摘要：Classical molecular dynamics(MD)simulations ae performed to investigate the effects of mechanical strain on the thermal conductivity of single-layer black phosphorus(SLBP)nanoribbons along different directions at room *** results show that the tensile strain afects the thermal conductivity of nanoribbons by changing thephonon density of state(DOS)and mean free path(M FP).The thermal conductivity shows a sharp enhancement with the tensile strain applied along the armchai diection,while it increases slowly with the strain applied along the zigzag *** phenomenon cm be mainly explained by effects of the phonon DOS and *** increasing strain along the armchai direction weakens DOS and strengthens MFP ***,when it comes to the increasing strain along the zigzag deection'DOS enliances significantly while MFP decreases *** findings explore the relationship between the tensile strain and the thermal conductivity reasonably and can provide a reliable method to estimate the MFP of black phosphorus.

摘要：随着数智时代的到来,数智化决策型管理会计在经济发展中的作用越发重要,智能财务决策转型迫在眉睫。从高校智能财务决策概念入手,剖析其基本框架的内在逻辑,并基于智能财务在经营战略和决策支持场景的分析,提出高校智能财务决策体系的架构和建设思路,细化了财务组织重构、复合型财务人员队伍建设、智能财务信息化平台升级、运营管理设计等建设要点,可为行政事业单位智能财务改革提供决策参考。

摘要：【目的】为解决一种直径与正常卷烟相同但长度较短的新型卷烟输送对接问题,设计了一种柜式先进先出卷烟存储输送装置。【方法】该装置由执行系统和控制系统组成,执行系统由提升机、高位输送器、先进先出储柜、低位输送器等组成;控制系统由嵌入式PLC、伺服电机、料位检测组件等组成。首先,通过提升机抬高烟支烟流,输送至先进先出储柜;其次,由料位检测组件监控烟流高度和输送速度,当速度不匹配时,控制先进先出储柜收缩或扩容;最后,烟流经过低位输送器输送至下游设备。【结果】该装置主要用于卷接包生产线上,通过将上游设备与下游设备柔性地连接起来进行先进先出,完成烟支的自动输送、存储和缓冲调节。【结论】该装置使卷接包生产线实现高度自动化,满足新型烟草的转运输送需求,提高了整条生产线的工作效率,且装置运行稳定可靠,操作简单,便于维护。

摘要：通过“高Ti+Mo”合金成分设计、优化加热和TMCP轧制工艺、轧后保温罩缓冷、高效回火等措施,实现了4~12 mm薄规格免调质高强钢稳定生产。结果显示:试验钢板表面质量良好,不平度≤1 mm/2 m。热轧态试验钢板的显微组织为铁素体、贝氏体,回火后显微组织近乎全部为铁素体和粒状碳化物,屈服强度776 MPa,抗拉强度822 MPa,断后延伸率20.9%。试验钢板顺利通过中船重工725所的焊接评定认证,焊接接头各项性能良好。

摘要：宽幅喷杆喷雾机作业过程中,田间路面激励和拖拉机自身的振动导致喷杆发生振动,喷杆末端触地现象频发,对雾滴沉积均匀性和喷杆寿命产生很大影响。为抑制喷杆振动对喷雾质量的影响,解译喷杆振动传递特性,以幅宽为24 m的喷杆式喷雾机为载体,通过试验模态分析获得固定支撑方式下喷杆的约束模态信息;对被动激励源之一的支撑架进行运行模态分析获取工况工作频率,并在此基础上通过建立支撑架的有限元模型以阐明药箱液位对支撑架模态参数的影响。最后,通过试验获得机械激励和不同工况下喷杆振动的时、频域信号,结合模态分析结果,分析了主、被动激励源对喷杆振动传递特性的影响。结果表明:喷杆的前8阶试验模态频率均低于120 Hz,模态振型以弯曲变形为主,变形主要分布在喷杆的第一段和末端;发动机的2阶惯性力频率与喷杆的第3阶试验模态频率43.562 Hz接近,支撑架前16阶运行模态的固有频率与前8阶的喷杆模态频率范围重合;机械激励下,0~150 Hz频率范围内的响应包含整个喷杆的模态特性,且在该频率范围内振动在传递过程中存在很大损失;在怠速工况下,喷杆振动主要由发动机的2阶惯性力所致,振动主频为40 Hz,支撑架模态对振动的影响忽略不计;颠簸路面工况下,喷杆振幅随着行驶速度的提升而增加,主振频率在20 Hz和120 Hz处,而平滑路面工况下振动信号几乎不受行驶速度的影响;药液负载下,激励源与药液晃动的耦合振动增加了喷杆的振动响应,且药液还增加了支撑架结构的质量和阻尼,对支撑架振动有抑制效果。研究结果可以为喷杆结构的优化设计与减振提供理论依据。

