Submitted Date
Subjects
Authors
Institution
  • 基于SecOC的车载网络通信安全模型研究

    Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2022-04-07 Cooperative journals: 《计算机应用研究》

    Abstract: The increase of in-vehicle electronic equipment makes the in-vehicle network face more and more threats. The lack of authentication of the Electronic Control Unit in the in-vehicle network and the lack of encryption of the communication data of the Controller Area Network make the in-vehicle network vulnerable to replay, ECU injection, man-in-the-middle forged messages, eavesdropping, etc, Witch make serious consequences. Aiming at the current vehicle network threats, a vehicle network security communication model based on SecOC is proposed. This model uses the SM4 cryptographic algorithm and the improved key management based on Bkake2s to realize the authentication of the vehicle ECU and the encryption and authentication of the vehicle network message. Finally, after analysis and testing, the model can protect the in-vehicle network security and be more efficient.

  • 社会化推荐研究进展与发展趋势演化* ——基于文献计量和社会网络分析的视角

    Subjects: Library Science,Information Science >> Information Science submitted time 2017-12-05 Cooperative journals: 《数据分析与知识发现》

    Abstract:【目的】从文献计量和社会网络分析的角度对社会化推荐进行内容特征及网络演化的研究, 归纳领域研究 热点和发展趋势。【方法】以 WoS 数据库为数据源, 采用人工判读法、关键词共现、文献计量、社会网络分析及 数据可视化等方法对样本数据进行数据挖掘和关联分析。【结果】检索到社会化推荐类文献 3 701 篇, 论文数量 整体呈上升趋势, 以发文量阈值为阶段划分标准, 将社会化推荐的发展演化趋势划分为三个阶段, 各阶段研究 特征明显。【局限】仅以关键词为探究文献内容特征的依据, 内容深度挖掘相对不足, 其中阶段划分是为了分析 研究内容及演化趋势的变化, 并不存在统一的划分标准。【结论】我国学者在该领域的国际影响力逐年上升, 领 域研究内容方面阶段性变化特征明显, 社会化媒介、协同过滤等传统研究方向一直保持较高关注度。

  • 社会化推荐研究进展与发展趋势演化* ——基于文献计量和社会网络分析的视角

    Subjects: Library Science,Information Science >> Information Science submitted time 2017-11-30 Cooperative journals: 《数据分析与知识发现》

    Abstract:【目的】从文献计量和社会网络分析的角度对社会化推荐进行内容特征及网络演化的研究, 归纳领域研究 热点和发展趋势。【方法】以 WoS 数据库为数据源, 采用人工判读法、关键词共现、文献计量、社会网络分析及 数据可视化等方法对样本数据进行数据挖掘和关联分析。【结果】检索到社会化推荐类文献 3 701 篇, 论文数量 整体呈上升趋势, 以发文量阈值为阶段划分标准, 将社会化推荐的发展演化趋势划分为三个阶段, 各阶段研究 特征明显。【局限】仅以关键词为探究文献内容特征的依据, 内容深度挖掘相对不足, 其中阶段划分是为了分析 研究内容及演化趋势的变化, 并不存在统一的划分标准。【结论】我国学者在该领域的国际影响力逐年上升, 领 域研究内容方面阶段性变化特征明显, 社会化媒介、协同过滤等传统研究方向一直保持较高关注度。

  • 断奶应激对幼龄反刍动物免疫系统的影响及其机理

    Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》

    Abstract:断奶初期,幼龄反刍动物的消化和免疫系统等尚未发育完全,断奶应激会导致幼畜体内激素水平及免疫功能改变,引起免疫系统抑制,诱发炎症反应,阻碍幼畜生长发育,增加患病风险。本文从糖皮质激素、免疫细胞、急性期蛋白和相关细胞因子4个方面阐述了断奶应激对幼龄反刍动物免疫系统的影响及其机理,旨在为相关研究提供科学依据。

  • 幼龄反刍动物纤维营养需要与影响因素

    Subjects: Biology >> Zoology submitted time 2017-10-23 Cooperative journals: 《动物营养学报》

