Subjects: Physics >> Nuclear Physics submitted time 2024-01-10
Abstract: The Lanzhou Heavy Ion Accelerator Cooling Storage Ring(HIRFL-CSR) is an ideal device for studying the decay of highly charged and short-lived isomers. In the lifetime measurement experiment of the short-lived highly charged ion 94mRu44+, we directly observed the decay of 94Ru from 8+ isomer to the ground state, and identified 49 decay events in the observation time window of (20 μs, 180 μs). In order to identify more decay events, a method based on spectral amplitude was studied in this paper. Based on the simulation results, this method can effectively identify decay events within (15 μs, 185 μs). By applying the new identification method to the experimental data processing, 54 decay events were identified within (15 μs, 185 μs). Based on these 54 decay events, the lifetime of 94mRu44+ in the rest frame was calculated to be 194(121) μs. The new lifetime result is within the error range of the previous result 218(148) μs, with higher precision.
Subjects: Physics >> Nuclear Physics submitted time 2023-11-03
Abstract: Multinucleon transfer reactions involving heavy actinide projectile and target nuclei hold significant potential as a groundbreaking method to synthesize
neutron-rich superheavy nuclei. The construction of a Principled Spectrometer for Neutron-rich Superheavy Nucleus Research is highly desirable to establish the technical, methodological, and device foundation to explore the stability island in superheavy nuclei and to study the mechanism of multinucleon transfer reactions. The gas cell of the Principled Spectrometer requires a continuous supply of high-purity helium gas to stop the energetic radioactive reaction products and to extract the energy-reduced ions to the subsequent experimental setup. The paper focuses on a newly developed cryogenic purification system for the gas cell of the spectrometer. This cryogenic purification system is designed to provide recyclable and high-purity helium for the Principled Spectrometer. With a series of tests, the cryogenic purification system has been proven to be able to purify the 99% helium gas to 99.999% or higher, fulfilling the requirements of the gas cell when used in conjunction with the chemical purification system.
Subjects: Physics >> Nuclear Physics submitted time 2023-09-11
Abstract: In this work, we presented the test results for a prototype of plastic scintillation detectors for time-of-flight measurement, aiming to provide preliminary research for the future development of time-of-flight detectors for HIAF-HFRS facility. Each timing detectors was composed of a fast scintillating plastic and four fast photomultiplier tubes coupled to its four sides. The time performance of the detectors was tested using pico-second pulsed laser, For two plastic scintillation detectors with different sizes, a pico-second pulsed laser was used to simulating the actual ion-beam situation by changing laser’s parameters including spot size, repetition rate, light intensity and hitting position. The data was processed utilizing CAEN-DT5742 digitizer and Mesytec-MCFD16+MTDC32 electronics. When the focused laser hit at the center of the plastic scintillators, the time-of-flight (ToF) resolution of two small-sized (7 cm×7 cm) plastic scintillation detectors could reach 8 ps, whereas the ToF resolution of the small and large (26 cm×10 cm) detectors could achieve 12 ps. After varying the parameters of the laser, the corresponding ToF resolutions were found to be in the range of 10–16 ps and 19–46 ps, respectively. The ToF resolutions from the test meets the timing-resolution requirement of the HFRS beamline, thereby establishing a solid foundation for further optimizing the time-of-flight detectors.
Subjects: Other Disciplines >> Synthetic discipline submitted time 2023-03-19 Cooperative journals: 《中国科学院院刊》
Abstract: In the field of synthetic biology research, the massive scale of trial-and-error experiments in engineering goes far beyond the traditional labor-intensive research paradigm, so it needs a transformative engineering research platform. With the introduction of various types of intelligent equipment to meet the production needs, engineering platforms carry out a large-scale of customization and research paradigm innovation, to realize the remote customization, offsite design, and economic scale production of organisms. Engineering platforms can accumulate experience and knowledge quickly, and serve as the scientific basis for the predictive synthesis of organisms. This article will introduce some cases and development trends of engineering platforms, as well as upstream and downstream institutions for synthetic biology research.
Subjects: Library Science,Information Science >> Information Science submitted time 2023-03-13
Abstract: ChatGPT is a dialogue system developed by OpenAI company. It appears as a Chatbot, but in essence, it uses Artificial Intelligence Generated Content (AIGC) technology to produce answers. Its key foundation is Generative Pre-trained Transformer and the core technology is InstructGPT. When compared to similar products in the early stages, its main characteristic is that there is a significant decrease in making up facts and generating toxic content. We present a systematic investigation of the technical structure, relevant research and practice, and applications scenarios of ChatGPT. Based on the investigation, we analyze the inspiration from the rapid development of AI technology as well as the influence of ChatGPT on Scientific Research and Library & Information Service. According to these influence, we present eight suggestions for the Library & Information Service field. Overall, the field should find its distinctive value orientation in the AI era, not only by maintaining the conventional scientific research paradigm, but also by exploring new technologies to boost scientific research.
Peer Review Status:Awaiting Review
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-05-20 Cooperative journals: 《计算机应用研究》
Abstract: Personalized aesthetic ranking plays an import role in Image Quality Assessment and Image retrieval. In order to solve drawbacks of the missing preference from the user and low accuracy in existing methods, this paper proposed a SVMRank based model to automatically rank the input images. The framework took as input a series of specific photos that users prefer, then deployed DCNN to extract the deep features and compare them with ones that are extracted from dataset to establish an User-specific aesthetic training dataset. Later, SVMRank was used to learn a customized hyper plane to produce a user-specific personalized aesthetic ranking. The paper conducted two experiments at mean time: 1) Several users were invited to evaluate the performance of user-specific aesthetic ranking. 2) The accuracy on binary-classification was tested. The experiment results show that the framework performs well on predicting user’s preference as well as on classifying the images from high to low quality. In conclusion, the proposed algorithm is an effective personalized ranking algorithm.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-04-12 Cooperative journals: 《计算机应用研究》
Abstract: Aiming at the bottleneck of traditional extraction method of topographic factor on soil erosion in processing massive data, we propose a method based on MapReduce. This method combined the parallel computing model MapReduce with the revised universal soil loss equation(RUSLE) . The method established the flow relationship search tree by the principle of steep slope and the B+ tree, and represented the correlation of topographic data; The method used the MapReduce model to search flow path and converge grid instead of the traditional forward and backward traversal algorithm, and solved the efficiency of the flow accumulation and slope length calculation in topographic factor calculation. The experimental results show that for the extraction of topographic factor from massive digital elevation model, the method can effectively improve the extraction efficiency in the range of the allowable accuracy.
Subjects: Library Science,Information Science >> Information Science submitted time 2017-11-08 Cooperative journals: 《数据分析与知识发现》
Abstract:【目的】利用专利数据对靶向技术创新网络进行量化分析, 从多个视角对技术创新网络的演化过程进行测度分析。【方法】以靶向技术创新网络为研究对象, 从德温特专利数据库中检索靶向技术专利数据, 利用动态网络分析方法与专利数据相结合, 将动态网络分析指标应用到技术创新网络分析中, 构建基于专利动态网络的技术创新演化测度体系。【结果】分析技术创新网络的4 个测度对象, 根据网络指标的变化从微观层次展现靶向技术的发展演化趋势和技术热点。【局限】技术创新网络评价测度指标不够丰富, 对指标的研究不够深入。【结论】该方法能够有效全面地测度技术创新网络演化趋势和技术热点。