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Low sound speed or low-density materials can be used as soft acoustic boundaries in water, potentially as low-frequency underwater sound insulation. This study uses a chiral structure to construct an acoustic metascreen with deep subwavelength thickness. The results show that the transmission coefficient of the metascreen decreases noticeably in the low-frequency range when adjusting the chiral structure. The displacement pattern and the effective acoustic impedance are used to investigate the sound insulation mechanism. Low sound speed and effective acoustic impedance are found in the anisotropic chiral structure, and an extensive range of quasi-longitudinal wave phase velocities from 116.70 m/s to 3935.48 m/s can be obtained by adjusting the structural parameters without changing the filling rate. Finally, the effect of the oblique incidence angle on the sound insulation of the metascreen is investigated.

In the scope of drug discovery, the molecular design aims to identify novel compounds from the chemical space where the potential drug-like molecules are estimated to be in the order of 10^60 - 10^100. Since this search task is computationally intractable due to the unbounded search space, deep learning draws a lot of attention as a new way of generating unseen molecules. As we seek compounds with specific target proteins, we propose a Transformer-based deep model for de novo target-specific molecular design. The proposed method is capable of generating both drug-like compounds (without specified targets) and target-specific compounds. The latter are generated by enforcing different keys and values of the multi-head attention for each target. In this way, we allow the generation of SMILES strings to be conditional on the specified target. Experimental results demonstrate that our method is capable of generating both valid drug-like compounds and target-specific compounds. Moreover, the sampled compounds from conditional model largely occupy the real target-specific molecules' chemical space and also cover a significant fraction of novel compounds.

In order to verify the feasibility of in-vehicle laser communication technology, the application scenarios and basic principles of vehicle-mounted laser communication system are researched. According to the index requirements, the overall design of the system is completed and field experiments are carried out. Under different atmospheric visibility and different communication distance Communication error rate, to evaluate the communication quality, and to detect and analyze the mast sloshing. Finally, the vehicle laser communication prototype was completed to achieve near-surface laser communication within 15km and 100mbps. The feasibility and design of vehicle-mounted laser communication were verified The correctness of the scheme and provide the basis for the improvement of the prototype of the principle in the future.

構造上の対立は事態に対する話者の捉え方の違いを反映するものであり、その違いの内実を明らかにしてこそ、それぞれの表現形式の意味に対するより本質的な理解が可能になる。本稿では、事物の静的存在状態を語る場合、どのような認識過程がなされているのか、それが静態存在文における「“着”静態存在文」と「“了”静態存在文」に見られる“着”と“了”の互換現象に如何なる影響を与えるのかを「話者の主観性」という観点から解釈する。「“着”静態存在文」の場合、話者の視点は事物の現在の存在状態だけに置かれている。一方、「“了”静態存在文」の場合、話者は事物の今現在の存在状態だけを観察するのではなく、その状態が形成される以前の状態を含めて出来事全体について把握している。静態存在文において“着”を“了”に置き換えられない現象も存在している。それは、話者が事物の存在状態を認識する際にその事物の現在の存在状態が形成される以前の状態について観察できなく、話者の認識、判断などといった主観性が働かないことにより、「“着”静態存在文」しか用いられないためである。

According to the laser cutter larch, this study has determined the reasonable process parameters such as focal length, light intensity, and optimized laser processing technology parameters to provide test methods. Firstly, for the cutting seam state analysis the precautions of software settings have been put forward. General rules of variations of process parameters in laser technology were determined through the orthogonal test method, and designs a three-dimensional curves, to observe the interaction of different factors, and then used two factor completely random repeat test method, to determine the reasonable parameters of intensity, The results showed that the reasonable process parameters: focal length is 6mm and focal intensity is 32% or the focal length is 6.5mm and focal intensity is 50%, last the cutting seam depth is about 5~6mm.

The tree graph method of evaluating the local molecular moment is proposed. By applying this method and the molecular moment formula of π-electron energy in the molecular orbital graph theory, a topological method of using the molecular moment to judge the relatively reactive point of even AH is achieved.