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Abstract Graphitic carbon nitride (g-C3N4) has gained increasing attention in artificial photosynthesis of H2O2, yet its performance is hindered by sluggish oxygen reduction reaction (ORR) kinetics and short excited-state electron lifetimes. Here we show a B-doped g-C3N4 (BCN) tailored with coordinatively unsaturated FeOOH and CoO x clusters for H2O2 photosynthesis from water and oxygen without sacrificial agents. The optimal material delivers a 30-fold activity enhancement compared with g-C3N4 under visible light, with a solar-to-chemical conversion efficiency of 0.75%, ranking among the forefront of reported g-C3N4-based photocatalysts. Additionally, an electron transfer efficiency reaches 34.1% for the oxygen reduction reaction as revealed by in situ microsecond transient absorption spectroscopy. Experimental and theoretical results reveal that CoO x initiates hole–water oxidation and prolongs the electron lifetime, whereas FeOOH accepts electrons and promotes oxygen activation. Intriguingly, the key to the direct one-step two-electron reaction pathway for H2O2 production lies in coordinatively unsaturated FeOOH to adjust the Pauling-type adsorption configuration of O2 to stabilize peroxide species and restrain the formation of superoxide radicals.

The classical deviatoric hardening models are capable of characterizing the mechanical response of granular materials for a broad range of degrees of compaction. This work finds that it has limitations in accurately predicting the volumetric deformation characteristics under a wide range of confining/consolidation pressures. The issue stems from the pressure independent hardening law in the classical deviatoric hardening model. To overcome this problem, we propose a refined deviatoric hardening model in which a pressure-dependent hardening law is developed based on experimental observations. Comparisons between numerical results and laboratory triaxial tests indicate that the improved model succeeds in capturing the volumetric deformation behavior under various confining/consolidation pressure conditions for both dense and loose sands. Furthermore, to examine the importance of the improved deviatoric hardening model, it is combined with the bounding surface plasticity theory to investigate the mechanical response of loose sand under complex cyclic loadings and different initial consolidation pressures. It is proved that the proposed pressure-dependent deviatoric hardening law is capable of predicting the volumetric deformation characteristics to a satisfactory degree and plays an important role in the simulation of complex deformations for granular geomaterials.

The Hilbert curve is an important method for mapping high-dimensional spatial information into one-dimensional spatial information while preserving the locality in the high-dimensional space. Entry points of a Hilbert curve can be used for image compression, dimensionality reduction, corrupted image detection and many other applications. As far as we know, there is no specific algorithms developed for entry points. To address this issue, in this paper we present an efficient entry point encoding algorithm (EP-HE) and a corresponding decoding algorithm (EP-HD). These two algorithms are efficient by exploiting the m consecutive 0s in the rear part of an entry point. We further found that the outputs of these two algorithms are a certain multiple of a certain bit of s, where s is the starting state of these m levels. Therefore, the results of these m levels can be directly calculated without iteratively encoding and decoding. The experimental results show that these two algorithms outperform their counterparts in terms of processing entry points.

Urban grid road is an important use scenario for mobile communication users.Compared with other static scenes, UE mobility on the road leads to relatively poor customer perception.The traditional urban grid road test optimization has some pain points, such as incomplete regulation, low optimization efficiency, repeated work orders, no focus and so on.A new method to improve 5G coverage of urban grid roads was proposed.The proposed method introduces the concept of problem circle, realizes the effective aggregation of sporadic test problem points, and uses“aggregation degree” and “repetition degree” to quantitatively identify the priority of test problems.By introducing the concepts of “ideal azimuth” and “appropriate cell”, the method of the optimal coverage cell of the problem circle was proposed, which can effectively output the optimization scheme of the problem circle.This method has been deployed in the current network and effectively supports the test and optimization of urban grid roads.The 5G coverage rate has increased from 89.95% to 98.86%.

