高速并行RS编译码系统实现系统

给出了一种高速并行RS编译码系统的实现方法,并就其中的几个关键技术进行了分析。采用该技术实现的纠错系统,可以使误码率在10^-3的情况下仍保证数据的高可靠,高速率传输。     

The longitudinal distribution of cadmium, zinc, copper, iron, and metallothionein in the small-intestinal mucosa of rats after administration of cadmium chloride

Different routes of Cd intake may influence the intestinal distribution of Cd, metallothionein (MT), and trace metals differently. Therefore, we compared the effects of parenteral and enteral administration of Cd on the distribution of trace metals and MT along the small intestine. In a first experiment three groups of rats were employed: a control, one receiving CdCl2 within the drinking water, and another receiving sc injections of CdCl2. In a second experiment, rats were fed three different diets with either 0, 0.3, or 1 mmol CdCl2/kg for one and two weeks to study the time- and dose-dependent effects of orally administered Cd. Metal concentrations (Cd, Zn, Cu, Fe) were measured by atomic emission spectrometry and MT was determined by radioimmunoassay. Intestinal MT levels did not show proximodistal gradients in controls or after sc administration of Cd, but orally administered Cd increased mucosal MT levels longitudinally from the duodenum to the ileum. Cd levels paralleled those of MT. Compared with the metal concentrations in the controls, sc administration of Cd did not change intestinal Zn, Cu, and Fe levels. Oral administration of Cd, however, increased Cu and decreased Fe levels in the intestinal mucosa significantly. The second experiment revealed that only high dietary concentrations of Cd increase intestinal Cd and MT levels longitudinally toward the distal parts, whereas at lower dietary concentration the longitudinal distribution was reversed. This shows that different routes and doses of Cd intake lead to a different trace metal and MT distribution and emphasizes the role of dietary Cd in the local induction of small-intestinal MT.     

汽车车身车间暖通设计

介绍了该车间的通风供暖方式,指出汽车厂焊接车间采用置换通风、转轮式热回收装置以及天然气燃烧加热的方式可以取得良好的室内空气环境和具有很好的节能效果。     

Psychopathy and sexual assault: Static risk factors, emotional precursors, and rapist subtypes.

This study compared psychopathic and nonpsychopathic rapists on static risk factors and on emotional and motivational precursors. Sixty incarcerated rapists were assessed for psychopathy with the Psychopathy Checklist—Revised (R. D. Hare, 1991), and they were classified according to the Massachusetts Treatment Center: Revised Rapist Typology, Version 3 (R. A. Knight & R. A. Prentky, l990b). Psychopathy was positively associated with past nonsexual offenses and negatively associated with age onset for criminal offending, number of sexual victims, and the intensity of negative emotions experienced before sexual offending. However, psychopathy was not related to sexual offense history, age of onset for sexual offending, or victim harm. Last, psychopaths were most likely to be classified as opportunistic and pervasively angry rapists. The findings indicate that psychopathy should be considered when developing intervention strategies for rapists. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response of reinforced concrete beams to hydrostatic pressure acting within primary cracks

This paper investigates the response of reinforced concrete beams to hydrostatic pressure acting within primary cracks. Notched beams were initially pre-cracked before pressurised water was introduced into the primary crack. The deflection and strain increase at tensile reinforcement level (due to the pressurised water load) was measured. Tests were carried out using applied hydrostatic pressures of 0.2 and 0.325 MPa. Results show that both deflection and strain at tensile reinforcement level increases immediately after the introduction of hydrostatic pressure into open primary cracks. If the crack is held open and hydrostatic pressure is allowed to build up within the depth of the crack, additional deformation occurs. A finite element (FE) model was constructed to investigate the effects of greater hydrostatic pressures acting within the primary crack. The FE model was first validated against the test data, before being used to assess the structural response of the reinforced concrete section to applied hydrostatic pressures of up to 1 MPa. It was found that section deformations increased as hydrostatic pressure was increased. At applied hydrostatic pressures of 0.8 MPa and above, the increases in strain at tensile reinforcement level were shown to be significant. DNV-0S-C205, which is the Det Norske Veritas (DNV) standard for offshore concrete structures states that the ‘effects of water pressure within cracks may be neglected for structural elements exposed to less than 100 m (0.981 MPa) of water head.’ The current research suggests that the effects of water pressure within cracks for structural elements exposed to slightly less than 100 m water head may also be significant (based on a 10 % threshold criteria). However, it is accepted that a more comprehensive parametric study would be required to determine whether or not the DNV should be redressed.     

Settlement due to Diaphragm Wall Construction in Reclaimed Land in Hong Kong

For more than two decades diaphragm walling has become commonly used for the construction of deep excavations in Hong Kong. For example, 13 of the main excavations for the Island Line of the Mass Transit Railway (MTR), completed in 1986, adopted diaphragm walls as the principal support to the excavation. Diaphragm walls were particularly appropriate to the MTR construction in over-crowded urban Hong Kong, limiting adverse effects on surrounding buildings and allowing top-down construction methods, thus reducing programming time. Settlement was predicted for buildings on deep foundations (piles), adjacent to deep excavations, and the actual settlement was monitored by conventional surveying techniques. The results indicate that settlement due to diaphragm walling is generally substantial and that preconstruction activities such as ground treatment, drilling, and preboring for wall panels, must be taken into account in any settlement predictions.     

