Phylogenetic Analysis of Chirality of Twining Plants

Phylogenetic relations of twining chirality of Dioscorea sp.in China were analyzed based on the genes matK,rbcL and trnL;phylogenetic character of higher-level phylogeny of twining plants was analyzed at a high taxon level based on matK gene.A significant phylogenetic framework of chirality was found:(i)based on matK analysis,right-handed Dioscorea species in China congregate completely to form a monophyly;(ii)rbcL and trnL data sets also supported Chinese right-handed Dioscorea a monophyly,although with ex...

Twinings品牌策略:让皇家传统在年轻范中延续

介绍了英国皇室御用茶品牌Twinings的发展历史及这个拥有300多年历史的茶叶品牌如何在品牌标志、店堂设计、产品包装、礼盒创新、品牌传播等方面既让其品牌形象富有历史底蕴、保有典雅英伦风,又能关注年轻群体,持续引领世界饮茶潮流。

Design and Grasping Force Modeling for a Soft Robotic Gripper with Multi-stem Twining

To improve the grasping power of soft robots,inspired by the scene of intertwined and interdependent vine branches safely clinging to habitats in a violent storm and the phenomenon of large grasping force after being entangled by aquatic plants,this paper proposes a soft robotic gripper with multi-stem twining.The proposed robotic gripper can realize a larger contact area of surrounding or containing object and more layers of a twining object than the current twining gripping methods.It not only retains the adaptive advantages of twining grasping but also improves the grasping force.First,based on the mechanical characteristics of the multi-stem twining of the gripper,the twining grasping model is developed.Then,the force on the fiber is deduced by using the twining theory,and the axial force of the gripper is analyzed based on the equivalent model of the rubber ring.Finally,the torsion experiments of fibers and the grasping experiments of the gripper are designed and conducted.The torsion experiment of fibers verifies the influence of a different number of fiber ropes and fiber torque on the grasping force,and the grasping experiment reflects the large load of the gripper and the high adaptability and practicability under different tasks.

奢享TWININGS川宁茶,品味健康生活

"下午时分,围坐在壁炉前,在桌布上绣花,或是坐在窗前捧读雪莱,都是小姐们不错的选择。"《傲慢与偏见》中年轻貌美的姑娘们,总是悠闲地喝着下午茶,等着与某个睿智不凡的绅士结为良缘。极品红茶、精致瓷器或银制茶具、纯白蕾丝花边桌巾、三层点心盘,配以悠扬典雅之曲、清芬馥郁之花,"英式下午茶"已成为英式典雅生活方式的一种象征,一首英国民谣这样唱:"当时钟敲响四下时,世上的一切瞬间为茶而停。"

轻量级密码算法TWINE的唯密文故障分析

研究了唯密文攻击下TWINE密码的安全性,即在唯密文故障攻击下,利用SEI、MLE、HW、GF、GF-SEI、GF-MLE、Parzen-HW、MLE-HE、HW-HE和HW-MLE-HE等一系列区分器进行分析,能够以至少99%的成功概率恢复TWINE密码的主密钥。仿真实验表明,所提新型区分器MLE-HE、HW-HE和HW-MLE-HE可以有效地减少故障数并提高攻击效率。研究结果为分析物联网中轻量级密码算法的安全性提供了重要参考。

Effect of pre-homogenizing treatment on microstructure and mechanical properties of hot-rolled AZ91 magnesium alloys

To improve the homogeneity and rolling formability of as-cast AZ91 magnesium,the effects of pre-homogenizing treatment on microstructure evolution,deformation mechanism,mechanical properties and tensile fracture morphology of hot-rolled AZ91 magnesium alloy were studied.The results showed that the amount of coarseβ-Mg17Al12 phase decreases dramatically,being distributed along the grain boundaries as small strips after homogenizing.Twining plays a dominant role in the deformation mechanism of AZ91 alloys in the experimental condition,while dynamic recrystallization(DRX)considerably occurred in homogenized-rolled alloys,contributed to microstructure uniformity andβ-Mg17Al12 phase precipitated refinement.The tensile strength of homogenized-rolled AZ91 alloys increases dramatically with elongation declining slightly in contrast to homogenized alloys.The fracture surface of homogenized-rolled specimen exhibits more ductile fracture with the manifestation of a large amount of dimples distributing higher density in matrix,while the micro cracks are prone to initiate around the Mg/Mg17Al12 phase interface and grain boundaries owing to the fragile interface bonding of two phases.

