小粒径再生粗骨料对预制混凝土力学性能影响的研究

研究5~10 mm小粒径再生粗骨料对预制混凝土抗压强度、劈裂抗拉强度和弹性模量的影响。结果表明,抗压强度随龄期延长而提高,且主要发生在前7 d,7 d抗压强度达到其28 d抗压强度的77%;劈裂抗拉强度随龄期的延长而提高,3 d劈裂抗拉强度达到其28 d强度的64%;弹性模量也随龄期的延长而提高,龄期为1、3、7和14 d时,弹性模量分别为其28 d弹性模量的32%、46%、62%和91%。通过与欧洲规范对比,基于试验结果,建议了劈裂抗拉强度和弹性模量的计算模型。研究结果更好的实现再生混凝土在小截面预制混凝土构件上的工程应用。     

Quantitative proteomics for epigenetics

Mass spectrometry has made many contributions to the chromatin field through the mapping of histone modifications and the identification of protein complexes involved in gene regulation. MS-based proteomics has now evolved from the identification of single protein spots in gels to the identification and quantification of thousands of proteins in complex mixtures. Quantitative approaches also allow comparative and time-resolved analysis of post-translational modifications. An important emerging field is the unbiased interaction analysis of proteins with other proteins, defined protein modifications, specific DNA and RNA sequences, and small molecules. Quantitative proteomics can also accurately monitor whole proteome changes in response to perturbation of the gene expression machinery. We provide an up-to-date review of modern quantitative proteomic technology and its applications in the field of epigenetics.     

Clogging in submerged entry nozzles

Casting high quality steel grades requires the use of a submerged entry nozzle (SEN) to prevent oxygen and nitrogen pick‐up and to achieve favourable steel flow conditions in the mould. Clogging of the SEN leads to instability of the casting operation as well as to a decrease in slab quality. To understand the interactions between liquid steel and the SEN, 156 nozzles from the Sidmar steel plant were investigated with respect to the amount of clogging. A linear relation between the clogging volume and the clogging weight was observed. This indicates that the clogging material's density remains constant during the clogging process for the different steel grades. A distinct relationship was also found between the amount of clogging and the cast steel weight. No relation between the amount of clogging and the superheating of the steel nor the steel flow rate was noticed, however. It was also concluded that for AI killed steels the high Mn (> 3000 ppm) and high C (> 500 ppm) grades cause less clogging than AI killed steel grades with low Mn content (< 3000 ppm) and that Al/Si killed steel grades cause less clogging when compared to AI killed steel grades. When comparing these different steel grades with respect to their total oxygen concentration in the ladle, it appears that steel grades, which have a low total oxygen concentration, cause less clogging in the SEN. Based on these observations three combinations SEN/steel grade were selected for further analysis with electron microscopy.     

Formalized three-layer system-level model and reuse methodology forembedded data-dominated applications

In embedded data-dominated applications, a global system-level data transfer and storage exploration phase is crucial in obtaining a cost- and performance-efficient solution. We have developed a novel formalism to describe reusable blocks such that the essential part of the design exploration freedom is retained. This formalism is the basis for a system-level reuse methodology which allows reusing large parts of the design as heavily optimized structural VHDL or assembly code and describes the costly data access-related constructs at higher levels in the code hierarchy. Compared to a reuse approach based on fixed blocks, considerable power and area savings can be obtained, as demonstrated on real-life video and modem applications     

Embodiment of emotion concepts.

Theories of embodied cognition hold that higher cognitive processes operate on perceptual symbols and that concept use involves partial reactivations of the sensory-motor states that occur during experience with the world. On this view, the processing of emotion knowledge involves a (partial) reexperience of an emotion, but only when access to the sensory basis of emotion knowledge is required by the task. In 2 experiments, participants judged emotional and neutral concepts corresponding to concrete objects (Experiment 1) and abstract states (Experiment 2) while facial electromyographic activity was recorded from the cheek, brow, eye, and nose regions. Results of both studies show embodiment of specific emotions in an emotion-focused but not a perceptual-focused processing task on the same words. A follow up in Experiment 3, which blocked selective facial expressions, suggests a causal, rather than simply a correlational, role for embodiment in emotion word processing. Experiment 4, using a property generation task, provided support for the conclusion that emotions embodied in conceptual tasks are context-dependent situated simulations rather than associated emotional reactions. Implications for theories of embodied simulation and for emotion theories are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Wear behavior of carbon fiber‐reinforced poly(phenylene sulfide)

