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Abstract Bacterial biofilms are one of the major contributors to the refractoriness of septic arthritis. Although nitric oxide (NO)-enhanced photodynamic (PDT) therapy has been involved in biofilm eradication, the anti-biofilm efficacy is usually hindered by the short half-life and limited diffusion distance of active molecules. Herein, we report a three-arm structure using the photosensitive core chlorin e6 to integrate three α-cyclodextrin (α-CD) polyrotaxane chains as the supramolecular nanocarrier of NO-enhanced PDT therapy, in which NO was loaded on the cationic rings (α-CDs). Beneficial from the enhanced permeability of the nanocarrier due to the collective act on biofilms by the molecular motions (slide and rotation of rings) of three chains in different directions, NO capable of inducing biofilm dispersal and reactive oxygen species were efficiently delivered deep inside biofilms under 660 nm laser irradiation, and reactive nitrogen species with stronger bactericidal ability was produced in-situ, further accomplishing bacteria elimination inside biofilms. In-vivo therapeutic performance of this platform was demonstrated in a rat septic arthritis model by eliminating the methicillin-resistant Staphylococcus aureus infection, and potentiating the immune microenvironment regulation and bone loss inhibition, also providing a promising strategy to numerous obstinate clinical infections caused by biofilms. Graphical Abstract

Abstract Background Many studies have explored the clinicopathological features and prognosis between colorectal mucinous adenocarcinoma (MAC) and adenocarcinoma (AC) and have given different results. This meta-analysis summarizes previous evidence and evaluates the clinicopathological and prognostic features of MAC relative to AC in colorectal cancers (CRCs). Methods The meta-analysis was conducted by searching the databases of PubMed, China National Knowledge Infrastructure (CNKI), WANFANG data, Embase, and Web of Science. Pooled odds ratios (ORs) and hazard ratios (HRs) and corresponding 95% confidence intervals (CIs) were calculated to assess the clinicopathological and prognostic differences between MAC and AC. Results Fifty-six studies involving 803157 patients met the inclusion criteria and were included in this meta-analysis. The clinicopathological features of MAC were greatly different from AC, except for lymphatic invasion (OR = 1.07, 95% CI: 0.99–1.15, P = 0.09) and perineural invasion (OR = 0.92, 95% CI: 0.79–1.06, P = 0.09). Further investigation found that MAC predicted poor OS (HR = 1.04, 95% CI: 1.03–1.04, P

Abstract The safety and efficacy of the lipid nanoparticle (LNP) delivery system are crucial for the successful development of messenger RNA vaccines. We designed and synthesized a series of ketal ester lipids (KELs), featuring a biodegradable ketal moiety in the linker and ester segments in the tail. Through iterative optimization of the head and tail groups of KELs, we tuned the pKa and molecular shapes, and identified (4S)‐KEL12 as a safe and efficient ionizable lipid for mRNA delivery. (4S)‐KEL12 LNP showed significantly higher delivery efficacy and lower toxicity than the DLin‐MC3‐DMA LNP. In comparison to SM‐102 LNP, (4S)‐KEL12 LNP exhibited better spleen tropism, reduced liver tropism, and hepatotoxicity. Additionally, (4S)‐KEL12 demonstrated good biodegradability following intramuscular or intravenous injection. Notably, (4S)‐KEL12 LNP encapsulated with a therapeutic mRNA cancer vaccine elicited robust cellular immune responses leading to substantial tumor regression along with prolonged survival in tumor‐bearing mice. Our results suggest that (4S)‐KEL12 LNP holds great promise for mRNA vaccine delivery. The comprehensive analysis of the structure‐activity relationship, toxicity, biodegradability, distribution, expression, efficacy, and stereochemistry of these LNPs will greatly contribute to the rational design and discovery of novel lipid‐based delivery systems.

ObjectiveTo evaluate postoperative cerebral perfusion changes and their influencing factors in carotid endarterectomy (CEA) patients by integrating multimodal monitoring methods, including cerebral regional oxygen saturation (rSO2), carotid ultrasound (CU), computed tomographic angiography (CTA), and computed tomographic perfusion imaging (CTP), with computational fluid dynamics (CFD) assessment.MethodsWe conducted a cohort study on patients with internal carotid artery (ICA) stenosis undergoing CEA at our institution. Pre- and postoperative assessments included CU, CTA, CTP, and rSO2 monitoring. Hemodynamic parameters recorded were mean flow velocity (MFV), peak systolic velocity (PSV), end diastolic velocity (EDV), resistance index (RI), rSO2, and cerebral blood flow (CBF). CFD quantified the total pressure (TP), wall shear stress (WSS), wall shear stress ratio (WSSR), and translesional pressure ratio (PR) of the ICA. Pearson correlation was used to analyze factors influencing cerebral perfusion changes. Multivariate logistic regression identified risk factors for cerebral hyperperfusion (CH). The predictive value of multimodal and single-modality monitoring for CH was evaluated using ROC curve analysis.ResultsFifty-six patients were included, with nine developing postoperative CH. CU showed significant reductions in MFV, PSV, EDV, and RI of the ICA (p

Objective Although previous research has indicated that human errors represent the primary cause of incidents in nuclear power safety, few studies have investigated the potential impact of psychological factors on the performance of operators. This study makes a pioneering contribution to the field by integrating the effect of personal states and personality traits on work evaluation.Method A total of 101 commissioning workers in nuclear power plants were recruited and monitored for ten consecutive workdays. The research collected their personality traits and personal states which were indexed by cognitive tasks before daily work. The participants rated their work performance after work as the dependent variable.Results The results of the LASSO regression analysis indicated that the perceptual speed, visual selective attention, and executive control before work were significantly correlated with the self-rated work performance. Furthermore, the interaction between personal states and personality traits exhibited moderating effects, with the effect of mindfulness being the most prominent.Conclusion The present study enhanced understanding of how personality traits may moderate the effect of pre-work personal states on daily work performance. It also provided practical insights for the selection and support of commissioning workers, with a particular focus on the role of appropriate personality traits and robust personal states.

