mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
《北宋开封气象编年史》评介

中国气象史是我国科技史中不可分割的组成部分,也是我国光辉灿烂的科学文化遗产,全面深入、系统地总结和研究我国气象发展史,具有重要的理论和现实意义。1983年12月4日在北京成立了中国气象史研究会,为气象史的研究打下了良好基础。以此为平台,目前学界对气象史的研究倾注了不少心血,也取得了较为丰硕的成果。但较之科技史其他方面的研究,气象史的研究还显得非常薄弱。在中国大陆,其代表性的论著有:洪世年、陈文言先生的《中国气象史》(农业出版社1983年版);温克刚先生主编的《中国气象史》(气象出版社2004年版);洪世年、刘昭民先生的《中国气象史——近世前》(中国科学技术出版社2006年版);葛全胜先生主编的《中国历朝气候变化》(科学出版社2011年版;)等。由此可见,气象史的研究主要集中于通史方面。“而为一个城市编著气象断代史,并作自然、社会综合研究,至少在国内还没有先例,在学术史上有另辟蹊径的意义。”(导言第9页)因此,程民生先生的大作《北宋开封气象编年史》的横空出世,可谓填补了这方面的空白,在学术上有重要的理论价值。
特发性肠系膜静脉硬化性肠炎一例

讨论因IMP发病率低,尚未被临床医师及影像科医师所熟识,故该患者多次因肠梗阻就诊于外院未能明确诊断。第1次来我院门诊时亦误诊为克罗恩病。此疾病虽然临床症状不是很典型,但有典型的影像学特征:腹部CT或腹部平片上可见右半结肠肠系膜静脉血管线性钙化、内镜下见右半结肠黏膜紫蓝色改变。其基本病理改变为病变肠段的静脉壁纤维化、增厚及钙化。因此临床上遇到慢性腹痛、腹泻或者反复肠梗阻患者,结合典型影像学特征,需考虑此病。
超声弹性成像诊断大鼠肝纤维化的价值

肝纤维化是各种慢性肝病的重要病理特征,常伴有炎性反应,并可发展为肝硬化~([1])。研究表明,早期的肝纤维化在经过临床干预后可以逆转。因此,早期肝纤维化的诊断对于临床上慢性肝病患者诊疗方案的制定具有重要意义。肝活组织病理检查是诊断肝纤维化的“金标准”,但有一定的局限性,比如出血、取样误差及观察者的主观依赖性等~([2])。无创评估肝纤维化一直是肝病领域的研究热点之一。目前,超声弹性成像如瞬时弹性成像、声脉冲辐射力成像及实时组织弹性成像技术等的研究备受瞩目。本研究对声脉冲辐射力成像及实时组织弹性成像技术在大鼠肝纤维化的诊断价值方面进行探讨,并比较两者的优劣。
失代偿期肝硬化420例病因及并发症特征分析

随着社会发展、医学进步和人们生活习惯的改变,肝硬化的病因和并发症也在发生变化,了解这种变化对预防肝硬化的发生及进展具有重要意义。本研究对2009年广州中山大学附属第一医院住院的所有失代偿期肝硬化患者进行了分析,借此了解肝硬化病因及并发症等情况。
内镜下黏膜十字切开挖除术治疗胃固有肌层肿瘤

近年随着内镜检查的普遍开展与内镜超声在临床的应用,起源于胃固有肌层的黏膜下肿瘤(submucosal tumor, SMT)发现率明显提高。由于起源于胃固有肌层的SMT大多为间质瘤(gastrointestinal stromal tumor, GIST),具有恶变潜能,需切除治疗。过去,外科手术是主要治疗方式,但外科手术创伤较大,尤其对位于近贲门或幽门的SMT,切除后常出现反流等症状,影响患者生活质量。自2008年起,台州医院内镜中心采用内镜黏膜下挖除术(endoscopic submucosal excavation, ESE)治疗起源于胃固有肌层的SMT,在治疗过程中发现十字切开肿瘤顶部黏膜与传统环形切开相比,肿瘤更易暴露,便于剥离,因此本研究探讨这2种不同黏膜切开方法对ESE治疗起源于胃固有肌层SMT的影响。
急性胰腺炎临床和形态学分类标准的新认识

