Resource Trading and Miner Competition in Wireless Blockchain Networks with Edge Computing

To promote the application of edge com-puting in wireless blockchain networks,this paper presents a business ecosystem,where edge comput-ing is introduced to assist blockchain users in imple-menting the mining process.This paper exploits re-source trading and miner competition to enable se-cure and efficient transactions in the presented busi-ness ecosystem.The resource trading problem is for-mulated as a Stackelberg game between miner candi-dates and edge computing servers,where computing,caching,and communication resources are jointly op-timized to maximize the potential profit.Partial of-floading is introduced to further enhance the system performance when compared with the existing work.We analyze the existence and uniqueness of the Nash equilibrium and Stackelberg equilibrium.Based on the optimization result,winners are selected from the set of miner candidates by bidding and constitute the mining network.Simulation results demonstrate that the proposal is able to improve the social welfare of blockchain miners,thus stimulating more blockchain users to join the mining network.

眼球震颤诊治进展

眼球震颤是指双眼有节律的、不自主的,常呈对称共轭性的异常摆动,可根据发病年龄分为先天性眼球震颤和后天获得性眼球震颤。由于目前有限的诊治手段使得眼球震颤成为较为复杂的眼科疑难疾病之一。近年来,国际和国内对该类疾病的检测和诊疗水平在不断进步。本文将对眼球震颤的分类及特点,检查记录方法以及治疗的新进展进行综述。

4D数字化弱视斜视矫治系统对远视性屈光不正性及屈光参差性弱视的疗效观察

目的:评估4D数字化弱视斜视矫治系统对远视性屈光不正性及远视性屈光参差性弱视儿童的疗效。方法:招募3~9岁远视性屈光不正性及远视性屈光参差性弱视患者48例(其中远视性屈光不正性弱视18例36眼,远视性屈光参差性弱视30例30眼),所有患者排除其他眼病,在屈光矫正、合理遮盖的基础上接受4D数字化弱视斜视矫治系统的训练。初期训练以提高视力为主,视力达0.6以上者加上脱抑制训练及双眼视功能训练。比较训练前、后的视力及双眼立体视变化情况。结果:远视性屈光不正性弱视患者共18例36眼,其中轻度弱视组13眼,中度弱视组19眼,重度弱视组4眼。远视性屈光参差性弱视患者共30例30眼,根据弱视程度分为轻度弱视组5眼,中度弱视组13眼,重度弱视组12眼。治疗60次后视力均有明显提高。治疗60次后立体视有明显提高,且与屈光度无关(P>0.05),与初始视力及治疗后视力均呈正相关(P<0.05),与屈光参差量呈正相关(P<0.05)。结论:4D数字化弱视斜视矫治系统联合传统的弱视治疗方法能有效提高3~9岁远视性屈光不正性弱视和远视性屈光参差性弱视儿童的视力并改善其双眼视功能。

Tracing the formation of oxygen vacancies at the conductive LaAlO3/SrTiO3 interface via photoemission

The two-dimensional electron gas(2DEG)generated at the LaAlO3/SrTiO3 interface has been in the focus of oxides re-search since its first discovery.Although oxygen vacancies play an important role in the generation of the insulator-to-metal transition of the SrTiO3 bare surface,their contribution at the LaAlO3/SrTiO3 interface remains unclear.In this work,we investigated a LaAlO3/SrTiO3 heterostructure with regional distribution of defect-based localized polar sites at the interface.Using static and time-resolved threshold photoemission electron microscopy,we prove that oxygen vacan-cies are induced near those polar sites,resulting in the increase of carrier density of the 2DEG states.In addition,oxy-gen-related surface states were uncovered,which we attributed to the release of lattice oxygen during the formation of oxygen vacancies.Such effects are mainly found spatially located around the defect sites at the buried interface,while other regions remain unaffected.Our results confirm that the itinerant electrons induced by oxygen vacancies can coex-ist with the charge transfer mechanism in the LaAlO3/SrTiO3 heterostructure,together leading to the formation of the metallic interface.These observations provide fundamental insights into the nature of LaAlO3/SrTiO3 interface based 2DEG and unique perspectives for potential applications.

Tailoring molecular island shapes:influence of microscopic interaction on mesostructure

Controlling the structure formation of molecules on surfaces is fundamental for creating molecular nanostructures with tailored properties and functionalities and relies on tuning the subtle balance between intermolecular and molecule-surface interactions.So far,however,reliable rules of design are largely lacking,preventing the controlled fabrication of self-assembled functional structures on surfaces.In addition,while so far many studies focused on varying the molecular building blocks,the impact of systematically adjusting the underlying substrate has been less frequently addressed.Here,we elucidate the potential of tailoring the mesoscopic island shape by tuning the interactions at the molecular level.As a model system,we have selected the molecule dimolybdenum tetraacetate on three prototypical surfaces,Cu(111),Au(111)and CaF2(111).While providing the same hexagonal geometry,compared to Cu(111),the lattice constants of Au(111)and CaF2(111)differ by a factor of 1.1 and 1.5,respectively.Our high-resolution scanning probe microscopy images reveal molecular-level information on the resulting islands and elucidate the molecular-level design principles for the observed mesoscopic island shapes.Our study demonstrates the capability to tailor the mesoscopic island shape by exclusively tuning the substrate lattice constant,in spite of the very different electronic structure of the substrates involved.This work provides insights for developing general design strategies for controlling molecular mesostructures on surfaces.

Cultivation and diversity analysis of novel marine thraustochytrids

Thraustochytrids are a group of unicellular marine heterotrophic protists,and have long been known for their biotechnological potentials in producing squalene,polyunsaturated fatty acids(PUFAs)and other bioactive products.There are less than a hundred known strains from diverse marine habitats.Therefore,the discovery of new strains from natural environments is still one of the major limitations for fully exploring this interesting group of marine protists.At present,numerous attempts have been made to study thraustochytrids,mainly focusing on isolating new strains,analyzing the diversity in specific marine habitats,and increasing the yield of bioactive substances.There is a lack of a systematic study of the culturable diversity,and cultivation strategies.This paper reviews the distribution and diversity of culturable thraustochytrids from a range of marine environments,and describes in detail the most commonly used isolation methods and the control of culture parameters.Furthermore,the perspective approaches of isolation and cultivation for the discovery of new strains are discussed.Finally,the future directions of novel marine thraustochytrid research are proposed.The ultimate goal is to promote the awareness of biotechnological potentials of culturable thraustochytrid strains in industrial and biomedical applications.