluster” and other technologies are field tested in 28 wells in Weiyuan area of southern Sichuan Basin. The casing deformation rate decreases from 54% (before this research) to 14.3%, and the segment loss rate decreases from 7.8% to 0, which reveals remarkable achievements in casing deformation treatment. In conclusion, the shear slip of fault and macro fractures (referred to as fault-fracture) is the main cause of casing deformation in shale gas horizontal wells, and some measures (e.g. “temporary fracture plugging + long segment and multi-cluster”, reducing fracturing scale and releasing wellbore pressure properly) shall be taken in advance to reduce the fault-fracture activity before the risk point of casing deformation is fractured, so as to reach the goal of casing deformation prevention.

Person re-identification plays an important role in the construction of the smart city. A reliable person re-identification system relieves users from the inefficient work of identifying the specific individual from enormous numbers of photos or videos captured by different surveillance devices. The most existing methods either focus on local discriminative features without global contextual information or scatter global features while ignoring the local features, resulting in ineffective attention to irregular pedestrian zones. In this article, a novel Transformer-CNN Coupling Network (TCCNet) is proposed to capture the fluctuant body region features in a heterogeneous feature-aware manner. We employ two bridging modules, the Low-level Feature Coupling Module (LFCM) and the High-level Feature Coupling Module (HFCM), to improve the complementary characteristics of the hybrid network. It is significantly helpful to enhance the capacity to distinguish between foreground and background features, thereby reducing the unfavorable impact of cluttered backgrounds on person re-identification. Furthermore, the duplicate loss for the two branches is employed to incorporate semantic information from distant preferences of the two branches into the resulting person representation. The experiments on two large-scale person re-identification benchmarks demonstrate that the proposed TCCNet achieves competitive results compared with several state-of-the-art approaches. The mean Average Precision (mAP) and Rank-1 identification rate on the MSMT17 dataset achieve 66.9% and 84.5%, respectively.

AbstractDuring the unconventional reservoir development, a proper modelling of the underground fracture networks and their effects on production is crucial for reservoir development potential and realistic economic analysis. Conventionally, the complex fracture system formed by hydraulic and natural fractures is extremely difficult to capture, let alone to numerically simulate it. Most importantly, the current best solution can only rely on the knowledge of the natural fractures from the geology and geophysics team and hydraulic fractures from the engineering team. Nevertheless, this solution fails to realize the dynamic stress regime variations when fracturing jobs are done within the horizontal wellbore. In this study, a variety of data source and modelling tools is harnessed to delineate a more realistic and representative discrete fracture network (DFN). The first step is to obtain the original natural fractures already depicted from geological and geophysical information and the statistical information regarding the spatial configurations of this DFN. Next, a new set of natural fractures is generated by an in-house natural fracture generator while preserving the spatial characteristics of the original natural fractures at the same time. Then, a combined DFN of the original natural fracture and newly generated natural fractures is accomplished. This combined DFN is then intensity-calibrated by the given microseismic cloud events, especially focusing on the near-wellbore region. Then, a displacement discontinuity method- (DDM-) based in-house hydraulic fracture propagation model is used to generate hydraulic fractures with complex boundaries, honoring the fracturing job logistics from the engineering team. After this step, an ultimate and highly representative DFN can be achieved. By applying this very novel workflow, DFN characterizations of both a single-well scenario and well-pad (3 wells) scenarios have been highly successful. Statistics such as the cluster-wise hydraulic fracture half-length, height, aperture, and numbers of activated/nonactivated natural fractures can be easily presented. Through the powerful numerical method called the embedded discrete fracture model (EDFM), production simulation and stimulated reservoir volume evaluation can be seamlessly studied. Extents of 3D drainage volumes can also be plotted with ease. Overall, a holistic picture regarding the unconventional reservoir’s underground DFN can be reliably depicted, using the proposed workflow.

