Synchronization Constructs Research Articles

Synchronously Consolidating Li, Se, S, and C for Robust Li-SeS Batteries.

S-redox involving solvated polysulfides is accompanied by volumetric change and structural decay of the S-based cathodes. Here, we propose a synchronous construction strategy for consolidating Li, Se, S, and C elements within a composite cathode via a paradigm reaction of 8Li+2Se+CS2 = 2Li4SeS+C. The obtained composite features crystalline Li4SeS encapsulated in a carbon nanocage (Li4SeS@C), exhibiting ultrahigh electrical conductivity, ultralow activation barrier, and excellent structural integrity, accordingly enabling large specific capacity (615 mAh g-1) and high capacity retention (87.3% after 350 cycles) at 10 A g-1. TOF-SIMS demonstrates its superior volumetric efficiency to a similar derivative SeS@C (2Se+CS2 = 2SeS+C), and DFT reveals its lower activation barrier than Li2S@C and Li2Se@C. This consolidation design significantly improves the electrochemical performance of S-based cathodes, and the paradigm reaction guarantees structural diversity and flexibility. Moreover, employing a synchronous construction mechanism to maximize the synergistic effect between element consolidation and carbon encapsulation opens up a new approach for developing robust S or chalcogenide cathodes.

Lightweight Dual-Functional Segregated Nanocomposite Foams for Integrated Infrared Stealth and Absorption-Dominant Electromagnetic Interference Shielding

HighlightsLightweight dual-functional segregated nanocomposite foams are developed via the supercritical CO2 (SC-CO2) foaming combined with hydrogen bonding assembly and compression molding strategyThe segregated nanocomposite foams exhibit superior infrared stealth performances benefitting from the synergistic effect of highly effective thermal insulation and low infrared emissivity.Excellent absorption-dominant electromagnetic interference shielding performances are achieved owing to the synchronous construction of microcellular structures and segregated structures

Synchronous construction of Cu and Ni single-atom sites in ordered porous TiO2 for enhanced photo-conversion of CO2 and H2O to methane

The solar-powered conversion of CO2 and H2O to hydrocarbons is highly compelling but remains a significant challenge because both CO2 reduction and H2O oxidation are thermodynamically unfavorable. Herein, the synchronous incorporation of Cu and Ni single-atom sites into ordered porous TiO2 was accomplished through a template-assisted calcination process, resulting in a series of Cu-Ni/TiO2 catalysts for photocatalytic CO2 reduction using H2O as a hydrogen source. The formation of Cu and Ni single atoms was verified by X-ray absorption fine structure (XAFS) spectroscopy. The optimal Cu-Ni/TiO2 photocatalyst exhibited excellent performance to reach a CH4 production rate of 63.88 μmol g−1 h−1 with a high selectivity of 96.4% under simulated sunlight, in the absence of sacrificial agents. The presence of Cu and Ni single atoms not only provided effective active sites for adsorption and activation of CO2 and H2O but also facilitated separation and transfer of photogenerated charge carriers. In situ spectroscopic analyses revealed that CO2 was adsorbed on the catalyst as bicarbonates, followed by the multistep reduction into CH4 via the electron-proton transfer processes, while the photogenerated holes were consumed by H2O oxidation to generate H2O2. The simultaneous enhancement of both H2O and CO2 activation guarantees excellent photocatalytic performance towards CH4 production. This study provides guidance on developing highly efficient photocatalysts by engineering active sites as well as insights into enhancing CO2 photoreduction.

Janus from the synchronous construction of CN network and P-π conjugation: Inhibiting volume expansion and promoting lithium-ion battery performance of ZnSe