    Abstract:幼龄反刍动物饲粮的纤维性碳水化合物(FC)来源与组成对调控其生长发育和瘤胃功能建立有重要作用,其来源各异,粒度不同,对正处于生长期的幼龄反刍动物的采食和消化、瘤胃液pH及瘤胃发育等生理参数的影响存在差异。本文综述了近年来关于幼龄反刍动物饲粮中性洗涤纤维(NDF)来源和粒度的研究,分别从生产性能、瘤胃发酵和瘤胃发育3个方面总结了二者对幼龄反刍动物的影响,并对相关机制进行了探讨。

  • 高精料饲粮条件下反刍动物瘤胃适应机制的解析

    Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》

    Abstract:饲喂高能、高淀粉饲粮是集约化生产中提高反刍动物生产性能的常用策略,但高精料饲粮易引起一系列的营养代谢疾病,其中以瘤胃酸中毒最为常见。反刍动物瘤胃不仅具有消化、吸收营养物质的功能,瘤胃上皮亦是重要的免疫屏障,故瘤胃健康对反刍动物至关重要。本文主要从反刍动物采食高精料饲粮时其瘤胃组织形态、瘤胃上皮适应分子机制和瘤胃微生物区系3个方面的变化进行阐述,以期为高精料饲粮条件下瘤胃适应机制的研究提供参考。

  • 作物生产潜力变化的区域差异[HT3H]——以陕西省为例

    Subjects: Environmental Sciences, Resource Sciences >> Basic Disciplines of Environmental Science and Technology submitted time 2019-06-14 Cooperative journals: 《干旱区地理》

    Abstract:作物生产潜力变化具有明显的区域差异性,亟需针对不同地理单元实施有效应对措施和调控策略。选择陕西省三大地理单元(陕北高原、关中盆地和秦巴山区)为研究对象,运用全球生态区模型(GAEZ)分析了陕西省不同地理单元作物生产潜力变化趋势,探讨了不同作物生产潜力变化的区域差异,辨识出影响不同作物生产潜力变化的主要因素,结果显示:(1) 1980—2015年间,陕西省玉米生产潜力总量增加了150.55×104 t,小麦生产潜力总量则下降了402.69×104 t。(2) 关中盆地的玉米和小麦生产潜力皆最大,陕北高原次之,秦巴山区的玉米和小麦生产潜力皆最小;陕北高原和秦巴山区的玉米生产潜力皆表现出先增加后减小再增加的变化趋势,关中盆地的玉米生产潜力则先减小后增加再减小;关中盆地和秦巴山区的小麦生产潜力都呈下降趋势,陕北高原的小麦生产潜力则有所提高。(3) 土地利用变化呈现减产效应,这一效应在关中盆地尤为显著,其次为陕北高原;气候变化导致玉米生产潜力增加,使小麦生产潜力下降;气候变化对不同地理单元的影响也不相同,在陕北高原表现为增产效应,在关中盆地和秦巴山区则为减产效应。(4) 在陕北高原,气候变化的增产效应是玉米和小麦生产潜力提高的主要原因,气候变化对玉米生产潜力的影响大于对小麦的影响,耕地向草地、林地和建设用地的转化是降低作物生产潜力最主要的土地利用变化因素;在关中盆地,作物生产潜力的变化主要是受气候变化的影响,小麦受气候变化的影响较玉米为大,以建设用地占用耕地为特征的土地利用变化对玉米生产潜力的影响大于对小麦的影响;在秦巴山区,土地利用变化是玉米生产潜力变化的主要原因,而小麦生产潜力的变化主要受气候变化影响。

  • 断奶日龄对湖羊羔羊瘤胃内微生物多样性的影响

    Subjects: Biology >> Zoology submitted time 2018-12-24 Cooperative journals: 《动物营养学报》

    Abstract:本试验旨在研究断奶日龄对湖羊羔羊瘤胃微生物多样性的影响。选择66只湖羊公羔,在羔羊1、14、28日龄各屠宰6只羔羊,剩余48只羔羊随机分为2组,分别于28和56日龄断奶,在42、56、70和84日龄每组屠宰6只羔羊,取瘤胃内容物样品。所有羔羊7 日龄开始饲喂开食料。试验期为羔羊1~84日龄。结果表明:断奶日龄对白色瘤胃球菌(Ruminococcus albus)、黄色瘤胃球菌(Ruminococcus flavefaciens)、牛链球菌(Streptococcus bovis)、产琥珀酸丝状杆菌(Fibrobacter succinogenes)和布氏密螺旋体(Treponema bryantii)的相对丰度无显著影响(P>0.05)。随着日龄增加,羔羊瘤胃微生物多样性不断增加,28日龄断奶的羔羊相对56日龄断奶的羔羊其瘤胃微生物多样性提高。结果提示,瘤胃微生物多样性受日龄和断奶日龄的影响,早期断奶可加速瘤胃微生物区系的建立。

