22 research outputs found
New advances in catalysts for polystyrene hydrogenation
Polystyrene is one of the most widely used plastics, and could be catalytic hydrogenated to polycyclohexylethylene with improved physical properties. The research progress in the efficiency palladium catalyst for polystyrene hydrogenation was illustrated and reviewed, further development was discussed
New advances in catalysts for C9 petroleum resin hydrogenation
C9 petroleum resin is a thermoplastic polymer produced by polymerization of C9 fraction obtaining from the steam cracking unit, and could be catalytic hydrogenated to remove the ethylenic C=C bond, aromatic ring with improved physical properties. The research progress in the efficiency supported nickel or/and palladium catalysts for C9 petroleum resin hydrogenation was illustrated and reviewed, further development was discussed
Photometric calibration of the Stellar Abundance and Galactic Evolution Survey (SAGES): Nanshan One-meter Wide-field Telescope g, r, and i band imaging data
In this paper, a total of approximately 2.6 million dwarfs were constructed
as standard stars, with an accuracy of about 0.01-0.02 mag for each band, by
combining spectroscopic data from the Large Sky Area Multi-Object Fiber
Spectroscopic Telescope Data Release 7, photometric data from the corrected
Gaia Early Data Release 3, and photometric metallicities. Using the
spectroscopy based stellar color regression method (SCR method) and the
photometric-based SCR method (SCR' method), we performed the relative
calibration of the Nanshan One-meter Wide-field Telescope imaging data. Based
on the corrected Pan-STARRS DR1 photometry, the absolute calibration was also
performed. In the photometric calibration process, we analyzed the dependence
of the calibration zero points on different images (observation time),
different gates of the CCD detector, and different CCD positions. We found that
the stellar flat and the relative gain between different gates depend on time.
The amplitude of gain variation in three channels is approximately 0.5%-0.7%
relative to the other channel, with a maximum value of 4%. In addition,
significant spatial variations of the stellar flat fitting residual are found
and corrected. Using repeated sources in the adjacent images, we checked and
discovered internal consistency of about 1-2 mmag in all the filters. Using the
PS1 magnitudes synthesized by Gaia DR3 BP/RP spectra by the synthetic
photometry method, we found that the photometric calibration uniformity is
about 1-2 mmag for all the bands, at a spatial resolution of 1.3 degree. A
detailed comparison between the spectroscopy-based SCR and photometric-based
SCR method magnitude offsets was performed, and we achieved an internal
consistency precision of about 2 mmag or better with resolutions of 1.3 degree
for all the filters. Which is mainly from the position-dependent errors of the
E(B-V) used in SCR' method.Comment: 15 pages in Chinese language, 8 figures, Chinese Science Bulletin
accepted and published online
(https://www.sciengine.com/CSB/doi/10.1360/TB-2023-0052), see main results in
Figures 6, 7 and
Multiple Positional Self-Attention Network for Text Classification
Self-attention mechanisms have recently caused many concerns on Natural Language Processing (NLP) tasks. Relative positional information is important to self-attention mechanisms. We propose Faraway Mask focusing on the (2m + 1)-gram words and Scaled-Distance Mask putting the logarithmic distance punishment to avoid and weaken the self-attention of distant words respectively. To exploit different masks, we present Positional Self-Attention Layer for generating different Masked-Self-Attentions and a following Position-Fusion Layer in which fused positional information multiplies the Masked-Self-Attentions for generating sentence embeddings. To evaluate our sentence embeddings approach Multiple Positional Self-Attention Network (MPSAN), we perform the comparison experiments on sentiment analysis, semantic relatedness and sentence classification tasks. The result shows that our MPSAN outperforms state-of-the-art methods on five datasets and the test accuracy is improved by 0.81%, 0.6% on SST, CR datasets, respectively. In addition, we reduce training parameters and improve the time efficiency of MPSAN by lowering the dimension number of self-attention and simplifying fusion mechanism
Construction and validation of an 18F-FDG-PET/CT-based prognostic model to predict progression-free survival in newly diagnosed multiple myeloma patients
