With the constant development of the national Infrastructure construction, the focus of the civil industry has been shifting to the detection and maintenance of existing structures. Many bridges have been in service for a long time with the increased traffic volumes. So regular detection is required to ensure the safe operation of those structures. The multifunctional underwater vehicles equipped with cameras, sonars, and other attachments have paid great attention to underwater operations. Also, that provides a critical idea and method for detecting underwater bridge structures. This paper demonstrates the feasibility of a Remotely Operated Vehicle (ROV) in detecting underwater bridge structures, then expounds on typical application scenarios and examples. Furthermore, considering that the weak anti-current of ROV is the main restriction of its popularization and application, the research on how to improve the anti-current of ROV is discussed in detail based on the kinematic force analysis. Finally, the critical guidance of ROV anti-current technologies is concluded, and the research interests of the high-stability ROV have been prospected.

In order to analyze the key and core technology of mass spectrometers and reveal the competitive advantages between countries, patent technologies of the global mass spectrometer are identified by artificial intelligence, and the research theme layout of global mass spectrometer manufacturing technology is obtained. Through a hybrid approach of supervised classification with unsupervised clustering, the research theme is compared with the mass spectrometer involved in export control. Results of supervised classification experiments show that the random forest algorithm has the best classification effect, with an accuracy of 94% and a recall rate of 94.3%. The clustering algorithm divides the global mass spectrometer manufacturing technology into five fields: mass spectrometer machine technology, ion mass analyzer technology, mass spectrometer data processing module, sampling components and devices, and ion source core technology. Then, this paper analyzes the research status and competition situation of mass spectrometer manufacturing technology between China and several key economic regions such as the United States, the European Union and Japan. It shows that China has made rapid progress in the manufacturing technology of mass spectrometers in the recent ten years, with the number of patents exceeding half of the number of global patents. China has obvious advantages in the themes such as sampling components and devices and mass spectrometer data processing module, while in the themes of mass spectrometer machine technology, ion mass analyzer technology, and ion source core technology, China has an obvious weakness. Results show China has certain risks in the face of American and Western technology export control regulation.

Abstract: Large scale scientific facilities are an important symbol of the country's scientific and technological innovation capability and comprehensive strength, economic strength and even soft power. As the largest target country of technological and economic sanctions by Western countries, its experience in the construction of large-scale scientific facilities have practical significance. This paper clarifies the concept of the Russian Megascience facilities, sorting out its policy evolution, examines its construction process and latest progress, and summarizes the characteristics of Russian Megascience facilities in terms of projects, goals, management and factors. There are only 7 Megascience facilities defined in Russia in a narrow sense. They are projects with international comparative advantages selected under the scientific management system of Russia's mandatory plan. The situation at home and abroad is highly sensitive. China should build a benign international cooperation mechanism with independent research and development as the main line, build a sustainable large-scale scientific development ecology, and strike a balance between accumulating resources to build large scale scientific facilities and expanding scientific and technological undertakings.

Through measuring ion mass-to-charge ratio, mass spectrometry technology accurately identifies unknown analytes, quantifies known compounds, and determines the structure and chemical properties of molecules. In recent years, its application in life science basic research and clinical detection analysis has become more and more extensive, providing important support for understanding the composition of life and the essence of life phenomena, and realizing rapid and accurate diagnosis of diseases. This article analyzes the development status and problems of international and Chinese clinical mass spectrometry technology, and puts forward relevant policy recommendations. It shows that technological advances in ion sources and mass analyzers, as well as the introduction of innovative ion mobility spectroscopy technology, have improved the sensitivity and resolution of mass spectrometry, broadened the range of detectable molecules, and significantly improved the qualitative and quantitative capabilities of mass spectrometry, which make the clinical application of mass spectrometry technology enter a stage of rapid development. Chinese clinical mass spectrometry technology research and application started relatively late, and it is necessary to further strengthen the independent innovation of source technology, promote the sinking of clinical applications, and gradually improve related regulatory standards in the future.