Abstract Previous deep multi-agent reinforcement learning (MARL) algorithms have achieved impressive results, typically in symmetric and homogeneous scenarios. However, asymmetric heterogeneous scenarios are prevalent and usually harder to solve. In this paper, the main discussion is about the cooperative heterogeneous MARL problem in asymmetric heterogeneous maps of the Starcraft Multi-Agent Challenges (SMAC) environment. Recent mainstream approaches use policy-based actor-critic algorithms to solve the heterogeneous MARL problem with various individual agent policies. However, these approaches lack formal definition and further analysis of the heterogeneity problem. Therefore, a formal definition of the Local Transition Heterogeneity (LTH) problem is first given. Then, the LTH problem in SMAC environment can be studied. To comprehensively reveal and study the LTH problem, some new asymmetric heterogeneous maps in SMAC are designed. It has been observed that baseline algorithms fail to perform well in the new maps. Then, the authors propose the Grouped Individual-Global-Max (GIGM) consistency and a novel MARL algorithm, Grouped Hybrid Q-Learning (GHQ). GHQ separates agents into several groups and keeps individual parameters for each group. To enhance cooperation between groups, GHQ maximizes the mutual information between trajectories of different groups. A novel hybrid structure for value factorization in GHQ is also proposed. Finally, experiments on the original and the new maps show the fabulous performance of GHQ compared to other state-of-the-art algorithms.

Androgenetic alopecia (AGA) is a common clinical condition, affecting over 200 million people globally each year. For decades, Minoxidil (Mi) tincture has been the primary treatment for this disease, but its low utilization rate and significant side effects necessitate new therapeutic strategies. Nitric oxide (NO) is a signaling molecule in various physiological processes, including vasodilation, immune responses, and cell proliferation. Herein, we constructed a hyaluronic acid liposome (HL) complex as a novel transdermal delivery system (HL@Mi/NONOate) for NO and Mi, which displayed promising transdermal and hair-regrowth effects. In-depth mechanistic studies revealed three potential pathways of the synergistic AGA therapy. First, NO promoted capillary dilation and accelerated blood flow, thus achieving efficient penetration of Mi. Due to the structural advantage of liposomes, the residence time of the Mi in the skin was prolonged. Moreover, HL@Mi/NONOate promoted cell proliferation and angiogenesis, and upregulated the expression of regulatory factors involved in follicle stem cell differentiation. In the AGA model, HL@Mi/NONOate down-regulated the expression of inflammatory factors, inhibiting the inflammation of follicle and improving the microenvironment of hair regrowth. Concurrently, HL@Mi/NONOate upregulated the expression of Ki67 and PCNA proteins in follicle tissues, inducing follicle regeneration and development, ultimately achieving the synergistic multimodal AGA therapy.

Abstract Maintaining soil productivity and sustainability remains a challenge in the face of a changing global agricultural framework, which includes the primary threat of soil degradation in many regions. Although soil erosion contributes to land degradation, how reductions in fertiliser nitrogen (N) affect erosion and soil microbial communities in sloped farmland remains unclear. In this study, effects of reductions in fertiliser N from 300 kg ha−1 (N1) to 225 kg ha−1 (N2), 150 kg ha−1 (N3), and 75 kg ha−1 (N4) on runoff, sediment yield and microbial community structure were evaluated in 12 maize farmlands with a 10° slope in Southwest China. Soil chemical properties were analyzed, and bacterial 16S rRNA and fungal ITS1 were sequenced from extracted DNA. Runoff and sediment yield in maize were significantly lower in N1 and N2 than in N3 and N4 (p 25% in N fertiliser (N3 and N4) did not meet crop N requirements, and because of the reduction in surface coverage, soil erosion was exacerbated, and soil fertility and diversity and complexity of microbial communities decreased. The results elucidated effects of N input on soil erosion and soil microbiomes in a sloped agroecosystem with the aim to rehabilitate or restore degraded land and increase sustainable agriculture development.