  • 反刍动物亚急性瘤胃酸中毒变异性的机制解析

    Subjects: Biology >> Zoology submitted time 2018-12-24 Cooperative journals: 《动物营养学报》

    Abstract:亚急性瘤胃酸中毒(SARA)是高产反刍动物过量采食高淀粉、易发酵碳水化合物饲粮所导致的一种常见营养代谢疾病,使瘤胃健康受损进而降低饲料转化效率。相同处理下,不同个体对SARA耐受性存在较大差异,因此研究反刍动物个体间SARA变异性的机制是重要的科学问题。本文分别从采食行为、瘤胃上皮吸收功能以及微生物区系3个方面解析动物个体间SARA变异性潜在机制,为反刍动物健康与高效生产提供参考和理论依据。

  • 反刍动物肌肉脂肪酸对肉品质的影响及其调控因素

    Subjects: Biology >> Zoology submitted time 2017-10-11 Cooperative journals: 《动物营养学报》

    Abstract:肌肉中脂肪酸的含量和组成成分在一定程度上影响肉品质以及消费者的健康。反刍动物的肉产品是具有保健作用的共轭亚油酸的主要来源。因此,揭示反刍动物肌肉脂肪酸的形成机制与调控手段十分必要。本文主要针对反刍动物肌肉脂肪酸的调控因素及肌肉脂肪酸对肉质风味、氧化稳定性和肉色的影响进行了综述,以期为改善反刍动物肌肉脂肪酸提供参考。

  • 反刍动物肌肉脂肪酸对肉品质的影响及其调控因素

    Subjects: Biology >> Zoology submitted time 2017-10-11 Cooperative journals: 《动物营养学报》

    Abstract:肌肉中脂肪酸的含量和组成成分在一定程度上影响肉品质以及消费者的健康。反刍动物的肉产品是具有保健作用的共轭亚油酸的主要来源。因此,揭示反刍动物肌肉脂肪酸的形成机制与调控手段十分必要。本文主要针对反刍动物肌肉脂肪酸的调控因素及肌肉脂肪酸对肉质风味、氧化稳定性和肉色的影响进行了综述,以期为改善反刍动物肌肉脂肪酸提供参考。

  • 国家植物园植物文化建设与植物多样性保护和管理

    Subjects: Biology >> Botany >> Applied botany submitted time 2023-07-26 Cooperative journals: 《广西植物》

    Abstract: Biological culture is of great significance to the conservation of biodiversity. The formation and development of botanical gardens have reflected the plant culture which formed by human beings due to material and spiritual needs in history. Modern botanical gardens have made outstanding achievements in plant ex-situ protection, while the plant culture construction is still a little insufficient. In the process of global biodiversity conservation, the important roles of traditional culture in biodiversity conservation and sustainable use of biological resources have been increasingly valued. At this background, this study emphasized the close connection and co-evolution relationship between biocultural diversity and biodiversity, and reviewed the implication of plant culture in early botanical gardens and Chinese classical gardens. And through the analysis of the main functions of 3 085 modern botanical gardens around the world, we found that only 7.36% of botanical gardens have carried out ethnobotanical research, while 11.18% have carried out conservation biology research, and 17.18% have a plant conservation programme 17.18%, revealed the improvement of the protection function and the weakening of the cultural function of modern botanical gardens. Based on the demand for the construction of plant culture in the effective protection of plant diversity in the current botanical garden, this study further analyzed the deficiencies of plant culture construction in botanical gardens in China, including: (1) Insufficient plant culture information data in plant species diversity information. (2) Lack of consideration of benefit-sharing of traditional knowledge in biodiversity conservation. (3) Lack of theme parks that display plant diversity with culture. Focused on the goal of plant diversity conservation and management in the China national botanical garden, we put forward suggestions on plant culture construction in the China national botanical garden system from three aspects, in order to provide a reference for the construction of a national botanical garden system with the characteristics of Chinese ecological civilization: (1) Plant diversity protection and utilization. To strengthen the consideration of plant culture in the construction of plant diversity information and germplasm resource bank, encourage ethnobotanical research. (2) Benefit-sharing. To establish access and benefit-sharing (ABS) standard procedures covering traditional knowledge to ensure fair and equitable benefit-sharing. (3) Public participation. To consider display the regionality and uniqueness in China national botanical garden, and add ethnic plant culture theme parks or exhibition halls.

