新型配电系统分布式经济调度信息安全问题研究综述

随着大规模高比例的分布式电源接入电网运行,分布式经济调度系统因其优势显著受到更多的关注。但是,该系统特有的分布式通信构架、优化问题迭代求解过程和多利益主体参与模式为从系统内部和外部实施网络攻击提供了更宽广的时空条件,攻击模式和手段更加复杂多样,解决信息安全问题是提高分布式经济调度系统实用化程度的重要前提和基础。文中对分布式经济调度系统可能出现的信息安全问题及应对措施的研究现状进行了综述。首先,讨论了电力系统各种通信技术对分布式经济调度系统的适应性以及通信技术本身存在的安全风险;其次,介绍了外部网络攻击和内部恶意行为两类典型的信息安全问题,并进行了相关的特点分析和影响评估;然后,归纳和分析了两类信息安全问题的检测、预防、抑制措施和方法;最后,对信息安全问题模型的建立和综合安全防御体系构建进行了探讨。

地质灾害监测复杂场景下压电式雨量计精度标定及适宜性分析

降雨尤其是局地集中强降雨是诱发滑坡、泥石流等突发地质灾害的主要因素之一。据中国历史灾情统计,局地短时集中强降雨是泥石流的最主要诱发因素,同时降雨诱发型滑坡数量也约占滑坡总数的70%。目前,中国南方的春汛、梅汛提前和北方的秋汛延后,造成地质灾害数量增加、防范区域扩大、防御时段延长。因此开展雨量监测对滑坡、泥石流预警预报具有十分重要的意义。受野外监测场地地形地貌、植被和局地小气候等影响,雨量监测设备的精度、灵敏性、稳定性以及安装位置的科学性是精准预警预报的前提。文章基于翻斗式和压电式两种类型雨量计测定原理、技术参数、安装方法和运维方式的对比,开展室内模拟降雨环境和野外复杂场景试验,进行压电式雨量计精度测定及适宜性分析。结果表明:压电式雨量计误差范围在4%以内。在野外地质灾害监测复杂场景下,压电式雨量计无论是量程大小、测量精度,还是安装方式和后期维护,均较翻斗式雨量计更为适宜。

降雨入渗条件下堆积体边坡致灾因子试验分析

堆积体边坡稳定性判别和分析是地质灾害防治重点,分别以密实细颗粒边坡和松散碎石体边坡为例,开展了降雨入渗作用下坡体失稳室内模型试验,系统分析了密实度、物质组成、坡度以及植被覆盖度对边坡稳定性和降雨阈值的影响。结果表明,降雨入渗作用下,物质组成较均匀、密实度高的细颗粒边坡稳定性较好,坡体失稳降雨阈值高,致灾性较低;物质组成不均、松散碎石体边坡相较于密实细颗粒边坡更容易失稳破坏,含石量对坡体稳定性的影响要大于坡体坡度;坡体失稳临界降雨量随植被覆盖度的增大先升高后降低,即当降雨入渗致使边坡土体过饱和时,较高的植被覆盖度反而会由于植被根系的强发育,触发坡体和植被整体破坏,并加大坡体致灾能力。研究成果可以为堆积体边坡失稳机理研究及其稳定性评价提供理论依据。

主动配电网分布式经济调度系统的时延稳定性分析

分布式经济调度模式具有更好的鲁棒性、更快的计算速度和更少的通信量等优点,适用于高渗透率分布式电源接入的主动配电网。但分布式模式下各单元之间通信的时延将可能破坏系统的稳定性。因此对采用分布式经济调度策略的主动配电网的时延稳定性进行了研究。首先,引入虚拟分布式电源,设计了主动配电网完全分布式的经济调度策略。然后,建立了采用该分布式经济调度策略下主动配电网对称/不对称时延下的稳定性分析模型。同时利用Lyapunov稳定性定理和自由权矩阵方法得出具有更低保守性的系统时延稳定判据,并通过线性矩阵不等式计算时延系统的稳定裕度。最后,通过IEEE-14节点配电网系统中的仿真算例验证了所提分布式经济调度控制系统时延稳定性分析和时延稳定裕度计算方法的正确性和有效性。

基于普适型监测的多参数预警研究--以三峡库区卡门子湾滑坡为例

笔者以三峡库区卡门子湾滑坡为例,介绍了此次滑坡监测预警实验选点踏勘设计,安装实施运行、监测数据实时传输、系统自动发出预警等全过程。监测数据前端采集选用普适型多参数集成监测设备(裂缝+倾角+加速度计)、雨量计、加速度计等,对“降雨+变形”等关键致灾因子开展专业化监测;通讯采用NB lot等公共通信网组合方式进行传输,有效降低了通信成本和设备功耗;监测数据汇聚至省级平台,并实时同步至自主研发的国家级监测预警系统,通过判据模型自动触发预警。通过近半年的系统运行,滑坡体上安装的裂缝计、加速度计等均及时捕捉到了明显的滑坡加速变形信息,初步显现了普适型设备的监测成效和预警作用。同时,系统将预警消息实时发送到相关责任人员的手机,预警结果可有效指导相关部门开展应急响应工作。

