- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Detection of Semen Stains in Rape Cases by a Very High Powered UV-VIS Light Source, Facilitated Conviction of Accused Person
摘要： Detection of semen in forensic cases mostly sexual assault or abuse is critical for evidence collection. A portable forensic light source, which emits wavelength from 430 nm to 700 nm (UV to VIS) and filters were used. The very high intensity light source detected semen in darkness and daylight using wavelength between 415 nm to 490 nm. ABO blood grouping method is an oldest method used in forensic biology for grouping purpose. But now a days, DNA fingerprinting is an advanced technique used to solve crimes like gang rape. Even though in this case, simplest and oldest ABO blood grouping method helped to solve gang rape case. In present case, victim was 5 years old girl who was raped by a person. Screening the semen stains using portable forensic light source and primary testing of semen stains from different places on victim’s undergarments was done. ABO blood grouping of each selected semen stains were done by absorption-elution method. Those selected stains showed blood group which matched with the accused person’s blood group. Thus the accused person was convicted in this heinous crime.
关键词： Portable forensic light source (Crime lite 80S),DNA fingerprinting,ABO grouping
更新于2025-09-10 09:29:36
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Transverse resonance island buckets for synchrotron-radiation based electron time-of-flight spectroscopy
摘要： At the Metrology Light Source (MLS), the compact electron storage ring of the Physikalisch-Technische Bundesanstalt (PTB) with a circumference of 48 m, a specific operation mode with two stable closed orbits for stored electrons was realized by transverse resonance island buckets. One of these orbits is closing only after three turns. In combination with single-bunch operation, the new mode was applied for electron time-of-flight spectroscopy with an interval of the synchrotron radiation pulses which is three times the revolution period at the MLS of 160 ns. The achievement is of significant importance for PTB’s future programs of angular-resolved electron spectroscopy with synchrotron radiation and similar projects at other compact electron storage rings. The scheme applied here for selecting the photons originating from a particular orbit by optical imaging has been used before in fs slicing applications and may be relevant for the BESSY VSR project of the Helmholtz-Zentrum Berlin.
关键词： BESSY VSR,transverse resonance island buckets,electron time-of-flight spectroscopy,Metrology Light Source,synchrotron radiation
更新于2025-09-10 09:29:36
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Line–planes deflectometry
摘要： The key issue in phase measurement deflectometry is the solution of incident light which is used to determine the surface normal. To restore the 3D mirror surface information, line–planes deflectometry is proposed to determine the surface normal from the reflected light and the incident light planes containing incident light. To this end, a point light source is used to replace the continuous surface light source of traditional deflectometry. Accordingly, the incident light is calculated by the intersection of incident light planes which are determined by two or more projected lights of a point light source. Finally, the precise mirror surface is restored through the radial basis function interpolation from the gradient which is transformed from the normal information. To verify the proposed method, a line–planes deflectometry system is developed with two projectors and one camera. The system can be applied for two measurement modes concerning different measurement requirements: the ‘line–plane model’ and the ‘line–planes model’. The ‘line–plane model’ can be inferred with a measurement error of less than 0.25 mm to measure objects with low accuracy and non-connectivity. In contrast, the ‘line–planes model’ can be used to measure objects with high accuracy and good area connectivity, and the measurement error is about 1 μm.
关键词： point light source,radial basis function interpolation,line–planes deflectometry,incident light plane,incident light
更新于2025-09-09 09:28:46
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Microbunch Rotation and Coherent Undulator Radiation from a Kicked Electron Beam
摘要： Coherent emission from a microbunched electron beam is the driving force behind the revolution in light sources, enabling x-ray free-electron lasers (FELs) to emit pulses 9 orders of magnitude brighter than previous sources. Microbunches form perpendicular to the electron travel direction, and the conventional understanding is that they shear rather than rotate in response to a transverse kick, locking FEL facilities into a single-user operating mode. In this paper, we show that microbunches rotate toward the new direction of travel if the electron beam is kicked and defocused. We provide evidence that microbunch rotation explains the unexpectedly large amount of off-axis radiation observed during experiments at the Linac Coherent Light Source. We demonstrate that LCLS can be multiplexed into at least three separate beams using this principle. Finally, we propose using a magnetic triplet to rotate microbunches through significantly larger angles without microbunch degradation. This new understanding of microbunch dynamics can lead to significantly improved multiplexing at FEL facilities, microbunch preservation through a bend, and x-ray pulses with a pulse-front tilt.
关键词： electron beam,Linac Coherent Light Source,coherent undulator radiation,x-ray free-electron lasers,microbunch rotation
更新于2025-09-09 09:28:46
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Design, development and use of the spectrometer for investigating coherent THz radiation produced by micro-bunching instabilities at Diamond Light Source
摘要： Schottky barrier diodes (SBDs) are known for their low noise, ultra-fast response and excellent sensitivity. They are often implemented as detectors in the millimetre wavelength regime. Micro-bunch instabilities (MBI) have been detected at many light sources around the world including the Diamond Light Source, UK. These MBI can result in bursts of coherent synchrotron radiation (CSR) with millimetre wavelengths. More research needs to be carried out with regards to the dynamics of MBI in order to con?rm the simulations and to eventually harness the power of the CSR bursts. A single shot spectrometer has been designed and is under operation at the Diamond Light Source (DLS). It is composed of eight SBDs ranging from 33-1000 GHz. Unlike previous measurements carried out, each of the SBDs has been individually characterised thus making the results obtained comparable to simulations. In this paper, we present the assessment of each SBD in the spectrometer and the ?rst results of the spectrometer’s use in the beam.