Continuous observation of twinning and dynamic recrystallization in ZM21 magnesium alloy tubes during locally heated dieless drawing

Compared to cold drawing,dieless drawing has shown great potential for manufacturing biodegradable Mg alloy microtubes due to the large reduction in area acquired in a single pass.However,owing to the local heating and local deformation,the deformation mechanism during dieless drawing is not clear,and thus causing difficulties in controlling the microstructure of dieless drawn tubes.For the purpose of acquiring a desired microstructure.in this study the deformation mechanism of ZM21 Mg alloy tube was clarified by conducting continuous observation of the microstructural evolution during dieless drawing.The results show that both SRX and DRX occurred during dieless drawing.SRX occurred before the plastic deformation to soften dieless drawn tubes.With increase of feeding speed,the deformation mechanism changed accordingly:(1) At the low-speed of 0.02 mm/s,the deformation mechanism was dominated by twin-slip sliding,during which {10-12} tension twins were generated inside grains to accommodate the plastic deformation by changing the crystal orientation.(2) At the intermediate-speed of 2 mm/s,a twin-DRX process related to {10-12} tension twin was observed,which was characterized by the generation of abundant {10-12} tension twins and the evolution of misorientation angle of {10-12} tension twins.Moreover,the transformation from twin-DRX to CDRX can be observed at the late stage of plastic deformation,which was attributed to the inhomogeneous conditions of dieless drawing.(3) At the high-speed of 5 mm/s,a CDRX process was observed,during which grain boundary sliding and grain tilting were observed,in addition to the gradual rotation of subgrains.These results show that during dieless drawing,DRX is not only a temperature-dependent phenomenon,but also influenced by the variation of feeding speed.

TWINE算法的相关密钥不可能飞来去器攻击

为了评估轻量级分组密码算法TWINE的安全性,利用相关密钥不可能飞来去器的方法对其进行了分析。构造了由16轮和17轮两条路径组成的相关密钥不可能飞来去器区分器,并将16轮和17轮的路径向前扩展4轮、向后分别扩展3轮和2轮,完成对23轮TWINE密码算法(80 bit密钥)的攻击。实验结果表明,该攻击的数据复杂度为262. 05个明文,时间复杂度为270.49次23轮加密,与现有算法相比有明显优势。

一种轻量级TWINE密码硬件优化实现研究

随着物联网的广泛应用,如何有效实现轻量级密码算法成为近年的研究热点。对2011年提出的TWINE加密算法进行了硬件优化实现,相同的轮运算只实现一次,采用重复调用方式完成。TWINE算法总共有36轮运算,其中前35轮运算结构相同,可以重复调用实现,而第36轮相比前35轮在结构上少了块混淆,因此原始算法最多只能进行35轮重复调用。直接进行36轮循环调用运算,同时在36轮循环运算完成后构造一个块混淆逆运算,运算一次块混淆逆运算即可使输出密文正确。这样使TWINE最后的第36轮不必重新实现,而是直接复用前面可重复轮函数模块,只需增加一个比原始算法最后一轮运算相对简单的块混淆逆运算。下载到FPGA上的实验结果表明,优化后的TWINE密码算法在面积上减少了2204个Slices,系统速率提高了5倍。

DEFORMATION TWINNING IN BALL MILLED COPPER

It was found that copper powder after 20h of milling shows the formation of a number of mechanical twins. The observed twins belong to two types: multiple twins and high-order ones.It is suggested that Venables model on mechanical twins in face-center-cubic metals is reasonable in this case. The generation of mechanical twins could be explained as follows:the shear stress (P_(max)) induced by ball milling exceeds the critical shear stress for twinning(τ):the grain size decreases to a critical value below which twinning rather than slip is the preferred mode of deformation as well as the strain rate induced by ball milling is high.