Synergistic catalytic ozonation of toluene with manganese and cerium varies at low temperature

The temperature of waste gas in refuse transfer station,airport smoking area,and RTO terminal is low,which needs deep oxidation.Catalytic ozonation is one of the most effective treatment techniques in these scenarios.In this study,we reported that catalysts were modified under the condition of mag-netic field to simulate the low temperature dynamic conditions of low concentration toluene for catalytic ozonation.This paper aims to explore the relationship between oxygen vacancy and active oxygen species,and the specific pathways of toluene oxidation.The study found that citric acid can enhance the syner-gistic effect between Mn and Ce,and promote the generation of oxygen vacancies.The surface molecule adsorption oxygen is more conducive to catalytic oxidation than subsurface atom adsorption oxygen.Fi-nally,we proposed the main pathways of toluene in this reaction system,which runs through the whole process of the reaction.

Artificial cilia for soft and stable surface covalent immobilization of bone morphogenetic protein-2

Preservation of growth factor sensitivity and bioactivity(e.g.,bone morphogenetic protein-2(BMP-2))post-immobilization to tissue engineering scaffolds remains a great challenge.Here,we develop a stable and soft surface modification strategy to address this issue.BMP-2(a model growth factor)is covalently immobilized onto homogeneous poly(glycidyl methacrylate)(PGMA)polymer brushes which are grafted onto substrate surfaces(Au,quartz glass,silica wafer,or common biomaterials)via surface-initiated atom transfer radical polymerization.This surface modification method multiplies the functionalized interfacial area;it is simple,fast,gentle,and has little effect on the loaded protein owing to the cilia motility.The immobilized BMP-2(i-BMP-2)on the surface of homogeneous PGMA polymer brushes exhibits excellent bioactivity(-87%bioactivity of free BMP-2 in vitro and 20%-50%higher than scaffolds with free BMP-2 in vivo),with conformation and secondary structure well-preserved after covalent immobilization and ethanol sterilization.Moreover,the osteogenic activity of i-BMP-2 on the nanoline pattern(PGMA-poly(N-isopropylacrylamide))shows-110%bioactivity of free BMP-2.This is superior compared to conventional protein covalent immobilization strategies in terms of both bioactivity preservation and therapeutic efficacy.PGMA polymer brushes can be used to modify surfaces of different tissue-engineered scaffolds,which facilitates in situ immobilization of growth factors,and accelerates repair of a wide range of tissue types.

The archaeal KEOPS complex possesses a functional Gon7 homolog and has an essential function independent of the cellular t^(6)A modification level

Kinase,putative Endopeptidase,and Other Proteins of Small size(KEOPS)is a multisubunit protein complex conserved in eukaryotes and archaea.It is composed of Pcc1,Kae1,Bud32,Cgi121,and Gon7 in eukaryotes and is primarily involved in N^(6)-threonylcarbamoyl adenosine(t^(6)A)modification of transfer RNAs(tRNAs).Recently,it was reported that KEOPS participates in homologous recombination(HR)repair in yeast.To characterize the KEOPS in archaea(aKEOPS),we conducted genetic and biochemical analyses of its encoding genes in the hyperthermophilic archaeon Saccharolobus islandicus.We show that aKEOPS also possesses five subunits,Pcc1,Kae1,Bud32,Cgi121,and Pcc1-like(or Gon7-like),just like eukaryotic KEOPS.Pcc1-like has physical interactions with Kae1 and Pcc1 and can mediate the monomerization of the dimeric subcomplex(Kae1-Pcc1-Pcc1-Kae1),suggesting that Pcc1-like is a functional homolog of the eukaryotic Gon7 subunit.Strikingly,none of the genes encoding aKEOPS subunits,including Pcc1 and Pcc1-like,can be deleted in the wild type and in a t^(6)A modification complementary strain named TsaKI,implying that the aKEOPS complex is essential for an additional cellular process in this archaeon.Knock-down of the Cgi121 subunit leads to severe growth retardance in the wild type that is partially rescued in TsaKI.These results suggest that aKEOPS plays an essential role independent of the cellular t^(6)A modification level.In addition,archaeal Cgi121 possesses dsDNA-binding activity that relies on its tRNA 3ʹCCA tail binding module.Our study clarifies the subunit organization of archaeal KEOPS and suggests an origin of eukaryotic Gon7.The study also reveals a possible link between the function in t^(6)A modification and the additional function,presumably HR.