1992年,在美国亚特兰大召开的国际急性胰腺炎讨论会提出了以临床为基础的急性胰腺炎(acute pancreatitis, AP)分类法(以下简称亚特兰大定义),按AP病情程度分为轻症急性胰腺炎(mild acute pancreatitis, MAP)和重症急性胰腺炎(severe acute pancreatitis,SAP)。这种临床分类方法曾经得到广泛的认同,先后依此制定了各种类似的AP指南。然而,随着临床实践认识及其诊治技术的进步,目前认为亚特兰大定义过于宽泛,尚难以精确地指导临床实践与研究,有必要进行修订,特别需要重新进行AP临床严重程度的分类,制定当代AP影像形态学标准。
双侧冠状动脉瘘伴严重冠状动脉狭窄一例

讨论患者心绞痛症状典型,结合冠状动脉造影结果可确诊冠心病,同时双侧冠状动脉瘘诊断明确。冠状动脉瘘是罕见的冠状动脉畸形,Yamanaka与Hobbs报道其检出率为0. 18%。冠状动脉瘘表现为先天性冠状动脉与心腔、冠状动脉窦或者肺动脉直接相通,可引起血液动力学障碍。常见临床症状为胸痛和呼吸困难,可并发动脉瘤、感染性心内膜炎、急性心肌梗死、心包积液等。冠状动脉瘘多为单侧起源,亦有双侧起源或者多个起源的病例。常见分流部位为右心室、肺动脉、右心房、左心房和左心室。双侧冠状动脉瘘比较罕见,而同时合并冠心病者报道更少。超声心动图、螺旋CT冠状动脉成像、冠状动脉造影可诊断冠状动脉瘘,其中冠状动脉造影是精确定位瘘口起源与分流部位的最可靠办法。
易栓症诊断中国专家共识(2012年版)

一、概述易栓症(Thrombophilia)是指存在抗凝蛋白、凝血因子、纤溶蛋白等遗传性或获得性缺陷,或者存在获得性危险因素而具有高血栓栓塞倾向。易栓症的血栓栓塞类型主要为静脉血栓栓塞症(VTE)。
利妥昔单抗治疗婴儿难治性自身免疫性溶血性贫血伴假性血小板减少一例报告附文献复习

自身免疫性溶血性贫血(AIHA)系体内B淋巴细胞免疫调节紊乱,产生自身抗体和(或)补体,并结合于红细胞膜上,致红细胞破坏加速而引起的一组溶血性贫血。婴儿难治性AIHA症状重,病程迁延,病死率高,治疗目标是迅速控制溶血。利妥昔单抗治疗成人原发免疫性血小板减少症(ITP)/AIHA及Evans综合征安全有效。但利妥昔单抗在婴儿患者应用少,既往仅国外有报道,且均为非前瞻性非随机对照的小样本研究,国内尚未见报道,其在婴儿患者中的最适剂量、有效性及安全性尚不明确。我们报告1例利妥昔单抗治疗成功的难治性AIHA伴假性血小板减少患儿,并进行文献复习。
RACK1基因过表达对子宫颈癌细胞增殖的影响

世界范围内,宫颈癌是第二常见的女性恶性肿瘤,其发病率仅次于乳腺癌,病死率却居女性恶性肿瘤之首。宫颈癌的侵袭性很强,常向周边组织器官侵袭性转移蔓延,且手术切除后盆腔内复发的概率高达70%。因此,宫颈癌对女性健康的威胁不容小觑。目前,宫颈癌的诊断缺乏特异性的分子标志物。研究发现,激活的蛋白激酶C受体1(receptorforactivatedC-kinase1,RACK1)在血管新生过程中表达上调,而在肿瘤病灶中新生血管增多,以供应肿瘤细胞快速增殖所需要的营养。目前已知RACK1基因在多种恶性肿瘤组织中有异常表达,其在宫颈癌发展中的作用尚属未知,但RACK1有望成为研究宫颈癌发展的分子学机制的理想分子。本研究探讨RACK1基因过表达对宫颈癌细胞增殖的影响及其意义。
微孔处女膜一例报告及文献复习

微孔处女膜是一种特殊的处女膜发育异常,阴道口有薄膜覆盖,仅有针尖大小的开口,因患者常有月经来潮而不易被诊断。本文报道1例因性交困难就诊,经手术确诊并治疗的微孔处女膜患者,并结合文献复习如下。
In-Plane Optical Anisotropy of a-Plane GaN Film on τ-Plane Sapphire Grown by Metal Organic Chemical vapour Deposition