Inhibition of protein synthesis by zinc: comparison between protein synthesis and RNA synthesis

Inhalation of zinc fumes may lead to the acute respiratory distress syndrome. The mechanisms of pulmonary zinc toxicity are not yet understood. Therefore we investigated zinc-dependent depression of protein and RNA synthesis in rat and human lung cell lines. 1. After exposure to 120 or 150 micromol/l zinc, RNA synthesis as assessed by uridine incorporation decreased by 60-70% between 0 and 2 h exposition in rat alveolar type II cells (L2 cells) and human fibroblast-like cells (11Lu and 16Lu cells), and by 90% between 0 and 4 h in carcinoma-derived cells (A549 cells). 2. After 2 h exposure, L2, 11Lu, and 16Lu cells were half-maximally inhibited by 50 micromol/l zinc, whereas A549 cells were more resistant with half-maximal inhibition at 100 micromol/zinc. 3. Protein and RNA synthesis was inhibited in parallel in L2, 11Lu, and A549 cells as indicated by simultaneous determination of uridine and amino acid incorporation. In 16Lu cells, the decline in protein synthesis preceded RNA synthesis inhibition. Pretreatment with RNA synthesis inhibitors (amanitin or actinomycin D) had no effect on time curve and intensity of RNA synthesis inhibition. Taken together, our results indicate that the suppression of RNA and protein synthesis likely are independent phenomena, due to direct zinc effects on these biosynthetic pathways.     

Novaco Anger Scale: reliability and validity within an adult criminal sample

Serum is used widely for culturing neurons and glial cells, and is thought to provide essential, albeit undefined, factors such as hormones, growth factors, and trace elements that promote the growth of cells in vitro. Moreover, serum can have profound effects on cell proliferation, differentiation, and cell morphology, and may even influence cell fate decisions. Despite the overall growth-promoting influence of serum on cell culture, frequent media changes have been shown to be detrimental to neuronal cultures, significantly reducing the yield of viable neurons. The reason for this loss of neurons by frequent media changes has been puzzling. We demonstrate that bovine and horse sera, the most popular serum complements for CNS cell culture, are a significant source for glutamate, supplying glutamate at concentrations sufficient to kill primary cultured hippocampal neurons. By using the bioluminescence detection method, we determined the glutamate concentration [Glu] in several batches of fetal bovine (calf) sera (FBS) to be close to 1 mM, and that of horse sera to be approximately 0.3 mM. Thus 10% serum supplement to culture media results in [Glu] of 30-100 microM due to serum alone. We subsequently produced glutamate depleted media (GDM) by using primary cultures of hippocampal astrocytes to absorb glutamate from media containing 10% FBS. Within 3 h, astrocytes reduced the [Glu] in the medium from approximately 90 microM to less than 1 microM. Sister cultures of hippocampal neuron that underwent frequent media changes with GDM or GDM + partial untreated media demonstrated that GDM significantly increase neuronal survival (10-fold at 21 DIV). Subsequent exposure to glutamate provided by either untreated serum or by equivalent doses of exogenous glutamate added to GDM led to dose-dependent neuronal cell death. The relative sensitivity of hippocampal neurons to glutamate increased with increasing culture age from initial ED50 values of > 100 microM (< 6 DIV) to approximately 6 microM in cultures maintained for 3 weeks or longer. The relative sensitivity to exogenous glutamate was at least 2-fold higher in neurons cultured in GDM than in sister cultures maintained in media containing untreated serum. The death of neurons exposed to untreated media was blocked by the NMDA receptor antagonist MK-801. These experiments suggest that the vulnerability of neurons to media changes can be solely explained by excitotoxicity resulting from serum-borne glutamate. Moreover, we propose that use of GDM may be advantageous for culturing hippocampal neurons and may eliminate the possible selection for glutamate resistant neurons. The use of GDM could be particularly important for studies of excitotoxicity; our study predicts that the ED50 for neuronal culture with regular serum will be artificially high and may not adequately reflect the in vivo state.     

Fatigue Crack Growth of Peened Friction Stir-Welded 7075 Aluminum Alloy under Different Load Ratios

The effect of peening on the fatigue crack growth performance of friction stir-welded 7075 aluminum alloy was investigated. The fatigue crack growth rates were assessed for laser- and shot-peening conditions at stress ratios (R) of 0.1 and 0.7. The surface and through thickness residual stress distributions were characterized for the different regions in the weld. The results indicate a significant reduction in fatigue crack growth rates using laser peening compared to shot peening and the as-welded condition. The effect of the compressive stresses obtained through laser peening was deemed responsible for increasing the resistance to fatigue crack growth of the welds.