摘要：In this work, we report a comprehensive study about the eco-environmental effects of the shelter forest along the Tarim Desert Highway, including the effects on aeolian environment, soil, micro-climate, biodiversity, and groundwater. The results show that: (1) The movement of windblown sand near the ground surface was affected by the shelter forest. The wind speed and sediment transport rate in the shelter forest decreased by 64%―80% and 87.45%―99.02%, respectively. In addition, there were also significant changes in the sand flux structure, the sand grain size, and the deflation and deposition on the ground surface. (2) Compared to the natural mobile sand, the soil bulk density in the forest area decreased while the total salt content, the total porosity, and the water content increased. In addition, the soil fertility was significantly improved in the forest area, and showed the "first rapid, then slow" variation pattern. (3) The shelter forest showed positive effects on the micro-climate. Within the 6 m height above the ground, the air temperature in the shelter forest at different heights was lower than that in the mobile sand, while the air humidity was higher, while, the soil temperature was also lower in the shelter forest than mobile sand. (4) The number of soil microbial species increased significantly with the improvement of habitat in the shelterbelt. However, the population of different species was not distributed evenly across the surveyed area. (5) Currently, no significant effects of groundwater-pumping and forest-irrigation water have been found on the groundwater level and its salinity. The variation amplitude of both groundwater level and salinity was at the level of centimeters and 1g/L, respectively. No obvious variation trend has been observed.

摘要：A compact interdigital H-mode drift-tube linac (IH-DTL) with the alternating-phase-focusing (APF) method, working at 325 MHz was designed for an injector of a proton medical accelerator. When fed in with a proper RF (radio frequency) power, the DTL cavity could establish the corresponding electromagnetic field to accelerate the ‘‘proton bunches’’ from an input energy of 3 MeV to an output energy of 7 MeV successfully, without any additional radial focusing elements. The gap-voltage distribution which was obtained from the CST■ Microwave Studio software simulations of the axial electric field was compared with that from the beam dynamics, and the errors met the requirements within ± 5%. In this paper, the RF design procedure and key results of the APF IH-DTL, which include the main RF characteristics of the cavity, frequency sensitivities of the tuners, and coupling factor of the RF power input coupler are presented.

摘要：为深入了解消费者对智能童鞋的功能和感性需求,选取3~6岁儿童父母进行问卷调研。首先运用层次分析法获得智能童鞋的五类功能需求顺序:精准定位、控温舒适和运动数据监测(并列第二)、健康成长指导、智能提醒;其次在功能需求优先级基础上,筛选出9对感性词汇,借助感性工学法对9款样品款式图进行均值和因子分析。结果表明,父母对不同智能童鞋款式感性印象差异较大,8号、3号样品图综合得分最高和最低;舒适性和科学性是影响父母对智能童鞋感性需求的2个主要影响因子。

摘要：高频谐振变换器因软开关和高功率密度的特有优势而成为近年来的研究热点。然而,随着谐振元件数量的增加,变换器参数设计变得愈加困难。传统参数设计过程主要依赖仿真软件和人为经验,难以充分优化电路性能。为此,文中提出一种应用于高频谐振变换器的参数优化设计方法,将反向传播(back propagation,BP)神经网络与多目标遗传算法相结合,对变压器传递的无功功率、谐振电感电流有效值、电感等无源元件体积等表征效率和功率密度的主要参数以及开关管和二极管电压应力进行综合考虑,以提高变换器的效率和功率密度。在实验室搭建一台48V输入、12V/60W输出、谐振频率为1MHz的原理样机,实验结果验证了所提出参数优化方法的有效性。

摘要：轮毂电机结构简单、控制灵活,是电动汽车的优选驱动方式。为减少电机和轮毂刚性连接引起的电磁冲击和机械冲击,提出一种可柔性连接电机和轮毂的永磁双稳态电磁离合器,其结构高度紧凑,外形小巧,可以匹配轮毂内狭小的可用空间。分别利用有限元法和磁路解析法对该离合器进行磁场分析,并以漏磁系数为目标函数确定离合器的最佳结构尺寸。在此基础上,制作单元样机并开展相关实验,实验结果证明了仿真分析和优化设计的合理性。

摘要：为了提高反舰导弹的突防能力,有效规避敌方舰空导弹的拦截,完成精确打击目标的战术要求,从便于工程实现的角度出发,应用时标分离的方法,将弹目相对运动模型分离为2个一阶的动力学子系统,这2个子系统分别对应于视线角速率层(慢动力学系统)和自动驾驶仪惯性滞后层(快动力学系统),对这2个子系统分别进行动态逆控制设计,设计了一种能够实现反舰导弹主动规避机动的动态逆导引律.通过控制视线角速率跟随期望视线角速率有界振荡,并控制视线角速率在末制导终端趋于零,来控制反舰导弹的弹道变轨.所设计的导引律考虑了自动驾驶仪的动态特性,并对目标的机动信息进行了估计,能够在保证打击精度的同时,实现导弹自身的规避机动,设计方法简单实用,利于工程实现.仿真结果验证了方法的正确性和有效性.

