山东桃村水库回填区浅层地震勘探应用效果

主要针对桃村水库同填区地质状况的勘探需求利用浅层反射波法、浅层折射波法和地震映像法进行实地探测,对所获取的地震资料进行处理,得到了反映浅层地质状况的有效信息.根据结果差异讨论各种方法在具体工程勘探中的应用局限性及其相辅相成的关系,对地震勘探方法应用于工程物探提出建议.     

Mathematical expressions for calculation of oil‐polymer blends

A study of the recent literature emphasized the importance of blending polymers with oils for improving the performance characteristics (like flexibility, corrosion resistance, etc.) of adhesives, coatings and laminates. Investigation of the available data revealed that several properties of such oil‐polymer blends could be correlated by molar refraction (R_M), with reasonable accuracies. The properties of the linseed oil‐polystyrene (PS) and linseed oil‐polymethyl methacrylate (PMMA) blends studied are iodine value (IV), hydroxyl value (HV), inherent viscosity (η), melting temperature (T_M), and glass transition temperature (T_g). In the case of safflower, palm and peanut oil‐sucrose polyester formulations, the viscosity at 40 °C (η₄₀) and the melting point T_M have been correlated by R_M with the average absolute deviations (ē) of 17.8% and 3.0%, respectively. Using the orientation polarization P_O (to represent polarity) in addition to R_M, η₄₀ and T_M of oil‐polyester formulations could be calculated with ē values of 8.9% and 1.7%, compared to 17.8% and 3.0% using R_M alone. The results indicated the importance of P_O in improving the accuracy of predictions for properties.     

Non‐Linear Beam Tracing on a GPU

Beam tracing combines the flexibility of ray tracing and the speed of polygon rasterization. However, beam tracing so far only handles linear transformations; thus, it is only applicable to linear effects such as planar mirror reflections but not to non‐linear effects such as curved mirror reflection, refraction, caustics and shadows. In this paper, we introduce non‐linear beam tracing to render these non‐linear effects. Non‐linear beam tracing is highly challenging because commodity graphics hardware supports only linear vertex transformation and triangle rasterization. We overcome this difficulty by designing a non‐linear graphics pipeline and implementing it on top of a commodity GPU. This allows beams to be non‐linear where rays within the same beam do not have to be parallel or intersect at a single point. Using these non‐linear beams, real‐time GPU applications can render secondary rays via polygon streaming similar to how they render primary rays. A major strength of this methodology is that it naturally supports fully dynamic scenes without the need to pre‐store a scene database. Utilizing our approach, non‐linear ray tracing effects can be rendered in real‐time on a commodity GPU under a unified framework.     

梯度折射率分布极坐标测量方法和误差分析

研究了测量聚合物光纤径向折射率分布的相移干涉法,建立了数学模型,分析了测量误差的来源及影响,为能准确测得聚合物光纤的折射率分布提供了保证。     

High-resolution X-ray refraction imaging of rat lung and histological correlations

This study was performed to observe microstructures of the rat lung, using a synchrotron radiation beam and to compare findings with histological observations. X-ray refraction images from ex-vivo ventilating rat lung were obtained with an 8 KeV monochromatic beam and 20-mum thick CsI(Tl) scintillation crystal. The visual image was magnified using a 20x microscope objective and captured using an analog CCD camera. Obtained images were compared with conventional light microscopic findings from the same tissue. Pulmonary microstructures, including alveolar ducts, alveolar sacs, alveoli, alveolar walls, and perialveolar capillary networks were clearly identified with spatial resolution of as much as 1.2 mum and had good correlation with conventional light microscopic findings. The shape of alveoli appeared more round in SR images than in the light microscopic images. The results suggest that X-ray microscopy study of the lung using synchrotron radiation demonstrates the potential for clinically relevant microstructure of lung tissue without sectioning and fixation.     

