Design of a 3D-printed liquid lithium divertor target plate and its interaction with high-density plasma

A liquid Li divertor is a promising alternative for future fusion devices.In this work a new divertor model is proposed,which is processed by 3D-printing technology to accurately control the size of the internal capillary structure.At a steady-state heat load of 10 MW m^(-2),the thermal stress of the tungsten target is within the bearing range of tungsten by finite-element simulation.In order to evaluate the wicking ability of the capillary structure,the wicking process at 600℃ was simulated by FLUENT.The result was identical to that of the corresponding experiments.Within 1 s,liquid lithium was wicked to the target surface by the capillary structure of the target and quickly spread on the target surface.During the wicking process,the average wicking mass rate of lithium should reach 0.062 g s^(-1),which could even supplement the evaporation requirement of liquid lithium under an environment>950℃.Irradiation experiments under different plasma discharge currents were carried out in a linear plasma device(SCU-PSI),and the evolution of the vapor cloud during plasma irradiation was analyzed.It was found that the target temperature tends to plateau despite the gradually increased input current,indicating that the vapor shielding effect is gradually enhanced.The irradiation experiment also confirmed that the 3D-printed tungsten structure has better heat consumption performance than a tungsten mesh structure or multichannel structure.These results reveal the application potential and feasibility of a 3D-printed porous capillary structure in plasma-facing components and provide a reference for further liquid-solid combined target designs.

灰色系统理论在化学检测不确定度评定中的应用

本文从灰理论原理出发,将化学检测过程视作一个灰色过程,应用灰理论对化学检测结果进行分析,评定测量不确定度,表述了灰色评定在化学检测领域不确定度评定中的可行性。

Superficial Layer MHD Effect and Full-Cover Free Surface Flow Characterizing

Up to now, no a real full-cover liquid metal (LM) free surface flow have been successfully used in magnetic fusion devices as MHD instability and unavoidable rivulet flow. Recently, after we carried out a guidable free curve-surface flow on theoretically and experimentally, seeking for other way to get a full-cover free surface flow is also in implementing. The superficial layer MHD effect in free surface flow is experimentally observed. After compared and analyzed the characteristic parameters of the free surface flow, the conditions of full-cover free surface flow are found. Meanwhile, the new two parameters of surface cover ratio and rivulet flow index are introduced to characterize the flowing characteristic of the full-cover free surface flow under magnetic field. According to the analysis rule, for different liquid metal, there are the different unique conditions to meet full-cover free surface flow under magnetic field. This may be a way to solve free surface flow major MHD key issue for LM PFCs.

Experimental Base of an Innovation S-Channel to Reduce MHD Pressure Drop

Consequent on MHD geometry sensibility phenomena was measured in an accident case;the more detail experiments have been conducted at the liquid metal experimental loop upgrade facility (LMEL-U). The experimental results indicate that MHD pressure drop can be greatly reduced in the special designed ducts. Base on the experimental data, an innovation channel concept (tentatively called as the secondary flow channel, short in “S-channel”) is addressed as a reducing MHD pressure drop channel for the application of a liquid metal blanket system in fusion reactor. It may be a dawn for solving MHD pressure drop key issue of liquid metal blanket system.

Threshold public key encryption scheme resilient against continual leakage without random oracles

Threshold public key encryption allows a set of servers to decrypt a ciphertext if a given threshold of authorized servers cooperate. In the setting of threshold public key encryption, we consider the question of how to correctly decrypt a ciphertext where all servers continually leak information about their secret keys to an external attacker. Dodis et al. and Akavia et al. show two concrete schemes on how to store secrets on continually leaky servers. However, their construc- tions are only interactive between two servers. To achieve continual leakage security among more than two servers, we give the first threshold public key encryption scheme against adaptively chosen ciphertext attack in the continual leak- age model under three static assumptions. In our model, the servers update their keys individually and asynchronously, without any communication between two servers. Moreover, the update procedure is re-randomized and the randomness can leak as well.

Photosynthesis and biochemical responses to elevated O_3 in Plantago major and Sonchus oleraceus growing in a lowland habitat of northern China

A field experiment was carried out to compare the responses to ozone （03） in two common herbaceous plant species, Plantago major L. and Sonchus oleraceus L., by building open-top growth chambers in situ to simulate 03 stress （＋03, 85 ± 5 ppb, 9 hr/day for 30 days） in a lowland habitat in Inner Mongolia, Northern China. Responses to 03 of gas exchange, chlorophyll a fluorescence, leaf pigment content, andoxidant capability, soluble protein content, membrane lipid peroxidation and dark respiration （Rd） were analyzed. Results showed that elevated 03 exposure significantly reduced the light-saturated net photosyn- thesis （PNsat）, stomata] conductance （gs） and transpiration rate （E） in both species. Although non-significant interactive effect between species and 0s on PNsat was analyzed, the reduction in PNsat in S. oleraceus might be due primarily to the higher fraction of close PSII reaction centers and impaired activities of plant mesophyll cells as evidences by decreased maximum efficiency of PSII photochemistry after dark adapted state （Fv/Fm） and unchanged intercellular CO2 concentration （Ci）. Besides, biochemical analysis showed that S. oleraceus had lower antioxidant ability compared to P. major. As a result, S. oleraceus was damaged to the larger extent in terms of lipid peroxidation and visible O3 injury, indicating that S. oleraceus was more sensitive to O3 than P. major. Our results indicated that wild herbaceous plant species growing in a lowland habitat in sandy grassland were sensitive to O3 stress and S. oleraceus can be considered as one of the bio-indicators for high O3 concentration in semi-arid -rassland of northern China.

New forward-secure signature schemes with untrusted update

In this paper, we present two forward-secure signature schemes （FSS） with untrusted update. Our constructions use ideas from the work of Abdalla et al. [1] and Kozlov and Reyzin [2] in their forward-secure digital signature schemes. Our schemes are proven to be forward-secure based on the hardness of factoring in the random oracle model. Both schemes use the same method to encrypt the private key and are more efficient than Libert scheme [3] without adding any burden to the original forward-secure schemes.