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991.
With the successful demonstration of terahertz (THz) high-speed wireless data transmission,the THz frequencies are now becoming a worth candidate for post-5G wi...  相似文献   
992.
As an important part of satellite communication network, LEO satellite constellation network is one of the hot research directions. Since the nonuniform distribution of terrestrial services may cause inter-satellite link congestion, improving network load balancing performance has become one of the key issues that need to be solved for routing algorithms in LEO network. Therefore, by expanding the range of available paths and combining the congestion avoidance mechanism, a load balancing routing...  相似文献   
993.
The convergence of information, communication, and data technologies(ICDT) has been identified as one of the developing trends of the sixth generation(6G) network. Service-based architecture(SBA) as one of the promising information technology, has been preliminarily introduced into the fifth generation(5G) core network(CN) and successfully commercialized, which verifies its feasibility and effectiveness. However, SBA mainly focuses on the control plane of CN at present and the SBA-CN user plane ...  相似文献   
994.
In the multi-target localization based on Compressed Sensing(CS), the sensing matrix’s characteristic is significant to the localization accuracy.To improve the CS-based localization approach’s performance, we propose a sensing matrix optimization method in this paper, which considers the optimization under the guidance of the t%-averaged mutual coherence. First, we study sensing matrix optimization and model it as a constrained combinatorial optimization problem. Second, the t%-averaged mutual ...  相似文献   
995.
In the future smart transportation system, reliable vehicle-to-infrastructure(V2 I) communication is very important to ensure vehicle driving safety and to improve vehicle driving efficiency. In this paper, V2 I channel measurements at 5.92 GHz are conducted in typical urban and highway scenarios.The frequency and bandwidth of transmission, as well as the deployment of the RSU(roadside unit) and the OBU(on board unit), are selected by considering the recommendation proposed by 3 GPP TR 36.885. T...  相似文献   
996.
总线型阀岛在ZL26纤维滤棒成型机组中的应用   总被引:1,自引:0,他引:1  
总线型阀岛能够减少气动系统接线,降低系统故障率,减少设计时间,降低维护成本,利于系统集成.介绍了利用相关软件配置组态一个基于PROFIBUS-DP总线阀岛网络的设计过程和系统的调试,从一个侧面体现了ZL26纤维滤棒成型机组的一些技术特点.  相似文献   
997.
针对郑万铁路某隧道上跨高速公路某隧道可能会导致其受压变形,产生一系列施工和运营安全等问题,提出一种新型隧道收敛自动监测系统,能够保障上跨、下穿施工期间高速公路隧道的安全,实时动态掌握施工对已运营高速公路的影响程度,同时,对其应用进行分析总结研究.  相似文献   
998.
针对煤衍生重质产品的组分分析,以高效液相色谱(HPLC)研究了其定量问题。首先,建立高分辨的色谱分离体系,使组分得以好的分离和定性。对各分离组分定量测定采用了外标法和外标-定量因子法。实验表明准确定量的技术关键在于:溶解样品溶剂的合理选择;配制样品溶液浓度的正确控制;配制样品溶液的进一步处理技术。  相似文献   
999.
Xu  Peng  Ni  YiKun  Liu  JingLong  Zhang  WeiRong  Liu  SiJian  Wang  LiZhen  Fan  YuBo 《中国科学:技术科学(英文版)》2021,64(5):1101-1106
Woodpeckers can withstand a fierce impact during pecking. Previous studies have focused on the biomechanical analysis of the pecking process, the properties of the beak and hyoid bone of woodpecker; however, the biological characteristics of the woodpecker brain are also important in resisting impact injuries. We employed impact experiments and biological analysis in normal and injured brains to reveal the impact-resistant biological characteristics of woodpecker brains, as well as the impact energy's biological effects on the woodpecker brain. The hoopoe, which has a similar size but only a slight pecking behavior, was selected as the control group to compare brain morphology and neuronal cells differences in normal brains between woodpecker and hoopoe by sectioning and staining. A loading device was designed to conduct a quantifiable impact energy to the woodpeckers' head. Four groups of woodpeckers were impacted with the same energy on the forehead, beak, tempus and occiput,respectively. Biological changes in the injured brains were evaluated by Nissl staining and enzyme-linked immunosorbent assay.The results showed that:(1) woodpeckers had a larger cerebellum and a higher density of Nissl bodies than hoopoe;(2) Nissl apoptosis appeared in the brain samples after the forehead and the occiput impact experiments, but no obvious Nissl body apoptosis was observed after impact on the tempus and the beak;(3) β-amyloid protein accumulated in the normal status woodpecker brain. This study reveals that: woodpecker brain morphology is well-adapted to impact, woodpecker heads display location-dependent protective performance, with beak and tempus regions having a better protective performance than the forehead and occiput, Nissl apoptosis appears in injured woodpecker brains, and that the accumulation of β-amyloid protein does not show a direct relationship with the injury state of woodpecker's brain tissue in our study.  相似文献   
1000.
A transparent cornea is paramount for vision. Corneal opacity is one of the leading causes of blindness. Although conventional corneal transplantation has been successful in recovering patients’ vision, the outcomes are challenged by a global lack of donor tissue availability. Bioengineered corneal tissues are gaining momentum as a new source for corneal wound healing and scar management. Extracellular matrix (ECM)-scaffold-based engineering offers a new perspective on corneal regenerative medicine. Ultrathin stromal laminar tissues obtained from lenticule-based refractive correction procedures, such as SMall Incision Lenticule Extraction (SMILE), are an accessible and novel source of collagen-rich ECM scaffolds with high mechanical strength, biocompatibility, and transparency. After customization (including decellularization), these lenticules can serve as an acellular scaffold niche to repopulate cells, including stromal keratocytes and stem cells, with functional phenotypes. The intrastromal transplantation of these cell/tissue composites can regenerate native-like corneal stromal tissue and restore corneal transparency. This review highlights the current status of ECM-scaffold-based engineering with cells, along with the development of drug and growth factor delivery systems, and elucidates the potential uses of stromal lenticule scaffolds in regenerative therapeutics.  相似文献   
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