mlsa-iai-msu-lab/ru_sci_bench_zho_cite_reranking huggingface dataset:
早二叠世-中三叠世四川盆地热演化及其动力学机制

四川盆地位于扬子板块西缘,是我国重要的含油气盆地之一。早二叠世-中三叠世是盆地发育及热演化的重要时期,其间经历了区域岩石圈拉张和峨眉山玄武岩活动两个重要构造热事件。本文采用地球动力学模型,分别模拟研究了区域岩石圈拉张和峨眉山玄武岩对盆地热演化的影响。研究结果表明,该时期岩石圈在拉张作用下温度场基本上处于增温状态,盆地基底热流也随时间整体呈增加趋势。但由于拉张系数较小,岩石圈的减薄量有限,受到的热扰动也不大。岩石圈拉张造成盆地基底热流升高约20%,最大基底古热流出现在早三叠世,约60~62mWm~(-2)。地幔柱模型显示,地幔柱活动对岩石圈热状态具有很大的影响,其影响主要集中在地幔柱头上方(内带),而四川盆地所处的外带及以外地区受到的影响很小。部分喷发到盆地地表的岩浆对盆地烃源岩热演化会有剧烈的影响,但影响时间和范围均有限。因此,早二叠世-中三叠世四川盆地热演化主要受区域岩石圈拉张控制,并在川西南局部地区又叠加了峨眉山玄武岩的热效应.
准噶尔盆地西北缘二叠系沸石矿物成岩作用及对油气的意义

近年来,硅酸盐矿物的成岩作用越来越受到人们的重视,特别是其对油气储层孔隙度和渗透率的影响。沸石作为自生铝硅酸盐矿物,在成岩演化过程中,其析出、胶结和溶蚀对研究区二叠系油气储层储集性能有不同程度的破坏与改善。准噶尔盆地西北缘地区二叠系沸石矿物形成于开放的水文环境,成因与大量火山物质的水化关系密切。地层水化学性质差异、孔隙水的pH以及阳离子的性质和比率决定沸石类型及其转化。沸石矿物类型主要有方沸石、片沸石和浊沸石。火山玻璃的沸石化蚀变过程为:火山玻璃-斜发沸石-方沸石-片沸石-浊沸石。方沸石的溶蚀对储层质量改善明显;片沸石的胶结现象普遍,对储层破坏严重。早期沸石的析出,使储层原始孔隙结构未被压实作用破坏,同时为后期溶蚀作用提供了物质基础。方沸石的溶蚀与烃源岩层排出的有机酸和NaHCO_3弱酸性地层水有关,同时受岩层渗透性影响;在CaCl_2型地层水中,片沸石和浊沸石难于溶蚀。在研究区,方沸石溶蚀带是次生孔隙发育带,可以作为寻找有利油气储层发育的目标区域.
台风“麦莎”(Matsa)诱发平流层重力波的数值模拟

本文利用新一代中尺度预报模式WRF-ARW(V3.0)对2005年台风"麦莎"诱发的平流层重力波进行了数值模拟研究.覆盖整个"麦莎"台风主要生命史为期8天的模拟再现了"麦莎"的主要特征,与观测资料进行对比,模拟结果在台风基本特征(路径、强度、螺旋云带分布)以及平流层大气平均状态方面上,都与观测资料有较好的一致性.在此基础上,对"麦莎"诱发的平流层重力波进行了分析研究,分析结果表明:伴随台风向西北方向移动,在其上空以台风为中心的区域中,持续地出现显著平流层重力波,这些波动呈弧状的波阵面离开台风,并主要在背景流的上游中传播.这些波动特征表明了平流层重力波与台风之间存在紧密联系,我们把这种波动称为"热带气旋-平流层重力波".模拟结果还显示,这些波动应该具有相当大的水平尺度,才使得在20km高度上清晰的波阵面出现在距台风中心1000km以外的位置,这与过去的观测分析结果揭示的与台风相伴的平流层大尺度重力波现象是一致的.
新疆北部石炭系大型火山岩风化体结构与地层油气成藏机制

新疆北部上石炭统发育于碰撞后松弛垮塌构造环境,火山岩和烃源岩间互广泛分布,石炭纪末受板块挤压整体抬升遭受风化淋滤,使火山岩不整合风化体形成5层结构,其中溶蚀带和崩解带是有利储层发育段,火山岩风化体发育于古地貌出露水面区,低洼处和斜坡带发育较完整的5层结构,高部位一般缺失土壤层。风化体厚度与风化淋滤时间呈正向非线性指数关系,风化体厚度动态平衡时间约为36.3Ma,最大风化体厚度约450m,断裂发育处风化体厚度更大,长期风化淋滤区各种火山岩岩性均能形成风化体.火山岩风化体和烃源岩组合,发育源内火山岩风化体层序型、源上火山锥风化体准层状和侧源火山岩风化体梳状3种成藏模式,均可形成大型火山岩风化体地层油气藏.该认识改变了火山岩油气勘探中寻找有利岩性和岩相带的传统模式,修正了新疆北部石炭系为盆地基底,不具备油气生成条件的观点,对指导火山岩风化体油气勘探具有重要的科学意义和应用价值.指出中国中西部古生界存在形成大规模火山岩风化体地层油气藏的条件,是今后油气勘探的新领域.
宁金岗桑冰芯不溶性微粒的岩石磁学性质及其环境意义