关键词： Schottky barrier diodes,micro-bunch instabilities,spectrometer,coherent synchrotron radiation,Diamond Light Source
更新于2025-09-09 09:28:46
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[IEEE 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Chongqing (2018.6.27-2018.6.29)] 2018 IEEE 3rd International Conference on Image, Vision and Computing (ICIVC) - Urban Night Image Restoration Algorithm Based on Space Model
摘要： In this paper, we propose a new algorithm to restore non-uniform illumination images at night. Building space model to simulate the night illumination environment, and propose a new detection light source algorithm based on this space model. Adaptive exposure according to the distance between the object and the light source, the illumination intensity of the original image is redistributed to make the whole image illumination uniform, and the aim of restoring the non-uniform illumination image is achieved. At the same time, in order to facilitate subsequent detection and recognition, this paper presents an algorithm to increase the contrast of images. The proposed algorithm is tested in the night non-uniform illumination environment. The experimental results show that the proposed algorithm is superior to the conventional exposure algorithm in image detail restoration.
关键词： adaptive exposure,detection light source,enhancing image contrast,space model
更新于2025-09-09 09:28:46
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Review on multi gas detector using infrared spectral absorption technology
摘要： To provide some references for researchers engaged in infrared multi gas detection, this study introduced the infrared multi gas detection system thoroughly from infrared light source, infrared detector, optical multiplexing structure, and detection method. Currently, the coherent source represented by quantum cascade laser has replaced the traditional incoherent source like thermal radiant infrared light source and became the dominant light source in infrared multi gas detection. Accordingly, the infrared photodetector is widely used. The optical multiplexing structure based on the “multiplexing thought” is the core of infrared multi gas detection system. It mainly includes the single-source multiplex detection structure and multi-source multiplexing detection structure. Nondispersive infrared spectroscopy, long optical distance spectroscopy, wavelength/frequency modulation spectroscopy, cavity enhancement spectroscopy, and photoacoustic spectroscopy are major detection methods used in the infrared multi gas detection. This has important significance to many fields, such as industrial and agriculture production, environmental monitoring, life science, etc.
关键词： optical multiplexing structure,infrared spectroscopy,infrared detector,Multi gas detection,infrared light source
更新于2025-09-04 15:30:14
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Image Judgment Auxiliary System for Table Tennis Umpiring under Low Light Conditions
摘要： In table tennis competitions, the rule violation judgment with the greatest controversy is the height of the ball serve. This is because inaccuracy in the ball height judgment, which results in erroneous judgment, is unavoidable. Thus, we designed an automatic image judgment auxiliary system for table tennis ball height during service in this study. We used a high-speed camera to record the ball toss in the table tennis service. The designed algorithm architecture can automatically search for the ball and the position of the hand action under low light source conditions. It is often di?cult to provide enough light when using high-speed photography and this leads to underexposure. The algorithm is mainly divided into hue-saturation-value color space processing and morphology processing using Hough transform to search for the circular ball. Experiment result shows that color segmentation can successfully and accurately determine the ball position under low light conditions. The morphology method can ?nd the position of the hand and help determine the moment when the ball leaves the hand during the service ball toss. Finally, the actual size of the target is used to estimate the actual distance unit represented by the image pixel.
关键词： Table tennis,low light source,automatic tracking,hue-saturation-value (HSV) image segmentation
更新于2025-09-04 15:30:14
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Perception of light source distance from shading patterns
摘要： Varying the distance of a light source from an object alters both the intensity and spatial distribution of surface shading patterns. We tested whether observers can use such cues to infer light source distance. Participants viewed stereoscopic renderings of rough objects with diffuse and glossy surfaces, which were illuminated by a point source at a range of distances. In one task, they adjusted the position of a small probe dot in three dimensions to report the apparent location of the light in the scene. In a second task, they adjusted the shading on one object (by moving an invisible light source) until it appeared to be illuminated from the same distance as another object. Participants’ responses increased linearly with the true light source distance, suggesting that they have clear intuitions about how light source distance affects shading patterns for a variety of different surfaces. However, there were also systematic errors: Subjects overestimated light source distance in the probe adjustment task, and in both experiments, roughness and glossiness affected responses. We find the pattern of results is predicted surprisingly well by a simplistic model based only on the area of the image that exceeds a certain intensity threshold. Thus, although subjects can report light source distance, they may rely on simple—sometimes erroneous—heuristics to do so.
关键词： lighting,reflectance,gloss,roughness,light source,illumination,material perception
更新于2025-09-04 15:30:14