摘要：短视频营销已成为当前助推消费升级的重要新生力量,研究其对用户购买意愿的影响对提升产品销量具有重要的理论意义和实践价值。通过文献总结分析,借助SOR理论模型,提出研究假设,构建探究服装服饰类短视频对用户的购买意愿影响模型,并通过结构方程模型进行验证分析。结果表明:短视频的有用性、易用性显著正向影响用户的购买意愿,而娱乐性影响不显著;感知匹配度在有用性、易用性、娱乐性刺激变量和购买意愿反应变量间存在中介作用。针对上述结论,建议服装服饰类短视频运营企业商家注重在有用性、易用性、感知匹配度方面进行改进,促使短视频营销更快更好的发展。

摘要：The transmission and distribution of moisture in cement-based materials are of great significance to the properties and durability of materials. Traditional macro-humidity monitoring equipment in civil engineering cannot capture the microscale humidity inside cement-based materials in situ. In this paper, a method of using rhodamine 6G fluorescence to characterize the change in relative humidity in cement-based materials is proposed. Two kinds of moulding processes are designed, which are premixed and smeared after moulding, and the optimal preparation concentration is explored. The results showed that rhodamine 6G can reflect the relative humidity of cement-based materials in situ by its fluorescence intensity and had little effect on the hydration heat release and hydration products of cement-based materials;the fluorescence intensity was much higher when the internal relative humidity was 63% and 75%. The research results lead the application of polymer materials in the field of traditional building materials, help to explore the performance evolution law of cement-based materials in micro scale, and have important significance for the evolution from single discipline to interdisciplinary.

摘要：随着智能制造技术的迅猛发展,制造业正在逐步实现智能化生产,特别是对于异常复杂的切削加工过程,智能化的实现尤为重要。刀具作为切削过程中最活跃的要素,其性能与寿命对零件的加工精度和生产效率有直接影响。材料切削性能的多样性、加工系统动态变化的非线性以及生产节拍的多变性等问题给刀具设计、制备与管控技术带来了巨大的挑战,智能制造技术使面向需求的刀具精准高效设计、精确可靠制备与科学全面管控得以实现,有利于生产过程节能降耗与提质增效。本文提出了面向智能制造过程的刀具设计、制备与管控的相关技术架构,从面向智能制造的刀具设计方法、制备过程与管控技术三个方面梳理了国内外相关研究成果及应用案例,并对基于虚实映射与迭代优化的面向全生命周期的刀具设计、制备与管控技术进行了展望。刀具全生命周期的智能化必将助力制造产业升级和结构优化,促进生产方式智能变革。

摘要：Magnesium alloys have shown prospective applications as a new biodegradable metal within bone. To garantee the longterm biocompatibility, a Mg-Zn-Ca alloy,composing of essential elements for human, was prepared and its feasibility for orthopedic applications was investigated. The in vitro and in vivo corrosion of Mg-Zn-Ca alloy as well as the biocompatibility were studied. The in vitro corrosion tests in five kinds of physiological solutions showed that the corrosion rates and corrosion morphologies of the alloy were strongly influenced by the solution used. The addition of serum in Hank’s and MEM significantly slowed down the corrosion rate and improved the corrosion uniformity of the alloy. The corrosion rate decreased with increasing serum *** alloy showed the slowest corrosion rate as well as homogeneous corrosion morphology in MEM＋10%FBS. Both the indirect and direct cell experiments indicated good cytocompatibility of the extruded Mg-Zn-Ca alloy. In vivo, we observed a gradual degradation process from the surface of extruded Mg-Zn-Ca alloy and only 40% in volume of implant was left after 4 weeks implantation in medullary cavities of mice. The micro-CT and histological analyses revealed its good biocompatibility with peri-implant new bone formation and increasing cortical bone thickness with increasing implantation period. This study showed that the extruded MgZn-Ca alloy provided sufficient biocompatibility for orthopedic application, though the in vivo corrosion rate should be further reduced for clinical use.