冰芯中所含不溶性微粒与大气粉尘沉降过程密切相关,是重建气候环境变化的良好载体。本文对宁金岗桑冰芯(56m,公元1864~2007年)样品中不溶性微粒进行了系统的岩石磁学研究。结果表明,不溶性微粒的载磁矿物以低矫顽力、准单畴颗粒的磁铁矿为主。在过去的144年中,磁性矿物的粒径无显著变化。但是其含量(饱和等温剩磁指标)变化以~1980年为界,之前变化稳定,之后显著增多。这一现象与青藏高原及北半球的气温变化在大的趋势上具有良好的相似性。我们认为磁性颗粒的增加与气候变暖有着一定的关系。其可能的机制是:在大的时间尺度上,气候变暖导致的冰川退缩和局地气候不稳定使得冰芯中含有磁性矿物的大颗粒物质增多,而与年降水变化相关的沙尘天气频率相关性较弱。因此,青藏高原冰芯不溶性微粒的饱和等温剩磁可能在趋势上反映了气候变暖,为研究该区大气粉尘的沉降过程提供新参数.
奥陶-志留纪之交黔中古陆的变迁:证据与启示

深入的奥陶-志留纪交替期生物地层划分对比使古地理精时研究成为可能。对滇、川、黔、渝4省市、24个县、58条剖面的生物地层、群落古生态和古地理资料的分析表明,晚奥陶世至志留纪早期黔中古陆北缘的海岸带一直处于变动之中:(1)奥陶纪凯迪晚期,本研究区广泛接受五峰组沉积,但五峰晚期黔东北海底出现起伏,个别孤岛露出海面;(2)赫南特早中期,当全球海面大幅下降时,观音桥层仍广泛沉积,黔东北出现少数岛屿;(3)赫南特晚期-鲁丹早期,全球海面大幅上升,黔北南部和黔东北不降反升,隆升速度超过海面上升速度,更多、更大的岛屿浮出海面;(4)志留纪鲁丹晚期,这些岛屿复被海水淹没,普遍发育龙马溪组沉积。奥陶纪-志留纪交界时期,黔中古陆以北海域的东区(黔北南部、黔东北、渝东南)和西区(黔西北、滇东北、川南)在地层发育和古地理格局上发生的重要差异,体现了黔中古陆北缘的升隆与扩展,在时空上与发生在湘鄂西的宜昌上升紧密相连,它们均受华南东部和南部深部大地构造活动的制约.
我国干旱区深厚大气边界层与陆面热力过程的关系研究

大气边界层是地球大气重要物理特征之一。干旱气候背景下的大气边界层特征与人们以往对典型大气边界层的认识有很大不同,其形成机制也比较特殊。本文利用冬、夏两季典型时段在极端干旱区敦煌开展的大气边界层和陆面过程综合观测试验,对大气边界层厚度与净辐射、地-气温差和感热通量等陆面热力因素的日变化特征进行了对比分析,研究了大气边界层的发展和维持衰退过程与陆面热力和动力过程的关系,发现发展过程消耗的能量要比维持衰退过程高得多,而且进入残余层后对流边界层发展对陆面热力作用更敏感,发展也更迅速。风速的动力作用对大气边界层发展也有一定的影响,尤其对冬季稳定大气边界层影响较大。极强的陆面热力作用是我国干旱区形成深厚大气边界层的主导因素.
干旱地区土壤-植被-水文耦合、响应与适应机制

从单个植株、坡面和流域三个尺度综述了干旱地区土壤-植被-水文耦合与响应的研究进展,并提出今后研究中需要关注的科学问题。未来研究需要通过多学科交叉与融合手段,加强土壤-植被系统整体性综合集成研究,主要包括地上与地下过程、植被退化与恢复过程、自然与人为扰动过程、多尺度与多要素综合观测与模拟。初步提出干旱地区植被的水分聚集适应理论,分析并讨论了树干茎流水分聚集系统、灌丛斑块水分聚集系统和沟道河网水分聚集系统的组成、结构和特点,揭示了不同水分聚集系统对水分胁迫的适应机制,可为干旱地区植被恢复提供理论支撑和实践指导.
全球变暖背景下中亚干旱区降水变化特征及其空间差异

