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101.
Time dispersion (TD) is computed for large neutron detectors using plastic scintillators. It is shown that TD seen by the photomultiplier (PM) tube does not necessarily increase with incident neutron energy, which is a result not fully in agreement with the usual finding 相似文献
102.
JF Delaloye S Leyvraz E Outcha Adjahoto J Bauer P De Grandi 《Canadian Metallurgical Quarterly》1996,19(2):204-206
We report two cases of metastatic non-functioning pancreatic endocrine tumour with very elevated plasma levels of alpha-fetoprotein. In these two cases, serial plasma levels of alpha-fetoprotein, initially normal, correlated well with hepatic tumour progression and were associated with fatal outcome. These results suggest that elevated plasma concentration of alpha-fetoprotein may be caused by metastatic pancreatic endocrine tumour and than alpha-fetoprotein serial measurement may be useful in prognostic evaluation. 相似文献
103.
A. Ureña J. M. Gomez De Salazar J. Quiñones S. Merino J. Martin 《Journal of Materials Science》1996,31(3):807-817
Diffusion bonds have been produced between sheets of an Al-Li-Cu-Mg-Zr alloy using aluminium-4% copper vapour deposited metallic interlayers. Microstructural changes occurred both in the parent alloy and in the bond interface after diffusion bonding cycles and post-bonding heat treatments were analysed. Different metallographic techniques (light microscopy, scanning and transmission electron microscopy) have been used. Diffusion bonding trials were carried out using the same alloy (AA8090), both in non-superplastic (T6) and superplastic conditions. Differences in their behaviours in relation to diffusion bonding were observed. 相似文献
104.
105.
This paper concerns the plasticity constitutive laws in small strain. In the thermodynamic approach developed here, the key concept is that of internal variables. The differential nature of plasticity law has been pointed out for a long time. If we unite the invariance condition of these laws in a state variable transformation, this involves, ultimately, that the natural mathematic frame of plasticity theory is Differential Geometry. The system state is defined as a point of a differentiable manifold. The state variable are the local coordinates of this point in a chart. The internal stresses are the components of a covariant vector of the cotangent bundle to internal state manifold and the elastic domain is a convex part of cotangent vector space. The plastic yield criteria such as von Mises condition define a Riemannian structure over the manifold. The metric element is identified with the internal dissipation element. Constitutive laws link the covariant derivatives of the thermodynamic stress with the state variable. Hardening modulus splits up in two parts, kinematic hardening and metric hardening. This last is defined by Christoffel connection coefficients. Applied to von Mises isotropic yield condition, the metric hardening is identified with isotropic hardening. The Baltov-Sawczuk model is also analysed. The use of appropriate polar coordinates simplifies significantly the computations. Generalization to a significant category of non-differentiable yield criteria, such as Tresca condition, is considered by introducting a metric tensor family. The adaptation of Drucker's postulate to the proposed model requires the introduction of parallel transport of the internal stress covector. Generally, this transport is different over distinctive paths joining two points. This fact expresses internal state manifold curvature. The Riemann-Christoffel tensor is computed for von Mises, Baltov-Sawczuk and Tresca models. 相似文献
106.
Hemagglutinins present in Amaranthus leucocarpus seed meal were extracted with saline buffer and nutritive value was estimated by PER, NPR as well as Digestible Energy Consumption Evaluations. Protein digestibility was determined both in vitro and in vivo. Trypsin inhibitor activity was also determined. Saline-extracted Amaranth meal had significantly higher PER and NPR values than whole meal (p<0.05). There were no significant differences in digestible energy (Kcal/day/ animal) and protein consumption (g/day/animal) between diets (p<0.05). A. leucocarpus improves in nutritive value after the saline extraction procedures and has a good potential as a complementary food due to its lysine content. In addition purified agglutinin may be a useful biochemical. 相似文献
107.
On-body communications around the human torso are considered, using ultra-wideband transmissions. The velocity of the diffracted wave propagating around the body is extracted from frequency- domain spatial correlation analyses. 相似文献
108.
109.
Nguyen-Huy Dung Pardo Marie-Paule Dogguy.Smiri Leïla 《Materials Research Bulletin》1982,17(3):293-300
The Mn0.23Ga1.85S3 phase belongs to the solid solution , stable at low temperature in the Ga2S3MnS system. It is hexagonal superstructure of the wurtzite, with the Ga2S3α′ type (; Z = 6; space groupe P61 or P65). Its crystal structure has been refined by the least squares method to a final R = 0.06 with 323 independant reflections. This structure is closely related to Ga2S3 α described by Hahn and Frank, and differs only by the partial occupation of the vacant metal site of Ga2S3 by Mn atoms in statistical disorder. 相似文献
110.
De Geronimo G. Bolotnikov A.E. Carini G. Fried J. O'Connor P. Soldner S.A. 《IEEE transactions on nuclear science》2006,53(2):456-461
A new version of the front-end application specific integrated circuit (ASIC) for co-planar-grid (CPG) sensors is presented. Compared to the first version, the ASIC is optimized for signal/noise performance, modified in peaking time, and it implements timing signals to measure the depth of interaction using the grids signals only. Experimental results using state-of the-art CPG sensors and different approaches for reducing the error due to electron trapping are reported. A new technique that makes use of the sum and difference of the grids signals is also presented. 相似文献