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The solving of quadratic matrix equations is a fundamental issue which essentially exists in the optimal control domain. However, noises exerted on the coefficients of quadratic matrix equations may affect the accuracy of the solutions. In order to solve the time-varying quadratic matrix equation problem under linear noise, a new error-processing design formula is proposed, and a resultant novel zeroing neural network model is developed. The new design formula incorporates a second-order error-processing manner, and the double-integration-enhanced zeroing neural network (DIEZNN) model is further proposed for solving time-varying quadratic matrix equations subject to linear noises. Compared with the original zeroing neural network (OZNN) model, finite-time zeroing neural network (FTZNN) model and integration-enhanced zeroing neural network (IEZNN) model, the DIEZNN model shows the superiority of its solution under linear noise; that is, when solving the problem of a time-varying quadratic matrix equation in the environment of linear noise, the residual error of the existing model will maintain a large level due to the influence of linear noise, which will eventually lead to the solution’s failure. The newly proposed DIEZNN model can guarantee a normal solution to the time-varying quadratic matrix equation task no matter how much linear noise there is. In addition, the theoretical analysis proves that the neural state of the DIEZNN model can converge to the theoretical solution even under linear noise. The computer simulation results further substantiate the superiority of the DIEZNN model in solving time-varying quadratic matrix equations under linear noise.

In recent years, as an important part of unconventional resources, the effective development of shale oil has been a key area of research in petroleum engineering. Given the widespread availability and low cost of air, the evaluation of air injection in shale reservoirs is a topic worth exploring. This paper analyzes the production performance of different methods of air injection development in the shale reservoir, including air flooding and air huff and puff (HnP), based on full-diameter core air injection experiments. Meanwhile, the characteristics of the residual oil and produced oil are revealed by forming a systematic evaluation method that includes nuclear magnetic resonance (NMR), laser scanning confocal microscopy (LSCM), and gas chromatographic (GC) analysis. The results show that air flooding development is characterized by early gas breakthrough, long oil production period, and “L” shape oil production decline; while air HnP is characterized by first producing gas and then producing oil, rapid oil production, and high oil recovery efficiency in the first round. Compared with air flooding, the replacement efficiency of the first round of air HnP is significantly higher, demonstrating higher feasibility of air HnP in the early stages of development, although the cumulative recovery of three rounds air HnP (17.17%) is lower than that of air flooding (23.36%). The large pores (T2 > 10 ms) are the main source of air injection recovery, while the residual oil is mainly concentrated in the medium pores (1–10 ms). Air injection development has a higher recovery factor for light components (C15−), resulting in a higher level of heavy components in the residual oil. This paper discusses the feasibility and development effectiveness of air injection in shale oil reservoirs, and its development characteristics are further clarified.

The International Maritime Organization (IMO) has set decarbonisation goals for the shipping industry. As a result, shipowners and operators are preparing to use low- or zero-carbon alternative fuels. The greenhouse gas (GHG) emission performances are fundamental for choosing suitable marine fuels. However, the current regulations adopt tank-to-wake (TTW) emission assessment methods that could misrepresent the total climate impacts of fuels. To better understand the well-to-wake (WTW) GHG emission performances, this work applied the life cycle assessment (LCA) method to a very large crude carrier (VLCC) sailing between the Middle East and China to investigate the emissions. The life cycle GHG emission impacts of using alternative fuels, including liquified natural gas (LNG), methanol, and ammonia, were evaluated and compared with using marine gas oil (MGO). The bunkering site of the VLCC was in Zhoushan port, China. The MGO and LNG were imported from overseas, while methanol and ammonia were produced in China. Four production pathways for methanol and three production pathways for ammonia were examined. The results showed that, compared with MGO, using fossil energy-based methanol and ammonia has no positive effect in terms of annual WTW GHG emissions. The emission reduction effects of fuels ranking from highest to lowest were full solar and battery-based methanol, full solar and battery-based ammonia, and LNG. Because marine ammonia-fuelled engines have not been commercialised, laboratory data were used to evaluate the nitrous oxide (N2O) emissions. The GHG emission reduction potential of ammonia can be exploited more effectively if the N2O emitted from engines is captured and disposed of through after-treatment technologies. This paper discussed three scenarios of N2O emission abatement ratios of 30%, 50%, and 90%. The resulting emission reduction effects showed that using full solar and battery-based ammonia with 90% N2O abatement performs better than using full solar and battery-based methanol. The main innovation of this work is realising the LCA GHG emission assessment for a deep-sea ship.