The in-plane optical anisotropic properties of the non-polar a-plane GaN films grown by metal organic chemical vapour deposition are investigated by using polarised photoluminescence (PL), optical transmission and Raman scattering measurements. Through polarised PL and transmission spectra, the in-plane optical anisotropic properties of a-plane GaN film are found, which are attributed to the topmost valance band (at Γ point) split into three sub-bands under anisotropic strain. The PL spectra also exhibit that the light hole band moves up more rapidly than the spin-orbit crystal-field spilt-off hole band with the increasing in-plane anisotropic compressive strain. Raman scattering spectra under different configurations further indicate the in-plane anisotropy and the hexagonal crystalline structure of these a-plane GaN films.
Spontaneous Magnetization and Magnon-TA Phonon Interaction during the Premartensitic Transformation in Ni_2 MnGa Alloy

The magnetic anomaly associated with the premartensitic transformation (PT) in Heusler alloy Ni2MnGa is investigated by using the Green's function technique based on the magnon-TA phonon interaction. The results of the numerical calculations suggest that the magnetic anomaly during the PT may originate from the strong magnon-TA phonon interaction, because this kind of coupling effect will destroy the magnetic ordering in some local zones and reduce the magnetization of the system. Magnon-magnon interaction plays a positive role in enhancing the magnetization and tends to reduce the PT temperature while this kind of interaction has little effect on the characteristic TA phonon-wavevector corresponding to the anomaly of spontaneous magnetization at the PT temperature.
Comparative Study of the Large Eddy Simulations with the Lattice Boltzmann Method Using the Wall-Adapting Local Eddy-Viscosity and Vreman Subgrid Scale Models

The wall-adapting local eddy-viscosity (WALE) and Vreman subgrid scale models for large eddy simulations are compared within the framework of a generalised lattice Boltzmann method. Fully developed turbulent flows near a Bat wall are simulated with the two models for the shear (or friction) Reynolds number of 183.6. Compared to the direct numerical simulation (DNS), damped eddy viscosity in the vicinity of the wall and a correct velocity profile in the transitional region are achieved by both the models without dynamic procedures. The turbulent statistics, including, e.g., root-mean-square velocity fluctuations, also agree well with the DNS results. The comparison also shows that the WALE model predicts excellent damped eddy viscosity near the wall.
Hydrogen Sulfide May Function Downstream of Nitric Oxide in Ethylene- Induced Stomatal Closure in Vicia faba L

Pharmacological, laser scanning confocal microscopic (LSCM), and spectrophotographic approaches were used to study the roles of hydrogen sulfide (H_2S) and nitric oxide (NO) in signaling transduction of stomatal movement in response to ethylene in Vicia faba L. Ethylene treatment resulted in the dose-dependent stomatal closure under light, and this effect was blocked by the inhibitors of H_2S biosynthesis in V. faba L. Additionally, ethylene induces H_2S generation and increases L-/D-cysteine desulfhydrase (pyridoxalphosphate-dependent enzyme) activity in leaves of V. faba L. Inhibitors of H_2S biosynthesis have no effect on the ethylene-induced stomatal closure, NO accumulation, and nitrate reductase (NR) activity in guard cells or leaves of V. faba L. Moreover, the ethylene-induced increase of H_2S levels and L-/D-cysteine desulfhydrase activity declined when NO generation was inhibited. Therefore, we conclude that H_2S and NO probably are involved in the signal transduction pathway of ethylene-induced stomatal closure. H_2S may represent a novel component downstream of NO in the ethylene-induced stomatal movement in V. faba L.
Satellite-based Studies on Large-Scale Vegetation Changes in China

