Robustα-Fe_(2)O_(3)/Epoxy Resin Superhydrophobic Coatings for Anti-icing Property

α-Fe_(2)O_(3)/epoxy resin composite superhydrophobic coating was prepared withα-Fe_(2)O_(3) nanoparticles and epoxy resin by spin coating method.The coating without epoxy resin has higher contact angle(CA)and lower ice adhesion strength(IAS),but the mechanical properties are poor.Theα-Fe_(2)O_(3)/epoxy resin composite superhydrophobic coating exhibits good mechanical durability.In addition,compared with the bare aluminum substrate,the Ecorr of the composite coating is positive and the Jcorr is lower.The inhibition efficiency of the composite coating is as high as 99.98%in 3.5 wt%NaCl solution.The difference in the microstructure caused by the two preparation methods leads to the changes in mechanical properties and corrosion resistance of composite superhydrophobic coating.

Study of Flow and Heat Transfer in an Ejector-Driven Swirl Anti-Icing Chamber

The formation of ice on the leading edge of aircraft engines is a serious issue,as it can have catastrophic consequences.The Swirl Anti-Icing(SAI)system,driven by ejection,circulates hot fluid within a 360°annular chamber to heat the engine inlet lip surface and prevent icing.This study employs a validated Computational Fluid Dynamics(CFD)approach to study the impact of key geometric parameters of this system on flow and heat transfer characteristics within the anti-icing chamber.Additionally,the entropy generation rate and exergy efficiency are analyzed to assess the energy utilization in the system.The research findings indicate that,within the considered flow range,reducing the nozzle specific areaφfrom 0.03061 to 0.01083 can enhance the ejection coefficient by over 60.7%.This enhancement increases the air circulating rate,thereby intensifying convective heat transfer within the SAI chamber.However,the reduction inφalso leads to a significant increase in the required bleed air pressure and a higher entropy generation rate,indicating lower exergy efficiency.The nozzle angleθnotably affects the distribution of hot and cold spots on the lip surface of the SAI chamber.Increasingθfrom 0°to 20°reduces the maximum temperature difference on the anti-icing chamber surface by 60 K.

白盒化Piccolo密码算法的设计与应用

白盒攻击环境下敌手可以完全获取甚至改变密码算法的运行过程,给数据安全带来巨大威胁,目前移动终端、无线传感器网络(WSN)等部分轻量级应用场景均可视作白盒环境。通过改进Piccolo算法的部分结构与迭代方式将其进行白盒化实现,采用自编码查找表,根据给定的映射关系对数据分区进行标记,添加数据标记编码,并结合仿射变换等操作将密钥信息进行隐藏,能够保障较高的查表效率与白盒安全性。经安全性分析与对比,白盒化的Piccolo算法白盒多样性与白盒含混度数值较高,并且可以应对侧信道攻击、代码提取攻击、BGE攻击、MGH攻击、仿射编码恢复攻击等多种密码攻击方式,能在WSN等硬件资源受限的场景下得到良好部署与应用。

State of the art and practice of pavement anti-icing and de-icing techniques

Pavement snow and icing are worldwide problems, but effective countermeasures are just beginning to be developed in China. The two most common snow and ice removal methods are mechanical clearance and chemical melting, and the advantages and disadvantages of each approach are discussed here, including environmental and structural damage caused by corrosive snow melting agents. New developments in chemical melting agents and mechanical equipment are discussed, and an overview of alternative thermal melting systems is presented, including the use of geothermy and non-geothermal heating systems utilizing solar energy, electricity, conductive pavement materials, and infrared/microwave applications. Strategic recommendations are made for continued enhancement of public safety in snow and ice conditions.