To study the casing deformation (CD) in shale gas well fracturing caused by natural fracture slip, a fracture face stress model is built based on stress analysis, and a CD prediction model is established based on complex function to analyze factors affecting wellbore shear stress and CD. (1) The fracture and wellbore approach angles have significant impacts on the wellbore shear stress. In Weiyuan shale gas field, Sichuan Basin, under the common wellbore approach angle of nearly 90°, the wellbore is subjected to large shear stress and high risk of CD at the fracture approach angle range of 20° to 55° or its supplementary angle range. (2) When the fracture is partially opened, the wellbore shear stress is positively correlated with the fluid pressure, and negatively correlated with the fracture friction coefficient; when the fracture is fully opened, the wellbore shear stress is positively correlated with the natural fracture area. (3) The lower the elastic modulus and the longer the fracture length, the more serious the CD will be, and the Poisson's ratio has a weak influence on the CD. The deformation first increases and then decreases with the increase of fracture approach angle, and reaches the maximum when the fracture approach angle is 45°. (4) At a given fracture approach angle, appropriately adjusting the wellbore approach angle can avoid high shear stress acting on wellbore, and reasonable control of the fluid pressure in the fracture can reduce the CD risk. The shear stress acting on casing is usually much greater than the shear strength of casing, so increasing casing strength or cementing quality have limited effect on reducing the risk of CD. Caliper logging data has verified that the CD prediction model is reliable, so the model can be used to establish risk analysis chart and calculate deformation value, to provide a reference for quick CD risk prediction in fracturing design.

In the field of question answering-based knowledge graphs, due to the complexity of the construction of knowledge graphs, a domain-specific knowledge graph often cannot contain some common-sense knowledge, which makes it impossible to answer questions that involve common-sense and domain knowledge at the same time. Therefore, this study proposes a knowledge graph-based question answering method in the computer science domain, which facilitates obtaining complete answers in this domain. In order to solve the problem of natural language problems being difficult to match with structured knowledge, a series of logic rules are first designed to convert natural language into triples of the question. Then, a semantic query expansion strategy based on WordNet is proposed and a priority marking algorithm is proposed to mark the order of triples of the question. Finally, when a question triple corresponds to multiple triples in the knowledge graph, it can be solved by the proposed SimCSE-based similarity method. The designed logic rules can deal with each type of question in a targeted manner according to the different question words and can effectively transform the question text into question triples. In addition, the proposed priority marking algorithm can effectively mark the order in the triple of the question. MKBQA can answer not only computer science-related questions but also extended open domain questions. In practical applications, answering a domain question often cannot rely solely on one knowledge graph. It is necessary to combine domain knowledge and common-sense knowledge. The MKBQA method provides a new idea and can be easily migrated from the field of computer science to other fields. Experiment results on real-world data sets show that, as compared to baselines, our method achieves significant improvements to question answering and can combine common-sense and domain-specific knowledge graphs to give a more complete answer.

A dual-coil inductive displacement transducer is a non-contact type measuring element for measuring displacement and is widely used in large power equipment systems such as construction machinery and agricultural equipment. However, the effect of the coil excitation method on the performance of dual-coil inductive displacement sensors has not been studied. This paper investigates the impact of different coil excitation methods on the operating performance of displacement transducers. The working principle, electromagnetic characteristics, and electrical characteristics were analyzed by building a mathematical model. A transducer measurement device was used to determine the relationship between core displacement and coil inductance. Three coil excitation methods were proposed, and the effects of the three coil excitation methods on the amplitude variation, phase shift, linearity, and sensitivity of the output signal were studied by simulation based on the AD630 chip as the core of the conditioning circuit. Finally, the study’s feasibility was demonstrated by comparing the experiment to the simulation. The results show that, under the uniform magnetic field strength distribution in the coil, the coil voltage variation is proportional to the inductive core displacement. The amplitude variation is the largest for the dual-coil series three-wire (DCSTW) and is the same for the dual-coil series four-wire (DCSFW) and dual-coil parallel differential (DCPD). DCSFW has an enormous phase shift. DCSTW has the best linearity. The research in this paper provides a theoretical basis for selecting a suitable coil excitation, which is conducive to further improving the operating performance of dual-coil inductive displacement transducers.

A double-coil inductive displacement transducer is a non-contact element for measuring displacement and is widely used in large power equipment systems such as construction machinery and agricultural machinery equipment. The type of coil excitation signal has an impact on the performance of the transducer, but there is little research on this. Therefore, the influence of the coil excitation signal on transducer performance is investigated. The working principle and characteristics of the double-coil inductive displacement transducer are analyzed, and the circuit simulation model of the transducer is established. From the aspects of phase shift, linearity, and sensitivity, the effects of a sine signal, a triangle signal, and a pulse signal on the transducer are compared and analyzed. The results show that the average phase shift, linearity, and sensitivity of the sine signal were 11.53°, 1.61%, and 0.372 V/mm, respectively; the average phase shift, linearity and sensitivity of the triangular signal were 1.38°, 1.56%, and 0.300 V/mm, respectively; and the average phase shift, linearity, and sensitivity of the pulse signal were 0.73°, 1.95%, and 0.621 V/mm, respectively. It can be seen that the phase shift of a triangle signal and a pulse signal is smaller than that of a sine signal, which can result in better signal phase-locked processing. The linearity of the triangle signal is better than the sine signal, and the sensitivity of the pulse signal is better than that of the sine signal.