Remotely-sensed vegetation indices, which indicate the density and photosynthetic capacity of vegetation, have been widely used to monitor vegetation dynamics over broad areas. In this paper, we reviewed satellite-based studies on vegetation cover changes, biomass and productivity variations,phenological dynamics, desertification, and grassland degradation in China that occurred over the past 2-3 decades. Our review shows that the satellite-derived index (Normalized Difference Vegetation Index, NDVI) during growing season and the vegetation net primary productivity in major terrestrial ecosystems (for example forests,grasslands, shrubs,and croplands) have significantly increased, while the number of fresh lakes and vegetation coverage in urban regions have experienced a substantial decline. The start of the growing season continually advanced in China's temperate regions until the 1990s, with a large spatial heterogeneity. We also found that the coverage of sparsely-vegetated areas declined, and the NDVI per unit in vegetated areas increased in arid and semi-arid regions because of increased vegetation activity in grassland and oasis areas. However, these results depend strongly not only on the periods chosen for investigation, but also on factors such as data sources, changes in detection methods, and geospatial heterogeneity. Therefore, we should be cautious when applying remote sensing techniques to monitor vegetation structures, functions, and changes.
从一起重金属水污染事件论加强突发性水环境污染事故中的风险沟通

突发性水环境污染事故是指在日常社会生产和生活中所使用的危险品在产生、运输、使用、储存和处置的整个过程中,由于自然灾害或者是人为操作失误和疏忽的因素,在瞬时间导致具有剧毒或者恶性危害的污染物质大量、非正常地排放或泄漏,对水体环境产生严重污染和破坏,给国家和人民群众的生命财产安全造成巨大损失和严重威胁的恶性事故。
2011年大连市生活饮用水放射性指标监测

为了解“311”日本核电站泄漏事故后大连市市政生活饮用水放射性指标的情况,笔者于2011年3月16日--5月31日(枯水期,每周1次)、6月8--30日(平水期,每周1次)/7月5日--8月11日(丰水期,每周1次)/9月7日(丰水期,1次)及10月18日--12月14日(平水期,每月1次)采集该市碧流河水库水源水及沙河口区某管网末梢水,并对其总α、总β放射性进行监测。水样的采集、保存与检测按照GB/T5750--2006《生活饮用水标准检验方法》进行。按照GB 5749--2006《生活饮用水卫生标准》进行评价,其中,总α、总β放射性的限值分别为0.5、l Bq/L。
深圳某地区大气PM2.5中重金属的污染特征及健康风险评价

为评价深圳市大气PM2.5中重金属元素通过呼吸途径对人群的健康风险,选择北京大学深圳研究生院作为采样点,隔日采集2008年12月至2009年12月间深圳市大气PM2.5样品159个,分析其中As、Cd、Cr、Ni、Pb、Hg、Zn、 Cu、Mn等9种重金属元素的含量和污染特征,运用美国环保局推荐的模型进行健康风险评价。结果显示,PM2.5中9种重金属元素的浓度在1.93x10~(-9)~2.48x10~(-3)mg/m~3之间,高低依次为Zn>Pb>Mn>Cu>Ni>As>Cr>Cd>Hg,其中As/Cd和Pb的浓度值接近国家环境空气质量标准中的参考浓度限值;9种重金属通过呼吸途径对暴露人群的年均超额危险度在5.19x10~(-14)~8.01x10~(-7)之间,大小依次为As>Cr>Cd>Ni>Pb>Mn>Zn>Cu>Hg。提示深圳大气PM2.5中9种重金属通过呼吸途径对人体健康产生潜在危害的年总风险接近人群的可接受水平(10~(-6)/年),其中以As和Cr的潜在危害最大。
基于MATLAB/Simulink的GIS盆式绝缘子闪络放电分析与处理

下坂地水力发电厂地处高寒、高海拔山区,装机容量为3 × 50 MW,电气主接线采用发变组单元接线,机端额定电压10.5 kV,经10.5 kV母线送至额定容量为63 MVA三相双线圈无励磁调压升压变压器SSP9 -63000/220的低压侧。由于常压下SF6的绝缘强度是空气的3.0倍,灭弧性能则是空气的上百倍,使得GIS具有结构紧凑、占地面积小、有利于环境保护,同时运行稳定可靠、安装维修工作量小、维护周期长等一系列优点,因而下坂地水力发电厂主变高压侧电器采用六氟化硫气体绝缘金属封闭开关设备GIS (Gas Insulated Metal-enclosed Switchgear简称GIS)。受现场布置条件限制[1](如与终端的相对位置、进出线形式、场地尺寸),220kV主变进线采用GIS管道母线引出;220 kV电缆出线采用SF6电缆密封终端引出至户外出线平台龙门架。
浅谈下坂地水利枢纽工程的技术档案管理

