A Mini Review on Controlling the Size of Ag Nanoclusters by Changing the Stabilizer to Ag Ratio and by Changing DNA Sequence

Ag nanoclusters have received considerable attention in the past decade due to their distinguished photo-physical properties, which lead to very wide potential applications for biosensing and imaging. To this point, synthesis of well-defined Ag nanoclusters for practical applications is a key issue, in particular, controlling the size (or specific number of silver atoms) of Ag nanoclusters. Herein, we briefly discuss the effect of ratio of reactants, in terms of specific functional groups, on the size of Ag nanoclusters. Also, taking DNA as an example of biopolymer, we review how the DNA sequence can affect the specific number of Ag atoms in Ag nanoclusters. These conducted principles should provide significant guidance for preparation of Ag nanoclusters of precise size

Research on the Integration and Development Path of College Students’ Labor Education and College Student Associations

Student organizations in colleges and universities are important carriers for implementing the fundamental task of cultivating morality and cultivating people and promoting quality education, and college and university organizations have a good foundation for the masses of students and play an important role in educating people in ideological and political education. Therefore, it is necessary to combine the educational platform of college student clubs to explore and analyze the reality of labor education integrated into college associations, clarify the community groups in college clubs that can effectively integrate labor education, and drive the implementation of labor education for college students from multiple perspectives

Research and Practice of Innovation and Entrepreneurship Education in Petroleum Colleges Based on OBE Concept

Deepening the research on the topic of “Research on the current situation of innovation and entrepreneurship practice among college students and analysis of response strategies” is of great value to the healthy operation and coordinated development of college students, higher education institutions, the whole society and the country, and plays a positive role in creating the excellent trend of mass entrepreneurship and innovation in the whole society. It plays a great role in promoting the optimization and adjustment of the economic and industrial structure, the rationalization of market resources, the increase of employment opportunities, the improvement of employment quality and the improvement of people’s living standards. At the same time, combined with the support of sociology and related innovation and entrepreneurship theories, the study from a new perspective provides a theoretical basis and practical guidance for university students to participate in innovation and entrepreneurship activities, and provides certain reference value for further in-depth study of social innovation and entrepreneurship development work

Insights into the behavior of polyphosphate lubricant in hot rolling of mild steel

Hot rolling with a large reduction is usually performed to produce the fine-grained strips, which leads to a severe wear of work roll and affect substantially the strip quality. As a result, lubricants are usually introduced to reduce these problems, with inorganic polyphosphate glass polymer showing the most promising prospective. This study aims to provide a new insight into the lubrication film at roll/strip interface in hot rolling. A series of lubricated hot rolling tests were performed by a 40wt% sodium metaphosphate aqueous solution under 20-60% reduction, at 950-1150 °C and 0.5 m/s. Thermal behaviors of sodium polyphosphate and the rolled strip samples were analyzed by high temperature laser confocal microscope, Secondary Electron Microscope (SEM) and Energy Dispersive X-ray Spectroscopy (EDX), Focused Ion Beam (FIB) and Transmission Electron Microscopy (TEM) etc. The results reveal that the lubrication film thickness at the roll/strip interface varied from 0.6 to 4.3 µm with the rolling load being reduced up to 6.1% and friction coefficient up to 16%. FIB and TEM analysis reveal that the polyphosphate film has an amorphous structure which was penetrated through by the oxide scale. It had been found that the polyphosphate lubrication performance was improved at a higher reduction and temperature, which contributes to the friction and oxidation-reduction

Seismic Data Interpolation based on Denoising Diffusion Implicit Models with Resampling

The incompleteness of the seismic data caused by missing traces along the spatial extension is a common issue in seismic acquisition due to the existence of obstacles and economic constraints, which severely impairs the imaging quality of subsurface geological structures. Recently, deep learning-based seismic interpolation methods have attained promising progress, while achieving stable training of generative adversarial networks is not easy, and performance degradation is usually notable if the missing patterns in the testing and training do not match. In this paper, we propose a novel seismic denoising diffusion implicit model with resampling. The model training is established on the denoising diffusion probabilistic model, where U-Net is equipped with the multi-head self-attention to match the noise in each step. The cosine noise schedule, serving as the global noise configuration, promotes the high utilization of known trace information by accelerating the passage of the excessive noise stages. The model inference utilizes the denoising diffusion implicit model, conditioning on the known traces, to enable high-quality interpolation with fewer diffusion steps. To enhance the coherency between the known traces and the missing traces within each reverse step, the inference process integrates a resampling strategy to achieve an information recap on the former interpolated traces. Extensive experiments conducted on synthetic and field seismic data validate the superiority of our model and its robustness on various missing patterns. In addition, uncertainty quantification and ablation studies are also investigated.Comment: 14 pages, 13 figure

Mapping knowledge of the stem cell in traumatic brain injury: a bibliometric and visualized analysis

BackgroundTraumatic brain injury (TBI) is a brain function injury caused by external mechanical injury. Primary and secondary injuries cause neurological deficits that mature brain tissue cannot repair itself. Stem cells can self-renewal and differentiate, the research of stem cells in the pathogenesis and treatment of TBI has made significant progress in recent years. However, numerous articles must be summarized to analyze hot spots and predict trends. This study aims to provide a panorama of knowledge and research hotspots through bibliometrics.MethodWe searched in the Web of Science Core Collection (WoSCC) database to identify articles pertaining to TBI and stem cells published between 2000 and 2022. Visualization knowledge maps, including co-authorship, co-citation, and co-occurrence analysis were generated by VOSviewer, CiteSpace, and the R package “bibliometrix.”ResultsWe retrieved a total of 459 articles from 45 countries. The United States and China contributed the majority of publications. The number of publications related to TBI and stem cells is increasing yearly. Tianjin Medical University was the most prolific institution, and Professor Charles S. Cox, Jr. from the University of Texas Health Science Center at Houston was the most influential author. The Journal of Neurotrauma has published the most research articles on TBI and stem cells. Based on the burst references, “immunomodulation,” “TBI,” and “cellular therapy” have been regarded as research hotspots in the field. The keywords co-occurrence analysis revealed that “exosomes,” “neuroinflammation,” and “microglia” were essential research directions in the future.ConclusionResearch on TBI and stem cells has shown a rapid growth trend in recent years. Existing studies mainly focus on the activation mechanism of endogenous neural stem cells and how to make exogenous stem cell therapy more effective. The combination with bioengineering technology is the trend in this field. Topics related to exosomes and immune regulation may be the future focus of TBI and stem cell research

Conversion of waste eggshells to mesoporous hydroxyapatite nanoparticles with high surface area

The objective of this work was to convert waste eggshells to mesoporous hydroxyapatte(HAp) with high surface area by using a simple and inexpensive protocol without complexes. The eggshells were initially dissolved in concentrated nitric acid under vigorous agitation to form Ca(NO3)2 solution, followed by the production of HAp nanoparticles through the addition of dilute phosphoric acid solution to the calcium solution at room temperature with a syringepump. The HAp product possessed high surface area (212.4m2/g), large pore size(16.8nm) and small particle size(o10nm)as shown by BET and small angle XRD analyses.Moreover,only about 8% of the HAp phase was converted to whitlockite at high temperature(950 1C), indicating its stability.This work is supported by NSFC (No.21276212) and SRFDP (No. 20100121110009)