The formation of the retroreflected light field is introduced in the paper and the components of the retroreflected light field are analyzed.Furthermore,a deep analysis of the factors affecting energy distribution of ...The formation of the retroreflected light field is introduced in the paper and the components of the retroreflected light field are analyzed.Furthermore,a deep analysis of the factors affecting energy distribution of the retroreflected light,such as design deviation,angle of incidence,was made.The simulation of the retroreflected light field was done.Recommendation is made in detail on both the energy distribution of the retroreflected light field at different working distances and the energy distribution of the retroreflected light field at a short distance when the diverging light comes.At last,two kinds of measuring instrument for the retroreflector are introduced,one is the long tunnel measuring instrument,the other is the minitype measuring instrument based on the character of the retroreflector when the diverging light comes.展开更多
Jet spreading width is one of the important characteristics of water jets discharging into the air.Many researchers have dealt with measuring this width,and contact measuring methods on the water jet surface were empl...Jet spreading width is one of the important characteristics of water jets discharging into the air.Many researchers have dealt with measuring this width,and contact measuring methods on the water jet surface were employed in a lot of the cases.In order to avoid undesirable effects caused by the contact on the jet surface,we introduce non-contact measuring methods with a laser instrument to the measurements of jet spreading width.In measurements,a transmitter emits sheet-like laser beam to a receiver.The water jet between the transmitter and the receiver interrupts the laser beam and makes a shadow.The minimum and maximum values of the shadow width are measured.In addition,pictures of the water jet are taken with a scale,and the shadow width is measured from the pictures.The experiments on various needle strokes were performed.Three kinds of width consistent with the jet structure were obtained.In the results,it can be concluded that our non-contact measuring methods are feasible.The data of jet spreading widths and jet taper were obtained and are useful for future applications.展开更多
In the standard model of particle physics, photons are massless particles with a particular dispersion relation. Tests of this claim at different scales are both interesting and important. Experiments in territory lab...In the standard model of particle physics, photons are massless particles with a particular dispersion relation. Tests of this claim at different scales are both interesting and important. Experiments in territory labs and several exterritorial tests have put some upper limits on photon mass, e.g., torsion balance experiment in the lab shows that photon mass should be smaller than 1.2 x 10-51g. In this work, this claim is tested at a cosmological scale by looking at strong gravitational lensing data available and an upper limit of 8.71 x 10-39g on photon mass is given. Observations of energy-dependent gravitational lensing with not yet available higher accuracy astrometry instruments may constrain photon mass better.展开更多
A novel miniature Fabry-Perot interferometric(FPI) temperature sensor is proposed and demonstrated experimentally. The modal interferometer is fabricated by just splicing a section of photonic crystal fiber(PCF) with ...A novel miniature Fabry-Perot interferometric(FPI) temperature sensor is proposed and demonstrated experimentally. The modal interferometer is fabricated by just splicing a section of photonic crystal fiber(PCF) with a single-mode fiber(SMF). The air holes of the PCF are fully collapsed by the discharge arc during the splicing procedure to enhance the reflection coefficient of the splicing point. The transmission spectra with different temperatures are measured, and the experimental results show that the linear response of 11.12 pm/°C in the range of 30–80 °C is obtained. This sensor has potential applications in temperature measurement field.展开更多
文摘The formation of the retroreflected light field is introduced in the paper and the components of the retroreflected light field are analyzed.Furthermore,a deep analysis of the factors affecting energy distribution of the retroreflected light,such as design deviation,angle of incidence,was made.The simulation of the retroreflected light field was done.Recommendation is made in detail on both the energy distribution of the retroreflected light field at different working distances and the energy distribution of the retroreflected light field at a short distance when the diverging light comes.At last,two kinds of measuring instrument for the retroreflector are introduced,one is the long tunnel measuring instrument,the other is the minitype measuring instrument based on the character of the retroreflector when the diverging light comes.
文摘Jet spreading width is one of the important characteristics of water jets discharging into the air.Many researchers have dealt with measuring this width,and contact measuring methods on the water jet surface were employed in a lot of the cases.In order to avoid undesirable effects caused by the contact on the jet surface,we introduce non-contact measuring methods with a laser instrument to the measurements of jet spreading width.In measurements,a transmitter emits sheet-like laser beam to a receiver.The water jet between the transmitter and the receiver interrupts the laser beam and makes a shadow.The minimum and maximum values of the shadow width are measured.In addition,pictures of the water jet are taken with a scale,and the shadow width is measured from the pictures.The experiments on various needle strokes were performed.Three kinds of width consistent with the jet structure were obtained.In the results,it can be concluded that our non-contact measuring methods are feasible.The data of jet spreading widths and jet taper were obtained and are useful for future applications.
文摘In the standard model of particle physics, photons are massless particles with a particular dispersion relation. Tests of this claim at different scales are both interesting and important. Experiments in territory labs and several exterritorial tests have put some upper limits on photon mass, e.g., torsion balance experiment in the lab shows that photon mass should be smaller than 1.2 x 10-51g. In this work, this claim is tested at a cosmological scale by looking at strong gravitational lensing data available and an upper limit of 8.71 x 10-39g on photon mass is given. Observations of energy-dependent gravitational lensing with not yet available higher accuracy astrometry instruments may constrain photon mass better.
基金supported by the National Natural Science Foundation of China(Nos.61205068 and 61475133)the College Youth Talent Project of Hebei Province(No.BJ2014057)"Xin Rui Gong Cheng"Talent Project and the Excellent Youth Funds for School of Information Science and Engineering in Yanshan University(No.2014201)
文摘A novel miniature Fabry-Perot interferometric(FPI) temperature sensor is proposed and demonstrated experimentally. The modal interferometer is fabricated by just splicing a section of photonic crystal fiber(PCF) with a single-mode fiber(SMF). The air holes of the PCF are fully collapsed by the discharge arc during the splicing procedure to enhance the reflection coefficient of the splicing point. The transmission spectra with different temperatures are measured, and the experimental results show that the linear response of 11.12 pm/°C in the range of 30–80 °C is obtained. This sensor has potential applications in temperature measurement field.