新疆下坂地水利枢纽工程位于新疆喀什地区塔什库尔干塔吉克自治县班迪尔乡境内,距乌鲁木齐市1 815 km,距喀什市315 km,为大(2)型Ⅱ等工程,主要建筑物由拦河坝、导流泄洪洞、引水发电隧洞、地下厂房组成,水库总库容8.67亿m3,电站总装机3×50 MW。整个工程建设周期长,从20世纪80年代末期陕西省水利水电勘察设计研究院开始下坂地工程的前期勘测设计,历经多年的前期努力,2003年7月开始“四通一平”,2005年7月工程奠基,2006年3月主体工程全面开工,2007年9月工程如期截流,2010年5月首台机组并网发电。下坂地工程从规划、勘测设计、招(投)标、施工、竣工验收过程中直接形成的具有保存价值的文字、图纸、图表等各种载体资料,形成了下坂地水利枢纽工程较为完整的档案资源。
下坂地水利枢纽工程对环境影响的分析及对策

下坂地水利枢纽工程位于新疆塔里木河主流叶尔羌河主要支流之一的塔什库尔干河中下游,该工程是塔里木河流域近期综合治理规划中唯一的山区水利枢纽工程,其主要任务是以生态补水,控制塔什库尔干河季节性洪水,调节年内水量平衡及春旱供水为主,并结合发电的综合性工程,具有显著的社会经济效益和环境效益,但在兴建过程中难免对区域原有的自然环境和生态平衡产生一定影响,应引起高度重视,因此,坚持科学的发展观,严格遵守自然经济规律,采取行政、法律、科技、经济等手段,在开发中保护,在保护中开发,切实加强水利枢纽工程项目的环保管理。把生态环境保护融人到工程规划、设计、施工、运行及管理的全过程,保证工程在取得经济效益和社会效益的同时,减少环境污染和生态破坏,维护河流健康,实现人与自然的和谐共处。
On the Temporal and Spatial Structure of Troposphere-to-Stratosphere Transport in the Lowermost Stratosphere over the Asian Monsoon Region during Boreal Summer

This study produced a novel characterization of the troposphere-to-stratosphere transport (TST) over the Asian monsoon region during boreal summer, using a comprehensive analysis of 60-day backward trajectories initialized in the stratosphere. The trajectory datasets were derived from the high-resolution Lagrangian particle dispersion model (FLEXPART) simulation driven by the wind fields acquired from the National Center for Environmental Prediction (NCEP). The results indicate that the distribution of residence time (tTST) of tropopause-crossing trajectories in the lowermost stratosphere represents a horizontal signature of the Asian summer monsoon. Vertically, the distribution of tTST can be roughly separated into two layers: a consistent lower layer with tTST < 5 days forming a narrow band, corresponding to a layer ~3 km thick following the location of the tropopause, and an upper layer at a larger distance from the local tropopause. The maximum residence time was ~20 days, especially within the Asian high anticyclone consistent with its confinement effects. In general, the overall geographical distribution of dehydration points was not coincident with the location of tropopause crossing. TST trajectories, which were initialized in the stratosphere, underwent their Lagrangian cold points mostly in the tropics and subtropics 1-4 days after the TST event; they were characterized by a wide range of temperature differences, with a mean value of 3-12 K. The vertical extent of the influence of tropospheric intrusion on the Asian monsoon region in the stratosphere exhibited a peak at~16.5-18.5 km, and the uppermost height was ~21 km.
A Study on the Dynamic Mechanism of the Formation of Mesoscale Vortex in Col Field

