无人机飞行控制地面仿真

针对某型无人机飞行设计要求,对无人机空中飞行进行模拟仿真,并综合测试仿真状态下的控制律运行情况。根据仿真试验的目的和要求,搭建适合无人机半实物仿真系统,介绍半实物仿真系统的组成;设计无人机的基本控制规律和逻辑,在此基础上建立某型无人机的简化数学模型,确定相关模型参数;对飞行控制系统进行仿真,构造某型无人机半实物仿真系统,并对无人机全飞行控制双机进行仿真试验、分析。试验结果表明:无人机飞行控制系统具有良好的控制效果,满足飞行控制要求。     

豫北鹤壁市誉达灰岩矿山地质环境影响评估与恢复治理

在收集豫北鹤壁市区域基础地质资料和现状调查的基础上,评估了矿山地质环境影响,提出了对矿山地质环境恢复治理的方案.研究结果表明:矿体赋存在中奥陶统下马家沟组第三段灰岩、白云质灰岩及角砾状灰岩,矿体裸露地表.工业场地和3个采场均为矿山地质灾害和地形地貌景观影响严重区,矿山道路为矿山地质灾害和地形地貌景观影响较轻区;矿山开采...     

Self-assembling reduced graphene quantum dots on hematite photoanode for passivating surface states toward significantly improved water splitting

Hematite is a promising photoanode material but limited by its large overpotential (0.5–0.6 V) toward water splitting. The slow kinetics and high density of trapping states are the main factors. The former could be improved by catalyst modification for improved kinetics, while the latter is normally suppressed by passivating trapping states with atomic layer deposition-formed conformal overlayers. Up to date only a few of oxides and carbon materials were used to passivate hematite photoanode via wet chemical method, such as Al₂O₃, TiO₂ and reduced graphene oxide sheets. Herein, rGQDs as another carbon material are self-assembly onto hematite for the first time, which remarkably increases the photocurrent by 8.0 times at 1.23 V. The passivation of surface states confirmed by photoluminescence spectroscopy has significantly change in the radiative recombination, and can used well explain the great improvement. Importantly, this work clearly demonstrates a mass-productive and inexpensive solution-based self-assembly approach is also an efficient surface passivation technique.     

热水处理后环境放置期间黄瓜果实温度及抗氧化系统变化

为探讨热水处理后黄瓜果实在非低温贮藏环境放置期间果体温度及抗氧化系统的变化,该试验将热水处理(40℃、20 min)后的黄瓜果实在非低温贮藏环境[20℃,相对湿度(55±5)％]中放置不同时间(0、1、2、4、8 h),并同时测定其果体温度和抗氧化系统的变化.结果表明:热水处理后0 h黄瓜果体温度高达36.5℃,随后的...     

Genome-Wide Identification of the Xyloglucan endotransglucosylase/Hydrolase (XTH) and Polygalacturonase (PG) Genes and Characterization of Their Role in Fruit Softening of Sweet Cherry

Fruit firmness is an important economical trait in sweet cherry (Prunus avium L.) where the change of this trait is related to cell wall degradation. Xyloglucan endotransglycosylase/hydrolase (XTH) and polygalacturonases (PGs) are critical cell-wall-modifying enzymes that occupy a crucial position in fruit ripening and softening. Herein, we identified 18 XTHs and 45 PGs designated PavXTH1-18 and PavPG1-45 based on their locations in the genome of sweet cherry. We provided a systematical overview of PavXTHs and PavPGs, including phylogenetic relationships, conserved motifs, and expression profiling of these genes. The results showed that PavXTH14, PavXTH15 and PavPG38 were most likely to participated in fruit softening owing to the substantial increment in expression during fruit development and ripening. Furthermore, the phytohormone ABA, MeJA, and ethephon significantly elevated the expression of PavPG38 and PavXTH15, and thus promoted fruit softening. Importantly, transient expression PavXTH14, PavXTH15 and PavPG38 in cherry fruits significantly reduced the fruit firmness, and the content of various cell wall components including hemicellulose and pectin significantly changed correspondingly in the transgenic fruit. Taken together, these results present an extensive analysis of XTHs and PGs in sweet cherry and provide potential targets for breeding softening-resistant sweet cherry cultivars via manipulating cell wall-associated genes.     

