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With the scarcity of water resources in various regions, the pressure on water supply projects is also increasing, which has led to a sharp increase in the water hammer effect in water supply pump projects. In response to this issue, the study proposes to apply a unidirectional pressure regulating tower based on mechanical hydraulic technology to water hammer protection in water supply pumps. In addition, the study also optimizes the calculation method of water hammer and designs one simulation software, which is used to simulate and analyze the proposed water hammer protection measures. The study first determines through simulation software that the optimal initial water level of the unidirectional pressure regulating tower is 2m and the optimal diameter of the make-up water pipe is 600 mm. Afterwards, simulation analysis is conducted on different water hammer protection measures, and it is found that the maximum pressure of the water hammer under the proposed protection measures is the lowest, at 14.8m, which was lower than the comparison measures. In addition, according to expert ratings, the average protective effect rating of protective measure 1 by relevant technical personnel is 9.4 points, which is better than the comparative measure. The above results indicate that through the simulation analysis of hydraulic transition process based on mechanical hydraulics, it can be found that the water hammer protection measures proposed in the study have good protective functions and can effectively reduce the water hammer effect in water supply engineering.

Triboelectrification is a well-known phenomenon that commonly occurs in nature and in our lives at any time and any place. Although each and every material exhibits triboelectrification, its quantification has not been standardized. A triboelectric series has been qualitatively ranked with regards to triboelectric polarization. Here, we introduce a universal standard method to quantify the triboelectric series for a wide range of polymers, establishing quantitative triboelectrification as a fundamental materials property. By measuring the tested materials with a liquid metal in an environment under well-defined conditions, the proposed method standardizes the experimental set up for uniformly quantifying the surface triboelectrification of general materials. The normalized triboelectric charge density is derived to reveal the intrinsic character of polymers for gaining or losing electrons. This quantitative triboelectric series may serve as a textbook standard for implementing the application of triboelectrification for energy harvesting and self-powered sensing. Triboelectric charging is a well-known phenomenon, but triboelectric polarization has only been ranked qualitatively. Here the authors develop a quantified triboelectric series for a wide range of polymers by measuring triboelectric charge density with respect to a liquid metal at well-defined conditions.

The polaron is a quasi-particle formed by a conduction electron (or hole) together with its self-induced polarization in a polar semiconductor or an ionic crystal. Among various polarizable examples of complex oxides, strontium titanate (SrTiO 3 ) is one of the most studied. Here we examine the carrier type and the interplay of inner degrees of freedom (for example, charge, lattice, orbital) in SrTiO 3 . We report the experimental observation of Fröhlich polarons, or large polarons, at the bare SrTiO 3 surface prepared by vacuum annealing. Systematic analyses of angle-resolved photoemission spectroscopy and X-ray absorption spectra show that these Fröhlich polarons are two-dimensional and only exist with inversion symmetry breaking by two-dimensional oxygen vacancies. Our discovery provides a rare solvable field theoretical model, and suggests the relevance of large (bi)polarons for superconductivity in perovskite oxides, as well as in high-temperature superconductors. A polaron is a quasiparticle formed through the strong interaction between an electron and the ions in a crystalline solid. Here, the authors observe Fröhlich polarons, formed by the coupling of electrons and long-wavelength optical phonons, in strontium titanate.

The unconventional superconductivity associated with iron pnictide materials has been the subject of intense interest. Using an annealing procedure to control the charge-carrier concentration, the behaviour of an FeSe monolayer deposited on SrTiO 3 is now investigated, and indications of superconductivity at temperatures up to 65 K observed. The recent discovery of possible high-temperature superconductivity in single-layer FeSe films 1 , 2 has generated significant experimental and theoretical interest 3 , 4 . In both the cuprate 5 , 6 and the iron-based 7 , 8 , 9 , 10 , 11 high-temperature superconductors, superconductivity is induced by doping charge carriers into the parent compound to suppress the antiferromagnetic state. It is therefore important to establish whether the superconductivity observed in the single-layer sheets of FeSe—the essential building blocks of the Fe-based superconductors—is realized by undergoing a similar transition. Here we report the phase diagram for an FeSe monolayer grown on a SrTiO 3 substrate, by tuning the charge carrier concentration over a wide range through an extensive annealing procedure. We identify two distinct phases that compete during the annealing process: the electronic structure of the phase at low doping (N phase) bears a clear resemblance to the antiferromagnetic parent compound of the Fe-based superconductors, whereas the superconducting phase (S phase) emerges with the increase in doping and the suppression of the N phase. By optimizing the carrier concentration, we observe strong indications of superconductivity with a transition temperature of 65±5 K. The wide tunability of the system across different phases makes the FeSe monolayer ideal for investigating not only the physics of superconductivity, but also for studying novel quantum phenomena more generally.