Glioma has a specific CpG island methylator phenotype (G⁃CIMP), which is closely related to isocitrate dehydrogenase (IDH) mutation. A hypermutation is present at recurrence in temozolomide⁃treated gliomas, and O6⁃methylguanine⁃DNA methyltransferase (MGMT) promoter methylation levels can help predict the risk of hypermutation to inform clinical decision. Whole genome DNA methylation analysis has become an effective auxiliary method for the classification of central nervous system tumors. This article reviews the research progress of DNA methylation analysis in glioma and discusses its clinical significance.

To effectively utilize the effectively the solid waste-soda residue (SR) and fly ash (FA), a mixture of 70% SR, 20% FA, and 10% clay was formed to produce soda residue soil (SRS). By adding cement and/or lime, four different SRS proportions were prepared. The compaction properties, mechanical properties, and dry–wet stability. Furthermore, the mechanical mechanisms of SRS were explored, and the improvement effect and efficiency of cement and/or lime on the mechanical performance of SRS were analyzed. The results show that the SRS is lightweight and easy to compact and shape, which is conducive to construction. Compared to cement, lime has a greater impat on the compaction properties of SRS. The mechanical properties of SRS are enhanced after adding cement and/or lime; the unconfined compressive strength (UCS), California Bearing Ratio (CBR), and resilient modulus all increase significantly. The UCS, CBR, and resilient modulus of SRS with different proportions all increase with the increase of compaction degree; the CBR and resilient modulus can meet the requirements of the subgrade, and the UCS can meet the requirements of the base and sub-base. The contribution rate of cement per unit amount is better than that of lime to the mechanical performance of SRS. As dry–wet cycles increase, the dry–wet stability of SRS with different proportions first increases and then decreases, which is affected by hydration and dry–wet deterioration together, with a critical cycle number for the strength transition. The excellent mechanical performance of SRS benefits from the gradation and chemical action. The particles of SR, FA, and clay can complement each other and perform an interlocking action. Therefore, SRS has a good gradation and forms a dense and stable structure. Also, the chemical reactions between materials are very important. The cement and/or lime have a hydration and gelling effect, FA and clay participate in pozzolanic reactions, and SR and FA have certain alkali-activated effects.

Abstract An efficient modes analyses technique for isotropic or anisotropic material filled 2D metallic waveguides with an arbitrary contour using the multifilament current method (MFCM) is presented. The ideal PEC boundary of a 2D waveguide is replaced by a shell with a high conductivity and electrical small thickness. The thin lossy shell not only can well approximate the boundary condition of PEC waveguide wall therefore without altering the initial waveguide modes, but also can let the external excitation penetrate through to excite the inside modes, resulting in a high internal field intensity at the frequency of each mode. In this case, the modes are revealed by the peaks of field intensity responses, and the spurious modes which existed in traditional source‐free modes determination techniques can be completely avoided. Based on this idea, a generalized impedance boundary condition (GIBC) is formulated to represent the lossy waveguide wall and further utilized in the MFCM for simulating the internal field intensity over frequency. Three different configurations of a 2D waveguide are considered. The computed modes are compared with that obtained from commercial software, and an excellent agreement is achieved, yet an competitive advantage on simulation performances is observed by using the proposed technique.

Objective: Compared with traditional surgery, laparoscopic surgery offers the advantages of smaller scars and rapid recovery and has gradually become popular. However, laparoscopic surgery has the limitation of low visibility and a lack of touch sense. As such, a physician may unexpectedly damage blood vessels, causing massive bleeding. In clinical settings, Doppler ultrasound is commonly used to detect vascular locations, but this approach is affected by the measuring angle and bone shadow and has poor ability to distinguish arteries from veins. To tackle these problems, a smart blood vessel detection system for laparoscopic surgery is proposed. Methods: Based on the principle of near-infrared spectroscopy, the proposed instrument can access hemoglobin (HbT) parameters at several depths simultaneously and recognize human tissue type by using a neural network. Results: Using the differences in HbT and StO2 between different tissues, vascular and avascular locations can be recognized. Moreover, a mechanically rotatable stick enables the physician to easily operate in body cavities. Phantom and animal experiments were performed to validate the system’s performance. Conclusion: The proposed system has high ability to distinguish vascular from avascular locations at various depths.