Abstract A reasonable width of the coal pillar is very important to the surrounding rock control of the gob‐side roadway. An unreasonable width of the coal pillar will make the roadway to be located within the range of strong mining influence, leading to severe deformation of the roadway. Severe subsidence at the coal pillar side of the roof and serious coal pillar deformation are problems caused by strong dynamic pressure due to mining in the gob‐side coal roadway. This paper studies the surrounding rock instability mechanism and rational coal pillar width of the gob‐side coal roadway under the influence of intense dynamic pressure. The results show that: (1) Under the condition of large mining height, the roadway overburden is a hinged structure, and an unreasonable coal pillar width makes the gob‐side coal roadway to be located below the main roof fracture line. The rotary movement of the key block of the main roof is the main reason for the roadway deformation. (2) According to the evolution law of stress field, displacement field and plastic zone of surrounding rock of roadway under different coal pillar widths during roadway driving and mining were studied, and it is concluded that a 6‐m‐width coal pillar is the most reasonable. (3) Based on the stress distribution and plasticizing range of surrounding rock in a narrow pillar roadway, the combined support scheme of “anchor cable + grouting + single prop” is proposed and applied to engineering practice. The practice results show that the roadway deformation is well controlled, and the safe mining of the working face is realized.

Predicting the remaining useful life (RUL) of lithium-ion batteries is crucial for enhancing their reliability and safety. Addressing the issue of inaccurate RUL predictions caused by the nonlinear decay resulting from capacity regeneration, this paper proposes an indirect lithium-ion battery RUL prediction method based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and convolutional neural network (CNN)–bidirectional gated recurrent unit (BiGRU). The method extracts Health Indicators (HI) from the battery-charging stage and employs CEEMDAN to decompose HI into several components. These components are then input into a component prediction model for forecasting. Finally, the predicted component results are fused and input into a capacity prediction model to achieve indirect RUL prediction. Validation is conducted using the lithium-ion battery dataset provided by NASA. The results indicate that, under prediction starting points (STs) of 80 and 100, the maximum average absolute errors do not exceed 0.0096 and 0.0081, and the maximum root mean square errors do not exceed 0.0196 and 0.0115, demonstrating high precision and reliability.

AbstractThe advent of non-pillar mining technology of self-formed roadway based on roof cutting theory (NPMTSFRRCT) has revolutionized the method of tackling the difficulties posed by hard suspended roofs in mining engineering. The design of roof cutting parameters plays a crucial role in determining the roof fracture characteristics. The principles of roof cutting parameter design have been analysed, with a focus on the key and challenging aspect of the collapse of single-layer thick hard rock under the condition of a thin immediate roof. A mechanical model of roof fracture has been established, and the impact of immediate roof thickness, roof cutting height, roof cutting angle, and main roof thickness on roof fracture has been analysed. A numerical model based on the UDEC software has been created, and the roof fracture, stress, and displacement variation characteristics have been studied using the failure criterion of polygonal blocks. The results of the theoretical analysis have been verified, and it was found that the roof fracture in partial roof cutting occurs in the form of hinge bite, while complete roof cutting results in step sinking. Engineering practice has shown that the deformation of the roadway surrounding rock has been effectively controlled.

AbstractThe traditional index to determine the width of the stopping coal pillar (WSCP) is generally only the front abutment pressure, but the direction of the principal stress will deflect due to the mining action, which brings significant challenges to controlling the surrounding rock. Based on theoretical calculation and numerical simulation, we studied the deflection law of principal stress under mining action, quantified the bearing capacity of roadway surrounding rock, and determined WSCP. The results show that: (1) With the deflection of the principal stress, the distribution of the surrounding rock plastic zone also rotates; (2) [Formula: see text] and repeated mining dominate and aggravate the deflection angle and range of the principal stress in front of the working face, respectively. When [Formula: see text] is close to 1, the deflection of principal stress should be paid attention to in determining WSCP; (3) The anchorage composite bearing structure (ACBS) provides a scientific basis for quantifying the bearing capacity of surrounding rock. WSCP of the lower coal seam is determined to be 60–75 m, and the corresponding principal stress deflection is about 135°. The control of the surrounding rock in the diagonal direction where the maximum principal stress is concentrated should be paid attention to.

Ebola virus (EBOV) infection leads to staggeringly high mortality rate. Effective and low-cost treatments are urgently needed to control frequent EBOV outbreaks in Africa. In this study, we report that a natural compound called berbamine hydrochloride strongly inhibits EBOV replication in vitro and in vivo. Our work further showed that berbamine hydrochloride acts by directly binding to the cleaved EBOV glycoprotein (GPcl), disrupting GPcl interaction with viral receptor Niemann-Pick C1, thus blocking the fusion of viral and cellular membranes. Our data support the probability of developing anti-EBOV small molecule drugs by targeting viral GPcl. More importantly, since berbamine hydrochloride has been used in clinic to treat leukopenia, it holds great promise of being quickly repurposed as an anti-EBOV drug.

Severe floor heave in underground soft rock roadways heavily affects mine safety and production efficiency. In the present study, the context of the Shanghaimiao mining area is analyzed as the research object. In this regard, the floor heave mechanism and floor control in water-rich soft rock roadways are investigated through laboratory experiments, theoretical analysis, numerical simulation, and field tests. Moreover, a mechanical model of asymmetric floor heave is established. The obtained results reveal that: the main contributors to serious floor deformation in mining roadways are low rock stratum strength, hydrophysical behavior, and mining disturbance. It is found that the roadway floor stability is relevant to the stress concentration coefficient of the roadway side, the burial depth of the roadway, and the cohesion and internal friction angle of the floor rock. Meanwhile, the correlation between the upward resultant stress of the floor and the stress concentration coefficient of the roadway sides is established. Furthermore, the horizontal stress distribution of the roadway floor within 20 m of the advanced working face is simulated and analyzed. Based on the performed analyses and the obtained results, a novel double-seal deep and shallow inverted bottom arch (DS-IBA) floor support strategy is proposed. The proposed strategy is expected to provide a reference for dealing with similar water-rich soft rock roadways.