The recent discovery of high-temperature superconductivity in iron-based compounds has attracted much attention. How to further increase the superconducting transition temperature ( T c ) and how to understand the superconductivity mechanism are two prominent issues facing the current study of iron-based superconductors. The latest report of high- T c superconductivity in a single-layer FeSe is therefore both surprising and significant. Here we present investigations of the electronic structure and superconducting gap of the single-layer FeSe superconductor. Its Fermi surface is distinct from other iron-based superconductors, consisting only of electron-like pockets near the zone corner without indication of any Fermi surface around the zone centre. Nearly isotropic superconducting gap is observed in this strictly two-dimensional system. The temperature dependence of the superconducting gap gives a transition temperature T c ~ 55 K. These results have established a clear case that such a simple electronic structure is compatible with high- T c superconductivity in iron-based superconductors. The exact mechanism for superconductivity in iron-based superconductors remains elusive, but is thought to involve complex interactions between many orbitals. Using angle-resolved photoelectron spectroscopy, Liu et al . report the electronic structure of the single-layer parent compound FeSe.

In van der Waals heterostructures (vdWHs), the manipulation of interlayer stacking/coupling allows for the construction of customizable quantum systems exhibiting exotic physics. An illustrative example is the diverse range of states of matter achieved through varying the proximity coupling between two-dimensional (2D) quantum spin liquid (QSL) and superconductors within the TaS 2 family. This study presents a demonstration of the intertwined physics of spontaneous rotational symmetry breaking, hidden magnetism, and Ising superconductivity (SC) in the three-fold rotationally symmetric, non-magnetic natural vdWHs 6 R -TaS 2 . A distinctive phase emerges in 6 R -TaS 2 below a characteristic temperature ( T * ) of approximately 30 K, which is characterized by a remarkable set of features, including a giant extrinsic anomalous Hall effect (AHE), Kondo screening, magnetic field-tunable thermal hysteresis, and nematic magneto-resistance. At lower temperatures, a coexistence of nematicity and Kondo screening with Ising superconductivity is observed, providing compelling evidence of hidden magnetism within a superconductor. This research not only sheds light on unexpected emergent physics resulting from the coupling of itinerant electrons and localized/correlated electrons in natural vdWHs but also emphasizes the potential for tailoring exotic quantum states through the manipulation of interlayer interactions. 6 R -TaS2 is a natural van der Waals heterostructure formed by 1 H - and 1 T -phase TaS 2 layers, which can individually exhibit Ising superconductivity, correlated states and charge density waves. Here, the authors show experimental evidence of emergent nematic Ising superconductivity with simultaneous hidden magnetism (extrinsic anomalous Hall effect and Kondo screening) in 6 R -TaS 2 under 30 K.

