64 research outputs found
Social4Rec: Distilling User Preference from Social Graph for Video Recommendation in Tencent
Despite recommender systems play a key role in network content platforms,
mining the user's interests is still a significant challenge. Existing works
predict the user interest by utilizing user behaviors, i.e., clicks, views,
etc., but current solutions are ineffective when users perform unsettled
activities. The latter ones involve new users, which have few activities of any
kind, and sparse users who have low-frequency behaviors. We uniformly describe
both these user-types as "cold users", which are very common but often
neglected in network content platforms. To address this issue, we enhance the
representation of the user interest by combining his social interest, e.g.,
friendship, following bloggers, interest groups, etc., with the activity
behaviors. Thus, in this work, we present a novel algorithm entitled SocialNet,
which adopts a two-stage method to progressively extract the coarse-grained and
fine-grained social interest. Our technique then concatenates SocialNet's
output with the original user representation to get the final user
representation that combines behavior interests and social interests. Offline
experiments on Tencent video's recommender system demonstrate the superiority
over the baseline behavior-based model. The online experiment also shows a
significant performance improvement in clicks and view time in the real-world
recommendation system. The source code is available at
https://github.com/Social4Rec/SocialNet
Evolution of iron-rich intermetallics and its effect on the mechanical properties of AlāCuāMnāFeāSi alloys after thermal exposure and high-temperature tensile testing
Si addition is commonly used to modify the iron-rich intermetallics in AlāCuāMnāFe alloys, which is beneficial to increasing the use of recycled aluminum. Most of the available research has focused on the effect of Si content on the room-temperature mechanical properties of AlāCuāMnāFe alloys. To expand the application of AlāCuāMnāFeāSi alloys as light heat-resistant structural components in the automotive and aerospace industries, it is of great importance to investigate the evolution of iron-rich intermetallics and its effect on the fracture behavior of AlāCuāMnāFeāSi alloys after thermal exposure and high-temperature tensile testing. In this work, the evolution of iron-rich intermetallics and the high-temperature mechanical properties of heat-treated Al-6.5Cu-0.6Mn-0.5Fe alloys with different Si contents after thermal exposure and high-temperature tensile testing were assessed by tensile tests, image analysis, scanning electron microscopy, X-Ray diffraction, transmission electron microscopy, and atomic probe tomography. The results indicate that the Al-6.5Cu-0.6Mn-0.5Fe alloys with 0.1Si and 0.5Si additions have excellent and stable high-temperature mechanical properties after long thermal exposure, which are better than those of most heat-resistant Al alloys. The high performance of the high-temperature mechanical properties is attributed to the high heat resistance of secondary intermetallics and precipitated particles. The addition of Si is detrimental to the strength of Al-6.5Cu-0.6Mn-0.5Fe alloys after long thermal exposure. This can be attributed to the solid-state phase transformation of iron-rich intermetallics from Ī±-Fe to Ī²-Fe, which results in the increase of needle-like Fe-rich phases and Si particles, the agglomeration of secondary intermetallics, and the consumption of AlCu phases
Preparative Separation and Identification of the Flavonoid Phlorhizin from the Crude Extract of Lithocarpus Polystachyus Rehd
The flavonoid phlorhizin is abundant in the leaves of Sweet Tea(ST, Lithocarpus Polystachyus Rehd). Phlorhizinwas preparatively separated and purified from a crude ST extract containing 40% total flavonoids by static adsorption and dynamic desorption on ADS-7 macroporous resin and neutral alumina column chromatography. Only water and ethanol were used as solvents and eluants throughout the whole separation and purification process. Using a phlorhizin standard as the reference compound, the target compound separated from the crude ST extracts was analyzed by thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and electrosprayionization mass spectrometry (EIS-MS) and identified as 99.87% pure (by HPLC-UV) phlorhizin. The results showed that 10g of the targetcompound could be obtained from 40g of the crude extracts in a single operation, indicating a 40% recovery. Therefore, this represents an efficientand environmentally-friendly technology for separating and purifying phlorhizinfrom ST leaves
Multiferroic Magnon Spin-Torque Based Reconfigurable Logic-In-Memory
Magnons, bosonic quasiparticles carrying angular momentum, can flow through
insulators for information transmission with minimal power dissipation.
