摘要：This study focused on differences in vehicle-to-vehicle radio channel character- istics in the same region but different traffic density and speeds at 5.9 GHz （congestion and non-congestion）. The continuous measurement campaign was conducted on a city expressway through the complex dense urban area in Wu- hart, China. Small-scale channel characteris- tics including power delay profile, amplitude fading distribution, K-factor, delay spread and Doppler shift were obtained, respectively. Spe- cifically, the cumulative distribution function of root mean square delay spreads and root mean square Doppler spreads in the non-con- gested scenario and congested scenario were all fitted well with Lognormal distribution. We also found out that different intensity of traffic and speed of vehicles have little effect on root mean square delay spreads, but have a big im- pact on root mean square Doppler spreads and level crossing rate. According to estimation outcomes, the V2V channel characteristics for urban areas in Chinese big city were differ- ent from the previous measured results under similar scenarios in Europe. Delay spread and level crossing rate in this study can provide significant references to design the wireless communication system for vehicle-to-vehicle channel.

摘要：With the development of world globalization, English works as a lingua franca for intercultural communication among different cultures in the world. This shift implies that introducing solely English native speaking cultures to students is not sufficient for their needs. This paper depicts the reflective teaching process of my ten years of experience of teaching intercultural *** paper describes how the teacher systematically reflects on the practice of teaching,continuously revises the curriculum, and finally formulates an efficient model of integrating students’ personal experiences into developing students’ intercultural communicative competence and awareness. This reflective study attempts to provide some pedagogical implications for intercultural communication education.

摘要：舵面效能损耗会直接影响柔性飞机阵风减缓效果,考虑舵面效能损耗是主动阵风减缓控制系统设计的关键。针对柔性飞机遭遇阵风干扰问题,以某大展弦比柔性飞机模型为对象,建立包含刚体运动和弹性模态的柔性飞机结构动力学模型,考虑舵面作动器存在舵面效能损耗的情况,设计一种自适应观测器实时在线估计舵面作动器效能因子,重构和求解自适应主动容错H_(∞)控制器,实现柔性飞机阵风载荷减缓。离散和连续阵风激励下的柔性飞机开/闭环时域响应仿真表明:在舵面无效能损耗情况下,H_(∞)控制与比例-积分-微分(PID)控制均能达到较好的减缓效果,H_(∞)控制相较于PID控制响应时间更快;在舵面存在效能损耗情况下,自适应观测器在4 s内能够完成效能因子评估,基于该效能因子设计的H_(∞)控制器能够达到与理想情况相当的阵风减缓效果。

摘要：The Chinese global carbon dioxide monitoring satellite （TanSat） was launched successfully in December 2016 and has completed its on-orbit tests and calibration. TanSat aims to measure the atmospheric column-averaged dry air mole fractions of carbon dioxide （XCO2） with a precision of 4 ppm at the regional scale, and in addition, to derive global and regional CO2 fluxes. Progress towards these objectives is reviewed and the first scientific results from TanSat measurements are presented. TanSat on-orbit tests indicate that the Atmospheric Carbon dioxide GratingSpectrometer is in normal working status and is beginning to produce LIB products. The preliminary TanSat XCO2 products have been retrieved by an algorithm and compared to NASA Orbiting Carbon Observatory-2 （OCO-2） measurements during an over- lapping observation period. Furthermore, the XCO2 retrievals have been validated against eight groundsite measurement datasets from the Total Carbon Column Observing Network, for which the preliminary conclusion is that TanSat has met the precision design requirement, with an average bias of 2.11 ppm. The first scientific observations are presented, namely, the seasonal distributions of XCO2 over land on a global scale.

摘要：特征交互在推荐系统领域的广告点击率(Click-Through Rate,CTR)预测任务中至关重要,当前业界做的特征交互往往是基于内积、外积等矩阵变换,这些操作没有引入额外的信息,可以作为衡量两个向量相似性的手段,但作为特征交互的表示不一定是可靠的,许多特征交互无法有效提高点击率预测性能。首先从改善特征交互方式的角度入手引入额外的参数来学习一个映射,假设这个映射能够将两个向量的表征映射成交互的表征。学习映射的过程能够通过元学习(Meta-learning)来实现,故构建一个学习器以函数的方式表征特征交互。另外,不同的特征对不一定采取相同的方式交互,不能通过同一种交互方式得到所有特征对,因此设计一组元学习器(meta-learner)来学习映射函数,引入门控网络(GateNet)学习模型中元学习器的分布,那么不同的特征嵌入可以由一组元学习器得到表征。基于以上两点提出了一种融合多个元学习器并结合门控网络(Multiple meta-learners combined with GateNet,gate-MML)的特征交互算法,通过学习不同特征的联系和差异提高每个特征交互的质量。为了验证所提算法的性能,在xDeepFM模型上采用gate-MML做进一步的特征交互,采用2个真实广告点击率预测的数据集进行实验,并使用Logloss作为损失函数,AUC作为评价指标。实验结果表明与传统的CTR预测模型相比,改进算法提升了广告点击率预测任务的预测性能。