Empirical correlations between shear wave velocity and penetration resistance for ground shaking assessments

Prediction of the ground shaking response at soil sites requires knowledge of the soil, expressed in terms of shear wave velocity. Although it is preferable to measure this dynamic soil parameter in situ, this is often not economic at all locations. Existing correlations between shear wave velocity and penetration resistance have been assessed in this study and compared with correlations with SPT values obtained based on geotechnical and geoseismic data collected from a first-degree earthquake zone in Turkey. The results obtained support the findings of earlier studies that blow-count is a significant parameter in these correlations while type of soil has no important influence. The regression equations developed in this study compare well with most of the previous equations and exhibit good prediction performance. It is noted that better correlations are obtained when uncorrected blow-counts are used.      

单向三角高程测量在大型场馆顶棚形变测量中的应用

大跨度钢结构建筑物的建设、改造和结构测试时,因荷载量的不断变化会产生顶棚变形,必须进行变形测量。当变形超限时,会严重影响到建筑物的使用安全,从而要求测量工作提供安全保障。本文探讨了采用单向三角高程测量进行顶棚变形监测的作业方法,并在实际应用中获得了比较满意的测量结果。     

Stability of peripheral refraction changes in orthokeratology for myopia

PurposeOrthokeratology (OK) is known to alter relative peripheral refraction (RPR) with this presumed to be its key myopia control mechanism. A prospective, longitudinal study was performed to examine stability of OK-induced RPR changes in myopic children and young adults.MethodsRPR of twelve children (C)(8–16 years) and eight adults (A)(18–29 years) with spherical equivalent refraction of -0.75 to -5.00D were measured unaided and while wearing single vision soft contact lenses (SCL). Measurements were repeated after 1, 6 and 12 months of OK wear. RPR was measured using an open-field Shin Nippon SRW-5000 autorefractor at 10, 20 and 30 degrees nasally (N) and temporally (T), converted into power vectors M, J0 and J45. On-axis refractions and axial lengths (IOL Master) were also measured.ResultsCompared to the unaided state, 1-month of OK wear shifted the RPR in the myopic direction at 30 T (C: p = 0.023; A:, p = 0.002) and 30 N (C&A, p = 0.003) and was stable thereafter, with similar changes compared to SCL wear. J0 showed a myopic shift in comparison to both unaided and SCL correction in children but not adults, and J45 did not change in either group. The on-axis OK correction was predictive of the RPR shift in both children and adults at 30 T (C: r=−0.58, p = 0.029; A: r=−0.92, p < 0.001) and 30 N (C: r=−0.60, p = 0.024; A: r=−0.74, p = 0.013) with symmetry of RPR shifts (C: r = 0.67, p = 0.008; A: r = 0.85, p = 0.004). No relationships between changes in RPR and axial length were found after twelve months of OK wear; level of myopia was stable in both groups.ConclusionRelative to both unaided and single vision SCL correction, OK shifted the RPR in the myopic direction; the RPR was stable from 1 to 12 months. The RPR shift in OK wear varied with the degree of myopia but was not correlated with myopia progression.     

A highly-sensitive label-free biosensor based on two dimensional photonic crystals with negative refraction

In this work, we present a novel high-sensitive optical label-free biosensor based on a two-dimensional photonic crystal (2D PC). The suggested structure is composed of a negative refraction structure in a hexagonal lattice PC, along with a positive refraction structure which is arranged in a square lattice PC. The frequency shift of the transmission peak is measured respect to the changes of refractive indices of the studied materials (the blood plasma, water, dry air and normal air). The studied materials are filled into a W1 line-defect waveguide which is located in the PC structure with positive refraction (the microfluidic nanochannel). Our numerical simulations, which are based on finite-difference time-domain (FDTD) method, show that in the proposed structure, a sensitivity about 1100 nm/RIU and a transmission efficiency more than 75% can be achieved. With this design, to the best of our knowledge, the obtained sensitivity and the transmission efficiency are one of the highest values in the reported PC label-free biosensors.