However, it remains challenging to develop a magnon-based logic due to the lack
of efficient electrical manipulation of magnon transport. Here we present a
magnon logic-in-memory device in a spin-source/multiferroic/ferromagnet
structure, where multiferroic magnon modes can be electrically excited and
controlled. In this device, magnon information is encoded to ferromagnetic bits
by the magnon-mediated spin torque. We show that the ferroelectric polarization
can electrically modulate the magnon spin-torque by controlling the
non-collinear antiferromagnetic structure in multiferroic bismuth ferrite thin
films with coupled antiferromagnetic and ferroelectric orders. By manipulating
the two coupled non-volatile state variables (ferroelectric polarization and
magnetization), we further demonstrate reconfigurable logic-in-memory
operations in a single device. Our findings highlight the potential of
multiferroics for controlling magnon information transport and offer a pathway
towards room-temperature voltage-controlled, low-power, scalable magnonics for
in-memory computing
Genome and pan-genome assembly of asparagus bean (Vigna unguiculata ssp. sesquipedialis) reveal the genetic basis of cold adaptation
Asparagus bean (Vigna unguiculata ssp. sesquipedialis) is an important cowpea subspecies. We assembled the genomes of Ningjiang 3 (NJ, 550.31 Mb) and Dubai bean (DB, 564.12 Mb) for comparative genomics analysis. The whole-genome duplication events of DB and NJ occurred at 64.55 and 64.81 Mya, respectively, while the divergence between soybean and Vigna occurred in the Paleogene period. NJ genes underwent positive selection and amplification in response to temperature and abiotic stress. In species-specific gene families, NJ is mainly enriched in response to abiotic stress, while DB is primarily enriched in respiration and photosynthesis. We established the pan-genomes of four accessions (NJ, DB, IT97K-499-35 and Xiabao II) and identified 20,336 (70.5%) core genes present in all the accessions, 6,507 (55.56%) variable genes in two individuals, and 2,004 (6.95%) unique genes. The final pan genome is 616.35 Mb, and the core genome is 399.78 Mb. The variable genes are manifested mainly in stress response functions, ABC transporters, seed storage, and dormancy control. In the pan-genome sequence variation analysis, genes affected by presence/absence variants were enriched in biological processes associated with defense responses, immune system processes, signal transduction, and agronomic traits. The results of the present study provide genetic data that could facilitate efficient asparagus bean genetic improvement, especially in producing cold-adapted asparagus bean
Microstructure and mechanical property of Al3Ti/Al-Mg-Mn composite in-situ synthesized at low temperature under vibration coupling fields
Al3Ti/Al-Mg-Mn composites were successfully prepared by in-situ reaction method under ultrasonic and mechanical vibration fields. The effects of reaction temperature and coupling time on microstructure evolution and mechanical properties at room temperature were studied. The results show that the coupling ultrasonic and mechanical vibration fields can promote the in-situ reaction, dispersal and refinement of Al3Ti particles. Compared with Al-Mg-Mn matrix, the room temperature tensile strength, yield strength and elongation of Al3Ti/Al-Mg-Mn composite treated under coupling fields at 760 ā for 10 min are 222, 119 MPa and 8.1%, respectively. The tensile strength and yield strength values increase by 17.5% and 25.2%, and the elongation value decreases from 8.7% to 8.1%. The improvement of mechanical properties is mainly attributed to grain refinement strengthening, load transfer strengthening and thermal mismatch strengthening caused by Al3Ti reinforced phase, among which the thermal mismatch strengthening plays a great role in the improvement of the strength of composites
The role and mechanism of JAK2/STAT3 signaling pathway regulated by m6A methyltransferase KIAA1429 in osteosarcoma
Osteosarcoma (OS) is the most malignant bone tumor which mainly occurs in childhood or adolescence. The previous studies indicated that OS is difficult to treat. KIAA1429 is one of the components of m6A complex that regulating the process of m6A modification, which plays a crucial role in tumorigenesis. But the mechanism of KIAA1429 regulating OS cell identity was not entirely clear, which needs further investigate. RT-qPCR and western blotting were applied to determine KIAA1429 expression station in OS cells and tissues. To further detect the KIAA1429 function in OS cells, the ability of proliferation, migration and invasion were analyzed by Edu, wound-healing and transwell experiments respectively. Besides, RNA sequencing was also used to further find the downstream of KIAA1429 regulation and small molecule inhibitor was added to explore the specific role of signaling pathway. Our data found that KIAA1429 is up-regulated in human OS cell lines compared to the human osteoblast cells. Meanwhile, the deletion of KIAA1429 significantly decreased cell proliferation, migration, and invasion. Interestingly, the JAK2/STAT3 signal pathway was involved in KIAA1429 regulation on OS cell characters. The KIAA1429 eliminated OS cells exhibited a decreased activity of JAK2/STAT3 signal. And the addition of JAK2/STAT3 stimulator (colivelin) could distinctly rescue the decreased OS cellsā proliferation, migration, and invasion upon KIAA1429 knockdown. In summary, these data demonstrated that KIAA1429/JAK2/STAT3 axis may a new target for OS therapy
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