[en] Highlights: • Ramp prediction is a novel research area, and a prediction approach by taking time windows as prediction units is proposed. • Two risk factors representing reliability and precision are used to build a risk model for selecting the optimal time window. • Support vector regression model and a swinging door algorithm are used to predict wind power ramp events. - Abstract: To reduce the harm of wind power ramp events in advance, an effective wind power ramp prediction system is needed. A new ramp prediction approach utilizing suitable selected time windows as units is proposed in this paper. Two risk factors are defined based on the performance analysis of ramp prediction, and the risk minimization principle is applied to build the risk model. Combining the correlation analysis and the statistical analysis of ramp duration, model constraints are studied. The optimal time window of industrial data is computed for ramp prediction based on a support vector regression model. Four evaluation indicators are chosen to verify that the proposed approach improves the performance of ramp prediction, and that the risk model is effective to select an optimal time window for prediction.

[en] A set of common used ancillary tritium processing systems including the tritium extract system (TES), the coolant purification system (CPS), and the tritium measurement system (TMS) have been designed for the two types of Chinese test blanket modules (TBM) located in a whole test port in the international thermonuclear experimental reactor (ITER), based on the structure features and technical parameters of Chinese helium cooled solid breeder (CHHCSB) and dual functional lithium lead (DFLL) TBMs. The functions, technical parameters, and process flows of these systems have been described. TES is designed to extract tritium produced in the breeder, to store and separate hydrogen isotope gases. Impurities and tritium in the helium coolant is removed through CPS. TMS has the function of testing the tritium breeding rate in TBM which sometimes replaces the function of TES. Tritium release to the environment from two types of Chinese TBMs and the common tritium systems is well controlled below the tritium safety limit of ITER, based on the tritium permeation and tritium safety analysis. (orig.)

[en] Objective: To analyze the health status of officers and soldiers exposed to radioactive materials. Methods: 73 convalescents who had been exposed to radioactive substances in our hospital in 2019 were selected as the observation group, and 80 convalescents who had not been exposed to radioactive substances in the same period were selected as the control group. The main observation items include subjective symptoms, blood routine (white blood cell count, red blood cells, platelets, hemoglobin), thyroid function (T3, T4, TSH), Eye Lens Examination and chromosome aberration analysis. Results: Compared with the control group, there was significant difference in subjective symptoms, but no significant difference in blood routine, thyroid function, Eye Lens and chromosome aberration. Conclusion: The peripheral blood picture, thyroid function, Eye Lens and cytogenetics of officers and soldiers exposed to radioactive materials were not affected by their work, but it is necessary to carry out mental health education, psychological service and radiation protection education. (authors)

[en] The variation of corrosion behaviors and microstructure of 2A02Aluminum alloy before and after Laser Shock Processing (LSP) were analyzed, and the effects of LSP on corrosion resistance of the alloy were explored. The results show that the corrosion resistance of aluminum alloys with different aging conditions is quite different before and after laser shock. The corrosion potentials of the aluminum alloys with different aging conditions vary with the initial state, the natural aging state, the two aging stages (150°C/6h, 190°C/6h, 8h+160°C/6h), indicating that the grain size and morphology and distribution of precipitated phase under different aging conditions before impact are the main controlling factors in the process of corrosion. The micro-analysis revealed that LSP can form a compact strengthened layer at the surface of the material and can refine grains, at this point the strengthening effect caused by LSP was the main controlling factor in the corrosion process. (paper)

[en] Highlights: • An OSA-GelDA viscous hydrogel was successfully prepared through the Schiff base reaction. • This composite hydrogel exhibits good wet adhesion and antibacterial ability. Organic-inorganic composite hydrogel materials have been widely studied. In order to expand the application of organic-inorganic composite hydrogel materials, in this work, we prepared a viscous hydrogel with antibacterial properties (OSA-GelDA@ACP/DA/Ag). First, we used polydopamine coating to deposit elemental silver on the surface of amorphous calcium phosphate (ACP) particles to prepare ACP/DA/Ag particles. Next, dopamine was grafted on the gelatin molecular chain by EDC/NHS to activate the carboxyl group to obtain dopamine-modified gelatin (GelDA). The content of DA in GelDA is about 14.09% by standard curve method. Then, the Schiff base reaction took place between the amino group on the GelDA molecular chain and the aldehyde group on the OSA molecular chain, and an OSA-GelDA viscous hydrogel was prepared. Finally, by changing the content of ACP/DA/Ag3 particles added to the OSA-GelDA gel, the corresponding performance of material was investigated. The results show that the introduction of dopamine provides wet viscosity for the hydrogel, and the ACP/DA/Ag3 particles introduced in the viscous hydrogel provide antibacterial properties. This hydrogel with antibacterial and wet viscosity is expected to become an injectable bone repair material for clinical use.