Micro-deformation are important in engineering to determine the health state of a target or to warn of natural disasters. Traditional deformation monitoring methods include displacement meter, accelerometer, GPS, 3D laser scanning, etc. However, they have certain disadvantages, such as installation difficulties, low working efficiency and weather sensitivity. Therefore, a solid target micro deformation Meter (TMDM) is designed. The system combines the frequency modulation continuous wave technology (FMCW) and interferometry, which is easy to operate, portable, and can operate all day long. Firstly, the system is tested in laboratory, and the accuracy of deformation measurement is verified to be up to sub-millimeter. Then, the system is used to carry out a micro-deformation monitoring experiment on a 32m double-line simply supported box girder of Haian Bridge. During the experiment, four typical monitoring points are selected. Under the experimental condition of single line loading and the same loading speeds of the girder, the system accurately measured the displacement of 1/4 span and 1/2 span of the beam and the displacement difference of 1/2 span of the uplink and downlink. The natural frequency and forced frequency of the bridge are obtained by further analysis of the measured time-history curve. The measured results are consistent with the theoretical analysis, proving the effectiveness of the TMDM.

The China Spallation Neutron Source (CSNS), including 20 distinctive time-of-flight neutron scattering spectrometers, is a major scientific platform for China’s neutron scattering research and a national scientific device constructed during the 12th Five-Year Plan of China. The neutron chopper is a neutron optical component that regulates the beam current on the scale of time, thereby being an indispensable part in a neutron scattering spectrometer. Its main functions are selecting the desired neutron band range and improving the signal-to-noise ratio. The CSNS needs approximately 73 sets of neutron choppers, which would require regular operation and maintenance. In order to avoid the import restriction of such critical instrument and ensure the success of the Big Scientific Engineering Construction, the CSNS formed a team for neutron chopper development in 2007, which overcame various key technological difficulties, successfully developed bandwidth limited chopper, T0 chopper and Fermi chopper in time, and realized the domestic production of neutron choppers with independent intellectual property rights. 9 sets, 27 sets and 37 sets of these neutron choppers have been or will be applied in the CSNS’s Phase I Project, Cooperative Spectrometer Project, and the future Phase II Project, respectively. The independently developed neutron choppers provided an important guarantee for the smooth construction of the CSNS. Their use is not restricted to China spallation neutron source projects, but can be extended to synchrotron radiation light source (X-ray chopper) projects, high-speed rotation mechanical equipments and other fields.

Ultrafast Transmission Electron Microscopy (UTEM) integrates high spatial and temporal resolution, making it possible to directly visualize the dynamic processes of materials. This paper mainly introduces the development and application of UTEM system, including: the basic principle of UTEM system based on pump-probe technology; the current UTEM systems in several major institutions around the world; the first generation UTEM system based on thermal emission electron gun and the second generation UTEM system based on field emission electron gun (FEG) independently developed by Li Jianqi's team from Institute of Physics, Chinese Academy of Sciences; the latest research achievements in UTEM system combined with ultrafast real space imaging, ultrafast electron diffraction (UED) and time-resolved electron energy loss spectrum (TREELS), such as lattice and electron dynamics, phase transition dynamics, photon-induced near-field electron microscopy (PINEM), etc. At present, UTEM has become a powerful tool for the study of non-equilibrium dynamics at micro-nano scale. In the future, as electron pulse quality and spatial resolution of TEM continue to improve, UTEM is expected to achieve higher spatial and temporal resolution. China has invested relatively less in the research of UTEM. At present, it is necessary to seize the development opportunity of UTEM, effectively promote the innovation and industrial development of key technologies, core components and major products in the field of UTEM, and closely link scientific and technological innovation with industrial development.

