ALIP: Adaptive Language-Image Pre-training with Synthetic Caption

Contrastive Language-Image Pre-training (CLIP) has significantly boosted the performance of various vision-language tasks by scaling up the dataset with image-text pairs collected from the web. However, the presence of intrinsic noise and unmatched image-text pairs in web data can potentially affect the performance of representation learning. To address this issue, we first utilize the OFA model to generate synthetic captions that focus on the image content. The generated captions contain complementary information that is beneficial for pre-training. Then, we propose an Adaptive Language-Image Pre-training (ALIP), a bi-path model that integrates supervision from both raw text and synthetic caption. As the core components of ALIP, the Language Consistency Gate (LCG) and Description Consistency Gate (DCG) dynamically adjust the weights of samples and image-text/caption pairs during the training process. Meanwhile, the adaptive contrastive loss can effectively reduce the impact of noise data and enhances the efficiency of pre-training data. We validate ALIP with experiments on different scales of models and pre-training datasets. Experiments results show that ALIP achieves state-of-the-art performance on multiple downstream tasks including zero-shot image-text retrieval and linear probe. To facilitate future research, the code and pre-trained models are released at https://github.com/deepglint/ALIP.Comment: 15pages, 10figures, ICCV202

Chitinase Genes in Lake Sediments of Ardley Island, Antarctica

A sediment core spanning approximately 1,600 years was collected from a lake on Ardley Island, Antarctica. The sediment core had been greatly influenced by penguin guano. Using molecular methods, the chitinolytic bacterial community along the sediment core was studied over its entire length. Primers targeting conserved sequences of the catalytic domains of family 18 subgroup A chitinases detected group A chitinases from a wide taxonomic range of bacteria. Using quantitative competitive PCR (QC-PCR), chitinase gene copies in each 1-cm section of the whole sediment column were quantified. QC-PCR determination of the chitinase gene copies indicated significant correlation with phosphorus and total organic carbon concentration, suggesting a historical connection between chitinase gene copies and the amount of penguin guano input into the lake sediment. Most of the chitinase genes cloned from the historic sediment core were novel. Analysis of the chitinase gene diversity in selected sediment layers and in the fresh penguin deposits indicated frequent shifts in the chitinolytic bacterial community over time. Sequence analysis of the 16S rRNA genes of chitinolytic bacteria isolated from the lake sediment revealed that the isolates belonged to Janthinobacterium species, Stenotrophomonas species of γ-Proteobacteria, Cytophaga species of the Cytophaga-Flexibacter-Bacteroides group, and Streptomyces and Norcardiopsis species of Actinobacteria. Chitinase gene fragments were cloned and sequenced from these cultivated chitinolytic bacteria. The phylogeny of the chitinase genes obtained from the isolates did not correspond well to that of the isolates, suggesting acquisition via horizontal gene transfer

Microstructures and Mechanical Properties of a Nanostructured Al-Zn-Mg-Cu-Zr-Sc Alloy under Natural Aging

Nanocrystalline (NC) structure can lead to the considerable strengthening of metals and alloys. Obtaining appropriate comprehensive mechanical properties is always the goal of metallic materials. Here, a nanostructured Al-Zn-Mg-Cu-Zr-Sc alloy was successfully processed by high-pressure torsion (HPT) followed by natural aging. The microstructures and mechanical properties of the naturally aged HPT alloy were analyzed. The results show that the naturally aged HPT alloy primarily consists of nanoscale grains (~98.8 nm), nano-sized precipitates (20–28 nm in size), and dislocations (1.16 × 1015 m−2), and exhibits a high tensile strength of 851 ± 6 MPa and appropriate elongation of 6.8 ± 0.2%. In addition, the multiple strengthening modes that were activated and contributed to the yield strength of the alloy were evaluated according to grain refinement strengthening, precipitation strengthening, and dislocation strengthening, and it is shown that grain refinement strengthening and precipitation strengthening are the main strengthening mechanisms. The results of this study provide an effective pathway for achieving the optimal strength–ductility match of materials and guiding the subsequent annealing treatment

Investigation of Microstructures and Mechanical Properties of Ultra-High Strength Al-Zn-Mg-Cu Alloy Prepared by Rapid Solidification and Hot Extrusion

Al-Zn-Mg-Cu aluminum alloys have the advantages of high specific strength, easy processing, and high toughness, showing great potential application in the aerospace field. However, ultra-high strength aluminum alloys usually contain coarse microstructures, micro-segregation, and casting defects that seriously deteriorate mechanical properties. Here, we report a high-strength aluminum alloy (Al-10.5Zn-2.0Mg-1.2Cu-0.12Zr-0.1Er) prepared by rapid solidification and hot extrusion to explore the microstructure modification of the alloy based on this strategy. The results show that: rapid-solidification technology can significantly refine alloy grains, alloy ribbons were composed of α (Al) equiaxed fine grains, and the average grain size was less than 6 μm. After extrusion, the alloy had partially recrystallized, existing coarse second-phase (T-phase) and needle-shaped precipitates were MgZn2 (η-phase), and the tensile strength and elongation of the extruded bar were 466.4 MPa and 12.9%, respectively. After T6 heat treatment, the tensile strength of the alloy reached 635.8 MPa, while elongation decreased to 10.5%. According to microstructure analysis and considering the contributions of grain boundary, dislocation, and precipitation-strengthening to the improvement of the mechanical properties, it was found that precipitation-strengthening is the main strengthening mechanism. Our research shows that rapid-solidification and hot-extrusion technology have great potential for improving the microstructures and mechanical properties of aluminum alloys

Intraoperative hypothermia and its clinical outcomes in patients undergoing general anesthesia: National study in China.

Inadvertent intraoperative hypothermia (core temperature 2 h) (OR = 2.60, 95% CI 2.09-3.24).The incidence of intraoperative hypothermia in China is high, and the rate of active warming of patients during operation is low. Hypothermia is associated with more postoperative shivering, increased ICU admissions, and longer postoperative hospital days

Incidence of Inadvertent Intraoperative Hypothermia and Its Risk Factors in Patients Undergoing General Anesthesia in Beijing: A Prospective Regional Survey.

Inadvertent intraoperative hypothermia (core temperature 2 h (OR = 3.44, 95% CI 1.90-6.22,), and intravenous un-warmed fluid (OR = 2.45, 95% CI 1.45-4.12) significantly increased the risk of hypothermia.The incidence of inadvertent intraoperative hypothermia in Beijing is high, and the rate of active warming of patients during operation is low. Concern for the development of intraoperative hypothermia should be especially high in patients undergoing major operations, requiring long periods of anesthesia, and receiving un-warmed intravenous fluids