Investigation on Preparation and Anti-icing Performance of Superhydrophobic Surface on Aluminum Conductor

Aluminum is widely used in transmission lines, and the accumulation of ice on aluminum conductor may inflict serious damage such as tower collapse and power failure. In this study, super-hydrophobic surface （SHS） on alurninurn conductor with rnicro-nanostructure was fabricated using the preferential etching principle of crystal defects. The surface rnicrostructure and wettability were investigated by scanning electron microscope and contact angle measurement, respectively. The icing progress was observed with a self-made icing experiment platform at different environment temperature. The results showed that, due to jumping and rolling down of coalesced droplets from SHS of aluminum conductor at low temperature, the formation of icing on SHS could be delayed. Dynamic icing experiment indicated that SHS on aluminum conductor could restrain the formation of icing in certain temperature range, but could not exert influence on the accumulation of icing. This study offers new insight into understanding the anti-icing performance of actual aluminum conductor.

Anti-Icing Method Based on Reducing Voltage of Transmission Lines

The icing of transmission lines threatens the security of power system. This paper proposes a novel anti-icing method based on reducing voltage of the transmission lines. The line voltage can be reduced by regulating the ratio of the transformers which install the both ends of the transmission lines. The line current can be increased and the power loss of the transmission lines can also be increased, which means the heat generated by power loss increases and the icing process of the transmission lines can be restrained. When the icing may occur in the atrocious weather, the anti-icing transformers installed the both ends of transmission line are put into operation. The ratios of transformers are regulated to the appropriate value. The current of transmission line can be increased to the value that is a little greater than the critical current, which can realize the purpose of anti-icing. At the same time, the conditions of normal running in the load side are kept invariably, which can ensure the security of power system. This method can be applicable to a wide range. It's an effective measure to prevent the icing of the transmission lines.

Super-hydrophobic film deposition by an atmospheric-pressure plasma process and its anti-icing characteristics

In this work,the super-hydrophobic(SH)surface was prepared through chemical vapor deposition process by an argon atmospheric pressure plasma jet source with HMDSN(hexamethyldisilazane)as the polymerization precursor.Plasma synthesized organosilicon(SiOxCyHz)thin films with water contact angle over 160°and sliding angle below 5°,were able to be achieved.FTIR and XPS analysis indicates a large number of hydrocarbon compositions were polymerized in the thin films enduing the latter very-low surface free energy.SEM shows the SH films display micro-nanostructure and with high degree of averaged surface roughness 190 nm evaluated by AFM analysis.From experiments under controlled low-temperature and moisture conditions,the prepared SH surface exhibits good anti-icing effects.Significantly prolonging freezing time was achievable on the SH thin films for both static and sliding water droplets.This investigation demonstrates the anti-icing potentials of SH surface prepared through low-cost simple atmospheric-pressure plasma polymerization process.

Fast Algorithm for Prediction of Airfoil Anti-icing Heat Load

Many flight and icing conditions should be considered in order to design an efficient ice protection system to prevent ice accretion on the aircraft surface. The anti-icing heat load is the basic knowledge for the design of a thermal anti-icing system. In order to help the design of the thermal anti-icing system and save the design time, a fast and efficiency method for prediction the anti-icing heat load is investigated. The computation fluid dynamics (CFD) solver and the Messinger model are applied to obtain the snapshots. Examples for the calculation of the anti-icing heat load using the proper orthogonal decomposition (POD) method are presented and compared with the CFD simulation results. It is shown that the heat loads predicted by POD method are in agreement with the CFD computation results. Moreover, it is obviously to see that the POD method is time-saving and can meet the requirement of real-time prediction.

Design and Development of Anti-Icing Aluminum Surface

An anti-icing surface has been designed and prepared with an aluminum panel by creating an artificial lotus leaf which is highly hydrophobic. The hydrophobicity of a solid surface can be generated by decreasing its surface tension and increasing the roughness of the surface. On a highly hydrophobic surface, water has a high contact angle and it can easily rolls off, carrying surface dirt and debris with it. Super-cooled water or freezing rain can also run off this highly hydrophobic surface instead of forming ice on the surface, due to the reduction of the liquid-solid adhesion. This property can also help a surface to get rid of the ice after the water becomes frozen. In this study, a Cassie-Baxter rough surface was modeled, and an aluminum panel was physically and chemically modified based on the modeled structure. Good agreement was found between predicted values and experimental results for the contact and roll-off angles of water. Most importantly, by creating this highly hydrophobic aluminum rough surface, the anti-icing and de-icing properties of the modified surface were drastically improved compared to the control aluminum surface, and the cost will be reduced.