依据Climatic Research Unit(CRU)1930~2009年间的最新0.5°×0.5°网格点的月均降水量序列,本文分析了中亚干旱区近80年来的降水变化特征及其区域差异.结果发现,近80年来主要受西风环流控制的中亚干旱区年降水整体上表现出增加趋势,年降水中以冬季降水的增加趋势最明显(0.7mm/10a).中亚干旱区近80年来的降水变化存在空间差异,可划分为五个降水变化区域(Ⅰ-哈萨克斯坦西区,Ⅱ-哈萨克斯坦东区,Ⅲ-中亚平原区,Ⅳ-吉尔吉斯斯坦区,Ⅴ-伊朗高原区),根据年降水分布模式以45°N为界划分为两类:研究区北部的两个区(Ⅰ和Ⅱ区)四季降水较均匀,南部的三个区均以春、冬季降水为主(占全年降水的60%~82%).在降水变化趋势上,除了中亚干旱区西南(Ⅴ区)在近80年来有微弱的减少趋势外,其他四区均表现为增加趋势,尤以干旱区西部的Ⅰ区和Ⅲ区降水增加显著.近80年来降水增加或者减少的趋势主要取决于冬季的变化趋势.研究还发现,中亚干旱区降水存在较明显的年际变化,中亚干旱区及其各分区都具有2~3 a的显著周期,南部三区(Ⅲ,Ⅳ,Ⅴ区)还存在5~6 a的显著周期,在此基础上都具有3~4个阶段性的变化趋势.最近一次趋势性变化开始于20世纪70年代中后期,研究区降水更多的表现出区域的差异性.近80年来,中亚干旱区降水对全球变暖的响应复杂,西风环流变化可能是影响中亚干旱区降水变化的主要因素.
近50年影响中国热带气旋的气候变化特征

本文用CMA-STI整编的热带气旋最佳路径和大风、降水观测资料,用分位数回归拟合法分析了过去50年热带气旋对我国及四个区域(华南、华东、东北和内陆地区)的风雨影响趋势。分析表明,在过去50年间,影响我国及各区域的热带气旋频数基本不变,但对全国及东北地区而言高频年份有显著减少。影响的热带气旋在南海西北部及广东和山东半岛一带的活动有显著减少。过去50年热带气旋影响季节特征最主要的变化是内陆地区的影响日数在分布的主峰区有明显变化,影响日数少的年份显著减少。过去50年间,热带气旋所致的大风在全国及各区的平均风速的大值一致减少,但阵风风速的趋势出现分化,且各区也不相同。而热带气旋的降水影响,最大过程降水量和最大1小时降水量虽有变化但趋势不显著.
上新世末期-更新世早期西北太平洋ODP882A孔沉积物的磁学特征及其古气候意义

风成粉尘是远洋沉积物中主要陆源组分之一,其搬运距离、粒度及含量随气候条件而变化,可用于古气候演化重建。本文以西北太平洋ODP882A孔深海沉积物为研究对象,利用重力分异的方法分离出其中不同粒径组分(<8,8~16,16~64,>64μm),并对各组分进行了详细的岩石磁学研究。结果表明钻孔中粉尘组分(<8μm)的磁性矿物以磁铁矿和赤铁矿为主。本文所研究的样品年代覆盖2.85~2.55Ma,其中2.73Ma对应于北半球冰川作用增强时期.在此之前的风成粉尘组分的强磁性矿物含量较少,而在冰川作用增强之后,强磁性矿物含量突然增加.与之对比,冰筏碎屑(>64μm)组分对样品的磁性贡献不大.因此,我们认为在2.73Ma前后样品磁性增强主要是由亚洲粉尘输入量的增加引起.这种新机制为进一步探讨该区的古环境信息提供了新的研究思路.
积云对流参数化方案对热带大气季节内振荡模拟的影响

本文利用中国科学院大气物理研究所大气科学和地球流体力学数值模拟国家重点实验室(LASG)的大气环流谱模式的最新版本SAMIL2.2.3系统分析了积云对流参数化方案对热带大气季节内振荡(ISO)模拟的影响.结果表明该模式的三种积云对流参数化方案都能模拟出热带地区气候平均季节内振荡(CISO)时空演变的基本特征;其中Tiedtke方案相比于Manabe方案和Zhang-McFarlane方案,模拟出的CISO与观测更为接近.而SAMIL2.2.3模式对ISO年际变化部分(TISO)的模拟结果显示尽管SAMIL2.2.3相对于之前的版本对Tiedtke方案和Zhang-McFarlane方案针对不同问题做了必要调整,但三种积云参数化方案中只有Zhang-McFarlane方案能够模拟出27~50天TISO模态的东传特征.另外,SAMIL2.2.3与其较早版本SAMIL2.08中的Manabe方案完全相同,物理过程的其他部分如辐射方案和气溶胶条件有所调整,但仅后者能模拟出100E以西热带27~50天TISO模态的东传特征.因此,模式发展过程中物理参数化方案的改进并非在每一方面上都产生正面效果.动力框架和物理过程,以及不同物理过程之间的协调发展是改进模式的重要途径.
豹属线粒体基因组分析