  • 一种改进的个性化查询引文推荐方法

    Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-04-24 Cooperative journals: 《计算机应用研究》

    Abstract: To make full use of the context information of the papers, combined with the construction method of graph model and query vector, this paper proposed a fusion query information personalized citation recommendation method. Built a three layer graph model through three kinds of paper information, and set different parameters on different layers to adjust the jump probability of nodes to different levels; the query vector constructed using word2vec technology can effectively use the text context information, so that similar papers are closer to the distance, and then the candidate papers are predicted and recommended. Computational analyzes performed on the Association of Computational Linguistics Anthology Network dataset showed an average increase of about 7% over recall@N and an average increase of about 11% over NDCG@N for the same query compared to the original method. Experimental results show that the proposed method can effectively improve the quality of citation recommendation and get better recommendation results.

  • 基于BIM技术的施工场地布置与应用

    Subjects: Civil Engineering and Building Construction >> Civil Construction Engineering submitted time 2017-12-05 Cooperative journals: 《土木建筑工程信息技术》

    Abstract:随着建筑技术的日益进步,施工现场的场地布置面临着巨大的挑战。如何合理的进行施工场地的布置关系着安全文明施工,也影响着企业形象。本文主要通过结BIM技术,进行三维场地布置,进而解决设备安置、材料堆放、设备进场、生活区布置等二维图纸难以解决的问题,并且通过BIM模型进行场地布置工程量计算、施工 场地布置资产管理等。

  • 基于BIM技术的施工场地布置与应用

    Subjects: Civil Engineering and Building Construction >> Civil Construction Structures submitted time 2017-11-30 Cooperative journals: 《土木建筑工程信息技术》

    Abstract:随着建筑技术的日益进步,施工现场的场地布置面临着巨大的挑战。如何合理的进行施工场地的布置关系着安全文明施工,也影响着企业形象。本文主要通过结BIM技术,进行三维场地布置,进而解决设备安置、材料堆放、设备进场、生活区布置等二维图纸难以解决的问题,并且通过BIM模型进行场地布置工程量计算、施工 场地布置资产管理等。

  • 用XPS研究硫化氢腐蚀产物生成及自燃历程

    Subjects: Materials Science >> Materials Science (General) submitted time 2017-03-31 Cooperative journals: 《腐蚀科学与防护技术》

    Abstract:模拟含硫原油加工过程中生成的具有高自然性的腐蚀产物,利用三氧化二铁与硫化氢反应制备硫铁化合物,将硫化反应产物分为两部分,一部分保存在乙醇中,一部分暴露于空气中。用XPS研究硫化产物及其氧化产物中硫、铁的存在形态。结果表明,硫化产物中硫元素主要存在形式是二硫化亚铁;氧化产物中主要存在形式是硫酸盐,少部分硫化亚铁、单质硫及FeSx。硫化产物和氧化产物中铁元素的主要存在形式都是三氧化二铁和二硫化亚铁。

  • 最小自我中的施动感

    Subjects: Psychology >> Developmental Psychology submitted time 2023-03-28 Cooperative journals: 《心理科学进展》

    Abstract: Sense of agency (SoA), an important part of minimal self, is the experience of influencing the outside world through controlling one’s behavior. Many researchers divided SoA into two parts according to the level of consciousness: feeling of agency (FoA) and judgment of agency (JoA). Different implicit and explicit paradigms are used to investigate the mechanism and connection of these two parts. Among the three core theories in this domain (i.e. comparator model, theory of apparent mental causation, and integration theory), integration theory has been supported by more evidence in recent years. Furthermore, researchers have made significant progress in the areas of distorted SoA and factors which influence SoA. In future, researchers could focus more attention on the changes in SoA in the social environment, the development of SoA, the multimodal integration in SoA, the relationship between SoA and sense of ownership (SO), as well as the neural mechanisms of SoA.