The mesoscale vortex associated with a mesoscale low-level jet (mLLJ) usually causes heavy rainfall in the col field. The col field is defined as a region between two highs and two lows, with the isobaric surface similar to a col. Using a two-dimensional shallow water model, the meso-β scale vortex couplets (MβVCs) induced by eight types of mesoscale wind perturbations in an ideal col field were numerically simulated. With the sizes of ~100 km, the M/βVCs induced by northerly perturbation (NP) and southerly perturbation (SP) moved toward the col point. The sizes of MβVCs induced by southwesterly perturbation (SWP), southeasterly perturbation (SEP), northwesterly perturbation (NWP), and northeasterly perturbation (NEP) were relatively small for the perturbations moving toward dilatation axis. The MβVC induced by easterly perturbation (EP) and westerly perturbation (WP) could not develop because they quickly moved away from the col point, before the circulation could form. The size of the circulation was determined by the distance between the vortex and the col point. The closer to the col point the vortex was, the larger the size of vortex. The comparisons of maximum vorticity and vorticity root mean square error (RMSE) of the NP, the SWP, and the WP show that the maximum vorticity and the vorticity RMSE of the NP decreased slower than other perturbations. Therefore, the weak environment of the col field favors the maintenance of vorticity and the formation of vortex. When a mesoscale vortex forms near the col point or moves toward the col point, it may maintain a quasi-stationary state in the stable col field.
Summer Persistence Barrier of Sea Surface Temperature Anomalies in the Central Western North Pacific

The persistence barrier of sea surface temperature anomalies (SSTAs) in the North Pacific was investigated and compared with the ENSO spring persistence barrier. The results show that SSTAs in the central western North Pacific (CWNP) have a persistence barrier in summer: the persistence of SSTAs in the CWNP shows a significant decline in summer regardless of the starting month. Mechanisms of the summer persistence barrier in the CWNP are different from those of the spring persistence barrier of SSTAs in the central and eastern equatorial Pacific. The phase locking of SSTAs to the annual cycle does not explain the CWNP summer persistence barrier. Remote ENSO forcing has little linear influence on the CWNP summer persistence barrier, compared with local upper-ocean process and atmospheric forcing in the North Pacific. Starting in wintertime, SSTAs extend down to the deep winter mixed layer then become sequestered beneath the shallow summer mixed layer, which is decoupled from the surface layer. Thus, wintertime SSTAs do not persist through the following summer. Starting in summertime, persistence of summer SSTAs until autumn can be explained by the atmospheric forcing through a positive SSTAs-cloud/radiation feedback mechanism because the shallow summertime mixed layer is decoupled from the temperature anomalies at depth, then the following autumnwinter-spring, SSTAs persist. Thus, summer SSTAs in the CWNP have a long persistence, showing a significant decline in the following summer. In this way, SSTAs in the CWNP show a persistence barrier in summer regardless of the starting month.
Effect of Length Scale Tuning of Background Error in WRFi 3DVAR System on Assimilation of High-Resolution Surface Data for Heavy Rainfall Simulation

We investigated the impact of tuning the length scale of the background error covariance in the Weather Research and Forecasting (WRF) three-dimensional variational assimilation (3DVAR) system. In particular, we studied the effect of this parameter on the assimilation of high-resolution surface data for heavy rainfall forecasts associated with mesoscale convective systems over the Korean Peninsula. In the assimilation of high-resolution surface data, the National Meteorological Center method tended to exaggerate the length scale that determined the shape and extent to which observed information spreads out. In this study, we used the difference between observation and background data to tune the length scale in the assimilation of high-resolution surface data. The resulting assimilation clearly showed that the analysis with the tuned length scale was able to reproduce the small-scale features of the ideal field effectively. We also investigated the effect of a double-iteration method with two different length scales, representing large and small-length scales in the WRF-3DVAR. This method reflected the large and small-scale features of observed information in the model fields. The quantitative accuracy of the precipitation forecast using this double iteration with two different length scales for heavy rainfall was high; results were in good agreement with observations in terms of the maximum rainfall amount and pquitable threat scores. The improved forecast in the experiment resulted from the development of well-identified mesoscale convective systems by intensified low-level winds and their consequent convergence near the rainfall area.
椎板关节突螺钉固定技术临床应用进展

随着腰椎解剖的深入,脊柱生物力学和医学影像的发展,以及操作技术的成熟,椎板关节突螺钉固定技术(translaminar facet screw fixation,TLFSF)已大量地应用于下腰椎病变的固定融合治疗,成为除椎弓根螺钉固定技术以外又一重要技术,现从应用解剖、生物力学、临床应用、置钉技术的演变、优缺点及手术适应症方面综述如下。
Nelumbonaceae: Systematic position and species diversification revealed by the complete chloroplast genome