采用PCR扩增方法,测定了虎、豹和雪豹线粒体基因组全序列,长度分别为16990,16964和16773bp。每个线粒体基因组包括:13个蛋白编码基因,22个tRNA,2个rRNA,一个非编码的控制区(D-loop)以及一个轻链复制起点(OLR),其基因组结构与家猫、美洲狮和云豹具有较高的相似性。基于两组线粒体合并序列和线粒体全序列,采用最大简约法、最大似然法及贝叶斯法(Bayesian)推测豹属的分子系统关系。结果显示,豹属(Panthera)由虎、豹、雪豹、美洲虎、狮和云豹组成,云豹并归于豹属。属内物种间的系统关系为:云豹(虎(美洲虎(豹(狮,雪豹))))。基于ML最优树的枝长和4个可靠的分歧时间校正点进行了分歧时间的估算,豹属约在11.3百万年前(MYA)从猫科动物中分化出来;云豹、虎、雪豹和豹的分化时间分别为8.66,6.55,4.63和4.35MYA,比化石时间略早.尤其是雪豹这一青藏高原的特有物种,其分歧事件、演化过程、物种形成和分布模式与发生在8,3.6,2.5和1.7MYA晚新生代青藏高原的地质构造事件及气候重大转型期呈现相关性.
用线性梯度平板准确测定药物敏感性和分离抗药性菌株

菌群在药物的最低抑菌浓度附近的动力学过程是抗生素药理学研究的核心问题。建立一种能确定精确的MIC且又能准确分离抗药性菌株的方法,是目前临床对药敏实验新的要求。根据Fick扩散定律制备了线性梯度平板:将15mL含适当浓度恩诺沙星的琼脂培养基在9cm培养皿中倾斜凝固,刚好覆盖整个平板底面,然后水平放置,再在其上层加入同样体积的无药琼脂培养基,凝固12h后,药物浓度达到扩散平衡而呈均匀连续线性梯度。通过实测验证药物浓度在平板表面呈线性梯度分布。将待检E.coli菌群均匀涂布在梯度平板上,培养12h后,随恩诺沙星浓度提高依次形成连续密集小菌落区和离散大菌落区,根据两区域的分界线可以确定菌群自然形成的真实的MIC,与常规药敏实验方法测定结果一致.大菌落重新涂布高梯度平板,分界线显著上升,并检测出抗药性基因突变,表明该方法很容易筛选出菌群中的抗药性菌株.梯度平板可以方便地呈现整个菌群在MIC附近的动力学过程和遗传生理变化,并预警该抗生素使用后可能出现的抗药性,从而指导临床抗菌药物的选择和使用.
A 1500 mA,10 MHz on-time controlled buck converter with ripple compensation and efficiency optimization

A 1500 mA,10 MHz self-adaptive on-time(SOT) controlled buck DC-DC converter is presented.Both a low-cost ripple compensation scheme(RCS) and a self-adaptive on-time generator(SAOTG) are proposed to solve the system stability and frequency variation problem.Meanwhile a self-adaptive power transistor sizing(SAPTS) technique is used to optimize the efficiency especially with a heavy load.The circuit is implemented in a 2P4M 0.35μm CMOS process.A small external inductor of 0.47μH and a capacitor of 4.7μF are used to lower the cost of the converter and keep the output ripple to less than 10 mV.The measurement results show that the overshoot of the load transient response is 8 mV @ 200 mA step and the dynamic voltage scaling(DVS) performance is a rise of 16μs/V and a fall of 20μs/V.With a SAPTS technique and PFM control,the efficiency is maintained at more than 81%for a load range of 20 to 1500 mA and the peak efficiency reaches 88.43%.
High breakdown voltage InGaAs/InP double heterojunction bipolar transistors with f_(max)=256 GHz and BV_(CEO)= 8.3 V

An InGaAs/InP DHBT with an InGaAsP composite collector is designed and fabricated using triple mesa structural and planarization technology.All processes are on 3-inch wafers.The DHBT with an emitter area of 1 x 15μm~2 exhibits a current cutoff frequency f_t = 170 GHz and a maximum oscillation frequency f_(max) = 256 GHz.The breakdown voltage is 8.3 V,which is to our knowledge the highest BV_(CEO) ever reported for InGaAs/InP DHBTs in China with comparable high frequency performances.The high speed InGaAs/InP DHBTs with high breakdown voltage are promising for voltage-controlled oscillator and mixer applications at W band or even higher frequencies.
Iterative convergence of boundary-volume integral equation method

The boundary-volume integral equation numerical technique can be a powerful tool for piecewise heterogeneous media,but it is limited to small problems or low frequencies because of great computational cost. Therefore,a restarted GMRES method is applied to solve large-scale boundary-volume scattering problems in this paper to overcome the computational barrier.The iterative method is firstly applied to responses of dimen-sionless frequency to a semicircular alluvial valley filled with sediments,compared with the standard Gaussian elimination method.Then the method is tested by a heterogeneous multilayered model to show its applicability. Numerical experiments indicate that the preconditioned GMRES method can significantly improve computational efficiency especially for large Earth models and high frequencies,but with a faster convergence for the left diagonal preconditioning.
Major bridge projects—a multi-disciplinary approach