For high-speed optical communication systems, laser phase noise (LPN) stands as a pivotal factor influencing the quality of the received signal. Therefore, the employment of a highly accurate carrier phase recovery (CPR) algorithm at the receiving end is indispensable to ensure the reliability of transmission. While a CPR algorithm called principal component-based phase estimation (PCPE) has been proven to be capable of achieving low-complexity and high-performance phase recovery for even-bit quadrature amplitude modulation (QAM) (i.e., square QAM) signals, it is not compatible with traditional cross-shaped odd-bit QAM signals. To circumvent this problem, a signal constellation design scheme based on geometric shaping (GS) is proposed. The pair-wise optimization (PO) algorithm is used to optimize the constellation structure of 32QAM and 128QAM signals in order to obtain results that are compatible with the PCPE algorithm. Monte Carlo simulation results reveal that for odd-bit QAM signals utilizing PCPE for phase recovery, the proposed GS constellations enhance the mutual information (MI) performance across the entire measured signal-to-noise (SNR) range. Moreover, compared with regular 32QAM and 128QAM constellations using the well-known blind phase search (BPS) algorithm, the proposed GS and PCPE scheme can achieve SNR gains of 1.10 dB and 2.59 dB, respectively, when considering the 20% soft-decision forward error correction (SD-FEC) overhead. Verification through commercial simulation software corroborates these findings, demonstrating that the proposed GS constellations are particularly suitable for the PCPE algorithm, especially under conditions of high optical signal-to-noise ratio (OSNR). To the best of our knowledge, this is the first time that the incompatibility between the PCPE algorithm and odd-bit QAM signals has been investigated, and the proposed GS scheme has broadened the application scope of the low-complexity CPR algorithm.

Power unevenness, mainly induced by stimulated Raman scattering, has been a major problem in multi-band transmission systems, especially in the upcoming field-deployed 400 Gbit/s widened C band plus L band system for backbone long-haul and ultra-long-haul scenarios. To reduce the impact of power unevenness, we propose an automatic power optimization (APO) algorithm to guarantee reliable transmission for all channels, especially the channels at short wavelengths. The simulation results show that the power unevenness of output power after 5-span transmission in the C band is up to 11 dB before APO, while after APO is applied, it is greatly improved to less than 1.6 dB. To further investigate the performance of the APO scheme, we conduct a real-time 44 Tbit/s C+L transmission system over 1900 km G.654.E fiber utilizing 400 Gbit/s transponders. The experimental results show that the power unevenness has been effectively compensated from 12 dB to 4 dB in the entire 11 THz range, making the received optical signal-to-noise ratio relatively flat (3.4 dB). Moreover, the capacity and distance product of this system is 83.6 Pbit/s·km (44 Tbit/s × 1900 km), and to the best of our knowledge, this is a record capacity and distance product in the real-time single-mode fiber transmission system.

The development history of reconfigurable optical add/drop multiplexer (ROADM) networks, ROADM technical solutions and the deployment of ROADM networks in China were described.And the development direction of the key technologies of ROADM was described, including optical cross-connect (OXC), high dimensions wavelength selected switch (WSS), colorless/directionless/contentionless ROADM (CDC-ROADM), 400 Gbit/s FlexGrid ROADM, and next-generation wavelength switched optical networks (WSON2.0) intelligent control plane technologies.The existing ROADM network application scenarios and technology development trend were analyzed, and the future prospects of the ROADM all-optical switching network were looked forward to.

Abstract Different from single coal seam mining, the stress evolution in the end mining stage of close‐distance coal seams is extremely complex. The unreasonable position and support of the lower retracement channel will cause serious deformation and damage to the surrounding rock. Taking the Yanzishan coal mine as the engineering background, the deformation and failure characteristics of the retracement channel under different overlay environments and the key influencing factors of position design were discussed by numerical simulation, theoretical analysis, and field investigation. The results show that the coupling superposition of upper coal pillar high stress and mining dynamic pressure will form a dangerous area with severe ground pressure behavior. The retracement channel should be preferentially designed in zone A (overlying mining roadways), followed by zone B (overlying end‐mining coal pillar), and finally, zone C (overlying section coal pillar). In addition, the rational horizontal distance between the lower retracement channel and the upper end‐mining coal pillar should make the channel in a good stress environment. The safety distance between the retracement channel and the nearest main roadway (end‐mining coal pillar width) should be greater than the severe range of advance abutment pressure. Finally, the design principle and control strategy for the lower retracement channel is proposed. The feasibility and rationality of the study are verified by industrial applications.

Abstract Polymeric systems that provide cationic charges or biocide‐release therapeutics are used to treat the bacteria‐infected wound. However, most antibacterial polymers based on topologies with restricted molecular dynamics still do not satisfy the clinical requirements due to their limited antibacterial efficacy at safe concentrations in vivo. Here a NO‐releasing topological supramolecular nanocarrier with rotatable and slidable molecular entities is reported to provide conformational freedom to promote the interactions between the carrier and the pathogenic microbes, hence greatly improving the antibacterial performance. With improved contacting‐killing and efficient delivery of NO biocide from the molecularly dynamic cationic ligand design, the NO‐loaded topological nanocarrier achieves excellent antibacterial and anti‐biofilm effects via destroying the bacterial membrane and DNA. MRSA‐infected rat model is also brought out to demonstrate its wound‐healing effect with neglectable toxicity in vivo. Introducing flexible molecular motions into therapeutic polymeric systems is a general design to enhance the healing of a range of diseases.

