基于深度强化学习的无人机集群协同信息筛选方法研究

针对未知复杂环境下无人机集群协同定位导航中算法计算量过大的问题,提出了两种基于深度强化学习的无人机集群协同信息筛选方法,将多无人机定位问题映射为部分可观的马尔可夫决策过程(POMDP),通过克拉美罗下界(CRLB)设置的精度阈值,使用最少协同信息满足所有无人机的定位精度要求.仿真结果表明,同无筛选情形相比,基于深度强化学习的筛选策略可以在不牺牲定位精度的同时,有效提高协同定位算法的实时性,解决协同信息冗余问题,显著提高了协同定位算法的执行效率.     

知母多糖复合酶提取工艺优化及其免疫活性

本文对知母多糖的提取工艺及体外免疫活性进行研究,为知母多糖的开发利用提供理论依据。试验以复合酶提取知母粗多糖,在正交试验确定复合酶比例的基础上,通过单因素实验和响应面优化试验,确定知母多糖的最佳提取工艺;采用DEAE-52纤维素层析柱进行分离得到4种多糖组分APSE-0、APSE-1、APSE-2和APSE-3。以RAW264.7巨噬细胞为研究模型,采用MTT法、Griess法测定知母多糖各组分对细胞增殖能力和一氧化氮（NO）释放量的影响。结果表明,最佳复合酶比例为:木瓜蛋白酶16000 U/g,纤维素酶1200 U/g,果胶酶1600 U/g。最优提取工艺为酶解时间2 h,液料比15:1（mL/g）,酶解温度52 ℃,在此条件下得率为（10.58%±0.03%）。体外免疫活性实验结果证明,四种知母多糖组分均能明显促进RAW246.7巨噬细胞的增殖,APSE-0、APSE-2和APSE-3均可极显著诱导NO的释放,其中,APSE-2的免疫活性最强,可作为潜在的功能性食品或作为免疫力低下人群的膳食补充剂。剂。     

基于多目标的小流域污染控制方案及效果——以苏州胥江小流域为例

在太湖流域大网模型基础上,根据设计水文条件、边界水质以及控制断面水质与其上游概化排污口污染源的响应关系,建立胥江小流域污染物限排总量3级串级模型。计算基于多个控制断面在不同水质目标下的流域污染物限排总量。根据流域污染现状及污染物限排总量,提出包括总量控制措施及末端河道微污染水治理措施在内的污染综合控制方案,对综合控制方案水质改善效果进行评估。结果表明：①现状 COD 排放量超出限排总量153％、NH3－N 超出73％、TP 超出236％;②胥江小流域污染综合控制方案实施后,各控制断面水质均能达到目标要求。     

不同粒径橡胶集料混凝土工程特性试验

用橡胶颗粒取代砂子,对橡胶集料混凝土进行工作性测定及单轴抗压试验、抗水渗试验、抗氯离子渗透试验、冻融循环试验。结果表明:存在最不利橡胶颗粒粒径0.63～1.25 mm,使混凝土流动性最差;混凝土抗压强度随橡胶颗粒粒径减小而下降,但掺入小粒径橡胶颗粒有助于保证混凝土完整性;存在最优取代粒径0.165～0.315 mm,使混凝土电通量、渗水高度、质量损失率、相对动弹性模量损失率分别为普通混凝土的53.15%、52.35%、16.35%、51.79%;利用耐久性最优配合比制备的橡胶集料钢筋混凝土简支梁起裂荷载高于普通钢筋混凝土简支梁,但极限荷载有所降低,降幅约为6.10%。     

Effect of Cationic (Na+) and Anionic (F−) Co-Doping on the Structural and Electrochemical Properties of LiNi1/3Mn1/3Co1/3O2 Cathode Material for Lithium-Ion Batteries

Elemental doping for substituting lithium or oxygen sites has become a simple and effective technique to improve the electrochemical performance of layered cathode materials. Compared with single-element doping, this work presents an unprecedented contribution to the study of the effect of Na⁺/F⁻ co-doping on the structure and electrochemical performance of LiNi_1/3Mn_1/3Co_1/3O₂. The co-doped Li_1-zNa_zNi_1/3Mn_1/3Co_1/3O_2-zF_z (z = 0.025) and pristine LiNi_1/3Co_1/3Mn_1/3O₂ materials were synthesized via the sol–gel method using EDTA as a chelating agent. Structural analyses, carried out by X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy, revealed that the Na⁺ and F⁻ dopants were successfully incorporated into the Li and O sites, respectively. The co-doping resulted in larger Li-slab spacing, a lower degree of cation mixing, and the stabilization of the surface structure, which substantially enhanced the cycling stability and rate capability of the cathode material. The Na/F co-doped LiNi_1/3Mn_1/3Co_1/3O₂ electrode delivered an initial specific capacity of 142 mAh g⁻¹ at a 1C rate (178 mAh g⁻¹ at 0.1C), and it maintained 50% of its initial capacity after 1000 charge–discharge cycles at a 1C rate.     