轻量级分组密码算法TWINE差分故障攻击的改进

针对轻量级分组密码TWINE的半字节分组差分扩散规律展开研究,提出一种新的差分故障攻击的方法,并基于S盒差分分布统计规律性计算出恢复轮密钥的概率下界,由此给出完整恢复种子密钥的故障注入次数期望。理论证明和实验结果同时表明,算法第33、34、35轮平均注入9次故障即可完全恢复种子密钥。最后提出故障注入位置的改进,提升了实际攻击的可行性。

轻量级分组密码TWINE的差分故障攻击

为了对轻量级分组密码TWINE的安全性进行研究,分析了轻量级分组密码TWINE的抗差分故障攻击特性,给出了TWINE一种差分故障分析方法,采用面向半字节的随机故障模型对TWINE算法进行攻击。实验结果表明,在35轮注入4次故障后可将密钥空间降低至约220,平均注入13.15次故障后可完全恢复80 bit密钥,最好的情况为注入12次故障完全恢复种子密钥。因此得到结论:TWINE算法易受差分故障攻击,需在使用前对设备加以保护。

分组密码TWINE的中间相遇攻击

将Biclique初始结构与标准的三子集中间相遇攻击相结合,给出了一种普遍的中间相遇攻击模式.与Biclique分析相比,该模式下的攻击作为算法抗中间相遇攻击的结果更为合理.进一步地,评估了算法TWINE抗中间相遇攻击的能力,通过合理选择中立比特位置以及部分匹配位置,给出了18轮TWINE-80以及22轮TWINE-128算法的中间相遇攻击结果.到目前为止,这是TWINE算法分析中数据复杂度最小的攻击结果.

Effect of twine thickness on size-selectivity of driftnet for the yellow croaker Larimichthys polyactis in southwestern Sea of Korea

In order to determine the effect of twine thickness on the size-selectivity of the driftnet used for the yellow croaker, size-selectivity tests were conducted with three different twine thicknesses(monofi lament diameters of 0.279 mm(number's method; No. 3), 0.321 mm(No. 4), and 0.360 mm(No. 5)) of driftnets for the yellow croaker in the seas around Chooja-do, Jeju Islands. The selectivity curve was estimated by using Kitahara's method. In order to determine the physical properties of the twine used in the experimental fi shing nets, we measured the breaking load, elongation, and stiffness under both dry and wet conditions. In terms of physical properties, the thinnest twine(No. 3) had the strongest breaking strength per unit cross-sectional area, along with good elongation and excellent fl exibility. The thickest twine(No. 5) had the lowest fl exibility. In terms of selectivity, the net of No. 3 twine showed the broadest selection range and, thus, a relatively low selectivity compared with the other nets, while the less fl exible net of No. 5 twine showed the narrowest selectivity range and high selectivity. In addition, it was found that a thicker twine resulted in a smaller haul of small fi sh. Therefore, it can be inferred that the thickness of the twine affects the size of the catch and selectivity, and thus the size composition of the catch as well.

Influence of Hot-Rolling Deformation on Microstructure,Crystalline Orientation,and Texture Evolution of the Ti6Al4V-5Cu Alloy

The influence of hot-deformation on the microstructure,crystalline orientation,and texture evolution of Ti6Al4V-5Cu,an antibacterial(α+β)titanium alloy,was investigated.The alloy was deformed using a hot rolling process in 15%,58%,and 73%thickness reduction ratios.It was found that the basal<α→>and pyramidal<c→+α→>type slip planes could be activated in theαphase,which dominated the deformation behavior of Ti6Al4V-5Cu alloy.Under various deformation conditions,the alloy revealed different microstructure features.On the 15%hot rolled alloy,the deformation was performed by the breakdown of priorβgrain boundaries(GBβ),which was attributed to the formation of coarseαgrains,rotated nearly 45°with respect to the transversal and rolling directions.The presence of different sub-structure geometries made the interior grain size distribution heterogeneous.On the 58%hot rolled alloy,Ti2Cu intermetallic compound was found at theα/βinterface.High-resolution transmission electron microscopy investigation showed the occurrence of grain rotation in different crystallographic directions.At room temperature,the percentage elongation(El)of the alloy reached 23.15%on the 58%hot rolled sample.On the 73%deformed alloy,refined and randomly oriented characteristics of grains were obtained due to higher thickness reduction,which resulted from the segregation of very fine granules.The influence of grain rotation during a hot rolling process revealed that theα/βtexture fiber separation angle to maintain the Burger orientation relationship of{0001}α//{110}βplanes decreased with increase of the thickness reduction ratio when Ti6Al4V-5Cu alloy was deformed by a hot rolling mechanism.Activation of tensile{1012}<1011>and compressive{1122}<1123>twins on the deformation of the alloy was also studied.