This paper proposes a novel method to improve the anti-dispersion ability of the all-optical orthogonal frequency division multiplexing (AO-OFDM) system. By replacing the Sinc-shaped filter with a Gauss-shaped filter for sub-carrier generation and inserting a cyclic prefix (CP), the impact of dispersion on the system can be significantly mitigated. Formula derivation and numerical analysis of the pulse-shaping function of the AO-OFDM system in the time domain for each cycle indicated that the pulse-shaping function generated by the Gauss-shaped filter was less affected by the dispersion effect than that of the Sinc-shaped filter. Meanwhile, less inter-carrier crosstalk between carriers was also observed. After carrying out system transmission simulations employing these two different filters, we found that the AO-OFDM system based on the Gauss-shaped filter could greatly improve the anti-dispersion ability compared with the system based on a Sinc-shaped filter. When the parameter settings in both schemes were identical, that is, the number of subcarriers was 32 and the power of a single subcarrier was −13 dBm, the bit error rate (BER) of the system based on the proposed Gauss-shaped filter after 60 km SMF transmission was only 1.596 × 10−3, while the BER of the traditional Sinc-shaped filter based system scheme was as high as 8.545 × 10−2.

In vehicle re-identification, identifying a specific vehicle from a large image dataset is challenging due to occlusion and complex backgrounds. Deep models struggle to identify vehicles accurately when critical details are occluded or the background is distracting. To mitigate the impact of these noisy factors, we propose Identity-guided Spatial Attention (ISA) to extract more beneficial details for vehicle re-identification. Our approach begins by visualizing the high activation regions of a strong baseline method and identifying noisy objects involved during training. ISA generates an attention map to mask most discriminative areas, without the need for manual annotation. Finally, the ISA map refines the embedding feature in an end-to-end manner to improve vehicle re-identification accuracy. Visualization experiments demonstrate ISA’s ability to capture nearly all vehicle details, while results on three vehicle re-identification datasets show that our method outperforms state-of-the-art approaches.

Ceramic coatings on R60705 zirconium alloy were prepared on the surface by the micro-arc oxidation (MAO) technique in electrolytes containing Na2SiO3, NaOH, and Na2EDTA. The growth behavior of the MAO ceramic coatings at different stages, including growth rate, microstructure, and phase composition, was investigated using the method of direct observation of the boundary area. The results showed that the growth of the MAO coatings on R60705 zirconium alloy occurred in both inward and outward directions. At an oxidation time of 5 min, the thickness of the oxidation layer increased fastest, reaching 103.43 μm, with a growth rate of 0.345 μm/s. After 5 min, the growth rate decreased and tended to level off around 15 min, with a thickness and growth rate of 162.7 μm and 0.181 μm/s, respectively. The total thickness of the coatings continuously increased throughout the process, with the outward growth thickness always higher than the inward growth thickness. The composition of the zirconium alloy micro-arc oxidation coatings mainly consisted of monoclinic zirconia (m-ZrO2), tetragonal zirconia (t-ZrO2), and a small amount of SiO2. The main elements in the coatings were Zr, O, and Si. The corrosion resistance of the zirconium alloy micro-arc oxidation coatings increased first and then decreased with increasing oxidation time, with a corrosion current density of 8.876 × 10−9 A·cm−2 at 15 min, indicating the best corrosion resistance.

Abstract Developing an economical, durable, and efficient electrode that performs well at high current densities and is capable of satisfying large‐scale electrochemical hydrogen production is highly demanded. A self‐supported electrocatalytic “Pt‐like” WC porous electrode with open finger‐like holes is produced through industrial processes, and a tightly bonded nitrogen‐doped WC/W (WC‐N/W) heterostructure is formed in situ on the WC grains. The obtained WC‐N/W electrode manifests excellent durability and stability under multi‐step current density in the range of 30–1000 mA cm−2 for more than 220 h in both acidic and alkaline media. Although WC is three orders of magnitude cheaper than Pt, the produced electrode demonstrates comparable hydrogen evolution reaction performance to the Pt electrode at high current density. Density functional theory calculations attribute its superior performance to the electrode structure and the modulated electronic structure at the WC‐N/W interface.

The integrated energy system (IES) with various energy demands and distributed energy resources has been a significant approach to improve the efficiency of energy utilization. Considering the uncertainties of renewable energy sources and loads, the energy dispatch optimization for multiarea IESs is studied in this paper. Different from the most current studies, not only the electrical power and heat distribution in each area is optimized, but also the coordination power dispatch between areas. A hierarchical learning method is proposed inhere to improve the operation performance of the multiarea IESs. The proposed method with data-driven way is a model-free method which has no requirement for the accurate mathematical model. With the hierarchical structure, the electrical power dispatched between areas is optimized in upper layer, together with the dispatching optimization in each area at lower layer, to decrease the operation cost for the system and power demand from the power grid. Finite horizon discrete dynamic process model is adopted to simulate the data for learning. The simulation results show the effectiveness of the optimization policy can achieve an economic and stable operation for the multiarea IES.