BackgroundMetabolic syndrome (MetS) has a potential connection with thyroid disease, but its relationship with thyroid nodules (TNs) is still controversial. This study aims to clarify the relationship between MetS and TNs, and this relationship in the subgroup of gender.MethodsThe recent nationwide cross-sectional study called Thyroid Disorders, Iodine Status, and Diabetes Epidemiological survey provided the newest data on the relationship between MetS and TNs from China and included 56,729 subjects. We also researched related literature in PubMed, EMBASE, Cochrane Library, and MEDLINE until Oct 30, 2020, in order to perform a meta-analysis. The relevant articles were examined, and the eligible studies were included to assess the association between MetS and TNs.ResultsThe meta-analysis included 15 studies (involving 468,845 subjects). Of these, 14 studies were from the databases, and one study was this cross-sectional data. The meta-analysis showed that TNs were associated with a higher prevalence of MetS (OR=1.87, 95% CI: 1.44–2.45) and the components of MetS, including central obesity (OR=1.41, 95% CI: 1.15–1.72), hypertriglyceridemia (OR=1.13, 95% CI: 1.10–1.15), low high-density lipoprotein cholesterolemia (OR=1.11, 95% CI: 1.02–1.20), abnormal blood pressure (OR=1.68, 95% CI: 1.62–1.75), and hyperglycemia (OR=1.59, 95% CI: 1.46–1.74). Central obesity displayed gender differences, being a risk factor in males (OR=1.38, 95% CI: 1.02–1.86) but not in females (OR=1.47, 95% CI: 0.97–2.23).ConclusionTNs were indeed associated with a higher prevalence of MetS. In addition, its component diseases, such as central obesity, hypertriglyceridemia, abnormal blood pressure, and hyperglycemia, were also associated with TNs. Females with MetS or its components had a higher risk of suffering from TNs than males.

Background: Immune checkpoint inhibitors have been successfully used in a variety of tumors, however, the efficacy of immune checkpoint blockade therapy for patients with glioma is limited. In this study, we tried to clarify gene expression signatures related to the prognosis of gliomas and construct a signature to predict the survival of patients with gliomas.Methods: Calcium-related differential expressed genes (DEGs) between gliomas and normal brain tissues were comprehensively analyzed in two independent databases. Univariate, multivariate Cox regression analysis and proportional hazards model were used to identify the prognostic of calcium-related risk score signature. The CIBERSORT algorithm and association analysis were carried out to evaluate the relationship between calcium-related signature and characteristic clinical features, tumor-infiltrating immune cell signatures as well as immune checkpoint molecules in glioma. A nomogram model was developed for predicting the overall survival for patients with gliomas.Results: We found the intersection of 415 DEGs between gliomas and normal brain tissues, and identified that an eighteen calcium-related gene panel was significantly enriched in these DEGs. A calcium-related signature derived risk score was developed to divide patients into high- and low-risk groups. Low levels of calcium-related gene expression in high-risk score cases were accompanied with worse outcomes of patients. Calcium-related risk scores were significantly associated with characteristic clinical features, immune infiltrating signatures of tumor microenvironment, and exhausted T cell markers including programmed cell death 1 (PD-1), lymphocyte activating 3 (LAG3), and T cell membrane protein 3 (TIM-3), which contribute to an adverse therapeutic effect of immunotherapy. Calcium-related signature risk score was considered as an independent prognostic parameter to predict the of overall survival of patients with gliomas in nomogram model.Conclusion: Our study demonstrated that calcium signaling pathway is highly associated with immunosuppression of gliomas and overall survival of patients. Targeting the calcium signaling pathway might be a new strategy to reverse the immunosuppressive microenvironment of gliomas and improve the efficacy of glioma immunotherapy.

Polymer and surfactant (S/P) binary flooding is a widely used chemical flooding technology for enhanced oil recovery (EOR). However, it is mostly used in the five-spot well pattern, and there is little research on the effect of well patterns on its flow law and EOR efficiency in the reservoir. In this paper, the flow intensity of S/P flooding in an inverted seven-spot well unit and its EOR efficiency are investigated. Based on the theoretical derivation and simulation, the flow distribution at different positions in the inverted seven-spot well pattern unit was calculated. The oil displacement efficiency was evaluated by simulating different flow intensities with various flow velocity. The microscopic residual oil of the core at the end of displacement was scanned and recognized. The 2D model was used to simulate the well pattern to clarify the EOR of S/P flooding. The results show that the swept area in the well unit can be divided into the strong swept region (>0.2 MPa); medium swept region (0.1–0.2 MPa); weak swept region (0.03–0.1 MPa); and invalid swept region (

Thyroid carcinoma is a solid malignant tumor that has had a fast-growing incidence in recent years. Our research used thyroid carcinoma gene expression profiling from TCGA (The Cancer Genome Atlas) database to identify differentially expressed ceRNAs. Using the gene expression profiling from 502 carcinoma thyroid tissues and 58 normal thyroid tissues from the TCGA database, we established the thyroid carcinoma-specific competitive endogenous RNA (ceRNA) network and found nine overall survival (OS)-associated genes (PRDM1, TGFBR3, E2F1, FGF1, ADAM12, ALPL, RET, AL928654.2, AC128688.2). We quantified the proportions of immune cells using the algorithm “CIBERSORT”, found three OS-associated immune cells (memory B cells, M0 macrophages, and activated dendritic cells), and established a thyroid carcinoma-specific immune cell network based on that. The good reliabilities AUC (area under the curve) of 10-year survival (0.955, 0.944, respectively) were accessed from the nomograms of genes and immune cells. Subsequently, by conducting co-expression analyses, we found a potential regulation network among ceRNAs and immune cells. Besides, we found that ALPL (alkaline phosphatase) and hsa-miR-204-5p were significantly correlated and that ALPL was related to activated dendritic cells. We took advantage of multi-dimensional databases to verify our discovery. Besides, immunohistochemistry (IHC) assays were conducted to detect the expression of a dendritic cell marker (CD11c) and ALPL in thyroid carcinoma (TC) and paracancerous tissues. In summary, our study found a potential mechanism in which hsa-miR-204-5p regulated ALPL in activated dendritic cells, which may allow them to play a critical role in thyroid carcinoma. These findings provide potential prognostic biomarkers and therapeutic targets for thyroid carcinoma.

