Electrothermal Control of Graphene Plasmon–Phonon Polaritons

Graphene plasmons are known to offer an unprecedented level of confinement and enhancement of electromagnetic field. They are hence amenable to interacting strongly with various other excitations (for example, phonons) in their surroundings and are an ideal platform to study the properties of hybrid optical modes. Conversely, the thermally induced motion of particles and quasiparticles can in turn interact with electronic degrees of freedom in graphene, including the collective plasmon modes via the Coulomb interaction, which opens up new pathways to manipulate and control the behavior of these modes. This study demonstrates tunable electrothermal control of coupling between graphene mid‐infrared (mid‐IR) plasmons and IR active optical phonons in silicon nitride. This study utilizes graphene nanoribbons functioning as both localized plasmonic resonators and local Joule heaters upon application of an external bias. In the latter role, they achieve up to ≈100 K of temperature variation within the device area. This study observes increased modal splitting of two plasmon–phonon polariton hybrid modes with temperature, which is a manifestation of increased plasmon–phonon coupling strength. Additionally, this study also reports on the existence of a thermally excited hybrid plasmon–phonon mode. This work can open the door for future optoelectronic devices such as electrically switchable graphene mid‐infrared plasmon sources.     

Released ATP Mediates Spermatozoa Chemotaxis Promoted by Uterus-Derived Factor (UDF) in Ascaris suum

Fertilization requires sperm migration toward oocytes and subsequent fusion. Sperm chemotaxis, a process in which motile sperm are attracted by factors released from oocytes or associated structures, plays a key role in sperm migration to oocytes. Here, we studied sperm chemotaxis in the nematode Ascaris suum. Our data show that uterus-derived factor (UDF), the protein fraction of uterine extracts, can attract spermatozoa. UDF is heat resistant, but its activity is attenuated by certain proteinases. UDF binds to the surface of spermatozoa but not spermatids, and this process is mediated by membranous organelles that fuse with the plasma membrane. UDF induces spermatozoa to release ATP from intracellular storage sites to the extracellular milieu, and extracellular ATP modulates sperm chemotaxis. Moreover, UDF increases protein serine phosphorylation (pS) levels in sperm, which facilitates sperm chemotaxis. Taken together, we revealed that both extracellular ATP and intracellular pS signaling are involved in Ascaris sperm chemotaxis. Our data provide insights into the mechanism of sperm chemotaxis in Ascaris suum.     

Research and Remote Implementation of Program Updation of DSP System by Ethernet

Based on the structure and bootloader principle of DSP system, a method for the remote updation, debugging and self-loading of DSP system is developed by Ethernet. Hardware circuit and DM9000 driven program are presented and TCP/IP protocol is embedded into DSP. Through the re-mapping of external memory address, it is easy to implement the load of program section selectively and DSP self-boot. The experimental results show that the problem of high cost in system maintenance by conventional field debugging b...     

基于参数化功率谱估计的车轮多边形动态识别

由于传统频谱估计方法存在固有缺陷,对车轮多边形振动频率的识别容易产生较大误差,尤其对于初期车轮多边形的识别更是困难。为解决上述问题,基于参数化功率谱估计理论,提出一种车轮多边形动态识别方法。首先,根据车轮多边形的动态特性,建立了谐波频率恢复模型;其次,基于奇异值分解法与归一化误差分析对谐波恢复模型的阶数进行确定;然后,采用总体最小二乘法对谐波恢复模型的参数进行计算;最后,根据Cadzow估计理论对异常磨耗信号进行功率谱估计,并以某地铁车辆的轴箱垂向振动加速度实测信号为例,对该方法的可行性与正确性进行了验证。结果表明：该方法可基于短时序列数据实现高精度频域估计,且对谐波信号敏感,尤其适用于早期车轮多边形异常磨耗信号的识别。     

消火栓箱石材暗门180°开启门轴装置研究

装饰暗门工艺在现行装饰工程中很常见,但当运用于有特殊规范要求的门扇时,传统工艺往往不能兼顾美观与实用性等问题.介绍一种干挂石材消火栓箱暗门通过特殊的转轴系统,使消火栓箱暗门既能够达到消防规范的180°开启角度,又能兼顾立面上整体美观性的要求,并且能保证施工的经济效益,可为类似其他装饰工程提供借鉴.     

基于机器视觉技术的曲轴自动探伤系统设计

设计了一种基于机器视觉技术的曲轴自动荧光磁粉探伤系统,能够对缺陷图像进行采集,预处理和缺陷识别。使用该系统可以有效减轻工人的劳动强度,为判断退役曲轴能否再次利用提供科学依据。     

高大顶板宴会厅满堂顶板支撑架体设计与施工

新疆大厦宴会厅,净高为8．9m,顶部为钢结构。为了承受钢梁带来的重力作用,在钢梁节点处和混凝土顶板处,采用不同的支撑方式,确保了结构的安全性。     

降低连铸浊环水中氟化物的生产实践

鞍钢股份有限公司炼钢总厂一分厂针对连铸浊环水中氟化物超标的问题,新建了除氟设施,包括一体化设备、石英砂过滤器及深度除氟系统等,采用了双钙法和高效絮凝沉淀法组合除氟工艺.采取上述措施后,连铸浊环水中氟离子含量由130 mg/L降至10 mg/L以下,满足了国家规定的排放标准要求.     

QuEChERS技术结合超高效液相-串联质谱同时测定薄皮甜瓜中7 种葫芦素

采用改良的QuEChERS方法,建立同时测定甜瓜中7 种葫芦素的超高效液相色谱-串联质谱检测方法。样品用乙腈提取,离心后取1 mL上清液经50 mg乙二胺-N-丙基硅烷和50 mg十八烷基硅烷净化,使用XBridge C18色谱柱分离,以乙腈和0.1%甲酸加5 mmol/L乙酸铵溶液为流动相进行梯度洗脱,采用电喷雾离子源电离,正/负离子快速切换多反应监测模式进行分析。在此条件下,7 种葫芦素在16 min内得到较好分离,在0.1～1 500 μg/L质量浓度范围内线性关系良好,相关系数均大于0.99;进行3 个水平添加实验（n=5）,7 种葫芦素在20、100 μg/kg和500.0 μg/kg三个添加水平下的回收率在75.7%～118.3%之间,相对标准偏差在0.5%～13.6%之间,该方法的检出限及定量限分别为0.16～4.33 μg/kg和0.27～13.11 μg/kg。该方法简便、灵敏度高、分析时间短,精密度和准确性良好,可用于甜瓜中7 种葫芦素的同时检测。     

Chemically driven synthesis of Ti3+ self-doped Li4Ti5O12 spinel in molten salt

Surface doping of Li₄Ti₅O₁₂ (LTO) with Ti³⁺ ions is an effective way to enhance its electrochemical properties for lithium ion batteries (LIBs). Herein, a molten salt approach was reported to synthesize Ti³⁺ self-doped LTO powder. The reaction mechanism and the role of molten salt for the synthesis have been systemically discussed. Finally, electrochemical performance of the LTO powder was preliminarily evaluated as anode material of LIBs. The molten salt accelerated the mass transportation for the formation of LTO by transferring a solid diffusion to the diffusion of ions in a liquid media. Self-doping of Ti³⁺ ions on the surface of LTO particles was achieved by controlling equilibriums of chemical reactions in the reactor. Electrochemical performance of the LTO powders was effectively promoted by doping Ti³⁺ ions on the surface. The discharge capacity of the Ti³⁺ self-doped LTO powder prepared at 850°C was 171 mAhg⁻¹, and the capacity dacayed 9.9% after 200 cycles at a rate of 0.5 C.