ABSTRACTObjective: To investigate the relationship between 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) related parameters and the prognosis of multiple myeloma and to establish and validate a prediction model regarding the progression-free survival (PFS) of multiple myeloma.Methods: A retrospective analysis of 126 newly diagnosed multiple myeloma patients who attended Nanjing Drum Tower Hospital from 2014–2021. All patients underwent PET/CT before treatment and were divided into a training cohort (n = 75) and a validation cohort (n = 51). Multivariate Cox proportional hazard regression analysis incorporated PET/CT-related parameters and clinical indicators. A nomogram was established to individually predict PFS in MM patients. The model was evaluated by calculating the C-index and calibration curve.Results: Here, 4.2 was used as the cut-off value of SUVmax to divide patients into high and low groups. PFS significantly differed between patients in the high-SUVmax group and low-SUVmax group, and SUVmax was an independent predictor of PFS in newly diagnosed multiple myeloma (NDMM) patients. Univariate and multivariate cox regression analysis suggested that lactate dehydrogenase (LDH), bone marrow plasma cell (BMPC), and SUVmax affected PFS. These factors were incorporated to construct a nomogram model for predicting PFS at 1 and 2 years in NDMM patients. The C-index and calibration curves of the nomogram exhibited good accuracy and consistency, and the DCA curves suggested that the model had good clinical utility.Conclusion: The PET/CT parameter SUVmax is closely related to the prognosis of myeloma patients. The nomogram constructed in this study based on PET/CT-related parameters and clinical indicators individually predicts the PFS rate of NDMM patients and enables further risk stratification of NDMM patients
Improving Emotional Expression and Cohesion in Image-Based Playlist Description and Music Topics: A Continuous Parameterization Approach
Text generation in image-based platforms, particularly for music-related
content, requires precise control over text styles and the incorporation of
emotional expression. However, existing approaches often need help to control
the proportion of external factors in generated text and rely on discrete
inputs, lacking continuous control conditions for desired text generation. This
study proposes Continuous Parameterization for Controlled Text Generation
(CPCTG) to overcome these limitations. Our approach leverages a Language Model
(LM) as a style learner, integrating Semantic Cohesion (SC) and Emotional
Expression Proportion (EEP) considerations. By enhancing the reward method and
manipulating the CPCTG level, our experiments on playlist description and music
topic generation tasks demonstrate significant improvements in ROUGE scores,
indicating enhanced relevance and coherence in the generated text.Comment: Becasue I find some important fourmulation need to chang
A Star-based Method for the Precise Flux Calibration of the Chinese Space Station Telescope Slitless Spectroscopic Survey
The upcoming Chinese Space Station Telescope (CSST) slitless spectroscopic survey poses a challenge of flux calibration, which requires a large number of flux-standard stars. In this work, we design an uncertainty-aware residual attention network, the UaRA-net, to derive the CSST spectral energy distributions (SEDs) with a resolution of R = 200 over the wavelength range of 2500–10000 Å using LAMOST normalized spectra with a resolution of R = 2000 over the wavelength range of 4000–7000 Å. With the special structure and training strategy, the proposed model provides accurate predictions not only of SEDs, but also of their corresponding errors. The precision of the predicted SEDs depends on the effective temperature ( T _eff ), wavelength, and the LAMOST spectral signal-to-noise ratios (S/Ns), particularly in the GU band. For stars with T _eff = 6000 K, the typical SED precisions in the GU band are 4.2%, 2.1%, and 1.5% at S/N values of 20, 40, and 80, respectively. As T _eff increases to 8000 K, the precision increases to 1.2%, 0.6%, and 0.5%, respectively. The precision is higher at redder wavelengths. In the GI band, the typical SED precisions for stars with T _eff = 6000 K increase to 0.3%, 0.1%, and 0.1% at S/N values of 20, 40, and 80, respectively. We further verify our model using empirical MILES spectra and find a good performance. The proposed method will open up new possibilities for the optimal use of slitless spectra of the CSST and other surveys