Modern bridge building is much more than concrete, steel and money. The overall socioeconomic impact, influence on people migration, traffic, use of primary materials, safety of construction impact on the environment, energy, risk scenarios, health, and most relevant now: climate and CO_2 emissions, are among the parameters which enter into the decision process at the overall holistic conceptual level, the more detailed level of selection of bridge sites, and selection of bridge types as well as construction methods and selection of materials and products. The paper illustrates these dilemmas and illustrates by specific examples how this complicated decision process can be managed and structured in order to arrive at an overall satisfactory solution for design, construction and maintenance throughout the lifetime (life cycle) to these sometimes contradictory parameters and requirements.
Seismic design of high-rise towers for cable-stayed bridges under strong earthquakes

This paper presents the first of a series of studies on the seismic design of high-rise towers for cable-stayed bridges under strong earthquakes. One practical cable-stayed bridge with a 730 m long main span and two high-rise towers over 200 m in height was selected for this study. The preliminary results show that compared with piers, the tower is more vulnerable to pulse-like earthquakes, and it may develop plasticity at certain locations. In addition, viscous dampers may not have the same effect during pulse-like earthquakes as they do under site-specific earthquakes. Hence, reoptimization of damper parameters or reconsideration of other energy dissipation devices will be needed if strong earthquakes are likely to occur.
Two-thirds simulation indexes and modal logic characterization

Two-thirds simulation provides a kind of abstract description of an implementation with respect to a specification. In order to characterize the approximate two-thirds simulation, we propose the definition of a two-thirds simulation index which expresses the degree to which a binary relation between processes is two-thirds simulation. λ -two-thirds simulation and its substitutivity laws are given in this paper. And, based on λ -two-thirds simulation, we present a measure model for describing the degree of approximation between processes. In particular, we give the modal logical characterization of λ -two-thirds simulation.
PIC simulation study of electron gun with rotational surface cathode

The electron gun with rotational surface cathode is presented to improve the laminarity of the converging electron beams in this paper, and the function expression of the rotational surfaces is given. The results of particle in cell (PIC) simulation indicate that anode-hole spherical aberration is the major cause for the nonlaminarity of the electron beams. By properly choosing the size of the shape, rotational surface cathode can effectively counteract the effect of the anode-hole spherical aberration and enhance the laminarity of the electron beams. The theoretical analysis was carried out for the explanation of the phenomenon that appeared in the PIC simulation.
Design and analysis of control system using neural network for regulated DC power supply

Conventional control systems used for regulated power supplies, including the proportional integral and derivation (PID) controller, have some serious disadvantages. The PID controller has a delayed feedback associated with the control action and requires a lot of mathematical derivations. This paper presents a novel controlling system based on the artificial neural network (ANN), which can be used to regulate the output voltage of the DC power supply. Using MATLAB?, the designed control system was tested and analyzed with two types of back-propagation algorithms. This paper presents the results of the simulation that includes sum-squared error (SSE) and mean-squared error (MSE), and gives a detailed comparison of these values for the two algorithms. Hardware verification of the new system, using RS232 interface and Microsoft Visual Basic 6.0, was implemented, showing very good consistency with the simulation results. The proposed control system, compared to PID and other conventional controllers, requires less mathematical derivation in design and it is easier to implement.
Electromagnetic properties of electro-textiles for wearable antennas applications

Wearable, textile-based antennas get more and more attention for body-centric communications because it could be easily worn on body and integrated into clothes. Electro-textiles (e-textiles) are used as antenna patch and ground plane. The electromagnetic properties of the textiles play important roles in antenna design and performance. This paper focuses on the study of the electromagnetic properties of e-textiles for wearable antennas applications and mainly discusses the electromagnetic properties of e-textile cell and the influences of different woven densities and different e-textile materials to antenna performances. Simulation and measurement results show that if the e-textiles adopt woven pattern, then when the distance between two conductive fibers is within 2 mm, the e-textiles could be regarded as metal plane to design antennas. In addition, the results show that metalplated woven fabric could be used as metal plane to design antennas, while non-woven fabric shows distinct differences.
A method of ICI cancellation for OFDM with delay diversity

In orthogonal frequency division multiplexing (OFDM) system, the time variation of a wireless channel destroys orthogonality among the sub-carriers, and this induces inter-carriers interference (ICI) and degrades system performance severely in mobile environment. In this paper, a new method of ICI cancellation based on delay diversity (DD) was proposed, which provides a way to mitigate the negative effect from the time variation of the wireless paths, thus improve the system performance greatly. The new method was called time-domain self-interference cancellation (TDSIC) algorithm, which is different from other existing methods, such as frequency-domain method. In a cyclically extended OFDM system, the fading characteristics of extended OFDM symbols with different cyclic delay are different with each other, so in our TDSIC method, a new diversity collection scheme at the receiver end is proposed, which can be used to improve the system performance by suppressing ICI through selecting appropriate parameters. Moreover, the cyclically extended OFDM symbol at the transmitter side and diversity collection with different delay added OFDM symbols at the receiver side are used in the TDSIC method with the tradeoff of time-expense, so the well-known fixed delay for symbol at the transmitter side may be detected by the receiver side through estimating several parameters of wireless channels. In summary, the key of the TDSIC method is to improve the system performance with the cost of time. Based on performance analysis, simulation has proved that TDSIC may effectively improve the performance of the time-variant wireless channel.
ID-based signature schemes from bilinear pairing: A survey