To reasonably evaluate the dispatching service quality of a power grid and comprehensively reflect the diversified demand satisfaction extent of the relevant stakeholders in the power system, it is imperative to construct an evaluation index system for power grid dispatching service quality, which should thoroughly consider the demand satisfaction of generation-side stakeholders, grid-side stakeholders, and load-side stakeholders. In this paper, the research status of the source-grid-load stakeholders' satisfaction indexes is overviewed from the perspective of their dispatching demand. The dispatching demand satisfaction indexes of the source-grid-load stakeholders and major evaluation methods in the literature are also summarized. According to current research progress, proposals for improving the rationality and efficiency of power grid dispatching service quality evaluation are also described. Finally, by combining the development demands of power grid dispatching service quality, we outline future research directions that involve dispatching demand satisfaction indexes evaluation for source-grid-load stakeholders in the power system.

Considering the serious asymmetric deformation and failure of the floor of 1# main roadway in Wanglou Coal Mine, the mechanism of roadway asymmetric floor heave was studied through on-site investigation, theoretical analysis, numerical simulation, and on-site test. The following conclusions were drawn: (1) the floor heave of 1# main roadway is mainly caused by high original rock stress, surrounding rock stress, water physical effect, support strength, etc. (2) A mechanical model of asymmetric floor heave is built and analyzed. Roadway floor stability is relevant to the stress concentration coefficient of the roadway sides, the burial depth of the roadway, and the cohesion and internal angle of friction of the floor rock. The relationship between the upward resultant force of the floor and the stress concentration coefficient of the roadway sides is established. Affected by mining, the upward force of roadway floor reaches 17.0 MPa, and serious floor heave is easy to occur when the floor is opened. (3) The floor heave curve of the position of 1# main roadway corresponding to working face is obviously asymmetric, the maximum value of floor heave being 948 mm. The floor heave curve of other positions of 1# main roadway is basically symmetric, the maximum floor heave value being merely 497 mm. A new “differentiated” combined support is proposed and field tested. It has been 13 months since the completion of main roadway repair in this section, no obvious deformation occurred, and the long-term stability of soft rock roadway support in deep mines is realized.

In order to mater the reasonable layout basis of the terminal mining line position in the repeated mining of close-distance thick coal seams, taking Yan mine as the engineering background, we conducted theoretical analyses, numerical simulations, and field measurements to study the action mechanism of the stress arch. The results show that (1) with repeated mining, the shape of the left and right half arches of the stress arch changes in the order of time and space until it is stable; (2) the shape of the stress arch is highly related to the distribution of abutment pressure in the working face. If the shape is unchanged, the distribution of abutment pressure is unchanged; (3) in the final mining stage of repeated mining, when the shape of the right half arch is stable, the difference stagger distance of the terminal mining line has little effect on the distribution of abutment pressure of the working face where the front arch foot is located; (4) when the internal stagger distance between 3216 working face and terminal mining line of 4216 working face is greater than 22 m or the external stagger distance is greater than 30 m, 3216 working face is located in a relatively safe position. This study clarifies the key factors for the layout of terminal mining lines in close-distance thick coal seams, which can provide a scientific basis for similar projects.

In this paper, a method to suppress the impact of the nonlinear effects on an all optical orthogonal frequency division multiplexing (AO-OFDM) system is proposed. By inserting a guard interval (GI), the duty cycle of the optical signal in each symbol period of each subcarrier is decreased, thus generating a ‘zeroed’ temporal. By giving different time delays to the sub-carriers, these ‘zeroed’ temporals and optical signals of the adjacent sub-carriers are interleaved, which reduces the coincidence of the optical signals between the sub-carriers and eliminates the products of the four-wave mixing (FWM) effect to suppress the influence of the nonlinear effect on the system. The simulation results show that for an AO-OFDM system with 32 subcarriers, inserting GI and introducing different delays for each subcarrier can improve the transmission distance by 30 km or enhance the spectral efficiency by 16.7%, considering the 7% hard decision forward error correction (HD-FEC) threshold. Moreover, even when the number of subcarriers is up to 256 and the power of each subcarrier is as high as 0 dBm, our proposed signal optimization scheme can still guarantee that the BER can satisfy the 7% HD-FEC threshold.

Autonomous underwater vehicles (AUVs) are widely used for ocean exploration; however, the way they are replenished becomes the biggest issue limiting their range and efficiency. A dual transmission coil wireless power transfer (DTCWPT) system based on parity–time (PT) symmetry is proposed in this paper to realize an autoadaptive constant power transmission. A shielded housing structure for coils is equipped to realize WPT in the ocean. In the offset experiments, the proposed dual transmitting coil structure was able to achieve a stable power transmission of 39 W within an offset range of 8.1 cm. It is obvious that the DTCWPT system based on PT symmetry could charge an AUV in the ocean with high robustness. This paper provides a novel solution based on DTCWPT for AUV energy supply. The proposed DTCWPT system could offer remarkable improvements in the navigation performance of AUVs.

