Security analysis of satellite-to-ground reference-frame-independent quantum key distribution with beam wandering

The reference-frame-independent(RFI)quantum key distribution(QKD)is suitable for satellite-based links by removing the active alignment on the reference frames.However,how the beam wandering influences the performance of RFI-QKD remains a pending issue in satellite-to-ground links.In this paper,based on the mathematical model for characterizing beam wandering,we present the security analysis for satellite-to-ground RFI-QKD and analytically derive formulas for calculating the secret key rate with beam wandering.Our simulation results show that the performance of RFI-QKD is better than the Bennett–Brassard 1984(BB84)QKD with beam wandering in asymptotic case.Furthermore,the degree of influences of beam wandering is specifically presented for satellite-to-ground RFI-QKD when statistical fluctuations are taken into account.Our work can provide theoretical support for the realization of RFI-QKD using satellite-to-ground links and have implications for the construction of large-scale satellite-based quantum networks.

ENTIRE SOLUTIONS OF HIGHER ORDER DIFFERENTIAL EQUATIONS WITH ENTIRE COEFFICIENTS HAVING THE SAME ORDER

In this paper,we consider entire solutions of higher order homogeneous differential equations with the entire coefficients having the same order,and prove that the entire solutions are of infinite lower order.The properties on the radial distribution,the limit direction of the Julia set and the existence of a Baker wandering domain of the entire solutions are also discussed.

Text Difficulty,Working Memory Capacity and Mind Wandering During Chinese EFL Learners’Reading

This experimental study investigated how text difficulty and different working memory capacity(WMC)affected Chinese EFL learners’reading comprehension and their tendency to engage in task-unrelated thoughts,that is,mind wandering(MW),in the course of reading.Sixty first-year university non-English majors participated in the study.A two-factor mixed experimental design of 2(text difficulty:difficult and simple)×2(WMC:high/large and low/small)was employed.Results revealed that 1)the main and interaction effects of WMC and text difficulty on voluntary MW were significant,whereas those on involuntary MW were not;2)while reading the easy texts,the involuntary MW of high-WMC individuals was less frequent than that of low-WMC ones,whereas while reading the difficult ones,the direct relationship between WMC and involuntary MW was not found;and that 3)high-WMC individuals had a lower overall rate of MW and better reading performance than low-WMC individuals did,but with increasing text difficulty,their rates of overall MW and voluntary MW were getting higher and higher,and the reading performance was getting lower and lower.These results lend support to WM theory and have pedagogical implications for the instruction of L2 reading.

Necrolytic migratory erythema caused by pancreatic hyperglycemia with emphasis on therapeutic and prognosis:A case report

BACKGROUNDWith the incidence of pancreatic diseases increasing year by year,pancreatichyperglycemia,as one of the common complications,is gradually gaining attentionfor its impact on the skin health of patients.CASE SUMMARYThis was the case of an elderly female with clinical manifestations of necrolyticmigratory erythema,“three more and one less,”diabetes mellitus,hypertension,anemia,hypoproteinemia,and other syndromes,which had been misdiagnosedas eczema.Abdominal computed tomography showed a pancreatic caudal spaceoccupyinglesion,and the magnetic resonance scanning of the epigastric regionwith dynamic enhancement and diffusion-weighted imaging suggested a tumorof the pancreatic tail,which was considered to be a neuroendocrine tumor orcystadenoma.The patient was referred to a more equipped hospital for laparoscopicpancreatic tail resection.Post-surgery diagnosis revealed a neuroendocrinetumor in the tail of the pancreas.To date,the patient’s general condition is good,and she is still under close follow-up.CONCLUSIONNecrolytic migratory erythema can be induced by endocrine system tumors orendocrine metabolic abnormalities,with complex clinical manifestations,difficultdiagnosis,and easy misdiagnosis by dermatologists.The initial treatment principlesin dermatology include symptomatic supportive therapy and effectivedrugs to relieve skin lesions.After clarifying the etiology of glucagonoma,comprehensive treatment in collaboration with endocrinologists,generalsurgeons,and oncologists can help provide individualized treatment for patientsand improve their prognosis.

