摘要：为了探究齿坎型重力式锚碇的承载特性与抗滑机制,依托贵州省牂牁江特大桥纳雍岸重力式锚碇工程,开展了相同试验条件下平底锚碇1/4埋深、齿坎锚碇1/4埋深、平底锚碇半埋深及齿坎锚碇半埋深四种工况的室内物理模型试验,并对各工况锚碇位移-荷载曲线、锚碇-地基接触应力、地基应变及地基宏观变形破坏特征进行分析。结果表明:四种工况锚碇模型的极限承载力分别为3P(平底1/4埋深)、4P(齿坎1/4埋深)、7P(平底半埋深)和8P(齿坎半埋深);同种型式锚碇模型增大埋深可以显著提升锚碇的承载能力,同等埋深条件下齿坎型重力式锚碇承载性能要优于平底重力式锚碇;齿坎构造能够充分调动地基联合承载;基于地基的宏观变形破坏特征将其变形破坏过程划分为无裂隙、裂隙初现、裂隙发展以及破坏四个阶段;对齿坎型重力式锚碇承力过程进行了力学分析,得出齿坎构造力学特性较好,对限制锚碇变位和提高锚碇承载能力作用明显。

摘要：针对光伏发电功率波动大,无法满足稳定电量供给需求的问题,提出了计及谐波信号的光伏发电功率控制方法。根据K因子取值范围,计算了谐波损耗量与附加损耗量,分析了光伏发电设备的谐波信号影响。考虑谐波信号的影响,确定了光伏发电功率特性,联合等效负荷参数,求解AGC参数,实现对光伏发电功率的控制。对比实验结果表明,所提方法的功率平稳波段的持续时间延长了23 min,并能够有效抑制功率波动,其极大值与极小值之间的数值差仅为77 W,满足稳定电量供给的实际应用需求。

摘要：合成了一种新型环氧树脂-己二酸基环氧树脂(AAEP),并将其用于增韧双酚A型环氧树脂(E-51)。使用红外光谱(FTIR)、核磁共振氢谱(1H-NMR)对AAEP的分子结构进行了表征,结果表明AAEP的合成符合分子设计,环氧值为0.425 mol/100 g,粘度为320 mPa·s。以合成的AAEP为增韧剂,与E51进行共固化,对固化后的AAEP/E-51进行力学性能测试和断裂面形貌表征,探究了AAEP添加量对AAEP/E-51力学性能的影响。结果表明,当AAEP与E-51的质量比为10∶100时,AAEP/E-51的力学性能最佳,拉伸强度、断裂伸长率、冲击强度和弯曲强度较纯E-51分别提升了30.4%、50.9%、68.2%和38.0%,并表现出明显的韧性断裂。

摘要：目的研究不同代糖配比替代蔗糖对炼乳品质的影响。方法本研究采用单因素实验和混料设计研究4种代糖不同配比,得出最优代糖配方,并将最优代糖配方制备的炼乳进行水分活度、水分分布状态、质构、黏度、色差和感官品质等方面测定。结果4种代糖不同配比对炼乳感官品质和黏度的影响差异较大;优化代糖配方为:麦芽糖醇添加量23.70%、甜菊糖苷添加量0.17%、低聚半乳糖添加量5.10%、低聚木糖添加量1.00%(均为质量分数),感官评分为(87.30±1.27)分,黏度为(377.67±1.70)mPa·s。与蔗糖添加组炼乳相比,最优代糖配方炼乳水分活度降低(水分活度为0.75±0.01)(P<0.05),水分流动性减小;炼乳浓稠度和黏性均降低[分别为(236.34±4.86)***和(26.94±5.53)g](P<0.05);色泽为淡亮黄色。结论最优代糖配方炼乳通过降低水分活度、减少水分流动性,从而有效地减少炼乳中自由水含量,进而改善了炼乳色泽和质构特性。

摘要：由于锂资源的匮乏,钠离子电池因其丰富的钠资源储量、低廉的价格受到了人们的广泛关注.其中,P2型层状氧化物被认为是一种非常有前途的正极材料.但Mn^(3+)的Jahn-Teller效应会导致相变和结构坍塌,使得电池寿命下降.本研究采用稀土元素对三元锰铁系层状正极材料进行结构调控,采用快速微波辅助法设计Sm掺杂取代Mn的Na_(0.67)Mn_(0.58)Cu_(0.1)Fe_(0.3)Sm_(0.02)O_(2),加速钠离子在电化学反应过程中的扩散,提高材料的倍率性能.在1.0 A/g的高电流密度下,Na_(0.67)Mn_(0.58)Cu_(0.1)Fe_(0.3)Sm_(0.02)O_(2)的放电容量大幅提高.此外,Sm和Cu取代有效缓解了材料在循环过程中的Jahn-Teller效应,提高了材料的循环稳定性.Na_(0.67)Mn_(0.58)Cu_(0.1)Fe_(0.3)Sm_(0.02)O_(2)在200 mA/g条件下,经过100圈循环后容量保持率高达69.8%.稀土元素的加入成功改善了P2型层状氧化物电极的电化学性能.