Nelumbonaceae is a morphologically unique family of angiosperms and was traditionally placed in Nymphaeales; more recently, it was placed in Proteales based on molecular data, or in an order of its own, Nelumbonales. To determine the systematic position of the family and to date the divergence time of the family and the divergence time of its two intercontinentally disjunct species, we sequenced the entire chloroplast genome of Nelumbo lutea and most of the chloroplast genes of N. nucifera. We carried out phylogenetic and molecular dating analyses of the two species and representatives of 47 other plant families, representing the major lineages of angiosperms, using 83 plastid genes. The N. lutea genome was 163 510 bp long, with a total of 130 coding genes and an overall GC content of 38%. No significant structural differences among the genomes of N. lutea, Nymphaea alba, and Platanus occidentalis were observed. The phylogenetic relationships based on the 83 plastid genes revealed a close relationship between Nelumbonaceae and Platanaceae. The divergence times were estimated to be 109 Ma between the two families and 1.5 Ma between the two Nelumbo species. The estimated time was only slightly longer than the age of known Nelumbo fossils, suggesting morphological stasis within Nelumbonaceae. We conclude that Nelumbonaceae holds a position in or close to Proteales. We further conclude that the two species of Nelumbo diverged recently from a common ancestor and do not represent ancient relicts on different continents.
Security Enhancement of Robust User Authentication Framework for Wireless Sensor Networks

In order to remedy the security weaknesses of a robust user authentication framework for wireless sensor networks, an enhanced user authentication framework is presented. The enhanced scheme requires proof of the possession of both a password and a smart card, and provides more security guarantees in two aspects: 1) it addresses the untraceability property so that any third party accessing the communication channel cannot link two authentication sessions originated from the same user, and 2) the use of a smart card prevents offline attacks to guess passwords. The security and efficiency analyses indicate that our enhanced scheme provides the highest level of security at reasonable computational costs. Therefore, it is a practical authentication scheme with attractive security features for wireless sensor networks.
Reverse Engineering Analysis Based on Differential Fault Analysis Against Secret S-boxes

To evaluate the security of cipher algorithms with secret operations, we built a new reverse engineering analysis based on Differential Fault Analysis (DFA) to recover the secret S-boxes in Secret Private Network (SPN) and Feistel structures, which are two of the most typical structures in block ciphers. This paper gives the general definitions of these two structures and proposes the reverse engineering analysis of each structure. Furthermore, we evaluate the complexity of the proposed reverse analyses and theoretically prove the effectiveness of the reverse method. For the Twofish-like and AES-like algorithms, the experimental results verify the correctness and efficiency of the reverse analysis. The proposed reverse analysis can efficiently recover the secret S-boxes in the encryption algorithms with SPN and Feistel structures. It can successfully recover the Twofish-like algorithm in 2.3 s with 256 faults and the AES-like algorithm in 0.33 s with 23 faults.
Detecting Compromised Kernel Hooks with Support of Hardware Debugging Features

Although there exist a few good schemes to protect the kernel hooks of operating systems, attackers are still able to circumvent existing defense mechanisms with spurious context information. To address this challenge, this paper proposes a framework, called HookIMA, to detect compromised kernel hooks by using hardware debugging features. The key contribution of the work is that context information is captured from hardware instead of from relatively vulnerable kernel data. Using commodity hardware, a proof-of-concept prototype system of HookIMA has been developed. This prototype handles 3 082 dynamic control-flow transfers with related hooks in the kernel space. Experiments show that HookIMA is capable of detecting compromised kernel hooks caused by kernel rootkits. Performance evaluations with UnixBench indicate that runtime overhead introduced by HookIMA is about 21.5%.
Dynamic Random Access Channel Allocation Scheme Based on the Pseudo-Bayesian Algorithm in OFDMA System

Random Access Channel (RACH) is an uplink contention-based transport channel usually used for initial channel access, bandwidth request, etc. How to use RACH resources effectively is very important in wireless communication system. In this paper, a dynamical RACH allocation scheme is proposed for Orthogonal Frequency-Division Multiple Access (OFDMA) systems. Based on the Pseudo-Bayesian algorithm, this mechanism predicts the number of RACHs for the next frame according to the current load. A new dynamic RACH assignment algorithm and an adaptive access probability method are adopted by the proposed scheme to improve the utilization ratio of RACH resources and increase the successful access rate. Numerical simulation shows that the proposed strategy achieves both improvement in the utilization ratio of RACHs and reduction in the access delay compared with other RACH allocation schemes.