摘要：纳米疫苗是肿瘤免疫治疗的重要组成部分,主要通过激活机体免疫系统抑制并清除肿瘤;但是肿瘤组织普遍存在的免疫抑制微环境会大大降低纳米疫苗的治疗效果.因此,设计制备既可以逆转肿瘤组织免疫抑制微环境,又可以激活机体抗肿瘤免疫响应的纳米疫苗,对肿瘤免疫治疗的发展具有重要意义.本文利用铁离子(Fe^(3+))和紫草素(Shik)之间的配位相互作用构筑了Fe/Shik超分子纳米结构,并通过负载鸡卵白蛋白(OVA,B16-OVA肿瘤抗原)和R837(TLR7激动剂,佐剂)制备了OVA/R837@Fe/Shik纳米疫苗.该纳米疫苗具有良好的胶体稳定性及抗肿瘤活性,可以在肿瘤微环境中特异性拆解并释放Fe^(2+),Shik,OVA和R837,通过诱导肿瘤细胞铁死亡和程序性坏死引发免疫原性细胞死亡并释放细胞裂解物,细胞裂解物协同OVA以及R837共同诱导树突细胞成熟,促进细胞毒性T淋巴细胞的激活与浸润以及巨噬细胞向M1表型极化,从而在逆转肿瘤组织免疫抑制微环境的同时激活机体的抗肿瘤免疫反应.

摘要：Carbon dioxide as a notorious greenhouse gas triggers severe global warming which is threatening the balance of ecosystem. In this respect, effectively capturing and transforming CO_(2)into value-added chemicals are essential but still challenging tasks. As a kind of emerging crystalline porous material, covalent organic frameworks(COFs) have been demonstrated to be able to adsorb gases and function as catalysts to facilitate chemical transformations. Herein, we report an imine-linked, cobalt sandwich complex-based COF(Co-BD-COF) with high crystallinity and large surface ***-BD-COF can efficiently catalyze the transformation of CO_(2)into cyclic carbonates due to abundant metal sites and high porosity. In addition, Co-BD-COF exhibits high catalytic selectivity toward small ethylene oxide derivatives in cycloaddition reaction due to the large steric hindrance around the cobalt complexes rendered by the peripheral phenyl *** new metal sandwich-type building block provides a new strategy for improving catalytic selectivity of COFs.

摘要：Two-dimensional(2D)hybrid perovskites with the Ruddlesden-Popper lattice(A')_(2)(A)_(n-1)M_(n)X_(3n+1)are emerging as the promising optoelectronic candidates,both the inorganic and organic ingredients of which can be tailored to modulate the physical ***,there is a scarcity of 2D multilayered motifs with the A-site large-size cations occupying perovskite ***,by rational mixedcation alloying,we present a new 2D hybrid perovskite,(4-TFBMA)_(2)(DMA)Pb_(2)I_(7)(1),in which the secondary cation of CH_(3)NH_(2)CH_(3)^(+)(DMA)is located inside the perovskite cage while the aromatic 4-(trifluoromethyl)benzylammonium(4-TFBMA)cation acts as a spacer *** from the quantum structure of alternating organic spacers and inorganic networks,crystal-array detectors of 1 show fascinating in-plane photodetection responses of large detectivity(~2.95×10^(12)Jones)and responsivity(~1.97AW^(-1)),comparable to those of some inorganic 2D *** addition,a fast response rate(~264μs)and a low dark current are also realized,related to the high crystalline quality and suppression of the hopping barrier due to the insulating organic spacing *** result sheds light on the further exploration of new 2D hybrid perovskites toward high-performance photodetector applications.

摘要：A low energy uneven cluster protocol design method is proposed. Aiming at the random choosing for cluster head of traditional Leach protocol, and the defect of the single hop from all the cluster heads to the sink node, an improved method for Leave protocol is advanced. Firstly, the election model of cluster head is improved, and the node residual energy is considered in the process of threshold and the cluster head election to improve the whole network life circle. In the multi-hop route, choosing the maximum energy and the nearest node as the next hop and a route transferring data among many clusters is formed. The experiment shows the method having great improvement compared with Leach protocol and prolonging the network life cycle.

摘要：互联网时代的到来,弹窗广告一度泛滥,如同“牛皮藓”关不掉、赶不走、躲不了,给用户的正常网络生活造成了骚扰与隐患。针对这种现象,我们采取了线上调研、问卷调查与深度访谈等研究方法对其进行了深度研究与分析,发现国内并非没有相应法规,但效果不佳;规制也并非不能通过技术得到解决,而是受到背后巨大利益网与复杂主体的阻碍。基于这一痛点,我们提出将技术与法律耦合,双管齐下整治违规无效弹窗广告对人们生活的无度侵入。