Small angle neutron scattering (SANS) is a coherent elastic scattering technique. It uses neutron as the probe to characterize the microscopic and mesoscopic structures of materials. SANS has been widely used in the fields of physics, chemistry, material science, biology and so on. At the early stage, SANS used pinhole geometry to collimate the neutron beam, and measured the length scales from 1 nm to 100 nm. With the increase in the neutron flux and the development of the neutron optics and detection technologies, SANS gradually develops into two directions, i.e., larger length scale, and smaller length scale, respectively. To detect larger length scale, Very Small Angle Neutron Scattering (VSANS), Ultra Small Angle Neutron Scattering (USANS) and Spin Echo Small Angle Neutron Scattering (SESANS) are developed; to detect smaller length scale, Neutron Total Scattering instrument for Disordered Macromolecules is developed. Nowadays, SANS is aiming at full-scale coverage and intelligent data analysis, hoping to measure the multi-scale structures of complex systems at one time. This article follows the development history of SANS technologies, explores its development direction and intersperses its role in the field of basic and applied scientific research.

Proton transfer reaction mass spectrometry (PTR-MS) is a rapid and sensitive technique for the detection of volatile organic compounds. Since its completion in 2008, domestic PTR-MS has reached the international advanced level in some technology and application fields. In this paper, we firstly introduced the principle of the instrument, and expounded the main influencing factors in the process of ionization, transmission and detection of the object to be measured. Then we showed the main products of domestic PTR-MS, including proton extraction reaction mass spectrometer (PER-MS), dipolar proton transfer reaction mass spectrometer (DP-PTR-MS), breath tester, spray inlet mass spectrometer (SI-PTR-MS), mobile proton transfer reaction mass spectrometer (M-PTR-MS), fast gas chromatography proton transfer reaction mass spectrometer (FGC-PTR-MS). Some products have been mass produced and sold. In terms of technological development, important progress has been made in the improvement of sensitivity and the preparation of multi reactive ions. Finally, we introduced the application of domestic PTR-MS in the fields of environment, medicine and safety, such as tracing the source of air pollution, excavating disease markers in human exhalation, rapid detection of explosives and soon. At the same time, the future development direction and application prospect of domestic PTR-MS were prospected.

In order to fully grasp the technical composition and development tendency of the collider, this paper analyzes the patents and papers related to the collider technology in the past 30 years. The statistics on the annual, national, and institutional distributions of the patents and paper are presented firstly. Then, this study uses the Context-LDA model and LDA topic models to study the topic compositions and hot topics of patents and papers respectively. Further, by using similarity index (JS distance) and information entropy, this study analyzes the topic evolution of papers. The results show that Japan and the United States are the countries with the highest amount of patents and papers respectively. China ranks in the forefront and the output of achievements has increased rapidly in recent years; electrode circuits of accelerated system, beam injection, superconducting devices, vacuum systems, radio frequency chambers, etc., are the most popular topics of the patents. The technical topics of papers related to the Large Hadron Collider have been hot topics at different times. Among them, the hot topics include magnets and solenoids, trace systems, beam cavities, superconducting magnets, calorimeters, etc.. Research topics in the field of collider technology are developing towards a more balanced and diversified trend. This paper recommends that China continues to increase the number of output in this field, increases the research and development (R&D) efforts of hot technology fields; scientific research institutions should seek R&D cooperation with superior enterprises, or promote the integrated development of production, education and research, and speed up the research to determine the construction of a large-scale collider.

