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List intersection plays a pivotal role in various domains such as search engines, database systems, and social networks. Efficient indexes and query strategies can significantly enhance the efficiency of list intersection. Existing inverted index-based algorithms fail to utilize the length information of documents and require excessive list intersections, resulting in lower efficiency. To address this issue, in this paper, we propose the LDRpV (Length-based Document Reordering plus Verification) algorithm. LDRpV filters out documents that are unlikely to satisfy the intersection results by reordering documents based on their length, thereby reducing the number of candidates. Additionally, to minimize the number of list intersection operations, an intersection and verification strategy is designed, where only the first m lists are intersected, and the resulting candidate set is directly verified. This approach effectively improves the efficiency of list intersection. Experimental results on four real datasets demonstrate that LDRpV can achieve a maximum efficiency improvement of 46.69% compared to the most competitive counterparts.

Cu/steel composites have the advantages of low cost and high heat dissipation performance, which make them ideal materials for applications in the industrial heat dissipation field. Because of the unique pore structure, the Gasar porous Cu is more excellent in heat transfer performance. However, systematic research still needs to be done on the joining technologies of Gasar porous Cu/steel. In this paper, Gasar porous Cu was joined to G4335V steel using Ag-28Cu-0.75Ni. The microstructure, shear strength, and fracture behavior of the Gasar porous Cu/G4335V steel joint were investigated. The results show that a clear interface of the brazed joint and no brazing defects were found. The joint microstructure mainly comprises α -Cu (ss.), β -Ag (ss.), and Ag-Cu eutectic phase. As the pore diameter of Gasar porous Cu increased, the joining area of the Gasar porous Cu/G4335V steel joint became larger, thereby improving the shear strength of the joint. For the same pore diameter, the shear strength of the mode 1 joint (The load direction and the pore direction are parallel to each other. The pore direction refers to the growth direction of the pore.) was higher than that of the mode 2 joint (The pore direction and the load direction are perpendicular to each other). The fracture analysis indicated that the joint crack was initiated in α -Cu (ss.) and propagated along the banded α -Cu (ss.). The joint fracture was a mixed fracture mechanism that combined ductile-brittle fractures.

Z-curve’s encoding and decoding algorithms are primely important in many Z-curve-based applications. The bit interleaving algorithm is the current state-of-the-art algorithm for encoding and decoding Z-curve. Although simple, its efficiency is hindered by the step-by-step coordinate shifting and bitwise operations. To tackle this problem, we first propose the efficient encoding algorithm LTFe and the corresponding decoding algorithm LTFd, which adopt two optimization methods to boost the algorithm’s efficiency: 1) we design efficient lookup tables (LT) that convert encoding and decoding operations into table-lookup operations; 2) we design a bit detection mechanism that skips partial order of a coordinate or a Z-value with consecutive 0s in the front, avoiding unnecessary iterative computations. We propose order-parallel and point-parallel OpenMP-based algorithms to exploit the modern multi-core hardware. Experimental results on discrete, skewed, and real datasets indicate that our point-parallel algorithms can be up to 12.6× faster than the existing algorithms.

Nanocatalysts are frequently connected to magnetic nanoparticles. These composites are easy to be retrieved from the reaction system under a magnetic field because of their magnetic properties. Magnetic separation is particularly promising in industry since it can solve many issues present in filtration, centrifugation, or gravitation separation. Herein, a facile method to prepare bismuth and Fe 3 O 4 nanoparticles loaded on reduced graphene oxide magnetic hybrids (Bi-Fe 3 O 4 @RGO) using soluble starch as a dispersant is demonstrated. The magnetic Fe 3 O 4 nanoparticles were synthesized by the co-precipitation of Fe 2+ and Fe 3+ ions, and Bi nanoparticles were fabricated by the redox reactions between sodium borohydride and ammonium bismuth citrate in the presence of soluble starch. Transmission electron microscopy images demonstrate that the average diameter of the Fe 3 O 4 nanoparticles is about 5 nm and the diameters of Bi nanoparticles range from 10 to 20 nm. The magnetic Bi-Fe 3 O 4 @RGO hybrids exhibit high catalytic activity in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH 4 with a first-order rate constant (K) of 0.00808 s −1 and is magnetically recyclable for at least five cycles. This strategy provides an efficient and recyclable catalyst for the use in environmental protection applications.

Nanocatalysts are frequently connected to magnetic nanoparticles. These composites are easy to be retrieved from the reaction system under a magnetic field because of their magnetic properties. Magnetic separation is particularly promising in industry since it can solve many issues present in filtration, centrifugation, or gravitation separation. Herein, a facile method to prepare bismuth and Fe sub(3)O sub(4) nanoparticles loaded on reduced graphene oxide magnetic hybrids (Bi-Fe sub(3)O sub(4)GO) using soluble starch as a dispersant is demonstrated. The magnetic Fe sub(3)O sub(4) nanoparticles were synthesized by the co-precipitation of Fe super(2+) and Fe super(3+) ions, and Bi nanoparticles were fabricated by the redox reactions between sodium borohydride and ammonium bismuth citrate in the presence of soluble starch. Transmission electron microscopy images demonstrate that the average diameter of the Fe sub(3)O sub(4) nanoparticles is about 5 nm and the diameters of Bi nanoparticles range from 10 to 20 nm. The magnetic Bi-Fe sub(3)O sub(4)GO hybrids exhibit high catalytic activity in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH sub(4) with a first-order rate constant (K) of 0.00808 s super(-1) and is magnetically recyclable for at least five cycles. This strategy provides an efficient and recyclable catalyst for the use in environmental protection applications.