Unmanned equipment, such as unmanned underwater vehicles (UUVs) and unmanned surface vehicles (USVs), are widely used in marine science for underwater observation, rescue, military purposes, etc. However, current vehicles are not applicable in complex cross-domain scenarios, because they can only perform well in either surface navigation or underwater diving. This paper deals with the design and fabrication of a cross-domain vehicle (CDV) with four hydrofoils that can both navigate at high speed on the surface, like a USV and dive silently underwater, like a UUV. The CDV’s propulsion is provided by a water jet propeller and its dive is achieved by a vertical propeller. The effect of hydrofoils and the performance of the CDV were tested and characterized in experiments, which showed that the hydrofoils improved the stability and surface sailing speed of the CDV. The maximum speed of the CDV was up to 14 kn, which is the highest of its kind according to current knowledge. This work confirmed the feasibility of high-performance CDVs and provided useful information for further improvements to the design.

In this paper, a low-density parity check (LDPC) coded GFDM with high-level modulation scheme is proposed for more flexible and advanced multicarrier modulation in intensity-modulated/direct-detection (IM/DD) optical systems. Then, we experimentally demonstrate an LDPC-coded GFDM with 16-quadrature amplitude modulation (16QAM) system transmitted over 20-km standard single-mode fiber at different symbol rates to verify the applicability of the proposed scheme. Furthermore, the proposed scheme with trellis-coded 32-quadrature amplitude modulation (TC-32QAM) has also been investigated and compared with the bit error rate (BER) performance with 16QAM-modulated condition. The results indicate that TC-32QAM-modulated GFDM method has a better performance than the 16QAM-modulated case. But with LDPC coding module added, the performance of the proposed system with TC-32QAM gets worse than that with 16QAM modulation. We also experimentally compare the proposed LDPC-coded scheme and the Turbo-coded scheme in the QAM-modulated GFDM IM/DD optical system. The results show the LDPC-coded optical (LCO-) GFDM scheme has lower power penalties and better BER performance. Moreover, the proposed LCO-GFDM scheme is applied in multiband transmission by optical simulation software, and the results show that multiband LCO-GFDM scheme has a better performance than that of LCO-OFDM scheme.

Person re-identification (ReID) is an important technology for target association in surveillance applications. Recently, sparse representation-based classification has been applied to person ReID with the advantage of discriminative feature extraction and has produced excellent results. The dictionary learning (DL) method is vital to the sparse representation, and the discriminative power of the learned dictionary determines the performance of ReID. Unlike previous approaches that only added constraints in DL, we propose a discriminative dictionary learning model (DDLM) that learns the discriminative dictionary by transforming the dictionary representation space in the training process. We determine the statistical distribution from the training data and divide the data into two categories according to the contribution for sparse representation: the high-contribution data and low-contribution data. Then, we extend the information space that contains the most high-contribution data and shrink the remaining parts. As the representation space of the dictionary is transformed, the solving process is modified accordingly. The experiments on the benchmark datasets (CAVIAR4REID, ETHZ, and i-LIDS) demonstrate that the proposed model outperforms the state-of-the-art approaches.

Under the condition of close-distance double-thick coal seams’ mining, the serious strata behavior occurred in the lower retracement channel, which is affected by the double disturbance with upper coal-pillar static load and mining dynamic pressure. Field investigation, laboratory test, and numerical simulation were used to study the failure characteristics and stress distribution of N0381 retracement channel. The results show that the plastic failure and stress of the surrounding rock are obviously asymmetric; specifically, the closer the roof is to N0381 gob, the stronger the strata behavior is. In addition, when the upper coal pillar is in critical stable or stable state (w/h>2), high stress concentration in the upper coal pillar is transmitted downward through floor rock so that two dangerous areas with severe strata behavior are formed in N0381 retracement channel. In view of this, a partition control strategy with “high-pressure water jet + asymmetric high-strength cable-beam net + three-hole anchor cable group + roof grouting” as the core is proposed to ensure the stability of the lower retracement channel. This study provides a reference for coal mines with similar production geological conditions.

The scientific and feasible method is extremely important for the evaluation of whether the support of coal mines needs to be scrapped, but it has not been formed. If the support cannot be continued to use, the determined reasonable working resistance of the support before the primary mining of coal seam should be optimized. Based on the field measurement and theoretical analysis, the concept of the actual rated working resistance of the support is proposed and analyzed accurately; the total amount of roof subsidence of circulating multiple coal cutting cycles during periodic pressure is calculated; the support performance is evaluated by multifactors; a new method for determining the reasonable working resistance of the support based on dynamic pressure is proposed. The study found that the safety valve of support is opened in advance and the resistance loss rate is large; the total amount of roof subsidence during periodic pressure is high; FAHP + EWM evaluation score of support system performance is 63.31 points. The scientific evaluation of multifactors showed that the support has reached service life, and as a result, the new 105 working faces required replacement with new support. The reasonable working resistance of the support in the 3-1 coal seam is optimized according to the new method based on dynamic pressure. This study can greatly improve the safety of roof control in the working face.