High-capacity lithium anode materials are very important for the development of lithium storage. However, the volume expansion and electron transport during charging and discharging hinder the development of high capacity and longevity. Herein, the three-dimensional P-π conjugate and nitrogen-doped carbon (CN) network framework was synchronously constructed by a simple and practical double construction strategy to solve the problems of volume expansion and electron transport. The experimental results indicate that the successfully synthesized transition metal zinc selenide (ZnSe) composites material possesses excellent electrochemical properties: an initial reversible capacity is capacity of 1211.8 mAh/g, and the reversible discharge capacity remains at 936.4 mAh/g after 300 cycles (at 1 A/g current density). It is much better than that of pure ZnSe. The enhanced electrochemical performances of the anode can be attributed to its high surface area and abundant mesopores constracted by the 3D CN network framework. Furthermore, the P-π conjugation reduces the system energy and thus accelerates the electron transport. These characteristics provide numerous pathways and sites for Li+ transfer and storage, thus contributing to the pseudo-capacitance capacity. The present work may provide new ideas and strategies for the solution of electrode material expansion and electron transport problems.

Synchronous construction of Ni2P/Cu3P in-situ loading and P doping for g-C3N4: Enhanced photocatalytic H2 evolution activity and mechanism

Research on the subject of photolysis focuses on the creation of effective non-precious metal co-catalysts. Graphitic carbon nitride (g-C3N4) is a promising candidate for photocatalytic hydrogen generation from water. But its photocatalytic activity is limited by the slow redox reaction, high carrier recombination rate, and inadequate optical absorption. Incorporating in situ loading Ni2P/Cu3P and phosphorus doping on g-C3N4 is effective in overcoming the drawbacks. Phosphorus doping reduces the band gap of g-C3N4 for increased light absorption and improves the separation of photogenerated charge. Additionally, Ni2P/Cu3P heterojunctions anchored on P-doped g-C3N4 (P-C3N4) as non-noble co-catalysts boost light adsorption, enabling charge transfer and speeding the hydrogen evolution process. The resultant Ni2P/Cu3P@P-C3N4 composite photocatalyst achieves an effective photocatalytic hydrogen evolution rate of 201 times greater than that of g-C3N4 (12.9 μmol·h−1·g−1). This work is instructive to develop efficient g-C3N4-based photocatalysts for photocatalytic water splitting without the need for noble metals.

Multimodality MRI synchronous construction based deep learning framework for MRI-guided radiotherapy synthetic CT generation

Synthesizing computed tomography (CT) images from magnetic resonance imaging (MRI) data can provide the necessary electron density information for accurate dose calculation in the treatment planning of MRI-guided radiation therapy (MRIgRT). Inputting multimodality MRI data can provide sufficient information for accurate CT synthesis: however, obtaining the necessary number of MRI modalities is clinically expensive and time-consuming. In this study, we propose a multimodality MRI synchronous construction based deep learning framework from a single T1-weight (T1) image for MRIgRT synthetic CT (sCT) image generation. The network is mainly based on a generative adversarial network with sequential subtasks of intermediately generating synthetic MRIs and jointly generating the sCT image from the single T1 MRI. It contains a multitask generator and a multibranch discriminator, where the generator consists of a shared encoder and a splitted multibranch decoder. Specific attention modules are designed within the generator for feasible high-dimensional feature representation and fusion. Fifty patients with nasopharyngeal carcinoma who had undergone radiotherapy and had CT and sufficient MRI modalities scanned (5550 image slices for each modality) were used in the experiment. Results showed that our proposed network outperforms state-of-the-art sCT generation methods well with the least MAE, NRMSE, and comparable PSNR and SSIM index measure. Our proposed network exhibits comparable or even superior performance than the multimodality MRI-based generation method although it only takes a single T1 MRI image as input, thereby providing a more effective and economic solution for the laborious and high-cost generation of sCT images in clinical applications.

Experimental investigation of a precast segmental Twin‐Deck box girder bridge simultaneously erected with double bridge erection gantries

AbstractPrecast segmental construction can shorten the construction time of the bridge and reduce the impacts on traffic and environment. Thus, this approach has been widely used in many countries. The relevant literature suggests that in the existing segmental precast bridges, nearly all of the centerlines of the girders are aligned with the centerline of the bridge piers. This paper introduces a wide urban viaduct comprising twin separate box girder cells using segmental prefabrication. To save space under the bridge, the bridge has only one row of piers and long cantilever crossbeams are set at the top of each pier. Additionally, the centerline of the girder and the centerline of the pier do not overlap. To prevent eccentric loading and improve the construction speed, two bridge erection gantries are used for synchronous construction. This study is a pioneering attempt at bridge construction with a precast segmental twin‐deck box girder bridge simultaneously erected with double gantries. To investigate the stress state of the whole system (crossbeam, gantries, and box girder segments) during construction and demonstrate the feasibility of the construction method, a real bridge was used. The test results provide a reference for the design and construction of similar projects.

