http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
CO2 Adsorption on the B12N12 Nanocage Encapsulated with Alkali Metals: A Density Functional Study
Haiyan Zhu,Qiyan Zhang,Qinfu Zhao,He Zhao,Yifan Feng,Bingbing Suo,Huixian Han,Qi Song,Yawei Li,Wenli Zou,Haiyan Zhu 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2019 NANO Vol.14 No.3
Density functional theory (DFT) calculations have been carried out to study the capacity of the B12N12 nanocage encapsulated with alkali metals (Li, Na, K) for the CO2 adsorption and activation. It is found that after encapsulating alkali metals, the alkali metal atoms are closer to one side of clusters instead of exactly lying at the center, and a considerable charge transfers from the inner alkali metal atoms to the B12N12 cage. Besides, the HOMO–LUMO gap (HLG) values of Li@B12N12, Na@B12N12 and K@B12N12 are decreased to about 6 eV, being much smaller than that of the pristine B12N12. Although the geometry structure parameters and the energy differences of M06-2X are slightly different from the ones of ωB97X-D, some identical results of two kinds of functional can be obtained. CO2 can be adsorbed chemically and physically on majority bonds of all the clusters, except for some bonds with large change in bond length and bond indices. The encapsulation of alkali-metal atoms may enhance the physical and chemical adsorption of CO2 on the surface of the clusters, in which Na@B12N12 and K@B12N12 are the most powerful physical and chemical adsorbent for CO2, respectively.
Structural evolution of the thermal conversion products of modified coal tar pitch
Qi Li,Dongyun Han,Haiyan Qiao,Weiwei Shi,Yuqi Zhang,Zubin Cao 한국탄소학회 2023 Carbon Letters Vol.33 No.1
Coal tar pitch is a product with high carbon content and aromatic compounds. Modified coal tar pitch is a high quality raw material for the preparation of intermediate phase pitch, needle coke, carbon microspheres, et al. In this paper, modified coal tar pitch was used as raw material, nitrogen was used as protective gas, and thermal conversion was carried out at constant temperatures (370, 390, 410, 420 °C). Polarized light microscopy, SEM, elemental analysis, FTIR spectroscopy, Raman spectroscopy and XRD diffraction combined with split-peak fitting were used to characterize the microstructures of the thermal transformation products. The results showed that the Iar and CH3/ CH2 contents of the products increased with the gradual increase of the thermal conversion temperature, and the aromatic content increased. And the higher the temperature at the same heating rate, the more the ideal graphite microcrystal content, and the defective graphite microcrystals are converted into ideal graphite microcrystals during the thermal conversion process. When the reaction temperature exceeds 390 °C, the microstructure of the thermal transformation products is anisotropic spheres, and the small spheres fuse with each other and tend to be basin-like and mosaic structure as the temperature increases.
Yang Baoju,Zeng Zhigang,Qi Haiyan,Wang Xiaoyuan,Ma Yao,Rong Kunbo 한국해양과학기술원 2015 Ocean science journal Vol.50 No.4
Fe-Si oxide deposits were recovered from the PACMANUS (Papua New Guinea-Australia-Canada-Manus) hydrothermal field in Eastern Manus basin. Samples were loose and fragile. Optical and scanning electron microscopy showed that the samples had abundant rod-like or twisted filamentous and granular structures. Electron probe microanalysis revealed that these filaments and grains were mainly composed of Fe and Si. The presence of spherical grains on the surface of the filaments suggests the intergrowth of biotic and abiotic reactions. Biotic and abiotic kinetics competition always exists in the redox gradient. Based on the physico-chemical conditions of PACMANUS hydrothermal fluids, we calculated a strict abiotic oxidation rate of Fe2+ to Fe3+, which is approximately 0.0123 g/min. If the fluids had been erupting consistently and the concentration of Fe2+ was constant, 3.232 kg per year of Fe would be deposited in this vent. The amount of Fe oxides around the studied vent was larger than the amount determined by strict abiotic kinetic calculation. Bacteria may also play an important role in Fe oxidation. A mesh-like microenvironment constructed by biogenic filaments ensured adequate Fe2+ and low oxygen content for the growth of bacteria. Moreover, this structure promoted the deposition of abiotic Fe-Si oxides.
