我怎样运用历史暗射地图

在历史教学中,早已普遍重视了历史地图的使用.我过去经常在课堂上利用课本上的地图加以放大.课后交代学生阅读课本上的地图,借以记忆重要的地名和明确位置.可是每个学生在学习中没有很好地阅读地图.到了测验时,才死记硬背几个有关历史事件的地名.这样在头脑里就没有形成空间的概念.因而在提问和考卷里,有的写错地名,有的颠倒位置.这种现象是历史教学中不可忽视的问题.我针对这种情况,曾下过功夫,

Estimation of Illuminant Direction and Albedo from Shading

Assuming uniform albedo and Lambertian surface for the imaging model, a new robust method for estimation of illuminant direction and albedo from shading is presented. If there is a singular point with maximum intensity in an image, the method use shading information of the singular point and its neighbors to estimate directly the elevation of illuminant direction, surface albedo, and the bias brightness. Some experiment results on synthetic images are given to illustrate the new approach is accurate and robust.

如何指导学生用好《地理填充图册》

如何指导学生用好《地理填充图册》□兰州市十二中张晋霞填充图亦称空白图或暗射图。它只绘有简略的地理轮廓（经纬网格、境界线等）和一些主要的地理事物（水系、地形、城市等）的符号，而没有地名注记，通常要求学生不直接依赖地图填绘内容，而是在熟悉地图基本内容的基...

Novel transmitter of dark RZ signal based on external modulator

A novel transmitter to generate a dark RZ signal with tunable duty cycle and extinction ratio is proposed, by modifying the process of preceding, modulating and coding, A dark RZ signal is generated simply by using one dual-arm Mach-Zehnder LiNbO3 modulator. We demonstrate experimentally that this optical dark RZ signal can be directly measured by a conventional binary intensity modulation direct detection （IM-DD） receiver. When different values of duty cycles at 2.5 Gbit/s are adjusted, the experimental results show different BER curves and eye diagrams of the optical dark RZ signal.

Reconstruction of Temperature Field in 3-D, Absorbing, Emitting, and Anisotropically Scattering Medium

The soft measurement technology of flame temperature field is an efficient method to learn the combustion status in furnace. Generally, it reconstructs the temperature field in furnace through the image of flame, which is a process to solve radiative inverse problem. In this paper, the flame of pulverized coal is considered as 3-D, absorbing, emitting, and anisotropically scattering non-gray medium. Through the study on inverse problem of radiative heat transfer, the temperature field in this kind of medium has been reconstructed. The mechanism of 3-D radiative heat transfer in a rectangular media, which is 2 m×3 m× 5 m and full of CO2, N2 and carbon particles, is studied with Monte Carlo method. The 3-D temperature field in this rectangular space is reconstructed and the influence of particles density profile is discussed.

鸡年猜"鸡谜"

谜语,源于民间口头文学,是一种暗射事物或文字等供人猜测的隐语,一般由谜面、谜底两部分组成。这里向小读者介绍有趣的"鸡谜"游戏--

First dark matter search results from the PandaX-Ⅰ experiment

We report on the first dark-matter(DM)search results from PandaX-I,a low threshold dual-phase xenon experiment operating at the China JinPing Underground Laboratory.In the 37-kg liquid xenon target with 17.4 live-days of exposure,no DM particle candidate event was found.This result sets a stringent limit for low-mass DM particles and disfavors the interpretation of previously-reported positive experimental results.The minimum upper limit,3.7×10-44cm2,for the spin-independent isoscalar DM-particle-nucleon scattering cross section is obtained at a DM-particle mass of 49 GeV/c2at 90%confidence level.

Sensitive semi-quantitative detection of respiratory syncytial virus by dark-field light scattering imaging of the infected host cells

A novel sensitive semi-quantitative virus detection technique was developed using the respiratory syncytial virus(RSV) as an example, through dark-field light scattering imaging of the surface state of the virusinvaded host cells. In this method, anti-RSV-antibody modified gold nanoparticles(Au NPs) could bind with the invading virus on the cell membrane of the infected host cells through the specific antibody-antigen binding. Then,the host cells could be imaged by the localized surface plasmon resonance light scattering properties of Au NPs under a dark-field light scattering microscopy, which could be further used to semi-quantify the invading virus.

Search for gamma-ray spectral lines with the DArk Matter Particle Explorer

The DArk Matter Particle Explorer(DAMPE)is well suitable for searching for monochromatic and sharpγ-ray structures in the GeV-TeV range thanks to its unprecedented high energy resolution.In this work,we search forγ-ray line structures using five years of DAMPE data.To improve the sensitivity,we develop two types of dedicated data sets(including the BgoOnly data which is the first time to be used in the data analysis for the calorimeter-based gamma-ray observatories)and adopt the signal-to-noise ratio optimized regions of interest(ROIs)for different DM density profiles.No line signals or candidates are found between 10 and 300 GeV in the Galaxy.The constraints on the velocity-averaged cross section for xx→γγand the decay lifetime for x→γv,both at 95%confidence level,have been calculated and the systematic uncertainties have been taken into account.Comparing to the previous Fermi-LAT results,though DAMPE has an acceptance smaller by a factor of~10,similar constraints on the DM parameters are achieved and below 100 GeV the lower limits on the decay lifetime are even stronger by a factor of a few.Our results demonstrate the potential of high-energy-resolution observations on dark matter detection.