Resonance From the Past to the Future:Mythological Metaphors in Chinese Science Fiction Films

This paper is centered on the extent to which contemporary Chinese science fiction is related to ancient Chinese mythologies according to the previous scholarly discussion and how these ancient mythologies are utilized specifically in the futuristic narratives of modern Chinese science fiction.By referring to academic dialogues,this paper argues that ancient mythologies can be recreated in modern science fiction and create modern mythologies in futuristic narratives to present or deal with modern human fears.Based on this argument,this paper then continues to explore what kinds of modern mythologies science fiction might deliver.The Chinese film The Wandering Earth(2019)will be discussed in terms of its mythological symbols and metaphors.This paper proposes a new approach through which to reconnect past stories with futuristic narratives and builds a frame in which to contextualize ancient mythologies in contemporary Chinese culture.

一种wandering B+tree问题解决方法

为了应对磁盘和固态硬盘随机写和顺序写性能差异较大的问题,文件系统和块存储系统通常采用日志结构(log-structured)技术将随机写转换为顺序写.因此,对于日志结构存储系统数据和元数据的修改都以异地写的方式执行.在日志结构存储系统中,B+tree常被用于管理元数据,这就会导致wandering B+tree问题,即树结点异地更新会导致树结构递归更新.目前,现有工作主要通过分离树结点的逻辑索引和物理地址,并使用额外的数据结构和物理设备空间存放树结点逻辑索引和物理地址的映射,从而避免递归更新树结构.但现有方法既引入额外空间开销,又存在额外物理设备空间非顺序写的问题.提出IBT B+tree,将树结点逻辑索引和物理地址均存放在树结构中.同时,基于IBT B+tree结构引入dirty链表设计,并提出了非递归更新的IBT B+tree下刷算法.IBT B+tree既解决了wandering B+tree问题,又不引入额外的数据结构和物理设备空间,消除了固定物理设备空间的非顺序写.分别实现IBT B+tree和基于F2FS中NAT设计的B+tree,在此基础上设计实现Monty-Dev块存储系统以评价2棵B+tree.实验表明,在HDD和SSD介质上,IBT B+tree在写放大和下刷效率方面均优于NAT B+tree.

Wandering spleen torsion with portal vein thrombosis:A case report

BACKGROUND Wandering spleen is rare clinically.It is characterized by displacement of the spleen in the abdominal and pelvic cavities and can have congenital or acquired causes.Wandering spleen involves serious complications,such as spleen torsion.The clinical symptoms range from asymptomatic abdominal mass to acute abdominal pain.Surgery is required after diagnosis.Cases of wandering spleen torsion with portal vein thrombosis(PVT)are rare.There is no report on how to eliminate PVT in such cases.CASE SUMMARY Ultrasound and computed tomography revealed a diagnosis of wandering spleen torsion with PVT in a 31-year-old woman with a history of childbirth 16 mo previously who received emergency treatment for upper abdominal pain.She recovered well after splenectomy and portal vein thrombectomy combined with continuous anticoagulation,and the PVT disappeared.CONCLUSION Rare and nonspecific conditions,such as wandering splenic torsion with PVT,must be diagnosed and treated early.Patients with complete splenic infarction require splenectomy.Anticoagulation therapy and individualized management for PVT is feasible.

An Analog Equalizer and Baseline-Wander Cancelle rfor 100/1000Base-TX Transceiver

A frequency-domain equalizer with a mixed-signal adaptive control loop and a novel baseline wander （BLW） canceller are proposed. The equalizer is independent of channel-modeling accuracy,and its control loop is intrinsically stable. An AGC function is incorporated into the equalizer without an extra AGC circuit. The proposed BLW canceller uses a peak detector to monitor the BLW and full feedback method to accomplish BLW canceling. High canceling accuracy and robust performance are achieved. The circuits are tested in 0.25μm CMOS technology. Better performance and smaller silicon area are achieved compared with results in the literature.