Synchronous construction of high sulfonic acid grafting degree and large surface area in conjugated microporous polymer adsorbents for efficient removal of uranium (VI)

Functionalization and specific surface area (BET) are two decisive factors for conjugated microporous polymers (CMPs) as an effective uranium adsorbent, but it remains challenging to simultaneously achieve high degree of functionalization and large BET in a CMP. Herein, we innovatively adopt an ingenious molecular engineering strategy to synchronously construct high sulfonic acid grafting degree and large BET in an adsorbent. The PePy containing the pyrene-based monomer with extended π-conjugation degree and high rigidity has narrow energy band and rigid skeleton, which leads to PePy-SO3H holding a higher degree of sulfonic acid grafting while maintaining a satisfactory BET. Astonishedly, the PePy-SO3H adsorben exhibits strong affinity toward uranium with the distribution coefficient of 2.3 × 104 mL g−1 and an exceptionally high adsorption capacity of 579.0 mg g−1. This work highlights the advantages of molecular engineering strategies in optimizing the purification performance of CMPs adsorbents for uranium-containing wastewater.

Towards the Sign Function Best Approximation for Secure Outsourced Computations and Control

Homomorphic encryption with the ability to compute over encrypted data without access to the secret key provides benefits for the secure and powerful computation, storage, and communication of resources in the cloud. One of its important applications is fast-growing robot control systems for building lightweight, low-cost, smarter robots with intelligent brains consisting of data centers, knowledge bases, task planners, deep learning, information processing, environment models, communication support, synchronous map construction and positioning, etc. It enables robots to be endowed with secure, powerful capabilities while reducing sizes and costs. Processing encrypted information using homomorphic ciphers uses the sign function polynomial approximation, which is a widely studied research field with many practical results. State-of-the-art works are mainly focused on finding the polynomial of best approximation of the sign function (PBAS) with the improved errors on the union of the intervals [−1,−ϵ]∪[ϵ,1]. However, even though the existence of the single PBAS with the minimum deviation is well known, its construction method on the complete interval [−1,1] is still an open problem. In this paper, we provide the PBAS construction method on the interval [−1,1], using as a norm the area between the sign function and the polynomial and showing that for a polynomial degree n≥1, there is (1) unique PBAS of the odd sign function, (2) no PBAS of the general form sign function if n is odd, and (3) an uncountable set of PBAS, if n is even.

Organophosphine ligand derived sandwich-structural electrocatalyst for oxygen evolution reaction

The synchronous construction of metal phosphate and phosphorus-doped carbon structures is of great significance to innovate the design, synthesis, and application of catalysts, as these phosphorus-containing composite materials have shown a remarkable contribution to electrocatalysts. However, their preparation procedure generally involves using large amounts of excess phosphorus sources for phosphorization, which inevitably release poisonous PH3 or dangerous phosphorus vapor. Here, a strategy for in-situ formation of FePO4 embedded in P-doped carbon 2D nano film (FePO4/PdC) is developed using a highly integrated precursor, which is a small molecular organophosphine ligand, 1,1′bis (diphenylphosphine) ferrocene (DPPF). The multi-source precursor DPPF that contains Fe, P, and C is molecular-vapor-deposited on the nickel foam (NF) supported ZIF-67 nanosheets to obtain the composite catalyst, namely DPPF-500/ZIF-67/NF. FePO4/PdC encapsulated the ZIF-67 derived Co/N-doped carbon matrix (CoNC) to form a sandwich structure FePO4/PdC@CoNC. The constructed catalyst shows good performance for OER, requiring an overpotential of only 297 mV to deliver 600 mA/cm2 with a Tafel slope of 42.7 mV dec−1. DFT calculations demonstrate that the synergistic effects between the metal active center and P-doped carbon film reduce the energy barriers and improve electron transport. This method of constructing P-containing catalysts overcomes the demand for additional P sources to realize eco-friendly fabrication and yields a unique structure with good catalytic activity.