Multidimensional linear cryptanalysis with key difference invariant bias for block ciphers

For block ciphers,Bogdanov et al.found that there are some linear approximations satisfying that their biases are deterministically invariant under key difference.This property is called key difference invariant bias.Based on this property,Bogdanov et al.proposed a related-key statistical distinguisher and turned it into key-recovery attacks on LBlock and TWINE-128.In this paper,we propose a new related-key model by combining multidimensional linear cryptanalysis with key difference invariant bias.The main theoretical advantage is that our new model does not depend on statistical independence of linear approximations.We demonstrate our cryptanalysis technique by performing key recovery attacks on LBlock and TWINE-128.By using the relations of the involved round keys to reduce the number of guessed subkey bits.Moreover,the partial-compression technique is used to reduce the time complexity.We can recover the master key of LBlock up to 25 rounds with about 260.4 distinct known plaintexts,278.85 time complexity and 261 bytes of memory requirements.Our attack can recover the master key of TWINE-128 up to 28 rounds with about 261.5 distinct known plaintexts,2126.15 time complexity and 261 bytes of memory requirements.The results are the currently best ones on cryptanalysis of LBlock and TWINE-128.

Multidimensional linear cryptanalysis with key difference invariant bias for block ciphers

For block ciphers,Bogdanov et al.found that there are some linear approximations satisfying that their biases are deterministically invariant under key difference.This property is called key difference invariant bias.Based on this property,Bogdanov et al.proposed a related-key statistical distinguisher and turned it into key-recovery attacks on LBlock and TWINE-128.In this paper,we propose a new related-key model by combining multidimensional linear cryptanalysis with key difference invariant bias.The main theoretical advantage is that our new model does not depend on statistical independence of linear approximations.We demonstrate our cryptanalysis technique by performing key recovery attacks on LBlock and TWINE-128.By using the relations of the involved round keys to reduce the number of guessed subkey bits.Moreover,the partial-compression technique is used to reduce the time complexity.We can recover the master key of LBlock up to 25 rounds with about 2^(60.4)distinct known plaintexts,2^(78.85)time complexity and 2^(61)bytes of memory requirements.Our attack can recover the master key of TWINE-128 up to 28 rounds with about 2^(61.5)distinct known plaintexts,2^(126.15)time complexity and 261 bytes of memory requirements.The results are the currently best ones on cryptanalysis of LBlock and TWINE-128.

Hydroelasticity analysis of a vessel-shaped fish cage under incident,diffraction and radiation wave fields

Vessel-shaped fish cages are promising large aquaculture structures developed in recent years,with an overall length of nearly 400 m.In this paper,a coupled hydroelasticity model of a vessel-shaped fish cage is used to calculate the motion and structural response in the time domain.First,the floating body of the cage is discretized into a multimodule system to calculate the frequency-domain hydrodynamic loads.Then,the multimodule system is connected by equivalent elastic beams to consider the hydroelastic be-havior in the time domain.The hydrodynamic loads of the multimodule system are transformed from the frequency-domain loads.Moreover,based on the velocity field transfer functions and the motion of the multimodule system,coupling wave fields considering incident,diffraction and radiation waves are built and used to calculate the loads on the net and steel frame.By iterating the motion response of the multi-module system and the hydrodynamic loads on the net and steel frame in the time domain,the balanced hydroelasticity response of the whole cage is finally obtained.The results show that the hydroelasticity effects have a significant influence on the vertical displacement and cross-sectional load effects of the vessel-shaped fish cage.

TWINE密码算法的多维零相关线性分析

TWINE密码算法的分组长度为64bit,支持2种密钥长度,分别为TWINE-80和TWINE-128,本文的研究对象为TWINE-128。本文构造了一个与TWINE算法等价的传统的双分支Feistel结构。利用此结构特性,首先构造了算法的14轮零相关线性逼近,之后对24轮的TWINE-128进行了多维零相关线性分析。攻击过程的数据复杂度约为262.1个明密文对,计算复杂度为2107.1次24轮加密。由此可得,缩减轮数(24轮)的TWINE-128对于零相关线性分析方法是不安全的。