试论华兹华斯的田园情结

华兹华斯是英国著名的"湖畔诗人",在他的诗篇中可以看到慵懒的田园、茫茫的草原、甚至绵延的山川和那山川间金色的水仙等等,这些大自然赋予人类的自然宝藏,都深深留在了这位浪漫主义田园诗人的心底,他将大自然的美凝练成诗,烘托出浓郁的生活气息和美感。大自然的美不仅赋予诗人慰藉和欢欣,同时还成为他创作的源泉。他以其优美的自然诗篇向世人展示了一幅幅独特新颖的哲理画卷,并以质朴、清新、自然的语言开创了全新的诗歌时代。

近地FSO长距离链路特性及建模

本文简要描述了采用不同传输介质作为光信道的三类自由空间光通信(FSO)系统。分析了FSO系统终端通用模型及实现的关键技术。在此基础上,重点讨论了近地FSO长距离链路特性及建模。

Intensity distribution properties of Gaussian vortex beam propagation in atmospheric turbulence

By using wave optics numerical simulation, the intensity-hole effect, beam spreading and wandering properties of Gaussian vortex beam propagation in atmospheric turbulence are investigated quantitatively. It is found that an intensity hole in the center of the beam pattern appears gradually as a Gaussian vortex beam propagates. The size of the intensity hole increases with the increase of the topological charge of the vortex phase. However, the intensity hole could to some extent be filled with optical energy by atmospheric turbulence, especially in strong turbulence. The radius of the intensity hole first decreases and then increases with the growth of turbulence strength. The effective radius of vortex beam with larger topological charge is greater than with a smaller topological charge. But the topological charge has no evident influence on beam wandering.

Wandering gravel-bed rivers and high-constructive stable channel sandy fluvial systems in the Ross River area,Yukon Territory,Canada

Mid-Cretaceous strata within the Tintina Trench, 3 km west of the community of Ross River, contain evidence of deposition in two distinct, alternating, fluvial settings. Coal-bearing, mud-dominated strata are commonly associated with high-constructive sandy channel systems, with extensive overbank, levee and splay deposits. Channels are between 3 and 30 m wide and 0.4-7 m thick. They show repetitive development of side and in-channel bar-forms, as well as up-channel widening of the rivers by selective erosion of associated overbank and levee deposits. Levees extended for several hundred metres away from the channels. In this setting low-angle inclined stratification and epsilon cross stratification may reflect lateral migration of crevasse channels or small streams. The paucity of exposure prevents recognition of the channels as products of multiple channel anastomosed systems or single channel high-constructive systems. Gravel-dominated strata, inter-bedded with, and overlying coal-bearing units, are interpreted as deposits of wandering gravel-bed rivers, with sinuosity approaching 1.4. In most exposures they appear to be dominated by massive and thin planar-bedded granule to small pebble conglomerates, which would traditionally be interpreted as sheet-flood or longitudinal bar deposits of a high-gradient braided stream or alluvial fan. Architectural analysis of exposures in an open-pit shows that the predominance of flat bedding is an artefact of the geometry of the roadside exposures. In the pit the conglomerates are dominated by large scale cross stratification on a scale of 1-5.5 m. These appear to have developed as downstream and lateral accretion elements on side-bars and on in-channel bars in water depths of 2-12 m. Stacking of strata on domed 3rd order surfaces suggests development of longitudinal in-channel bar complexes similar to those observed in parts of the modern Rhone River system. Mudstone preserved in some of the channels reflects intervals of channel abandonment or avulsion. Minimum channel width is from 70 to 450 m.

LIMITING DIRECTION AND BAKER WANDERING DOMAIN OF ENTIRE SOLUTIONS OF DIFFERENTIAL EQUATIONS

In this paper, we mainly investigate entire solutions of complex differential equations with coefficients involving exponential functions, and obtain the dynamical properties of the solutions, their derivatives and primitives. With some conditions on coefficients, for the solutions, their derivatives and their primitives, we consider the common limiting directions of Julia set and the existence of Baker wandering domain.

Apparent Polar Wander Path from the Tarim Block in China

The apparent polar wander (APW) path from the Tarim block consists of palaeo-magnetic poles ofDevonian (λ=16°N, ψ= 165° E. A_(95)=4°). Late Carboniferous (λ=41° N, ψ=160° E, A_(95)=4°).Permian (λ=61°N, ψ=177° E. A_(95)=9°). Early Triassic (λ=69° N. ψ=183° E. A_(95)=11°) andJurassic/Cretaceous (λ=65° N, ψ=214° E. A_(95)=6°) times. On the basis of this APW path, it is con-cluded that the Tarim block was subducted beneath the Kazakstan plate between Devonian and Permiantimes. The Tarim, North China and South China blocks were sutured between the Early Triassic and EarlyCretaceous. Tarim had moved eastward some 2000 km relative to Siberia since the Cretaceous.