Research on the critical technique of synchronous rotation construction with large angle for T-shape curve rigid frame bridge

The superstructure rotation method (SRM) has been widely used in recent years due to its rapid construction, low cost and less impact on existing traffic.This paper focuses on construction method and the key parameters related with large angle synchronous rotation construction of T-shape curved rigid frame bridges, taking two bridges of the Wuyi Expressway over the Chengdu-Kunming Railway as the engineering background.The results show that the construction methods used in this project can accomplish the realization of complexed synchronous rotation execution of T-shape curve rigid frame bridge. The construction methods consist of the installation process of ball joint, the design of traction system, accuracy control method and rotation control strategy.The friction coefficients from practical measurements were compared with the analytical ones from existing formulas, and it shows that the calculation method can give good predictions for the friction coefficients at the SRM of curve rigid frame bridge.Finally, the key technologies and determination of key parameters applicable for large angle synchronous rotation construction of curve T-shape rigid frame bridge are summarized. Furthermore, the research results in this paper can provide technical recommendation for the construction of the similar bridges.

Synchronous Construction of High Sulfonic Acid Grafting Degree and Large Surface Area in Conjugated Microporous Polymer Adsorbents for Efficient Removal of Uranium (Vi)

Synchronous Construction of High Sulfonic Acid Grafting Degree and Large Surface Area in Conjugated Microporous Polymer Adsorbents for Efficient Removal of Uranium (Vi)

Synchronous construction of oxygen vacancies with suitable concentrations and carbon coating on the surface of Li-rich layered oxide cathode materials by spray drying for Li-ion batteries

Lithium-rich layered oxide materials with high reversible capacities (over 250 mAh g−1) are considered as one of the most promising cathode materials for the next generation of lithium-ion batteries. However, some challenges including low initial Coulombic efficiency, voltage decay and poor cycling restrict their commercial application. Herrin, Li-rich layered oxide materials Li1.2Ni0.2Co0.08Mn0.52O2 co-modified by constructing oxygen vacancies with suitable concentration and C coating layer have been synthesized via a facile spray drying process. The oxygen vacancies with suitable concentration can not only suppress the release of O2 and improve the stability of the layered structure, but also facilitate Li diffusion. Moreover, C coating layer acts as a physical barrier to protect the materials from electrolyte, and reduce the interface impedance. The co-modified material shows excellent electrochemical properties: a high initial Coulombic efficiency of 83.1%, a small voltage decay rate of 0.306 mV, and a capacity retention of 78.3% after 1000 cycles at 5 C. And it provides a simple and feasible way to improve the properties of lithium-rich layered oxide materials.

Synchronous Construction of the Hierarchical Pores and High Hydrophobicity of Stable Metal-Organic Frameworks through a Dual Coordination-Competitive Strategy.

Hierarchical-pore construction and functionalities are critical to further extend the applications of some stable MOFs, such as water remediation, fuel purification, oil/water separation, and self-cleaning, which are rarely achieved simultaneously. Herein, we demonstrate a method of synchronously constructing high-hydrophobicity Zr-based metal-organic frameworks with hierarchical pores (HP-UiO-66) through a dual coordination-competitive strategy. The addition of alkanoic acids and Zn2+ ions as coordination-competitors could reduce the coordinative degree between the ligand and Zr4+ ions to effectively induce defect formation. The resulting unsaturated Zr4+ ions could fully combine with the existing alkanoic acid with a long chain to afford HP-UiO-66 with high-hydrophobicity characteristics. In addition, the particle size of pristine UiO-66 could be adjusted effectively from around 280 to 120 nm using different alkanoic acids when Zn2+ ions are not added. This study provided a simple way for effectively controlling the morphology and structure of UiO-66 at the same time. Moreover, this kind of high-hydrophobicity HP-UiO-66 showed potential applications in oil/water separation and selective adsorption of organic mixtures.