基于随机有限元法的圆形基础沉降最不利波动尺度分析

波动尺度(SOF)是表征土体空间变异性的重要参数,不同的波动尺度可以模拟土体参数的空间变异程度。基于随机有限元(RFEM)和蒙特卡罗模拟,假设弹性模量服从对数正态分布对土体实现非均质性建模,研究不同波动尺度下圆形基础的沉降变形规律。研究结果表明：中心沉降值符合对数正态分布,差异沉降值符合正态分布;随着波动尺度的增加,中心沉降和差异沉降均值基本不变,中心沉降标准偏差先增大最后趋于平缓,差异沉降标准偏差先增大后减少,在其峰值处平均绝对差异沉降达到最大,此时的波动尺度为最不利波动尺度,在勘察数据相对有限的情况下可以对基础沉降概率进行保守估计。     

Yes激酶相关蛋白活化对急性肺损伤修复的影响及其机制

目的:探讨Yes激酶相关蛋白（YAP）活化对感染性急性肺损伤修复的影响及可能机制。方法:SPF级雄性ICR小鼠90只,随机分为2组,LPS组和LPS+XMU组。LPS组腹腔注射脂多糖（LPS）（7.5 mg/kg）,LPS+XMU组在给予LPS的同时腹腔注射XMU-MP-1（YAP激动剂）（1 mg·kg-1·d-1,连续3 d）。在给予LPS 0 h、24 h、48 h、72 h后,采用苏木素-伊红（HE）染色观察肺组织形态。制备小鼠肺泡灌洗液,BCA法检测总蛋白含量,酶联免疫吸附法（ELISA）检测TNF-α和IL-6含量,比色法检测髓过氧化物酶（MPO）活性。Western blot法检测小鼠肺细胞核内YAP及胞浆磷酸化YAP（P-YAP）、肺组织YAP靶基因-结缔组织生长因子（CTGF）及增殖细胞核抗原（PCNA）蛋白的表达。结果:与LPS组比较,LPS+XMU组核内YAP蛋白表达在24 h、48 h、72 h表达分别上调39.2%、148.1%和42.9%（P均<0.05）,同时YAP下游靶蛋白CTGF蛋白表达分别上调186.6%、10.1%、146.1%（P均<0.05）,而胞浆中P-YAP显著下调。与LPS组比较,LPS+XMU 24 h组肺泡灌洗液中IL-6和TNF-α含量分别降低28.4%和23.7%,48 h组肺泡灌洗液MPO活性和TNF-α含量分别降低13.5%和39.5%,72 h组肺泡灌洗液IL-6和TNF-α含量分别降低42.8%和16.7%（P均<0.05）。与LPS组比较,LPS+XMU 24 h组肺组织PCNA蛋白表达无统计学差异,而48 h、72 h PCNA表达分别上调44.2%、14.9%（P均<0.05）。与LPS组比较,LPS+XMU 24 h组、48 h组和72 h组肺泡灌洗液蛋白含量分别降低32.4%、46.0%和26.3%（P均<0.05）。HE染色结果显示,与LPS组比较,LPS+XMU组肺组织炎症细胞渗出减少,肺泡壁重构增加,肺组织修复明显加快。结论:YAP活化通过多种机制来改善肺损伤,促进肺损伤修复,损伤期抑制炎症,修复期促进炎症消减和诱导细胞增殖。     

基于图像生成的多模态视网膜图像配准方法

针对多模态视网膜的全局粗配准,提出了一种基于图像生成的多模态视网膜配准方法. 不同于当前主流的提取多模态视网膜图像血管再进行配准的方法,使用GAN模型对不同模态的视网膜图像进行像素级映射,再通过特征点匹配的方式计算图像仿射矩阵,实现图像粗配准. 基于彩色眼底图像与荧光素血管造影图像的实验结果表明,该方法与当前主流的视网膜粗配准方法相比,具有快速且鲁棒的优势.