An Abrasion Resistant TPU/SH-SiO_(2) Superhydrophobic Coating for Anti-Icing and Anti-Corrosion Applications

As a passive anti-icing strategy,properly designed superhydrophobic coatings can demonstrate outstanding performances.However,common preparation strategies for superhydrophobic coatings often lead to environmental pollution,high energy-consumption,high-cost and other undesirable issues.Besides,the durability of superhydrophobic coating also plagues its commercial application.In this paper,we introduced a facile and environment-friendly technique for fabricating abrasion-resistant superhydrophobic surfaces using thermoplastic polyurethane(TPU)and modified SiO_(2)particles(SH-SiO_(2)).Both materials are non-toxicity,low-cost,and commercial available.Our methodology has the following advantages:use of minimal amounts of formulation,take the most streamlined technical route,and no waste material.These advantages make it attractive for industrial applications,and its usage sustainability can be promised.In this study,the mechanical stability of the superhydrophobic surface was evaluated by linear wear test.It is found that the excellent wear resistance of the superhydrophobic coating benefits from the characteristics of raw materials,the preparation strategy,and the special structure.In anti-icing properties test,the TPU/SH-SiO_(2)coating exhibits the repellency to the cold droplets and the ability to extend the freezing time.The electrochemical corrosion measurement shows that the asprepared superhydrophobic surface has excellent corrosion resistance that can provide effective protection for the bare Q235 substrates.These results indicate that the TPU/SH-SiO_(2)coating possesses good abrasion resistance and has great potential in anti-corrosion and anti-icing applications.

Neurosyphilis complicated by anti-γ-aminobutyric acid-B receptor encephalitis: A case report

BACKGROUND Syphilis is an infectious disease caused by Treponema pallidum that can invade the central nervous system,causing encephalitis.Few cases of anti-N-methyl-Daspartate receptor autoimmune encephalitis(AE)secondary to neurosyphilis have been reported.We report a neurosyphilis patient with anti-γ-aminobutyric acid-B receptor(GABABR)AE.CASE SUMMARY A young man in his 30s who presented with acute epileptic status was admitted to a local hospital.He was diagnosed with neurosyphilis,according to serum and cerebrospinal fluid(CSF)tests for syphilis.After 14 d of antiepileptic treatment and anti-Treponema pallidum therapy with penicillin,epilepsy was controlled but serious cognitive impairment,behavioral,and serious psychiatric symptoms were observed.He was then transferred to our hospital.The Mini-Mental State Examination(MMSE)crude test results showed only 2 points.Cranial magnetic resonance imaging revealed significant cerebral atrophy and multiple fluidattenuated inversion recovery high signals in the white matter surrounding both lateral ventricles,left amygdala and bilateral thalami.Anti-GABABR antibodies were discovered in CSF(1:3.2)and serum(1:100).The patient was diagnosed with neurosyphilis complicated by anti-GABABR AE,and received methylprednisolone and penicillin.Following treatment,his mental symptoms were alleviated.Cognitive impairment was significantly improved,with a MMSE of 8 points.Serum anti-GABABR antibody titer decreased to 1:32.The patient received methylprednisolone and penicillin after discharge.Three months later,the patient’s condition was stable,but the serum anti-GABABR antibody titer was 1:100.CONCLUSION This patient with neurosyphilis combined with anti-GABABR encephalitis benefited from immunotherapy.

Piccolo密码代数故障分析研究

应用代数故障分析方法,对Piccolo密码抗故障攻击安全性进行了评估.首先利用代数方法建立Piccolo密码等效布尔方程组;然后通过故障攻击手段获取故障密文并将故障注入差分进行表示,给出了一种故障注入位置未知情况下的故障差分布尔方程组表示方法;最后使用CryptoMiniSAT解析器求解联立方程组恢复密钥.结果表明,代数故障分析相比传统差分故障分析具有以下优点:(1)在线故障注入较少,在Piccolo-80第23轮注入4bit故障,1次故障注入即可恢复80位密钥;(2)离线分析方法简单,无需结合算法和故障模型判断故障位置,执行繁琐的故障差分传播分析,自动化程度较高;(3)计算资源利用率高,可将故障攻击下的密钥恢复转化为代数方程求解问题,充分利用计算资源;(4)通用性较好,可扩展到宽度故障模型、深度故障模型、其它版本的Piccolo密码以及多种分组密码,有望成为评估分组密码抗故障攻击能力的通用方法.