On a pin‐on‐disc test rig, online measurements of the wear and friction of steel sliding against carbon fiber‐reinforced polyphenylene sulfide were done. Instead of the standard set‐up, a rotating composite disc and steel pin are used. The frictional behavior of this material pair results in a friction coefficient of 0.33, while a carbide film is formed in the wear track. This results in the lowering of the frictional behavior. The wear rate is rather low, but when the wear track is covered with a carbide film, suddenly the wear rate raises. This is not due to the wear of the composite material but only as a result of the start of terrible wear of the steel counter face. Moreover, the wear of the pin is strongly related to the wear track. The pin is flattened at the sides of the formed wear track, but in contact with the carbide film there is less wear, resulting in a pin with two flat sides, making contact with the original surface, and a rig in the middle of the pin following the roundness of the wear track. The frictional behavior is strongly dependent on the weft‐warp direction. POLYM. COMPOS., 27:92–98, 2006. © 2005 Society of Plastics Engineers     

Stokes-Anti-Stokes Iterative Resonator Method for Modeling Raman Lasers

We present a novel modeling method to describe the steady-state and transient regimes of a continuous-wave pumped Raman laser emitting both Stokes and anti-Stokes photons. Our so-called "Stokes-anti-Stokes iterative resonator method" evaluates for every half round-trip time the longitudinal distribution of the intracavity pump, Stokes and anti-Stokes fields propagating in forward and backward directions. Although this Stokes-anti-Stokes iterative resonator method is widely applicable, its most important asset resides in its ability to accurately model Raman lasers that feature cavity enhancement of the pump power and that emit both Stokes and anti-Stokes photons. Important here is that our modeling method correctly incorporates the longitudinal intracavity field distributions, the generation of anti-Stokes photons, and the interference effects between incident and intracavity pump fields, and that it describes not only the lasers' steady-state operation but also their transient characteristics. We demonstrate for both a hydrogen-based and a silicon-based Raman laser with pump cavity enhancement that the Stokes-anti-Stokes iterative resonator method performs better than the modeling methods presently used for these categories of Raman lasers. Finally, to demonstrate the potentialities of our modeling method, we numerically simulate, for the first time according to our knowledge, the anti-Stokes emission generated by a silicon-based Raman laser     

Remote Attestation on Legacy Operating Systems With Trusted Platform Modules

A lot of progress has been made to secure network communication, e.g., through the use of cryptographic algorithms. However, this offers only a partial solution as long as the communicating end points still suffer from security problems. A number of applications require remote verification of software executing on an untrusted platform. Trusted computing solutions propose to solve this problem through software and hardware changes, typically a secure operating system and the addition of a secure coprocessor respectively. On the other hand, timed execution of code checksum calculations aims for a solution on legacy platforms, but can not provide strong security assurance. We present a mixed solution by using the trusted computing hardware, namely the time stamping functionality of the trusted platform module, in combination with a timing based remote code integrity verification mechanism. In this way, we do not require a secure operating system, but at the same time the overall security of the timed execution scheme can be improved.     

Presurgical columellar elongation and primary retrograde nasal reconstruction in one-stage bilateral cleft lip and nose repair

We present a new combined approach to primary bilateral cleft lip, nose, and alveolus repair using presurgical nasoalveolar molding combined with a one-stage lip, nose, and alveolus repair. Presurgical alveolar molding is used to bring the protruding premaxilla back into proper alignment with the lateral segments in the maxillary arch. Presurgical nasal molding produces tissue expansion of the short columella and nasal lining. A coordinated surgical approach involves a one-stage repair of the lip, nose, and alveolus. The nasal repair uses a retrograde approach in which the prolabial flap and columella are reflected over the nasal dorsum by continuing the dissection behind the prolabium up the membranous septum and over the septal angle. Tissues are dissected out from between the tip cartilages, and the domes are sutured together in the midline. This method joins a new class of bilateral cleft repairs that place the primary emphasis on correction of the deformity of the nasal tip cartilages.     

In situ characterization of leucocyte subpopulations after infection with Eimeria tenella in chickens

We characterized the leucocyte subpopulations after infection with Eimeria tenella in both naive and immune chickens. Immunocytochemical staining was used to characterize the cells in situ, so that the interaction between host and parasite could be studied. More leucocytes were detected in the lamina propria of immune chickens, and leucocytes infiltrated the ceca more rapidly than in naive chickens, but the infiltration was less pronounced than in naive chickens. In naive chickens, most infiltrated leucocytes were macrophages and T cells. Two days after inoculation the number of CD4+ cells had increased greatly. In immune chickens, mainly T cells (CD4+ and CD8+) infiltrated the lamina propria, and in contrast to naive chickens, the number of CD8+ cells exceeded the number of CD4+ cells. Furthermore, we characterized which cells contained a parasite and which cells were detected next to the parasites, because these cells are probably involved in the arrested development of the parasites. In naive chickens, sporozoites were significantly more often located within or next to macrophages than in immune chickens. In immune chickens, sporozoites were significantly more often located within or next to CD3+, CD8+, and TCR2+ cells. In conclusion, the marked increase of CD4+ cells after primary infection suggests that these cells are involved in the induction of the immune response, whereas the increase of CD8+ cells after challenge infection suggests that these cells act as effector cells.