Traditional general architecture chips have shown excessive power consumption and insufficient functional redundancy in some customized applications. Flexible electronics also call for customized chips in smart wearable devices. Common chips in intelligent systems process digital signals, and continuous operation of the system clock brings great power consumption. Herein, an intelligent gesture recognition system is developed by combining the flexible 2D materials and an analog computing chip. The pressure‐sensitive sponge with graphene fillings is proposed as a piezoresistive sensor. A nine‐sensor array is used to detect the pressure field distribution caused by hand movement. To get rid of the power consumption caused by the system clock, a novel analog‐computing customized chip which adopts a near‐sensor processing architecture is proposed. It implements the binary neural network algorithm with an analog circuit and completes the recognition of the transmission signal at the hardware level. The chip possesses a low power consumption which is less than 1.8 mW. Moreover, a glove assembled by highly pressure‐sensitive material recognizes mute gestures including Arabic numerals 0–9, with a recognition rate as high as 98.5%. Herein, the prospects for the application of customized smart chips in the field of smart wearable electronics are illuminated.

Abstract Continuous approaching and detaching displacement usually occurs in an adhesion test. Here, we found a transient adhesion force at the end of a non-fully detached contact. This force occurred when the nominal detaching displacement was less than the traditional quasi-static theory predicted zero force point. The transient adhesion force was ascribed to interfacial adhesion hysteresis, which was caused by the cracking process of the contact and the deformation competition between the sphere and supporting spring. Results indicated that the testing of adhesion can be significantly affected by different combinations of stiffnesses of the contact objects and the supporting spring cantilever. This combination should be carefully designed in an adhesion test. All these results enabled increased understanding of the nature of adhesion and can guide the design of adhesive actuators.

Geckos can climb steadily and quickly on different surfaces under various environmental conditions. Extensive experiments have been conducted using gecko toe, setal array, single seta and single spatula to explore the physical principles of gecko adhesion and friction. This work focuses on the effect of environment (i.e. substrate materials and relative humidity [RH]) and experimental conditions (i.e. preload, sliding velocity, and sliding direction) on gecko adhesion and friction through an isolated gecko setal array. Experimental results show that when sliding a setal array in gripping direction, adhesion and friction can be enhanced by more than 200% by increasing surface energy, 60% by increasing relative humidity, and only slightly by increasing sliding velocity; an appropriate preload increase can also cause an enhancement. When RH >40%, adhesion and friction become saturated, and higher sliding velocity and preload can realize the saturation at a lower RH. When a preload is oversized in gripping direction or when sliding a setal array against substrates in releasing direction, the setal array deforms severely and always exhibits a preload-dominated repulsion. A strong anisotropic property is revealed when sliding a setal array in gripping and releasing direction. These results help understand the remarkable abilities of gecko swiftly controlling strong attachment and easy detachment, which inspire the design and fabrication of gecko-inspired reversible dry adhesives.

Flexible electronic devices, such as the typical thin-film transistors, are widely adopted in the area of sensors, displayers, wearable equipment, and such large-area applications, for their features of bending and stretching; additionally, in some applications of lower-resolution data converters recently, where a trend appears that implementing more parts of system with flexible devices to realize the fully flexible system. Nevertheless, relatively fewer works on the computation parts with flexible electronic devices are reported, due to their poor carrier mobility, which blocks the way to realize the fully flexible systems with uniform manufacturing process. In this paper, a novel circuit architecture for image processing accelerator using Oxide Thin-film transistor (TFT), which could realize real-time image pre-processing and classification in the analog domain, is proposed, where the performance and fault-tolerance of image signal processing is exploited. All of the computation is done in the analog signal domain and no clock signal is needed. Therefore, certain weaknesses of flexible electronic devices, such as low carrier mobility, could be remedied dramatically. In this paper, Simulations based on Oxide TFT device model have demonstrated that the flexible computing parts could perform 5 × 5 Gaussian convolution operation at a speed of 3.3 MOPS/s with the energy efficiency of 1.83 TOPS/J, and realize image classification at a speed of 10 k fps, with the energy efficiency of 5.25 GOPS/J, which means that the potential applications to realize real-time computing parts of complex algorithms with flexible electronic devices, as well as the future fully flexible systems containing sensors, data converters, energy suppliers, and real-time signal processing modules, all with flexible devices.