Piccolo算法的差分故障分析

Piccolo算法是CHES 2011上提出的一个轻量级分组密码算法,它的分组长度为64-bit,密钥长度为80/128-bit,对应迭代轮数为25/31轮.Piccolo算法采用一种广义Feistel结构的变种,轮变换包括轮函数S-P-S和轮置换RP,能够较好地抵抗差分分析、线性分析等传统密码攻击方法.该文将Piccolo算法的S-P-S函数视为超级S盒(Super Sbox),采用面向半字节的随机故障模型,提出了一种针对Piccolo-80算法的差分故障分析方法.理论分析和实验结果表明:通过在算法第24轮输入的第1个和第3个寄存器各诱导1次随机半字节故障,能够将Piccolo-80算法的密钥空间缩小至约22-bit.因此,为安全使用Piccolo算法,在其实现时必须做一定的防护措施.

Piccolo相关性功耗分析攻击技术研究

为了评测轻量级密码算法Piccolo抗功耗分析攻击的能力,提出一种针对首轮的功耗分析攻击模型,搭建了功耗模拟采集平台,对该算法进行了相关性功耗分析攻击.针对Piccolo算法首轮运算中包含白化密钥和轮置换操作的特点,将首轮相关攻击密钥(包括轮密钥RK0L、RK0R、WK0、WK1)分成6段子密钥,逐个完成各段子密钥的攻击,将80位种子密钥的搜索空间从280降低到(2×220+2×24+2×28+216),使种子密钥的恢复成为可能.攻击结果表明,只需500条功耗曲线即可恢复首轮攻击密钥,由此可见,未加任何防护措施的Piccolo硬件实现极易遭受相关性功耗分析攻击,研究并采取切实有效的防护措施势在必行.据现有资料,这是首次评估Piccolo密码算法在相关性功耗分析攻击方面的安全性.

一种Piccolo加密算法硬件优化实现研究

Piccolo轻量级密码算法是近年来物联网领域提出的重要安全算法之一。研究了一种Piccolo加密算法硬件优化实现方法,相同的轮运算只实现一次;原始算法共有r轮运算,其中密钥为80和128位时,r分别取值为25和31。优化方法直接把r-1轮重复调用变成r轮循环运算,同时在r轮循环运算完成后构造一个RP-1轮置换函数。实验表明优化后的Piccolo-80密码算法在面积上少了3227个Slices,优化效率达到24.6%,有效节省了硬件实现面积,同时加密速率提高了10%。

轻量级密码算法Piccolo的统计故障分析

Piccolo算法是于2011年CHES会议上提出的一种轻量级分组密码算法,用于物联网环境中保护RFID、传感器、智能卡等电子设备的通信安全.目前国内外安全性分析研究集中在该算法的已知明文攻击和选择明文攻击,在攻击者能力最弱条件下的唯密文攻击尚无相关研究.文中提出了统计故障分析下Piccolo密码的安全性,即在唯密文条件下,使用SEI、HW、ML、GF、MAP、GF-SEI、GF-ML、ML-SEI、ML-MAP、MM-HW及MM-HW-ML等一系列区分器,恢复Piccolo密码的主密钥.实验结果表明,Piccolo算法不能抵御统计故障分析的攻击,文中提出的新型区分器ML-MAP、MM-HW和MM-HW-ML仅需164和262个故障,可以分别恢复出80比特和128比特主密钥,有效地减少了故障数,并提升了攻击效率.该结果为物联网环境中轻量级密码的安全设计与实现提供有价值的参考.