[en] Highlights: • Government should undertake the obligations of supervision to reduce collusion. • Under current re-verification policy GCs tends to collusion in some situations. • The initial re-verification probability is the major factor to collusion behavior. • The GCs with a decreasing IVA are more likely to conceal emission. • The proposed re-verification policy outperforms the current one in some conditions. -- Abstract: Carbon emission verification is one of the key factors required for proper implementation of a cap-and-trade (C&T) system. However, to obtain more revenue, emission generating companies (GCs) may collude with third-party verifiers (3 PVs) and conceal real carbon emission data. Based on actual practice of Shenzhen's C&T system, a three-player game model has been devised in this paper to analyze the behaviors among GCs, 3 PVs and government. Given the government's current piecewise linear re-verification policy, the optimal reported carbon intensity for GCs has been provided. Our research reveals that if the actual carbon intensity is larger than historical carbon intensity GCs may report less carbon intensity and conceal actual carbon emission. To deal with this issue, a new exponential re-verification policy is proposed. Based on authentic data from Shenzhen's C&T system, the experimental results show that the government should devote more attention to GCs with a decreasing industrial product output value-added (IVA) than to those with high carbon emissions when selecting GCs for re-verification. Our experiments also illustrate that the new policy outperforms the current one on both total concealed amount of carbon emission and total re-verification cost if the initial re-verification probability is set within a specific range.

[en] Recently, the concept of superlensing has received considerable attention for its unique ability to produce images below the diffraction limit. The theoretical study has predicted a 'superlens' made of materials with negative permittivity and/or permeability, is capable of resolving features much smaller than the working wavelength and a near-perfect image can be obtained through the restoration of lost evanescent waves (Pendry 2000 Phys. Rev. Lett. 85 3966-9). We have already demonstrated that a 60 nm half-pitch object can indeed be resolved with λ₀/6 resolution with the implementation of a silver superlens with λ₀ = 365 nm illumination wavelength, which is well below the diffraction limit (Fang et al 2005 Science 308 534-7). In order to further support the imaging ability of our silver superlens, a two-dimensional arbitrary object with 40 nm line width was also imaged (Fang et al 2005 Science 308 534-7). In this paper, we present experimental and theoretical investigations of optical superlensing through a thin silver slab. Experimental design and procedures as well as theoretical studies are presented in detail. In addition, a new superlens imaging result is presented which shows the image of a 50 nm half-pitch object at λ₀/7 resolution

[en] Highlights: • A vacuum pressure and temperature swing adsorption process was presented to enrich (separate) hydrogen isotopes, in which two identical separation columns and a transfer bump is used to improve the enrichment (separation) performance. • The presented process was quantitatively compared with other hydrogen isotope chromatographic separation processes, based on three technical indicators: enrichment factor, recovery rate and daily treatment capacity. Aiming to efficiently enrich heavier hydrogen isotope on a large scale, a process named Dual-Column Vacuum Pressure and Temperature Swing Adsorption (DC-VPTSA) was proposed and experimentally tested. The process has the following characteristics: 1) two identical separation columns work together; 2) Pressure Swing Adsorption (PSA) process and Temperature Swing Adsorption (TSA) process are coupled; 3) the gas always keeps one-way flow in different separation columns; 4) the process is always carried out under low temperature or low pressure condition. To verify the feasibility of the process, an experimental device was set up and the hydrogen isotopes enrichment performance was tested. The experimental results show that the process can steadily and efficiently enrich D₂ from H₂. For a H₂-HD-D₂ mixture with 3.63 at.% of D₂ abundance, the enrichment factor reaches about 19.7 and the recovery ratio is better than 99%. The treatment ability reaches a level of 560 SL/day under the condition of the individual column capacity of 71.5 SL. Compared with other processes, the presented process is superior in treatment ability, enrichment factor and recovery ratio.

[en] Ni3Al-based superalloys have excellent mechanical properties which have been widely used in civilian and military Fifield. In this study, the influence of the residual thickness of the interlayer on the stress-strain state in the nodes with soft interlayer was investigated by ccomputer simulation.To establish the general patterns of SSS formation when loading cylindrical nodes with interlayers of soft rigidity and checking the adequacy of the simulation, thickness of interlayer (0.01, 0.03, 0.05, 0.08mm) were calculated. The result shows that in all the thicknesses of the interlayer, both in the main material and in the interlayers, the nature of the distribution and the magnitude of the stiffness coefficients of the stressed state kstiff are practically identical. In the base metal, over most of the joint length, this coefficient is close to 1, decreasing to 0.88 in the nodes with “soft”. This corresponds to the general laws of mechanics and confirms the adequacy of the results of computer simulation. (paper)

[en] Optically generated 20-GHz microwave carriers with phase noise lower than −75 dBc/Hz at 10 kHz offset and lower than —90 dBc/Hz at 100 kHz offset are obtained using single- and double-sideband injection locking. Within the locking range, the effect of sideband injection locking can be regarded as narrow-band amplification of the modulation sidebands. Increasing the current of slave laser will increase the power of beat signal and reduce the phase noise to a certain extent. Double-sideband injection locking can increase the power of the generated microwave carrier while keeping the phase noise at a low level. It is also revealed that partially destruction of coherence between the two beating lights in the course of sideband injection locking would impair the phase noise performance. (fundamental areas of phenomenology(including applications))