Electric vehicles (EVs) can have massive benefits in energy sector especially for a small island country like the Maldives that imports oil with high transportation costs while power could have been generated from abundantly available local renewable resources. However, EV charging may also impose significant investment requirement for the power system that needs to be analyzed carefully including the capacity of the existing distribution network system, investments needed in solar PV together with battery storage and additional diesel capacity to meet the incremental demand from EVs. We explore an EV adoption scenario for Maldives for 2030 with 30% of all vehicles including two-wheelers that dominate the transport on the island under two different charging regimes: uncoordinated and optimized coordinated mode. The latter is achieved through a system wide optimization using a modified version of the World Bank Electricity Planning Model (EPM) that optimizes charging load subject to a range of constraints on allowable timing for different categories of vehicles. If charging from the fleet is uncoordinated, a relatively small increase in energy requirement of 3.1% due to EV may lead to a 26.1% increase in generation capacity requirement and hence 15.7% additional investment. While the optimized charging regime helps to drastically cut down on generation capacity requirements to just 1.8% increase and also considerably eases feeder loading, it may also lead to higher emissions as more EV load during off-peak hours lead to an increase in diesel-based generation. We have therefore explored an additional scenario wherein the annual emissions from the power sector are constrained to the baseline (“No EV”) scenario. The analysis shows the importance of focused modeling analysis to understand the ramifications of EV load impact on the power system including significant increase in generation capacity and potential increase in power sector emissions in a fossil-fuel dominated system.

Abstract Background Osteosarcoma (OS) is a common primary malignant bone tumour. Growing evidence suggests that circular RNAs (circRNAs) are closely related to the development of tumours. However, the function of circRNAs in OS remains unknown. Here, we aimed to determine the regulatory mechanisms of circRNAs in OS. Methods The expression profiles of OS circRNA (GSE96964), microRNA (GSE65071) and mRNA (GSE33382) were downloaded from the Gene Expression Omnibus (GEO) database to identify differentially expressed circRNAs, miRNAs and mRNAs in OS. A ceRNA network was constructed based on circRNA-miRNA pairs and miRNA-mRNA pairs. MRNAs with significant prognostic differences were identified by the TARGET database in the network. Functional and pathway enrichment analyses were performed, and interactions between proteins were predicted using Cytoscape. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were performed to elucidate the possible functions of these differentially expressed circRNAs. Results A total of 15 downregulated circRNAs, 136 upregulated miRNAs and 52 downregulated mRNAs were identified in OS. Finally, a circRNA-miRNA-mRNA network was constructed in OS based on 14 circRNAs, 24 miRNAs, and 52 mRNAs. GO and KEGG pathway analyses suggested that the mRNAs in the network may be involved in the pathogenesis and progression of OS. Four mRNAs identified by the TARGET database were significantly associated with OS survival prognosis. A circRNA-miRNA-mRNA subnetwork was constructed based on these four mRNAs. Conclusion Our results provide a deeper understanding of the regulatory mechanisms by which circRNAs compete for endogenous RNAs in OS.

Canine parvovirus (CPV-2) is one of the most important pathogens in dogs, and despite the continual development of vaccines against CPV-2, CPV-2 is still circulating in the canine population. The CPV-2a/2b/2c variant has replaced the original CPV-2 virus and seems to exhibit accelerated transmission. Although CPV-2 infection has been frequently reported, no studies have summarized information of CPV-2 variants currently circulating worldwide. To track the evolution of CPV-2, we downloaded and analyzed all VP2 sequences from the NCBI database (from 1978 to 2022). We found that CPV-2c shows a tendency to replace CPV-2a as the new dominant variant in Asia, South America, North America and Africa. Additionally, CPV-2c, which is prevalent in most regions of Asia, carries two special mutations in VP2, A5G and Q370R, and has become a dominant mutation with spillover already occurring. In conclusion, this summary of the types of global epidemic variants provides new insight into the evolution of CPV-2 and raises awareness for blocking the spread of this virus. The spread of Asian-derived CPV-2c urgently needs to be further under surveillance.