两室气体互通对光合微生物燃料电池性能的影响

以斜生栅藻生长产生氧为电子受体的光合微生物燃料电池(PMFC)和外加CO2光合微生物燃料电池(AC-PMFC)联合构建成微生物碳捕获电池(MCC).研究MCC在不同运行条件下的产电性能及影响因素.测量MCC,PMFC和AC-PMFC三种系统中的电压、溶解氧和pH.结果表明,产电压趋势与所有系统中的藻类阴极的氧浓度相关,...     

Superhydrophobic and ultraviolet-blocking cotton textiles

Cotton textile was coated with ZnO@SiO(2) nanorods in order to obtain superhydrophobic and ultraviolet (UV)-blocking properties. The coating process was conducted in mild conditions, which involved the low-temperature preparation of ZnO seeds, hydrothermal growth of ZnO nanorods, bioinspired layer-by-layer deposition of a SiO(2) shell on the surface of ZnO nanorods, and hydrophobic modification of ZnO@SiO(2) nanorods with octadecyltrimethoxysilane. Despite the highly curved morphology of cotton fibers, the ZnO@SiO(2) nanorods coated the textile densely and uniformly. The treated cotton textile was found to have a large UV protection factor (UPF = 101.51) together with UV-durable superhydrophobicity, as determined by contact-angle measurement under long-term UV irradiation. The good UV-blocking property can be ascribed to the high UV absorbance and scattering properties of ZnO nanorods, and the UV-durable superhydrophobicity is a result of suppression of the photoactivity of ZnO nanorods by a SiO(2) shell.     

Photocatalytic Reduction of Graphene Oxide–TiO2 Nanocomposites for Improving Resistive‐Switching Memory Behaviors

Graphene oxide (GO)‐based resistive‐switching (RS) memories offer the promise of low‐temperature solution‐processability and high mechanical flexibility, making them ideally suited for future flexible electronic devices. The RS of GO can be recognized as electric‐field‐induced connection/disconnection of nanoscale reduced graphene oxide (RGO) conducting filaments (CFs). Instead of operating an electrical FORMING process, which generally results in high randomness of RGO CFs due to current overshoot, a TiO₂‐assisted photocatalytic reduction method is used to generate RGO‐domains locally through controlling the UV irradiation time and TiO₂ concentration. The elimination of the FORMING process successfully suppresses the RGO overgrowth and improved RS memory characteristics are achieved in graphene oxide–TiO₂ (Go‐TiO₂) nanocomposites, including reduced SET voltage, improved switching variability, and increased switching speed. Furthermore, the room‐temperature process of this method is compatible with flexible plastic substrates and the memory cells exhibit excellent flexibility. Experimental results evidence that the combined advantages of reducing the oxygen‐migration barrier and enhancing the local‐electric‐field with RGO‐manipulation are responsible for the improved RS behaviors. These results offer valuable insight into the role of RGO‐domains in GO memory devices, and also, this mild photoreduction method can be extended to the development of carbon‐based flexible electronics.     

基于改进Faster R-CNN的光伏电池内部缺陷检测

光伏电池近红外图像中复杂异构背景使内部缺陷检测成为一项极具挑战性的问题,为此,提出了一种基于深度学习的目标检测框架-残差通道注意力Faster R-CNN(residual-channel-attention-faster R-CNN,RCA-Faster R-CNN),该网络通过卷积层-池化层提取图像特征,再送入新颖...     

支持撤销的位置分层属性加密研究

基于属性加密的位置分层访问方案允许用户依据自身情况灵活设置自己的位置访问信息,不仅解决了社交网络中位置共享问题,还在算法上进行改进使解密效率得以提升。但在系统运行过程中,存在用户有更正自己属性信息的需求或运行过程中部分私钥遭泄露的可能,因此支持撤销对于系统安全非常必要。基于此提出了一种支持撤销的位置分层属性加密方案,将部分解密运算外包给解密服务器,并结合了双因子身份认证的方法。该方案在减少用户计算代价的同时,提高了算法的安全性。