A common origin of muon g-2 anomaly,Galaxy Center GeV excess and AMS-02 anti-proton excess in the NMSSM

The supersymmetric model is one of the most attractive extensions of the Standard Model of particle physics.In light of the most recently reported anomaly of the muon g-2 measurement by the FermiLab E989 experiment,and the excesses of gamma rays at the Galactic center observed by Fermi-LAT space telescope,as well as the antiproton excess observed by the Alpha Magnetic Spectrometer,we propose to account for all these anomalies or excesses in the Next-to-Minimal Supersymmetric Standard Model(NMSSM).Considering various experimental constraints including the Higgs mass,B-physics,collider data,dark matter relic density and direct detections,we find that a~60 GeV bino-like neutralino is able to successfully explain all these observations.Our scenario can be sensitively probed by future direct detection experiments.

Search for strong gravitational lensing effect in the current GRB data of BATSE

Because gamma-ray bursts （GRBs） trace the high-z universe, there is an appreciable probability for a GRB to be gravitational lensed by galaxies in the universe. Herein we consider the gravitational lensing effect of GRBs contributed by the dark matter halos in galaxies. Assuming that all halos have the singular isothermal sphere （SIS） mass profile in the mass range 101~h 1Mo 〈 M 〈 2×10^13h^-1M and all GRB samples follow the intrinsic redshift distribution and luminosity function derived from the Swift LGRBs sample, we calculated the gravitational lensing probability in BATSE, Swift/BAT and Fermi/GBM GRBs, re- spectively. With an derived probability result in BATSE GRBs, we searched for lensed GRB pairs in the BATSE5B GRB Spectral catalog. The search did not find any convincing gravitationally lensed events. We discuss our result and future obser- vations for GRB lensing observation.

Revisit of constraints on holographic dark energy:SNLS3 dataset with the effects of time-varying β and different light-curve fitters

Previous studies have shown that for the Supernova Legacy Survey three-year （SNLS3） data there is strong evidence for the redshifl- evolution of color-luminosity parameter β of type Ia supernovae （SN Ia）. In this paper, we explore the effects of varying β on the cosmological constraints of holographic dark energy （HDE） model. In addition to the SNLS3 data, we also use Planck distance prior data of cosmic microwave background （CMB）, as well as galaxy clustering （GC） data extracted from Sloan Digital Sky Survey （SDSS） data release 7 and Baryon Oscillation Spectroscopic Survey （BOSS）. We find that, for the both cases of using SN data alone and using SN＋CMB＋GC data, involving an additional parameter of β can reduce χ^2 by - 36; this shows that β deviates from a constant at 6σ- confidence levels. Adopting SN＋CMB＋GC data, we find that compared to the constant β case, varying β yields a larger fractional matter density Ωm0 and a smaller reduced Hubble constant h; moreover, varying β significantly increases the value of HDE model parameter c, leading to c ≈ 0.8, consistent with the constraint results obtained before Planck. These results indicate that the evolution of β should be taken into account seriously in the cosmological fits. In addition, we find that relative to the differences between the constant β and varying β（z） cases, the effects of different light-curve fitters on parameter estimation are very small.

Implications of the cosmic infrared background excess for the cosmic star formation

By phenomenologically describing the high-redshift star formation history, i.e., ,ρ.（z） oc [（1 ＋z）/4.5]-% and semi-analytically calculating the fractions of high-redshift Pop I/II and Pop II! stars, we investigate the contributions from both high-redshfit Pop I/II and Pop II/stars to the observed near-infrared （3 μm 〈// 〈 5 μm） excess in the cosmic infrared background emission. In order to account for the observational level of the near-infrared excess, the power-law index or of the assumed star formation history is constrained to within the range of 0 ≤a≤1. Such a constraint is obtained under the condition that the viral temperature of dark matter halos belongs to the range of 500 K ≤ Tvir≤ 104 K.

Nonautonomous Dark Solitons and Rogue Waves in a Graded-Index Grating Waveguide

We analytically present a family of nonautonomous dark solitons and rogue waves in a planar graded-index grating waveguide with an additional long-period grating.The dark solitons whose dynamics described by the explicit expressions such as the valley,background and wave central position are investigated.We find that dark soliton's depth and the long-period grating have effects on soliton's wave central position;the gain or loss term affects directly both the background and valley of the soliton.For rogue waves,it is reported that one can modulate the distribution of the light intensity by adjusting the parameters of the long-period grating.Additionally,more rogue waves with different evolution behaviors in this special waveguide are demonstrated clearly.