摘要：基因是遗传的基本单元,是DNA或RNA分子上具有遗传信息的特定核苷酸序列,它不仅与生物体的生、老、病、死等一切生命现象直接相关,也是决定生命健康的内在因素,下一代基因测序仪的研制目标是希望能够将基因测序的成本大幅度降低,测序速度快速提高,推进基因组技术的个性化医学走向现实,基于固体纳米孔的基因测序是最有可能实现高通量的物理测序技术,但目前面临生物分子电信号的信噪比低、生物分子过孔速度太快以及生物分子在纳米孔内的输运规律缺失等挑战,设计多模式纳米孔传感器,通过多模式信号交叉对比,同时降低纳米孔长度等方法,是提高检测灵敏度的有效方法,借鉴生物纳米孔对DNA过孔速度的控制,利用磁场、声叉等外力场可以为单碱基的辨识奠定基础,当纳米通道的几何尺寸小于双电层厚度时,基于连续理论的泊松-玻尔兹曼方程和纳维-斯托克斯方程将面临挑战,建立纳通道内生物分子输运规律将丰富流体力学的研究内容。

摘要：A physical model of bulk-nanochannel-bulk with buffer baths is built up using nonequilibrium molecular dynamics （MD） simulation to study the effects of vibrating silicon atoms on the viscosity of aqueous NaCl solutions confined in the nanochannel. The simulation is performed under different moving speeds of the upper wall, different heights and different surface charge densities in the nanochannel. The simulation results indicate that with the increase in the surface charge density and the decrease in the nanochannel height and the shear rate, the vibration effect of silicon atoms on the shear viscosity of the confined fluid in the nanochannel cannot be ignored. Compared with still silicon atoms, the vibrating silicon atoms result in the decrease in the viscosity when the height of the nanochannel is less than 0.8 nm and the shear rate is less than 1.0 ×10^11 s^-1, and the effect of the vibrating silicon atoms on the shear viscosity is significant when the shear rate is small. This is due to the fact that the vibrating silicon atoms weaken the interactions between the counter-ions （Na^＋ ） and the charged surface.

摘要：基于有限元法(FEM)和节点位移方法,研究了在中间裂纹与侧裂纹处裂纹尖端的应力强度因子和应力场.使用8节点四边形等参元和1/4节点退化单元,对网格密度和裂纹长度对计算精度的影响进行了研究.改善裂纹尖端周围子区域的节点密度,在保证结果精度的同时,可以节省计算时间.为了计算和分析裂纹尖端的应力强度因子、应力场与位移场,利用Matlab/Simulink编写了关于平板Ⅰ型和Ⅱ型应力强度因子的代码,并比较了有限元方法与精确方法的计算结果.结果表明,所提出的方法有助于提高计算精度与收敛速度,且算法合理,可以提高仿真精度并指导工程设计.

摘要：The surface and adhesion forces between chitosan- coated mica surfaces in an acetic acid buffer solution were measured using a surface force apparatus （SFA）. The force- distance profiles were obtained under different pressure conditions. It was found that the chitosan was adsorbed on the mica surface and formed a stable nanofilm under acid conditions. The adsorbed chitosan nanofilms induced a short- range monotonically steric force when two such surfaces came close in the acid buffer. The adhesion forces between the two chitosan-coated mica surfaces varied with the loads. Strong adhesion between the two chitosan-coated mica surfaces was observed at high pressure. Such pressure-dependent adhesion properties are most likely related to the molecular configurations and hydrogen bonds reordering under high confinement.

摘要：对飞高为 50nm的 2种负压磁头的静特性进行了数值仿真,所采用的润滑模型中引入Fukui Kaneko滑流修正模型考虑低飞高时气体稀薄效应的影响.数值求解采用控制体方法离散修正雷诺方程,离散后的方程用交替方向迭代法求解.由仿真结果可知,采用优化设计的方法设计磁头的形状和尺寸可以得到性能更优的负压磁头,同时还可以看到凹槽深度对气膜承载力影响明显,合理设计凹槽深度能够进一步提高系统的静力学特性.