Superhydrophobic surfaces can be applied to environmental, energy, and healthcare fields. However, the weak durability issue has significantly limited the practical industrial applications. To overcome the readily destroyed interfacial structures and chemical compositions, the superhydrophobic surfaces with high mechanical and chemical durability have been created on a stainless steel mesh (SSM) as a protective frame based on tightly crosslinked polydimethylsiloxane (PDMS)−candle soot (CS) composite coatings through simple mechanical transfer and candle burning processes, which abbreviated to SSM/PDMS−CS and showed a water contact angle (WCA) of 159.4° ± 1.6° and a sliding angle (SA) of 2.3° ± 0.5°. Harsh abrasion examinations based on sandpaper and fiber paper have been conducted by applying 100 g weight and 200 cm sliding distance. And the obtained WCAs and SAs were 155° ± 3.7°, 155.7° ± 2° and 3.7° ± 0.5°, 3.5° ± 0.3°. Scanning electron microscope showed scratches on the surface, but the superhydrophobic property has been well maintained. After 40 kHz ultrasonication treatment for 30 min, WCA and SA were 152° ± 0.9° and 4.1° ± 0.8°. Finally, SSM/PDMS−CS surfaces exhibit good chemical resistance to corrosive solutions even after pH 2, pH 10, 1 M NaCl, and toluene treatments for 15 days.

Person re-identification (ReID) classifies the discriminative features of different people. Human perception usually depends on the minority of discriminative colors to classify targets, rather than the majority of mutual colors. ReID uses a small number of fixed cameras, which create a small account of similar backgrounds, leading to the majority of background pixels becoming non-discriminative (this is expanded in the feature map). This paper analyzes the distributions of feature maps to discover their different discriminative power. It also collects statistics that classify feature map values into individual ones and general ones according to the deviation of the mean value on each mini-batch. Finally, our findings introduce a learning irregular space transformation model in convolutional neural networks by enlarging the individual variance while reducing the general one to enhance the discrimination of features. We demonstrate our theories as valid on various public data sets, and achieve competitive results via quantitative evaluation.

In order to improve the wear and corrosion resistance of micro-arc oxidation (MAO) coating on a Ti-5Al-1V-1Sn-1Zr-0.8Mo alloy, 0–0.20 g/L graphene was added to the electrolyte to prepare micro-arc oxidation coating. The thickness, roughness, micro-morphology, and composition of the MAO coating were characterized, and the wear and corrosion resistance of the coating was tested and analyzed. The results show that with 0.05 g/L of graphene in the electrolyte, the roughness of the coating decreased from 56.76 μm to 31.81 μm. With the increase in the addition of graphene, the microstructure of the coating became more compact, the diameter of micro-holes and micro-cracks decreased, and the corrosion resistance of the coating improved. The wear tests showed that the mass loss of the coating at the early wear stage (0~100 revolutions) was greater than that at the later stage (100~250 revolutions), and the wear resistance of the coating obtained by the addition of 0.10 g/L of graphene was the highest. With 0.10 g/L of graphene, the adhesion force between the coating and the substrate alloy is the largest, reaching 57.1 N, which is 9.98 N higher than that without graphene. After salt spray corrosion for 480 h, the coating with graphene has better corrosion resistance than that of a graphene-free coating.

The self-assembled hierarchical micro-nanostructures with geometric complexity and/or constituent diversity are becoming a promising class of candidates for the next generation nanotechnology. Different from conventional vapor-liquid-solid (VLS) eutectic liquid droplets for one-dimensional(1D) nanowires, the Zn-Bi VLS monotectic liquid droplets are employed to build 1D, 2D and 3D ZnO into 3D hierarchical micro-nanostructures. As-obtained micro-nanostructures are well defined self-assembly and have not yet been observed in the conventional eutectic alloys. The synergy of monotectic droplets and nonthermal equilibrium is responsible for the evolution of ZnO hierarchical micro-nanostructures. Raman spectra show that E _2H and E _1L modes are shifted slightly towards the high-wavenumber side by an amount of 3.7 and 2 cm ^−1 as compared with undoped ZnO nanowires and an additional peak at 519.5 cm ^−1 is associated with Bi _38 OZn _60 . The results manifest that 3D ZnO micro-nanoarchitectures possess a bulk phonon structure. The monotectic liquid droplet route presented in this paper may offer a new opportunity to the fabrication of hierarchical nanostructures for realistic technology platforms with multifunctional coupling and interplay.

To aid the design of a hierarchically porous unconventional metal-phosphonate framework (HP-UMPF) for practical radioanalytical separation, a systematic investigation of the hydrolytic stability of bulk phase against acidic corrosion has been carried out for an archetypical HP-UMPF. Bulk dissolution results suggest that aqueous acidity has a more paramount effect on incongruent leaching than the temperature, and the kinetic stability reaches equilibrium by way of an accumulation of a partial leached species on the corrosion conduits. A variation of particle morphology, hierarchical porosity and backbone composition upon corrosion reveals that they are hydrolytically resilient without suffering any great degradation of porous texture, although large aggregates crack into sporadic fractures while the nucleophilic attack of inorganic layers cause the leaching of tin and phosphorus. The remaining selectivity of these HP-UMPFs is dictated by a balance between the elimination of free phosphonate and the exposure of confined phosphonates, thus allowing a real-time tailor of radionuclide sequestration. Moreover, a plausible degradation mechanism has been proposed for the triple progressive dissolution of three-level hierarchical porous structures to elucidate resultant reactivity. These HP-UMPFs are compared with benchmark metal-organic frameworks (MOFs) to obtain a rough grading of hydrolytic stability and two feasible approaches are suggested for enhancing their hydrolytic stability that are intended for real-life separation protocols.