  • Effect of Thermo-mechanical Control Processing on Microstructure and Properties of High Toughness X90 Pipeline Steel

    Subjects: Materials Science >> Materials Science (General) submitted time 2023-03-18 Cooperative journals: 《材料研究学报》

    Abstract: Effect of the main TMCP parameters on mechanical properties and microstructure characteristics of X90 pipeline steel was investigated by a labroratory simulated TMPC with desired processing parameters, including reheating temperature, intermediate slab thickness and coiling temperature. Results show that the strength increases with the increment of reheating temperature at first, but dramatically reduces when the grain size gets coarse at reheating temperature of 1250℃. Thicker intermediate slab contributes to higher strength and toughness because of a homogenized microstructure with refined grains was brought out. Coiling temperature plays the most important role in controlling the steel property. A microstructure composed of proper combination of granular banite and lath banite of the steel with optimal matching of strength and toughness can be achieved when coiling at 320℃. An industrial production of X90 coil were carried out employing the parameters obtained through the investigation, high strength combined with great low temperature toughness has been achieved, which proves that TMCP technology in this study has a good practice effect.

  • 断奶时间及日龄变化对湖羊羔羊肌肉中脂肪酸组成的影响

    Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》

    Abstract:本试验旨在研究断奶时间及日龄变化对湖羊羔羊肌肉中脂肪酸组成的影响。试验选取体重[(3.51±0.57) kg]接近、健康状况良好的54只初生湖羊公羔,饲养至28日龄后屠宰6只。将剩余的48只按照同质性原则分为28日龄断奶组[(8.21±0.97) kg]和56日龄断奶组[(8.06±0.53) kg],每组24只。2组在42、56、70、84日龄分别屠宰6只,屠宰后测定羔羊背最长肌脂肪酸组成和瘤胃中氢化菌含量的影响。结果表明:1)56日龄断奶组肌肉中大部分脂肪酸的含量高于28日龄断奶组;随着日龄的增长羔羊肌肉中脂肪酸的含量逐渐升高,种类变得越来越多。2)70日龄时,28日龄断奶组的瘤胃中溶纤维丁酸弧菌含量显著高于56日龄断奶组(P<0.05);56日龄断奶组溶纤维丁酸弧菌的含量在42日龄时显著高于70和84日龄(P<0.05)。由此可见,与28日龄断奶相比,羔羊在56日龄断奶更利于肌肉中脂肪酸的沉积。

  • 低聚木糖对断奶仔猪生长性能、腹泻率和血浆生化参数的影响

    Subjects: Biology >> Zoology submitted time 2017-10-10 Cooperative journals: 《动物营养学报》

    Abstract:本文旨在评价不同剂量的低聚木糖(XOS)同时替代抗生素与氧化锌对断奶仔猪生长性能、腹泻率和血浆生化参数的影响,并筛选出其最佳XOS添加剂量。试验选取28日龄的“杜×长×大”断奶仔猪150头,随机分为5组,每组6重复,每重复5头猪。各组分别为空白对照组(不添加抗生素、氧化锌)、阳性对照组(添加抗生素、氧化锌)及100、250和500 g/t XOS添加组。记录每栏仔猪的日采食量和腹泻情况,于试验第1、7、21和56天,记录每栏仔猪的体重,计算平均日采食量(ADFI)、平均日增重(ADG)和料重比;前腔静脉采血,分离血浆,检测其生化参数。试验期56 d。结果表明:1)试验第8~21天和第1~56天时,100 g/t XOS组的ADG显著高于空白对照组(P0.05)。3)试验第7天时,500 g/t XOS组血浆天冬氨酸转氨酶(AST)和乳酸脱氢酶(LDH)活性显著高于阳性对照组(P<0.05);试验第21天时,100和500 g/t XOS组血浆丙氨酸转氨酶(ALT)活性显著高于空白对照组(P<0.05);试验第56天时,100 g/t XOS组血浆ALT活性、500 g/t XOS组血浆AST活性、250和500 g/t XOS组血浆碱性磷酸酶(ALP)活性均显著高于空白对照组和阳性对照组(P<0.05),100 g/t XOS组血浆LDH活性显著高于空白对照组(P<0.05),500 g/t XOS组血浆α-淀粉酶活性显著高于阳性对照组(P<0.05)。上述结果表明,饲粮中添加100~250 g/t的XOS可通过调控断奶仔猪营养素代谢增强肠道健康、减少腹泻,从而促进生长;随着仔猪日龄的增加,可适当增加XOS的添加量。