摘要：目的：克隆变形链球菌葡聚糖结合蛋白C基因(Glucan-binding protein C gene,gbpC)编码序列的特异片段,并在大肠杆菌中实现原核表达。方法：根据gbpC序列设计并合成一对寡核苷酸引物,PCR扩增位于gbpC编码序列1342 bp～1794 bp间的一段特异片段,扩增产物经回收、酶切后,定向插入克隆载体puc18中,连接产物转化感受态大肠杆菌DH5α,挑选阳性克隆,鉴定后进行序列测定。将克隆获得的约0．45 kb的gbpC基因特异片段经EcoRI/SalI双酶切后。定向插入pGEX-4T-1中,构建pGEX-4T-1/gbpCE原核融合表达载体,转化感受态大肠杆菌DH5α,挑选阳性克隆,酶切及PCR鉴定后,异丙基硫代-β-D-半乳糖苷(Isopropyl-β-D-thiogalactoside,IPTG)诱导表达融合蛋白GST—GbpC^E,SDS—PAGE检测表达产物。结果：测序结果与Sato等报道的序列一致；原核表达后,在SDS—PAGE凝胶上出现一条新生蛋白条带,其相对分子量约43000,与预计大小相符合。结论：成功克隆并表达gbpC特异片段,获得了融合蛋白GST-GbpC^E,为制备GbpC抗体打下了基础。

摘要：This paper addresses the problem of three-dimensional trajectory tracking control for underactuated autonomous underwater vehicles in the presence of parametric uncertainties,environmental disturbances and input ***,a virtual guidance control strategy is established on the basis of tracking error kinematics,which resolves the overall control system into two cascade ***,a first-order sliding mode differentiator is introduced in the derivation to avoid tedious analytic calculation,and a Gaussian error function-based continuous differentiable symmetric saturation model is explored to tackle the issue of input *** with backstepping design techniques,the neural network control method and an adaptive control approach are used to estimate composite items of the unknown uncertainty and approximation ***,Lyapunov-based stability analysis guarantees that control error signals of the closed-loop system are uniformly ultimately ***,simulation studies are conducted for the trajectory tracking of a moving target and a spiral line to validate the effectiveness of the proposed controller.

摘要：常规后浇带双排支撑架对于快速穿插项目的地下室机电穿插效率低、可操作性差,为了适应快速穿插项目,研究结合以往项目经验,采用了一种单体独立支撑架,其是不受双排支撑影响的三角式(矩形式)独立支撑技术,其结构安全性验算也能满足设计要求。

摘要：以设计新颖、造型复杂的某机场航站楼金属屋面工程为背景,对该双曲面连续焊接不锈钢金属屋面系统的施工技术展开研究。系统介绍了该屋面构造系统施工工艺,针对该屋面系统曲面造型控制、檩条高空运输、固定座施工控制、超长板加工运输以及屋面板焊接等施工重点与难点进行分析并提出技术对策,可为类似工程施工提供参考。

摘要：Molecular nitrogen is relatively inert and the activation of its triple bond is full of challenges and of ***,searching for an efficiently heterogeneous catalyst with high stability and dispersion is one of the important targets of chemical ***,we report a Ba‐K/Ru‐MC catalyst with Ru particle size of 1.5–2.5 nm semi‐embedded in a mesoporous C matrix and with dual promoters of Ba and K that exhibits a higher activity than the supported Ba‐Ru‐K/MC catalyst,although both have similar metal particle sizes for ammonia ***,the Ba‐K/Ru‐MC catalyst is more active than commercial fused Fe catalysts and supported Ru *** techniques such as high‐resolution transmission electron microscopy,N2 physisorption,CO chemisorption,and temperature‐programmed reduction suggest that the Ru nanoparticles have strong interactions with the C matrix in Ba‐K/Ru‐MC,which may facilitate electron transport better than supported nanoparticles.