Synchronous construction of a porous intramolecular D-A conjugated polymer via electron donors for superior photocatalytic decontamination

The development of conjugated polymers with intramolecular donor–acceptor (D-A) units has the capacity to enhance the photocatalytic performance of carbon nitride (g-C3N4) for the removal of antibiotics from ambient ecosystems. This strategy addresses the challenge of narrowing the band gap of g-C3N4 while maintaining its high LUMO position. For this study, we introduced the above donor units into g-C3N4 to construct intramolecular D-A structures through the copolymerization of dicyandiamide with creatinine, which strategically extended light absorption into the green region and expedited photoelectron separation. The introduction of electron donor blocks kept the LUMO distributed on the melem, which maintained the high LUMO energy level of the copolymer with the potential to generate oxygen radicals. The as-prepared porous D-A conjugated polymer enhanced the photocatalytic degradation of sulfisoxazole with kinetic constants 5.6 times higher than that of g-C3N4 under blue light and 15.3 times higher under green light. Furthermore, we surveyed the degradation mechanism including the effective active species and degradation pathways. This study offers a new perspective for the synchronous construction of a porous intramolecular D-A conjugated polymer to enhance water treatment and environmental remediation capacities.

Synchronous Construction Technology of Prestressed Anchor Cable for Deep Foundation Pit Support

Synchronous Construction Technology of Prestressed Anchor Cable for Deep Foundation Pit Support

Synchronous Construction of Piezoelectric Elements and Nanoresistance Networks for Pressure Sensing Based on the Wheatstone Bridge Principle

Fabrication of flexible piezoelectric sensing nanomaterials is essential for the development of wearable and microscopic electronic devices. However, existing piezoelectric sensing materials usuall...

Pd modified defective HNb3O8 with dual active sites for photocatalytic coproduction of hydrogen fuel and value-added chemicals

Developing photocatalysts for coproduction of hydrogen fuel and valuable chemicals is highly desired but still challenging. Herein, Pd-modified defective HNb3O8 photocatalyst (denote as Pd/HNb3O8-H2) consisting of dispersive Pd sites and abundant surface oxygen vacancies (VOs) was prepared via the thermal treatment of Pd2+-incorporated HNb3O8 in H2/Ar gas. The existence of Pd favors the formation of VOs on HNb3O8, enabling the synchronous construction of Pd and VO dual active sites. The spectroscopy and photoelectrochemical studies demonstrate the advantages of Pd/HNb3O8-H2 photocatalyst in promoting the separation and migration of photoinduced charge carries. The Pd/HNb3O8-H2 photocatalyst exhibits the outstanding performance toward photocatalytic proton reduction coupled with selective benzyl-alcohol oxidation, achieving the optimal production rates of H2 and benzaldehyde as high as 3.17 and 2.76 mmol·gcat−1 h−1, respectively. The experimental and theoretical investigations have expounded the synergistic mechanism of Pd and VO dual active sites in boosting photocatalytic coproduction of H2 and benzaldehyde.

Design and Application of Mechanized Construction Equipment in Shallow Excavation Precast Utility Tunnel

Traditional open-cut method for utility tunnel has many disadvantages such as long-term occupation and large area of land, great disturbance to urban traffic and environment, high labour intensity of workers and so on. In order to overcome the disadvantages above, a machine for prefabricated utility tunnel construction was designed which drawing on the working principle of shield machine and pipe jacking machine. The above-machine is applied in shulong road utility tunnel of Chengdu. The applicable results show that: (1) The above-machine achieve movable streamlined synchronous construction of earth excavation, components assembling and earth backfill. It improve the shortcoming of traditional open cut method and cancel the majority of foundation pit bracing structure. (2) The above-machine can make mechanized and assemblage construction of shallow excavation precast utility tunnel come true. It effectively control construction quality and reduce difficulty of construction management.

Synchronous construction of Fe1−xS-embedded and interconnected carbon matrices for high‐performance lithium‐ion batteries anode

Synchronous construction of Fe1−xS-embedded and interconnected carbon matrices for high‐performance lithium‐ion batteries anode