Feline stool-associated circular DNA virus (FeSCV) is an unclassified circular replication-associated protein-encoding single-stranded (CRESS) DNA virus that was discovered in cats in Japan in 2018. Few studies on the genomic characteristics and prevalence of FeSCV have been conducted. To investigate whether FeSCV has been circulating in domestic cats in Guangdong, China, fecal samples were collected from cats with diarrhea in an animal hospital in 2018 to promote research on FeSCV. The FeSCV genome was obtained by PCR amplification and sequencing, and the detected virus was named PY4 (GenBank No. MT732515). The genome of PY4 was 2,034 nt in size, which was 12 nt smaller than the reported genome of Japanese FeSCV strains (KU7, KU8, KU9, KU14) (2,046 nt). The PY4 strain shared 95.1 ~ 95.5% homology with Japanese FeSCV strains. Notably, the Cap protein of PY4 was mutated at 15 amino acid sites, and the PY4 genome contained a unique open reading frame 3. In addition, there were two additional base insertions in the stem-loop structure of PY4, and the nucleotide homology of the spacer region was not high. A phylogenetic tree based on Rep proteins showed that PY4, Japanese FeSCVs and rodent stool-associated circular viruses (RodSCVs) clustered together, suggesting that they might share a similar origin in their phylogenetic evolution. In this study, samples collected in Guangzhou, China, in 2018 were subjected to an etiological investigation, and 20% (2/10) of the samples were positive for FeSCV. The ORFs, stem-loop structures, Cap proteins and intergenic region sequences of PY4 were significantly different from those reported in Japan. This is the first report of FeSCV in domestic cats with diarrhea in China, and further epidemiological studies are urgently needed to assess the impact of the virus on cats.

The monitoring results of production logging show that almost one third of perforation clusters produce no or less gas after volumetric fracturing is initially applied in shale gas reservoirs. Besides, the production decline after the commissioning is commonly faster. In this paper, a fracture network prediction model and a fracturing well productivity prediction model were established based on microseismic interpretation data and hydraulic fracture network propagation results. After petrophysics, microseism, production performance were taken into consideration comprehensively, shale re-fracturing development potential evaluation index (RDPEI) was proposed. Then, a re-fracturing design and evaluation method was developed and targeted interval selection and evaluation was realized and applied on site. And the following research results were obtained. First, due to the heterogeneity of natural fractures, hydraulic fracture networks are more different, so an obvious “dead gas zone” can be easily formed and its re-fracturing potential is high. Second, the initial hydraulic fracture network is more affected by natural fractures. The main part of a fracture network propagates along the direction of maximum horizontal major stress, the fractures in regional stimulated intervals propagate in the form of double wing, and the length of a liquid swept fracture network is 52–70% of seismic interpretation result. Third, the RDPEI model avoids the limitations of single factor analysis and realizes the quantitative prediction on three types of indexes of recoverability, compressibility and re-fracturing. Fourth, re-fracturing of the case well is remarkable in stimulation effect. Its shale gas productivity is increased by 38.9%, and its cumulative gas production in one year is increased by 62.5%. In conclusion, re-fracturing is an effective and feasible method for improving the single well ultimate recovery reserves of shale gas. This method provides a theoretical and technical support for the selection and effect evaluation of re-fracturing intervals in shale-gas horizontal wells. Keywords: Shale gas, Re-fracturing, Productivity, Prediction, Fracture network propagation, Microseismic, Production decline, Single-well ultimate recoverable reserves

Canine circovirus (CanineCV) is an emerging virus in canines. Since the first strain of CanineCV was reported in 2012, CanineCV infection has shown a trend toward becoming a global epidemic. CanineCV infection often occurs with coinfection with other pathogens that may aggravate the symptoms of disease in affected dogs. Currently, CanineCV has not been successfully isolated by laboratories, resulting in a lack of clarity regarding its physicochemical properties, replication process, and pathogenic characteristics. To address this knowledge gap, the following results were obtained in this study. First, a CanineCV strain was rescued in F81 cells using infectious clone plasmids. Second, the Rep protein produced by the viral packaging rescue process was found to be associated with cytopathic effects. Additionally, the Rep protein and CanineCV inhibited the activation of the type I interferon (IFN-I) promoter, blocking subsequent expression of interferon-stimulated genes (ISGs). Furthermore, Rep was found to broadly inhibit host protein expression. We speculate that in CanineCV and canine parvovirus type 2 (CPV-2) coinfection cases, CanineCV promotes CPV-2 replication by inducing immunosuppression, which may increase the severity of clinical symptoms.