In identity (ID)-based cryptosystems, a user can use his/her identity as the public key, which simplifies the key management procedure compared to certificate-based cryptosystems. Authentication is a desired property in cryptographic protocols. The signature scheme provides this property. Notion of pairing reduces the computation overheads and makes the system simple and efficient. In this survey, we have tried to cover some ID-based signature schemes based on bilinear pairings with their protocol and security analysis to the best of our knowledge. We hope this survey will provide a ready reference to work in the related area.
Speech enhancement based on modified a priori SNR estimation

To solve the frame delay problem and match the previous frame, Plapous et al. [IEEE Transactions on Audio, Speech, and Language Processing, 2006, 14(6): 2098–2108] introduced a novel approach called two-step noise reduction (TSNR) technique to improve the performance of the speech enhancement system. However, TSNR approach results in spectral peaks of short duration and the broken spectral outlier, which degrade the spectral characteristics of the speech. To solve this problem, a cepstral smoothing step is added in order to remove these spectral peaks brought by TSNR approach. Theory analysis shows that the proposed approach can effectively smooth the spectral peaks and keep the spectral outlier so as to protect the speech characteristics. Experiment results also show that the proposed approach can bring significant improvement compared to decision-directed (DD) and TSNR approaches, especially in non-stationary noisy environments.
Power allocation for collaborative transmission in LTE-Advanced

Collaborative transmission among evolved Node-Bs (eNBs) is one of the promising techniques for LTE-Advanced to provide broader coverage and higher spectral efficiency. The interference among multi-cell transmission can be mitigated by joint precoding, such as multi-cell block diagonalization (BD) at cooperative eNBs. The major difference between multi-cell and single-cell transmission is that the power constraint has to be considered on a per-eNB basis. To satisfy per-eNB power constraint (PePC), a simplified power allocation algorithm for the multi-cell BD based collaborative transmission is proposed in this paper. The algorithm provides a power allocation coefficient matrix for BD to meet PePC. Simulation results demonstrate that the proposed algorithm has a near-optimal performance with simplicity.
IPCC影响评估中的社会经济新情景(SSPs)进展

气候变化情景在全球和区域气候变化预估中得到广泛应用,温室气体排放情景是气候模拟的基础,影响温室气体排放的社会经济驱动因素,如人口增长、经济发展、技术进步、环境条件、社会管理等假设组成了社会经济情景。IPCC先后发展了SA90、IS92、SRES等情景,应用于历次评估报告。随着气候变化影响评估的发展,SRES情景的不足逐步显现,为此,IPCC调整了情景的发展方法和过程,发展了新的情景框架,于2007年发布典型浓度路径(representative concentration pathways, RCPs)来描述温室气体浓度,并在RCPs的基础上发展共享社会经济路径(shared socio-economic pathways, SSPs)来构建社会经济新情景。本文通过回顾气候变化情景的发展过程,分析社会经济新情景的设计思路和特点,并对其未来应用进行展望。
A novel and effective multi-constrained QoS routing scheme in WMNs

Multi-constrained quality of service (QoS) routing aims at finding an optimal path that satisfies a set of QoS parameters, as an NP complete problem, which is also a big challenge for wireless mesh networks (WMNs). Heuristic algorithms with polynomial and pseudo-polynomial-time complexities are often used to deal with this problem. However, existing solutions, most of which suffered either from excessive computational complexities or from low performance, were proposed only for wired networks and cannot be used directly in wireless mesh networks. In this paper, we propose a novel routing scheme based on mean field annealing (MFA-RS) to solve this problem. MFA-RS first uses a function of two QoS parameters, wireless link’s delay and transmission success rate as the cost function, and then seeks to find a feasible path by MFA. Because MFA-RS uses a set of deterministic equations to replace the stochastic process in simulated annealing (SA) and uses saddle point approximation in the calculation of the stationary probability distribution at equilibrium, the convergence time is much less than the routing scheme based on SA (SA-RS). Simulation results demonstrate that MFA-RS is an effective algorithm and is very fit for WMNs.
帕瑞昔布钠超前镇痛对下肢骨科手术止血带疼痛控制的影响

止血带在骨科四肢手术中的应用极为普遍,使用的目的是为了减少手术中的出血量。但是止血带所引起的疼痛又困扰着麻醉医生、手术医生以及患者本人。因此,如何减缓止血带引起的疼痛是值得我们研究以及解决的一个问题。国外许多学者对此进行许多临床研究,寻找可以减缓止血带疼痛的途径。Takada等对32例术中使用止血带进行全膝置换术或者前交叉韧带重建患者进行临床分析:术前使用氟比洛芬酯的一组患者(B组),其术后使用镇痛药的量明显少于术前未使用组(A组)。帕瑞昔布钠作为特异性COX-2抑制药,静脉注射后透过血脑屏障,抑制中枢神经系统的COX-2,降低了脑脊液中的PGE2发挥镇痛效果。本文就帕瑞昔布钠超前镇痛能否减缓术中及术后止血带疼痛的进行临床分析。
中国疼痛医师队伍的建设