基于FPGA平台的Piccolo功耗分析安全性评估

为了评估Piccolo密码算法的功耗分析安全性,该文提出一种针对Piccolo末轮的攻击模型,基于SASEBO(Side-channel Attack Standard Evaluation BOard)实测功耗数据对该算法进行了相关性功耗分析攻击。针对Piccolo末轮运算中包含白化密钥的特点,将末轮攻击密钥(包括轮密钥RK24L,RK24R,WK2,WK3)分成4段子密钥,逐个完成各个子密钥的攻击,使80位种子密钥的搜索空间从280降低到(2×220+2×212+216),使种子密钥的恢复成为可能。攻击结果表明,在实测功耗数据情况下,3000条功耗曲线即可恢复80位种子密钥,证实了该攻击模型的有效性和Piccolo硬件面向功耗分析的脆弱性,研究并采取切实有效的防护措施势在必行。

青枯病生防菌ANTI-8098A的微胶囊化技术

以明胶和阿拉伯胶为壁材,通过复凝聚法进行青枯病生防菌ANTI-8098A微胶囊的制备,研究壁材浓度、 生防菌ANTI-8098A发酵液添加浓度、搅拌速度、酸碱度和甲醛固化条件对微胶囊粒径、形状的影响。试验结果表 明.用2.5％明胶和2.5％阿拉伯胶为壁材制备青枯病生防菌ANTI-8098A微胶囊,条件为pH值4.0、生防菌发酵 液浓度10％～30％、搅拌速度400 r·min-1、固化时添加1％的甲醛溶液.生防菌的包被率可稳定在70％左右,微 胶囊为圆形.平均直径为30.8～57.3μm,生防菌微胶囊萌发率达93％以上。

MAPKs在anti-β_2 GPI/β_2 GPI刺激THP-1细胞表达TF过程中的作用探讨

目的:探讨丝裂原活化蛋白激酶(Mitogen-activated protein kinases,MAPKs)在anti-β2 GPI/β2 GPI复合物诱导单核细胞株THP-1表达组织因子(TF)中的活化及其作用。方法:利用荧光定量PCR(Real-time PCR)、TF活性试剂盒等分别检测anti-β2 GPI/β2 GPI复合物诱导THP-1细胞表达TF mRNA及TF活性,Western blot检测细胞表达p38、磷酸化-p38(p-p38)、ERK1/2、磷酸化-ERK1/2(p-ERK1/2)、JNK、磷酸化-JNK(p-JNK)的情况。进一步采用p38、ERK1/2、JNK抑制剂(SB203580、U0126、SP600125)观察是否能阻断anti-β2 GPI/β2 GPI复合物诱导THP-1细胞表达TF。结果:Anti-β2 GPI/β2 GPI复合物(100μg/ml)能够显著增强THP-1细胞表达TF,并使p-p38、p-ERK1/2、p-JNK水平显著升高(P<0.05 vs control);其引发的MAPKs磷酸化具有时间效应性,均在刺激30分钟时达到高峰;对应的特异抑制剂SB203580(10μmol/L)、U0126(5μmol/L)、SP600125(90 nmol/L)单独或合并处理THP-1细胞后,anti-β2 GPI/β2 GPI复合物诱导细胞TF mRNA表达及TF活性的效应明显被阻断(P<0.01 vs control)。结论:Anti-β2 GPI/β2 GPI复合物诱导THP-1细胞表达TF过程中,MAPKs被激活进而发挥重要作用。

轻量级分组密码Piccolo的积分攻击

为了评估分组密码Piccolo的积分性质,提出Piccolo算法的5轮积分区分器,对无白化密钥的Piccolo进行了7轮和8轮攻击。其中,7轮攻击的数据复杂度为2^(17)个明文,时间复杂度为2^(20. 368)次7轮加密,8轮攻击的复杂度分别为2^(18)和2^(53. 000)。随后,将5轮区分器向解密方向扩展2轮,得到7轮区分器,对Piccolo进行了9轮攻击。若考虑白化密钥,数据复杂度为2^(48)个明文,时间复杂度为2^(52. 237)次9轮加密;若无白化密钥,复杂度均为2^(48)。据现有资料,这是首次评估Piccolo算法在积分攻击方面的安全性。