Sound and effective investment mechanism and fund management measures are the key contents to improve the input-output efficiency of large scientific research infrastructure. In this regards, EU takes large scientific research infrastructure as a strategic scientific and technological resource to support R&D development. EU strengthens investment in large scientific research infrastructure through governmental funds and joint investment, and mobilizes the resources of Member States to build a resource sharing network. Meanwhile, the funding model of “Public Construction with Private Operation” and “Cost and Risk Sharing” has been established, which helps to resolve the risks in investment and construction. Besides, EU has established a mature funding system in supporting the capitalization cost, operation cost and transnational access cost of large scientific research infrastructure in combination with the whole life cycle. The sound and effective investment mechanism provides excellent financial guarantee for the construction, operation and use of large infrastructure. In addition, the EU has formed a mature funding management system, established a fair and reliable funding review and prior evaluation methods, and determined a scientific and economic cost accounting method, which has effectively improved the input-output efficiency of large scientific research infrastructure funding. The EU experience has significance reference for promoting the construction and operation of large scientific devices. In combination with China’s reality, it is suggested to expand and coordinate the investment channels of China’s large scientific research infrastructure, improve the cost accounting methods, and increase the support for the operation, maintenance and use of facilities, so as to improve the social and economic benefits of the construction and operation of China’s large scientific research infrastructure, and ultimately enhance the “hard power” of science, technology and innovation in China.

Scientific research instruments are the material resources necessary for scientific research, and the primary basis and necessary prerequisite for the realization of scientific and technological self-reliance and self-improvement. China has been pouring heavy investment annually to purchase foreign scientific instruments and equipment, and almost all advanced precision instruments are imported. This paper discusses the influence of the import dependence of scientific research instruments on scientific research undertakings, analyzes the main reasons for the import dependence of scientific research instruments in China from the perspective of environment, and puts forward corresponding countermeasures and suggestions. It is found that there is a certain degree of import dependence of scientific research instruments in China, and the main reason is the lack of localization environment, including four aspects: talent environment, policy environment, market environment and cultural environment. In this regard, it is recommended that China should speed up the deployment of the talent strategy for scientific research instrument development, build a basic institutional system that encourages independent research and development of scientific research instruments, build a national supply and demand docking platform for scientific research instruments, and strive to create a cultural environment for the localization of scientific research instruments for R&D.

Taking “science and technology to create a country” as the starting point, and to get rid of its dependence on foreign advanced scientific instruments, the Japanese government has formulated the Development of Advanced Measurement and Analysis Systems, laying a solid research and development foundation for Japanese science and technology. Taking the plan as the research object, this paper makes an in-depth analysis on its introduction background, management structure, field distribution, fund investment and implementation effect using case analysis method, bibliometric method and social network analysis method. By comparing the management process of the natural science foundation of China, it is found that China's national-level scientific research project planning and inter-departmental scientific research projects are far behind those of Japan., as well as the efforts in the combination of production, education and research and the commercialization of scientific research results. Combined with the national conditions in China, suggestions are put forward, including to strengthen the top-level design of scientific instruments, increase funding, promote the research and development of key core technologies, optimize the project evaluation system, promote industry-university-research cooperation, and the transformation of scientific and technological achievements to promote the high-quality development of advanced scientific instruments in China.

Under the background of China-US trade embargo, a series of external technical threats are increasingly prominent in China, which affects a variety of fields such as economics, military, politics etc. Developed countries, led by the United States, restrict the export of key core technologies to China through Export Control. The commerce control list (CCL) issued by the United States contains export restrictions on a large number of technologies, equipment and products, including important scientific instruments and their related parts. This paper compares the contents of the CCL with the classification of domestic scientific instruments, taking the commercial control list as object text, and taking the classification of scientific instruments in China as standards. Through text mining and clustering, the analysis of the technology of export control list is carried out. Then, the distribution of the control situation of the United States in each type of scientific instrument and technology is analyzed. It is found that 42.08% of the list items are related to the control of scientific instruments, suggesting serious situation for the field of scientific instruments in China. Among the 12 categories of scientific instruments, Analytical Instruments, Process Experimental Equipments, Electronic Measuring Instruments, etc. are subject to a wide range of control. Medical Diagnostic Instruments, Atmospheric Detection Instruments are controlled slightly. On the basis of the analysis, this paper puts forward some suggestions for the development of scientific instruments in China.