2011年11月26日在北京举办了"中国医师协会疼痛医师专业委员会成立大会暨首届中国医师协会疼痛医师专业委员会年会"。本届年会的主题是"疼痛医师的责任、权利和义务"。大会首先肯定了以韩济生院士为代表的老一代疼痛医务工作者为中国疼痛事业发展做出的突出贡献,重点对中国疼痛医师的队伍建设问题作了讨论,这些讨论对于疼痛专科未来的发展至关重要。通过讨论提高了医学界同行对我们“疼痛医学专业”的认同感,也提高了我们自己对疼痛专科的认知程度。专家们一致认为,中国医师协会疼痛医师专业委员会的成立,对保障卫生部227号文件的正确贯彻落实、建设符合临床二级学科要求的疼痛学科与专科队伍,具有重要意义。
以语音障碍为特征的语言发育迟缓学龄前儿童语言治疗1例报道

目的探讨以语音障碍为特征的语言发育迟缓学龄前儿童语言治疗的效果。方法采用理解训练、语法训练、表达训练、构音训练、游戏治疗、构音器官运动等训练,用中国康复研究中心构音障碍评定法、S-S法进行评定。结果患儿的语言状况明显改善。结论语言治疗可以改善以语音障碍为主的语言发育迟缓的症状。
超声诊断右心发育不良综合征1例

患儿男,55天,以"生后颜面、口唇、指趾青紫,近两日加重伴呼吸困难"就诊。体格检查:一般状况差,面色灰暗,全身皮肤黏膜发绀。三凹征(+)。心率:110次/分。胸骨左缘第2肋间闻及3~4级收缩期杂音。胸部X线示心影略大。超声心动图:内脏位置正常,内脏心房连接正常;房间隔中部回声失落约6~8mm,房水平探及右向左为主双向分流信号(图1);可见左右房室环及十字交叉结构,右侧房室间未见正常瓣膜样结构,代之以厚约2mm强回声结构(图2),中央可见约1 cm~2较薄的膜性结构,随心动周期膨向右心室或右心房,未探及右侧房室间血流沟通。
三维超声诊断胎儿小下颌畸形1例

孕妇,23岁,孕1产0,孕28+3周来院接受产前常规超声检查。超声:羊水指数17.20cm,二维矢状切面显示胎儿下唇及下颌正常曲线消失,下颌后缩,下唇后移,呈小弧形(图1);3D超声显示胎儿下颌明显后缩,面颊至下颌的平滑曲线消失,呈半张口状态(图2)。
脱硫废水设计方案及经济性分析

探讨了石灰石/石膏湿法烟气脱硫过程中产生废水的处理工艺方案及其经济性。以国电费县发电厂(2×600MW)脱硫废水设计方案为例,分析了系统在设计、设备、运行、维护等环节上的优缺点。对原方案进行改进,改造后的工艺经调试后取得了满意的运行效果。
改良封闭式负压引流技术在骨科创面治疗中的应用

目的通过与常规封闭式负压引流技术(vacuum sealing drainage,VSD)进行比较,探讨改良VSD在骨科创面治疗中的优越性。方法2008年3月-2010年4月,共治疗37例42处创面,其中17例20处创面采用常规VSD治疗(常规组);20例22处采用改良VSD治疗(改良组),即在常规VSD敷料中加入1根冲洗管,进行持续灌注冲洗。两组患者性别、年龄、病程、创面部位及创面范围等一般资料比较,差异均无统计学意义(P>0.05),具有可比性。结果改良组泡沫敷料维持时间较常规组长(t=2.70,P=0.01)。常规组术后15例(88%)进行注射器冲管,改良组仅1例(5%),差异有统计学意义(χ2=3.80,P=0.04)。改良组术后更换泡沫敷料次数为(1.0±0.1)次,较常规组(2.2±0.6)次少(t=2.90,P=0.01)。改良组费用为(6 330±550)元,较常规组(12 990±1 120)元少(t=2.70,P=0.01)。结论改良VSD延长了泡沫敷料使用时间,减少了患者更换敷料的次数,降低了治疗费用。
2012年度国家自然科学基金项目指南(地球科学部分)

地球科学是认识行星地球系统的形成和演化的一门自然科学,主要包括地理学、地质学、地球化学、地球物理与空间物理学、大气科学和海洋科学以及这些分支学科与其他学科的交叉研究。
中国田园交响曲的执棒者——袁隆平

中国有13亿人口,其中9亿农民。民以食为天,在老百姓的粮食库中,水稻无疑是占据重要地位的一种作物。为解决吃饭问题,古代的祖先、现当代的科学家,不知在培育粮食优质品种上花费了多少心血。
陡山沱组球形化石新解难获认同