Unusual association of Axenfeld-Rieger syndrome and wandering spleen:A case report

BACKGROUND Axenfeld-Rieger syndrome(ARS)is an autosomal dominant genetic disease characterized by ocular developmental disorders and its association with torsion of wandering spleen(WS)has not been reported to date to the best of our knowledge.This study aimed to describe a rare case of ARS observed at our emergency department.CASE SUMMARY A 25-year-old female presented with a constant lower abdominal pain of increasing severity.Diagnostic computed tomography with intravenous contrast material showed a non-homogenously enhanced splenic parenchyma with a twisted vascular pedicle.Further,an emergent laparoscopic exploration was performed,and an ischemic spleen without its normal ligamentous attachments was noted.Notably,the spleen did not regain its normal vascularity after detorsion;thus,we performed the laparoscopic total splenectomy.The postoperative course was uneventful,and the patient was discharged on the 5th postoperative day.This case demonstrates a rare association of WS and ARS.CONCLUSION Early diagnosis of WS in the emergency department is important to prevent pedicle torsion or splenic necrosis and to avoid splenectomy.

Tectonic geomorphological characteristics for evolution of the Manas Lake

Owing to global climatic changes and human activities,the lakes have changed dramatically in the Junggar Basin of Xinjiang in recent 50 years. Based on the remote sensing images from Beijing Satellite No.1 in 2006 together with the measured topographical data in 1999 and other data since the 1950s,this paper analyzes mainly the features of landforms around the Manas Lake and the changes of feeding sources of the lake. The results are as follows:(1) Tectonic movement brought about the fundamental geomorphological basis for lacustrine evolution,and the Manas Lake is one of small lakes broken up from the Old Manas Lake due to tectonic movement and drought climate; the Manas Lake had existed before the Manas River flowed into it in 1915. The geomorphologic evidences for evolution of the Manas Lake include:(a) Diluvial fans and old channels at the north of the lake indicate that the rivers originating from the north mountains of the Junggar Basin had fed the Old Manas Lake and now still feed the lake as seasonal rivers; (b) The Old Manas Lake was fed by many rivers originating from the mountains,except for the Manas River,from the evidence of small lakes around the Manas Lake,old channels,alluvial fans,etc.; (c) The elevations of the alluvial and diluvial fans are near to the 280 m a.s.l. and all of the small lakes and lacustrine plains are within the range of the 280 m a.s.l.,which may prove that the elevation of the Old Manas Lake was about 280 m a.s.l.; (d) Core analysis of the Manas Lake area also indicates that the Manas Lake has existed since Late Pleistocene epoch. (2) Analysis on the feeding relations between the lakes and the lacustrine evolution shows that human activities are one of main driving forces of the lacustrine evolution in recent 50 years,and it is the precondition of restoring and maintaining the lacutrine wetlands in the study area to satisfy the feeding of the Baiyang and Manas rivers to the Manas Lake.

Transcendence and Wandering

Shen Congwen and Thomas Hardy are both known for their regional novels,Hardy for his "Wessex" novels,and Shen Congwen for his "World of Xiangxi" .Both writers display a sense of transcendence and wandering in their female characters.Both Xiao Xiao in Shen Congwen' s Xiao Xiao and Eustacia in Hardy' s The Return of the Native transcend the traditions and customs of their times,and experience a consequent wandering.But the ways of the two writers in presenting their heroines is quite different.While Xiao Xiao was mentally active but did nothing except follow the traditional system,Eustacia' s thought was followed by her own words and actions.

A Stylistic Appreciation of Song for the Wandering Jew

As an important romantic poet,William Wordsworth produced large numbers of poems known for refined rhymes,images and thoughts,which are exemplified by Song for the Wandering Jew.This paper analyzes this poem by a stylistic approach which shows how sounds,images and syntax artistically made contribution to the poetic quality.

Wandering crowd simulation based on space syntax theory

Space syntax has proven there appears to be a fundamental process that informs human and social usage of an environ- ment, and the effects of spatial configuration on movement patterns are consistent with a model of individual decision behavior. In- troducing space syntax to crowd simulation will enable space structure guide the random movement of the crowd with no specific targets. This paper proposes a simulation method of the wandering crowd, which calculates the crowd distribution corresponding to the space through space syntax and uses a hybrid path planning algorithm to dynamically navigate the crowd to conform to the dis- tribution. Experiments show the presented method can obtain reasonable and vision-realistic simulation results.