Diagnostic Utility of Diffusion-weighted Magnetic Resonance Imaging in Differentiating Small Solid Renal Tumors （≤4 cm） at 3.0T Magnetic Resonance Imaging

Background： The aim of this study was to assess the performance of apparent diffusion coefficient （ADC） measurement obtained with diffusion-weighted magnetic resonance imaging （DW-MRI） to distinguish renal cell carcinomas （RCCs） from small benign solid renal tumors （〈4 cm）. Methods： In this cross-sectional study, 49 consecutive patients with histopathologically confirmed small solid renal tumors, and seven healthy volunteers were imaged using nonenhanced MRI and DW-MRI. The ADC map was calculated using the b values of 0, 50, 400, and 600 s/ mm2 and values compared via the Kruskal-Wallis and Mann-Whitney tests. The utility of ADC for differentiating RCCs and benign lesions was assessed using a receiver operating characteristic curve. Multiple nonenhanced MRI features were analyzed by Logistic regression. Results： The tumors consisted of 33 cases of clear-cell RCCs （ccRCCs） and 16 cases of benign tumors, including 14 cases of minimal fat angiomyolipomas and 2 cases ofoncocytomas. The ADCs showed significant differences among benign tumors （[0.90 ±0.52] x 10 x mm2/s）, ccRCCs （[1.53 ± 0.31 ] x 10 ^3 mm2/s） and the normal renal parenchyma （[2.22 ± 0.12]x 10^-3 mmVs） （P 〈 0.001）. Moreover, there was statistically significant difference between high and low-grade ccRCCs （P = 0.004）. Using a cut-offADC of 1.36± 10 3 mm2/s, DW-MRI resulted in an area under the curve （AUC）, sensitivity, and specificity equal to 0.839, 75.8%, and 87.5%, respectively. Nonenhanced MRI alone and the combination of imaging methods led to an AUC, sensitivity and specificity equal to 0.919, 93.9%, and 81.2%, 0.998, 97%, and 100%, respectively. The Logistic regression showed that the location of the center of the tumor （inside the contour of the kidney） and appearance of stiffblood vessel were significantly helpful for diagnosing ccRCCs. Conclusions： DW-MRI has potential in distinguishing ccRCCs from benign lesions in human small solid renal tumors （〈4 cm）, and in increasing the accuracy for diagnosing ccRCCs when combined with nonenhanced MRI.

Fabrication and evaluation of a BMP-2/dexamethasone co-loaded gelatin sponge scaffold for rapid bone regeneration

Improving the osteogenic activity of BMP-2 in vivo has significant clinical application value.In this research,we use a clinical gelatin sponge scaffold loaded with BMP-2 and dexamethasone(Dex)to evaluate the osteogenic activity of dual drugs via ectopic osteogenesis in vivo.We also investigate the mechanism of osteogenesis induced by BMP-2 and Dex with C2C12,a multipotent muscle-derived progenitor cell.The results show that the gelatin scaffold with Dex and BMP-2 can significantly accelerate osteogenesis in vivo.It is indicated that compared with the BMP-2 or Dex alone,100nM of Dex can dramatically enhance the BMP-2-induced alkaline phosphatase activity(ALP),ALP mRNA expression and mineralization.Further studies show that 100nM of Dex can maintain the secondary structure of BMP-2 and facilitate recognition of BMP-2 with its receptors on the surface of C2C12 cells.We also find that in C2C12,Dex has no obvious effect on the BMP-2-induced Smad1/5/8 protein expression and the STAT3-dependent pathway,but Runx2-dependent pathway is involved in the Dex-stimulated osteoblast differentiation of BMP-2 both in vitro and in vivo.Based on these results,a potential mechanism model about the synergistic osteoinductive effect of Dex and BMP-2 in C2C12 cells via Runx2 activation is proposed.This may provide a theoretical basis for the pre-clinical application of Dex and BMP-2 for bone regeneration.

极端嗜热古菌尿嘧啶DNA糖苷酶的研究进展

高温会加快碱基脱氨基反应形成损伤碱基的速率,进一步对脱氨基的碱基进行复制会导致突变。因此,极端嗜热古菌基因组的稳定性面临着其生存高温环境的挑战。胞嘧啶脱氨基形成尿嘧啶,是常见的脱碱基类型,复制DNA中尿嘧啶会造成GC→AT的突变。尿嘧啶DNA糖苷酶(Uracil DNA glycosylase,UDG)是修复DNA中尿嘧啶的关键酶。基于识别底物的特异性,UDG分为6个家族,广泛分布在细菌、古菌、真核生物以及一些病毒中。基因组序列显示,极端嗜热古菌至少编码一种UDG。目前,对于细菌和真核生物的UDG已进行了大量的研究,但是关于极端嗜热古菌UDG的研究相对较少,尚处于初期阶段。本文综述了极端嗜热古菌UDG的研究进展,并对今后的研究提出了展望。