A series of laboratory fracturing experiments was performed on samples mined from an outcrop of the Silurian Longmaxi Formation shale in the Sichuan Basin, using a true triaxial fracturing simulation system. To reveal the characteristics of acoustic emission (AE) response in hydraulic fracture (HF) propagation, the HF propagation geometry obtained by specimen splitting and CT scanning technology was compared with the interpretation results of AE monitoring. And the difference of hypocenter mechanism between hydraulically connected and unconnected regions was further discussed. Experimental results show that the AE events distribution indicates well the internal fractures geometry of the rock samples. Numerous AE events occur and concentrate around the wellbore where the HF initiated. Sparse AE events were presented nearby bedding planes (BPs) activated by the HF. AE events tended to be denser where HF geometry was more complex. The hydraulically connected region was obviously distinct with the spatial distribution of AE events, which resulted in the overestimation of stimulated reservoir volume (SRV) based on micro-seismic mapping result. Both tensile and shear events occurred in the zone connected by the HFs, while only shear events were observed around BPs which were not hydraulically connected. Thus, the hydraulically connected and unconnected region can be identified in accordance with the hypocenter mechanism, which is beneficial to improve the accuracy of SRV evaluation. Key words: shale, bedding plane, hydraulic fracture, propagation geometry, acoustic emission, CT scanning

Classical swine fever (CSF) is one of the most important viral diseases in swine, causing severe economic losses in the swine industry. In China, CSF is one of the key diseases that needs to be controlled; the government has implemented control measures, and vaccination with C-strain vaccines (C-vacs) has been compulsory since the 1950s. C-vacs do not allow the differentiation of field virus-infected and vaccinated animals (DIVA). In 2012, China proposed a goal of eradicating CSF. Additionally, a baculovirus-expressed E2 subunit vaccine (E2-vac) was licensed in 2018. However, the C-vac and E2-vac characteristics have not been compared. Here, we demonstrate that both the C-vac and E2-vac provide complete protection against CSF in pigs. The E2-vac allows DIVA, and the E2 antibody responses of stimulated pigs are developed earlier and are stronger than the C-vac antibody responses. Therefore, the E2-vac is a new candidate licensed vaccine to completely eradicate CSF on pig farms.

Considering the influence of particle shape and the rheological properties of fluid, two artificial intelligence methods (Artificial Neural Network and Support Vector Machine) were used to predict the wall factor which is widely introduced to deduce the net hydrodynamic drag force of confining boundaries on settling particles. 513 data points were culled from the experimental data of previous studies, which were divided into training set and test set. Particles with various shapes were divided into three kinds: sphere, cylinder, and rectangular prism; feature parameters of each kind of particle were extracted; prediction models of sphere and cylinder using artificial neural network were established. Due to the little number of rectangular prism sample, support vector machine was used to predict the wall factor, which is more suitable for addressing the problem of small samples. The characteristic dimension was presented to describe the shape and size of the diverse particles and a comprehensive prediction model of particles with arbitrary shapes was established to cover all types of conditions. Comparisons were conducted between the predicted values and the experimental results.

Multistage multi-cluster hydraulic fracturing has enabled the economic exploitation of shale reservoirs, but the interpretation of hydraulic fracture parameters is challenging. The pressure signals after pump shutdown are influenced by hydraulic fractures, which can reflect the geometric features of hydraulic fracture. The shutdown pressure can be used to interpret the hydraulic fracture parameters in a real-time and cost-effective manner. In this paper, a mathematical model for shutdown pressure evolution is developed considering the effects of wellbore friction, perforation friction and fluid loss in fractures. An efficient numerical simulation method is established by using the method of characteristics. Based on this method, the impacts of fracture half-length, fracture height, opened cluster and perforation number, and filtration coefficient on the evolution of shutdown pressure are analyzed. The results indicate that a larger fracture half-length may hasten the decay of shutdown pressure, while a larger fracture height can slow down the decay of shutdown pressure. A smaller number of opened clusters and perforations can significantly increase the perforation friction and decrease the overall level of shutdown pressure. A larger filtration coefficient may accelerate the fluid filtration in the fracture and hasten the drop of the shutdown pressure. The simulation method of shutdown pressure, as well as the analysis results, has important implications for the interpretation of hydraulic fracture parameters. [ABSTRACT FROM AUTHOR]