产于贵州省瓮安县翁福磷矿采区埃迪卡拉纪陡山沱期(距今约6.35-5.51亿年)磷酸盐化特异埋藏化石群全球闻名。该化石群中绝大多数化石为球形,具有多种带装饰的外包膜,包膜内部可见数目不等的分裂球,是全球已知最古老的与后生动物相关的化石群,其属性判定直接影响着包括人类在内的后生动物起源和早期演化过程的确定。
花生种子人工老化对萌发期种子活力的影响

种子是农业生产重要的基本生产资料,种子活力反映了种子在各种条件下具有的潜在萌发与出苗能力以及贮藏性能,其受遗传、种子发育期间的环境及贮藏条件等诸多因素的影响[1]。种子活力比发芽率更能体现种子质量的高低,它与种子的使用价值及贮藏性能密切相关[2]。高活力种子具有明显的生长优势和生产潜力,可以提高田间出苗率,增强抵御不良环境的能力,增加产量,因此对花生生产具有十分重要的意义。
系统性红斑狼疮母亲所产婴儿回顾性分析及随访

目的了解患系统性红斑狼疮(SLE)母亲对其所产婴儿的影响。方法2003-2010年患SLE产妇所产28例婴儿进行回顾性分析及随访。结果SLE母亲狼疮活动者较不活动者早产、低体重、宫内生长发育受限的比例高。28例婴儿中1例死亡,3例发生贫血,7例发生非感染引起的血小板减少,2例出现皮疹,3例有一过性心率下降,无房室传导阻滞,2例发现房间隔缺损。随访患儿未出现明显生长发育落后,复查心脏B超和免疫学指标正常,暂未出现自身免疫性疾病。结论SLE母亲可致所生婴儿在新生儿期出现多系统损害,但损害可能只是暂时的。
2011年度国家自然科学基金微生物学学科项目申请与资助情况及简要分析

本文详细介绍了2011年度国家自然科学基金委员会生命科学部微生物学学科的项目申请、受理和资助的情况,着重介绍了项目申请中应当引起申请人普遍关注的问题,对获资助项目情况的特点进行了概括和分析,希望为科研人员今后申请基金项目提供有用的参考。
1∶2000基础地形图自动缩编体系的研究

为解决1∶2 000基础地形图的需求量与更新速度慢之间的矛盾,讨论实用化地图综合体系的开发与构建,并从软件开发、系统构建两个方面着重讨论整个地形图缩编体系及其所采用的关键技术。结合项目的实际应用情况,明确该技术体系的先进性。
测定既有拱桥拱圈线形的改进悬高测量法

提出一种测量既有拱桥拱圈线形的改进悬高测量法,根据测量误差传播定律,推导Z坐标测量中误差的计算公式,并讨论影响测量精度的主要因素,分析测量时的注意事项。理论分析和工程实例表明,改进的悬高测量法具有观测精度高、操作简便、适应性强等优点,是拱圈线形测量的一种较好方法。
数码航测成图像控布设方案研究

针对现有的国家技术标准对数码航测成图像控布设尚无确定性标准的现状,对生产中常用的航线网解析空中三角测量的精度估算公式进行改进,并用DMC航摄影像进行验证。试验结果表明,改进的精度估算公式适用于数码航测加密精度估算,能很好地解决生产需求,具有一定的推广价值。
基于多尺度分割的煤矿区典型地物遥感信息提取

根据煤矿区典型地物类型的特点,研究遥感影像信息提取时面向对象分类方法的最优分割尺度问题。试验结果表明:在适于不同地物提取的最优分割尺度下,充分利用煤矿区影像对象的光谱、形状、纹理以及类间相关等特征,并综合应用隶属函数法和最邻近分类法,能有效地提取出煤矿区地物信息,与最大似然分类法相比,能够较好地消除"椒盐现象",其总体分类精度可提高26.2%。
交叉配血主侧不合48例分析

目的了解本院48例交叉配血主侧不合的原因。方法对用盐水法、凝聚胺方法和抗球蛋白法对交叉配血中主侧不合的48份标本的鉴定结果进行分析。结果48例主侧不合,其中,由特异性血型抗体引起37例,单纯自身抗体引起7例,药物引起1例,B亚型引起1例,献血者红细胞直抗阳性引起2例。结论输血前试验可有效地降低或避免溶血性输血反应的发生,提高输血安全性。
无菌接合密闭性确认及接合失败补救方法初探

<正>近年来,无菌接合机(sterile connection devices,SCD)已常规应用于血液及成分保存袋等聚氯乙烯(polyvinyl chlo-ride,PVC)管路间的接合。采用无菌接合连接的血液成分,只要保证接合口完整、无渗漏、无气泡,其制品的保存期与密闭系统制备的血液成分保存期一致[1,2]。故无菌接合的密闭性与血液质量及其保质期密切相关,但目前尚缺乏统一的确认及接合失败补救方法。本中心初步探索使用滚轮钳加压实验确认无菌接合效果并对接合失败者予以补救,效果满意,现报告如下。