Applications of Bacterial Cellulose-Based Composite Materials in Hard Tissue Regenerative Medicine
Liu Yingyu,Liu Haiyan,Guo Susu,Qi Jin,Zhang Ran,Liu Xiaoming,Sun Lingxiang,Zong Mingrui,Cheng Huaiyi,Wu Xiuping,Shanxi Medical University School and Hospital of Stomatology 한국조직공학과 재생의학회 2023 조직공학과 재생의학 Vol.20 No.7
BACKGROUND: Cartilage, bone, and teeth, as the three primary hard tissues in the human body, have a significant application value in maintaining physical and mental health. Since the development of bacterial cellulose-based composite materials with excellent biomechanical strength and good biocompatibility, bacterial cellulose-based composites have been widely studied in hard tissue regenerative medicine. This paper provides an overview of the advantages of bacterial cellulose-based for hard tissue regeneration and reviews the recent progress in the preparation and research of bacterial cellulose-based composites in maxillofacial cartilage, dentistry, and bone. METHOD: A systematic review was performed by searching the PubMed and Web of Science databases using selected keywords and Medical Subject Headings search terms. RESULTS: Ideal hard tissue regenerative medicine materials should be biocompatible, biodegradable, non-toxic, easy to use, and not burdensome to the human body; In addition, they should have good plasticity and processability and can be prepared into materials of different shapes; In addition, it should have good biological activity, promoting cell proliferation and regeneration. Bacterial cellulose materials have corresponding advantages and disadvantages due to their inherent properties. However, after being combined with other materials (natural/ synthetic materials) to form composite materials, they basically meet the requirements of hard tissue regenerative medicine materials. We believe that it is worth being widely promoted in clinical applications in the future. CONCLUSION: Bacterial cellulose-based composites hold great promise for clinical applications in hard tissue engineering. However, there are still several challenges that need to be addressed. Further research is needed to incorporate multiple disciplines and advance biological tissue engineering techniques. By enhancing the adhesion of materials to osteoblasts, providing cell stress stimulation through materials, and introducing controlled release systems into matrix materials, the practical application of bacterial cellulose-based composites in clinical settings will become more feasible in the near future.
Coordinated Direct and Relayed Transmission based on NOMA and Backscattering
Zhaoxi Fang,Yingzhi Lu,Jing Zhou,Qi Li,Haiyan Shi 한국인터넷정보학회 2022 KSII Transactions on Internet and Information Syst Vol.16 No.9
We propose a spectral-efficient coordinated direct and relayed transmission (CDRT) scheme for a relay-assisted downlink system with two users. The proposed scheme is based on backscatter communication (BC) and non-orthogonal multiple access (NOMA) technique. With the proposed BC-NOMA-CDRT scheme, both users can receive one packet within one time slot. In contrast, in existing NOMA-CDRT schemes, the far user is only able to receive one packet in two time slots due to the half-duplex operation of the relay. We investigate the outage of the BC-NOMA-CDRT scheme, and derive the outage probability expressions in closed-form based on Gamma distribution approximation and Gaussian approximation. Numerical results show that the analytical results are accurate and the BC-NOMA-CDRT scheme outperforms the conventional NOMA-CDRT significantly.
Shang-Guan, Keke,Wang, Min,Htwe, Nang Myint Phyu Sin,Li, Ping,Li, Yaoshen,Qi, Fan,Zhang, Dawei,Cao, Min,Kim, Chanhong,Weng, Haiyong,Cen, Haiyan,Black, Ian M.,Azadi, Parastoo,Carlson, Russell W.,Stacey American Society of Plant Biologists 2018 Plant Physiology Vol.176 No.3
<P>Lipopolysaccharides induce a long-lasting burst of reactive oxygen species that is largely associated with chloroplasts.</P><P>Lipopolysaccharides (LPS) are major components of the outer membrane of gram-negative bacteria and are an important microbe-associated molecular pattern (MAMP) that triggers immune responses in plants and animals. A previous genetic screen in Arabidopsis (<I>Arabidopsis thaliana</I>) identified LIPOOLIGOSACCHARIDE-SPECIFIC REDUCED ELICITATION (LORE), a B-type lectin <I>S</I>-domain receptor kinase, as a sensor of LPS. However, the LPS-activated LORE signaling pathway and associated immune responses remain largely unknown. In this study, we found that LPS trigger biphasic production of reactive oxygen species (ROS) in Arabidopsis. The first transient ROS burst was similar to that induced by another MAMP, flagellin, whereas the second long-lasting burst was induced only by LPS. The LPS-triggered second ROS burst was found to be conserved in a variety of plant species. Microscopic observation of the generation of ROS revealed that the LPS-triggered second ROS burst was largely associated with chloroplasts, and functional chloroplasts were indispensable for this response. The lipid A moiety, the most conserved portion of LPS, appears to be responsible for the second ROS burst. Surprisingly, the LPS- and lipid A-triggered second ROS burst was only partially dependent on LORE. Together, our findings provide insight on the LPS-triggered ROS production and the associated signaling pathway.</P>