Background Immunological nonresponders (INRs) living with HIV are at increased risk of co-infection and multiple tumors, with no effective strategy currently available to restore their T-cell immune response. This study aimed to explore the safety and efficacy of thymosin α1 in reconstituting the immune response in INRs. Methods INRs with CD4 + T cell counts between 100 and 350 cells/μL were enrolled and received two-staged 1.6 mg thymosin α1 subcutaneous injections for 24 weeks (daily in the first 2 weeks and biweekly in the subsequent 22 weeks) while continuing antiretroviral therapy. T cell counts and subsets, the expression of PD-1 and TIM-3 on T cells, and signal joint T cell receptor excision circles (sjTREC) at week 24 were evaluated as endpoints. Results Twenty three INRs were screened for eligibility, and 20 received treatment. The majority were male (19/20), with a median age of 48.1 years (interquartile range: 40.5–57.0) and had received antiretroviral therapy for 5.0 (3.0, 7.3) years. Multiple comparisons indicated that CD4 + T cell count and sjTREC increased after initiation of treatment, although no significant differences were observed at week 24 compared to baseline. Greatly, levels of CD4 + T cell proportion (17.2% vs. 29.1%, P  < 0.001), naïve CD4 + and CD8 + T cell proportion (17.2% vs. 41.1%, P  < 0.001; 13.8% vs. 26.6%, P  = 0.008) significantly increased. Meanwhile, the proportion of CD4 + central memory T cells of HIV latent hosts (42.7% vs. 10.3%, P  < 0.001) significantly decreased. Moreover, the expression of PD-1 on CD4 + T cells (14.1% vs. 6.5%, P  < 0.001) and CD8 + T cells (8.5% vs. 4.1%, P  < 0.001) decreased, but the expression of TIM-3 on T cellsremained unaltered at week 24. No severe adverse events were reported and HIV viral loads kept stable throughout the study. Conclusions Thymosin α1 enhance CD4 + T cell count and thymic output albeit as a trend rather than an endpoint. Importantly, it improves immunosenescence and decreases immune exhaustion, warranting further investigation. Trial registration This single-arm prospective study was registered with ClinicalTrials.gov (NCT04963712) on July 15, 2021.

Topological magnets are a new family of quantum materials providing great potential to realize emergent phenomena, such as the quantum anomalous Hall effect and the axion-insulator state. Here, we present our discovery that the stoichiometric ferromagnetMnBi8Te13with natural heterostructureMnBi2Te4/(Bi2Te3)3is an unprecedented “half-magnetic topological insulator,” with the magnetization existing at theMnBi2Te4surface but not at the opposite surface terminated by tripleBi2Te3layers. Our angle-resolved photoemission spectroscopy measurements unveil a massive Dirac gap at theMnBi2Te4surface and a gapless Dirac cone on the other side. Remarkably, the Dirac gap (about 28 meV) at theMnBi2Te4surface decreases monotonically with increasing temperature and closes right at the Curie temperature, thereby representing the first smoking-gun spectroscopic evidence of a magnetization-induced topological surface gap among all known magnetic topological materials. We further demonstrate theoretically that the half-magnetic topological insulator is desirable to realize the surface anomalous Hall effect, which serves as direct proof of the general concept of axion electrodynamics in condensed matter systems.

The demands of body armor on level of protection, weight, flexibility and comfort have always been difficult to strike an optimal balance. Most studies aim to promote the impact resistance of bulletproof materials, flexibility and comfort have not been sufficiently emphasized. Weft-knitted insertion fabric has excellent flexibility and body fitting ability, and the insertion yarns dissipate energy rapidly. In this paper, flexible composite laminates reinforced by aramid weft-knitted insertion fabrics (WKIFs) were developed. The ballistic performance was comprehensively studied based on the external damage appearance and internal damage image by high velocity impact tests and X-ray computed tomography. The finite element analysis was carried out to further explore the damage modes and failure mechanisms of composite materials. The results show that laminates reinforced by WKIFS have the potential to be applied in the bullet-proof field with the ballistic limit velocity of 365.31 m/s, 339.76 m/s and 338.29 m/s, respectively. For the laminates reinforced by weft-insertion fabrics, the front layers tend to be destroyed in shear, while the back layers are more probably to fail in tension. Further, the specific damage modes of the laminate were affected by the impact velocity of projectile. This study is of great significance to the development of flexible bullet-proof composite materials.

This paper focuses on programing mechanics of patterned spacer materials with double inlay-jacquard systems. Because of quite complex warp knitting paths and jacquard principles, an in-depth research on this double-jacquard techniques is conducted and then this paper proposes separate programing models of jacquard loop and jacquard underlap for the first time. Also, it studies a mapping method between the jacquard patterns design and colored loops formation process to automatically transfer what you design and see into what you knit. For the deviation between the design and the knitting result generated during the mapping process, an automatic detection method and an automatic correction algorithm are designed to ensure the accuracy of the mapping model. To comprehensively verify the programing model, an experimental design is exampled and then transferred into knitting parameters based on the programing system to fabricate a corresponding patterned material. This researched programing method shows great potential in increasing design efficiency and decreasing chemicals consumption in printing.