掺铒单模光纤飞秒脉冲激光器和放大器

为了获得一种被动锁模掺铒光纤振荡器及功率放大器，数值模拟出超短脉冲在光纤中的传输和演化过程，并基于此搭建了一种被动锁模掺铒光纤飞秒振荡器及功率放大器。实验获得了中心波长1560 nm、重复频率100 MHz、输出功率30 mW、脉冲宽度85 fs超短脉冲。通过采用PPLN晶体进行倍频，进一步获得了输出功率5 mW，中心波长780 nm的飞秒脉冲。该光纤激光器为全保偏光纤结构，具有体积小巧、可靠性高、稳定性好的特点。     

液压支架让缩性能试验特性分析与探讨

分析研究国家标准中液压支架让缩性能试验的技术要求,设计开发让缩性能试验系统,以双伸缩立柱液压支架为研究对象进行让缩性能试验分析与研究,为让缩性能试验的开展提供了试验条件,为液压支架国标的实施提供基础。     

On Cost Aware Cloudlet Placement for Mobile Edge Computing

As accessing computing resources from the remote cloud inherently incurs high end-to-end (E2E) delay for mobile users, cloudlets, which are deployed at the edge of a network, can potentially mitigate this problem. Although some research works focus on allocating workloads among cloudlets, the cloudlet placement aiming to minimize the deployment cost (i.e., consisting of both the cloudlet cost and average E2E delay cost) has not been addressed effectively so far. The locations and number of cloudlets have a crucial impact on both the cloudlet cost in the network and average E2E delay of users. Therefore, in this paper, we propose the Cost Aware cloudlet PlAcement in moBiLe Edge computing (CAPABLE) strategy, where both the cloudlet cost and average E2E delay are considered in the cloudlet placement. To solve this problem, a Lagrangian heuristic algorithm is developed to achieve the suboptimal solution. After cloudlets are placed in the network, we also design a workload allocation scheme to minimize the E2E delay between users and their cloudlets by considering the user mobility. The performance of CAPABLE has been validated by extensive simulations.      

Single-Crystalline TiO2(B) Nanobelts with Unusual Large Exposed {100} Facets and Enhanced Li-Storage Capacity

The {100} facet of single-crystalline TiO₂(B) is an ideal platform for inserting Li ions, but it is hard to be obtained due to its high surface energy. Here, the single-crystalline TiO₂(B) nanobelts from H₂Ti₃O₇ with nearly 70% {100} facets exposed are synthesized, which significantly enhances Li-storage capacity. The first-principle calculations demonstrate an ab in-plane 2D diffusion through the exposed {100} facets. As a consequence, the nanobelts can significantly accommodate Li ions in LiTiO₂ formula with specific capacity up to 335 mAh g⁻¹, which is in good agreement with the electrochemical characterizations. Coating with conductive and protective poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), the cut-off discharge voltage is as low as 0.5 V, leading to a capacity of 160.7 mAh g⁻¹ after 1500 cycles with a retention rate of 66% at 1C. This work provides a practical strategy to increase the Li-ion capacity and cycle stability by tailoring the crystal orientation and nanostructures.     

S6-11综放工作面回风巷支护设计优化

针对常村矿回采巷道变形严重,影响正常生产的问题,通过对矿井赋存条件、巷道现有支护形式和围岩变形过程分析,采用新型联合支护技术对S6-11回风巷道支护进行优化。现场实测巷道顶底板相对移近量最大120mm,两帮相对移近量最大140mm,均在允许正常范围之内。     

15000Nm~3/h变压吸附提氢装置运行小结

通过对变压吸附提氢工艺选择、技术方案、工艺流程的描述,指出装置运行状况良好,达到了设计要求,产生了可观的经济效益、环保效益。     

京津冀协同发展下的河北省技术技能人才培养对策研究

京津冀协同发展战略是我国当前重点推进的国家顶层战略,河北省作为京津产业转移对接的重要基地,在产业升级、爬坡过坎中面临重要的战略任务。破解困境的突破点在于技术技能人才的培养和使用。在京津冀协同发展背景下,亟待我省政府和职业院校尤其是高等职业院校,适应经济新常态,大力推进现代职教改革,培养我省转型升级需要的高素质技术技能人才,为服务国家战略提供技术技能支撑。     

Functionalized graphene oxide nanosheets with unique three-inone properties for efficient and tunable antibacterial applications

Developing antibiotics-independent antibacterial agents is of great importance since antibiotic therapy faces great challenges from drug resistance.Graphene oxide(GO)is a promising agent due to its natural antibacterial mechanisms,such as sharp edgemediated cutting effect.However,the antibacterial activity of GO is limited by its negative charge and low photothermal effect.Herein,the amino-functionalized GO nanosheets(AGO)with unique three-in-one properties were synthesized.Three essential properties(positive charge,strong photothermal effect,and natural cutting effect)were integrated into AGO.The positive charge(30 mV)rendered AGO a strong interaction force with model pathogen Streptococcus mutans(330 nN).The natural cutting effect of 100 ng·mL^-1AGO caused 27%loss of bacterial viability after incubation for 30 min.Most importantly,upon the near-infrared irradiation for just 5 min,the three-in-one properties of AGO caused 98%viability loss.In conclusion,the short irradiation period and the tunable antibacterial activity confer the three-in-one AGO a great potential for clinical use.     

基于机器视觉技术的古陶瓷器型三维还原算法

器型研究对于古陶瓷的真伪鉴别、价值认知和其文化类型与传播途径的研究具有重要的意义.本文在研究和解决了复杂背景下旋转体古陶瓷轮廓提取、图像畸变校正、轮廓线非线性建模等一系列技术难题的基础上,研究并实现了一套古陶瓷器型三维还原算法.通过该算法利用旋转体古陶瓷的二维图像建立了精确的轮廓模型,进而实现器型的三维建模.最终试验结果表明,该三维建模算法可以精确获取旋转体古陶瓷三维器型模型,对探索古陶瓷器型研究发展新方向有一定意义.     

生物可降解PCL/PLA开孔发泡材料制备及吸油性能

以聚己内酯（PCL）为基体，添加不同含量聚乳酸（PLA）熔融共混制备具有不同分散相形态的PCL/PLA共混物，利用超临界二氧化碳（scCO₂）微孔发泡工艺制备不同发泡倍率和开孔率的PCL/PLA多孔材料用于吸油应用。针对边长3 mm正方体样品溶解度实验发现100 min后CO₂在PCL中已达到饱和吸附状态。PLA分散相含量的增加显著增大了PCL/PLA共混物泡孔密度，并使共混泡孔尺寸减小且分布更加均匀；发泡温度升高6℃，泡孔尺寸增大50%，发泡倍率增大38%，开孔率减小了20%。PCL/PLA开孔材料具有明显的亲油疏水性，发泡倍率越高，疏水性越好；针对花生油和硅油的吸油实验发现材料吸油率与发泡倍率和开孔率整体呈正比，实际吸油量高于理论计算值，10次循环吸油测试后样品吸油率仅降低8.5%，材料吸油量与油品特性黏度关系不大。