Nanocatalysts are frequently connected to magnetic nanoparticles. These composites are easy to be retrieved from the reaction system under a magnetic field because of their magnetic properties. Magnetic separation is particularly promising in industry since it can solve many issues present in filtration, centrifugation, or gravitation separation. Herein, a facile method to prepare bismuth and Fe^sub 3^O^sub 4^ nanoparticles loaded on reduced graphene oxide magnetic hybrids (Bi-Fe^sub 3^O^sub 4^@RGO) using soluble starch as a dispersant is demonstrated. The magnetic Fe^sub 3^O^sub 4^ nanoparticles were synthesized by the co-precipitation of Fe^sup 2+^ and Fe^sup 3+^ ions, and Bi nanoparticles were fabricated by the redox reactions between sodium borohydride and ammonium bismuth citrate in the presence of soluble starch. Transmission electron microscopy images demonstrate that the average diameter of the Fe^sub 3^O^sub 4^ nanoparticles is about 5 nm and the diameters of Bi nanoparticles range from 10 to 20 nm. The magnetic Bi-Fe^sub 3^O^sub 4^@RGO hybrids exhibit high catalytic activity in the reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) by NaBH^sub 4^ with a first-order rate constant (K) of 0.00808 s^sup -1^ and is magnetically recyclable for at least five cycles. This strategy provides an efficient and recyclable catalyst for the use in environmental protection applications.

Unveiling the correlations among molecular structures, morphological characteristics, macroscopic properties and device performances is crucial for developing better photovoltaic materials and achieving higher efficiencies. To achieve this goal, a comprehensive study is performed based on four state-of-the-art non-fullerene acceptors (NFAs), which allows to systematically examine the above-mentioned correlations from different scales. It’s found that extending conjugation of NFA shows positive effects on charge separation promotion and non-radiative loss reduction, while asymmetric terminals can maximize benefits from both terminals. Another molecular optimization is from alkyl chain tuning. The shortened alkyl side chain results in strengthened terminal packing and decreased π-π distance, which contribute high carrier mobility and finally the high charge collection efficiency. With the most-acquired benefits from molecular structure and macroscopic factors, PM6:BTP-S9-based organic photovoltaics (OPVs) exhibit the optimal efficiency of 17.56% (certified: 17.4%) with a high fill factor of 78.44%, representing the best among asymmetric acceptor based OPVs. This work provides insight into the structure-performance relationships, and paves the way toward high-performance OPVs via molecular design. Understanding correlations between molecular structures and macroscopic properties is critical in realising highly efficient organic photovoltaics. Here, the authors conduct a comprehensive study based on four non-fullerene acceptors revealing how the extended conjugation, asymmetric terminals and alkyl chain length can affect device performance.

The Dunhuang Mogao Grottoes are a UNESCO World Heritage Site. The largest known Buddhist grotto complex in the world with the longest continuous construction period and the richest available content, the grottoes are also an important witness to the exchanges that occurred between ancient China and other Silk Road civilizations. This paper discusses problems caused by environmental changes and the challenges involved with the long-term preservation of digital resources in the digital protection of the cultural heritage of the Dunhuang Mogao Grottoes. It also discusses international cooperation in digital cultural heritage protection and the results achieved from this cooperation, which have made an important contribution to the field of digital protection of items of world cultural heritage.

3-Hydroxymethylglutaryl-CoA synthase 2 (HMGCS2) is the rate-limiting enzyme for ketone body synthesis, and most current studies focus on mitochondrial maturation and metabolic reprogramming. The role of HMGCS2 was evaluated in a pan-cancer multi-database using R language, and HMGCS2 was lowly expressed or not differentially expressed in all tumor tissues compared with normal tissues. Correlation analysis of clinical case characteristics, genomic heterogeneity, tumor stemness, and overall survival revealed that HMGCS2 is closely related to clear cell renal cell carcinoma (KIRC). Single-cell sequencing data from normal human kidneys revealed that HMGCS2 is specifically expressed in proximal tubular cells of normal adults. In addition, HMGCS2 is associated with tumor immune infiltration and microenvironment, and KIRC patients with low expression of HMGCS2 have worse prognosis. Finally, the results of cell counting kit 8 assays, colony formation assays, flow cytometry, and Western blot analysis suggested that upregulation of HMGCS2 increased the expression of key tumor suppressor proteins, inhibited the proliferation of clear cell renal cell carcinoma cells and promoted cell apoptosis. In conclusion, HMGCS2 is abnormally expressed in pan-cancer, may play an important role in anti-tumor immunity, and is expected to be a potential tumor prognostic marker, especially in clear cell renal cell carcinoma.

This work proposes and experimentally demonstrates a high-performance polarization space parity-time (PT) symmetric fiber ring laser to achieve a low-noise, narrow-linewidth, and highly stable single-longitudinal-mode output. The gain/loss and coupling coefficients are regulated by adjusting a polarization controller (PC) and the pumping current of an erbium-doped fiber amplifier (EDFA) within the ring cavity. The results show that the single longitudinal mode oscillation of the laser can be implemented by PT symmetry breaking. The frequency noise spectral density and the linewidth characteristics of the laser are evaluated by the short-delay self-heterodyne method. The results reveal that excellent low-frequency noise (181 Hz2/Hz at a 10 kHz offset frequency) and narrow fundamental linewidth (68 Hz) can be achieved. Additionally, the laser exhibits outstanding stability with only 0.64 pm wavelength drift over 30 min. By tuning an optical tunable filter (OTF), the wavelength tunable range of the laser can cover the entire C-band. Furthermore, the impacts of different fiber length on the frequency noise spectral density and the filter bandwidth on stability are analyzed, offering guidance for component selection in such laser systems.