几种铜带轧制润滑剂的性能评价与研究

对收集到的７种国内外铜带轧制润滑剂进行了基础性能测试，并对其工艺使用性能进行了评价研究，其结果将为有关工厂润滑剂的选用与研制提供一些依据。     

Effect of chitosan and Dysphania ambrosioides on the bone regeneration process: A randomized controlled trial in an animal model

The focus of this triple‐blind study was on evaluating the effect of chitosan combined with Dysphania ambrosioides (A) extract on the bone repair process in vivo. In total, 60 male Wistar rats (Rattus norvegicus albinus) weighing between 260 and 270 g were randomly selected for this study and distributed into four groups (n = 15). Group C (chitosan), Group CA5 (chitosan + 5% of D. ambrosioides), Group CA20 (chitosan + 20% of D. ambrosioides), and Group CO (Control‐Blood clot). In each animal, bone defects measuring 2 mm in diameter were performed in both tibias for placement of the substances. After 7, 15, and 30 days, the animals were sedated and sacrificed using the cervical dislocation technique and the tissues were analyzed under optical microscope relative to the following events: inflammatory infiltrate, necrosis, osteoclasts, osteoblasts, fibroblasts, periosteal, and endosteal bone formation. The data were evaluated to verify distribution using the Kolmogorov–Smirnov test, and variance, using the Levene test; as distribution was not normal, data were subjected to the Kruskal–Wallis and Dunn nonparametric tests (p < .05). A significant inflammatory infiltrate was observed in Group CA5 (p = .008) in the time interval of 7 days, and in Group C at 15 (p = .009) and 30 (p = .017) days. Osteoblastic activity was more significant in Group CA20 (p = .027) compared with CA5 in the time interval of 7 days. Group CA20 demonstrated a significantly higher endosteal and periosteal bone formation value in the time interval of 7 (p = .013), 15 (p = .004), and 30 days (p = .008) compared with the other groups. The null hypothesis was refuted, bone regeneration was faster in spheres with an association of chitosan and 20% extract, and complete bone repair occurred clinically at 15 days and histologically at 30 days. The spheres proved to be a promising method for the biostimulation of alveolar bone repair and bone fractures.     

基于弯曲板波的延迟线振荡器的ANSYS仿真

针对复合板结构中弯曲板波谐振频率计算相对复杂的问题,建立并分析了基于弯曲板波延迟线振荡器的理论模型,计算得到A0(0阶反对称)模式板波的谐振频率为41 MHz;为了验证理论分析的结果,利用有限元软件ANSYS建立了基于弯曲板波的延迟线振荡器的3D有限元模型,并对其进行了谐响应分析以及瞬态动力学分析。谐响应分析得到A0模式的谐振频率为37.2 MHz,与理论计算结果的相对误差为9.3%;瞬态动力学分析得到A0模式的谐振频率为39.1 MHz,与理论计算结果的相对误差为4.6%。计算和仿真为基于弯曲板波的延迟线振荡器的结构设计提供了重要的依据。     

The Creation of Play Spaces in Twentieth-century Amsterdam: From an Intervention of Civil Actors to a Public Policy

This case study uncovers a turning point in the production of play space in Amsterdam. Whereas over the first half of the twentieth century the creation of play spaces used to be the primary responsibility of the Amsterdam civil society, this situation started to change after the Second World War. Between 1947 and 1970, the Amsterdam Urban Planning Department created over 700 public play spaces. These spaces were little niches in the urban public domain, specifically designed and constructed to enable city children's play. This remarkable change from a predominantly private to a public intervention, is explained through a rapid increase of the number of children (the post-war baby-boom), the existence of the General Extension Plan (AUP) with its detailed age specific approach and the fruitful collaboration between powerful urban planners and politically dominant socialist politicians.     

靖边气田马五段碳酸盐岩层序地层研究

鄂尔多斯盆地聚集了丰富的石油天然气资源,靖边气田就是该盆地发现的特大型气田。储集层类型为下古生界奥陶系古风化壳型,其主力含气层为马家沟组第五段。吸收了前人关于储层地质方面研究的大量成果,从高分辨率层序地层学的角度,研究奥陶系马家沟组马五,一马五,亚段风化壳储层,并展开以准层序级别的层序地层格架分析研究,在此基础上探讨了高分辨率层序地层格架中风化壳的储层特征和天然气藏聚集模式。     

Myo-Inositol Limits Kainic Acid-Induced Epileptogenesis in Rats

Epilepsy is a severe neurological disease characterized by spontaneous recurrent seizures (SRS). A complex pathophysiological process referred to as epileptogenesis transforms a normal brain into an epileptic one. Prevention of epileptogenesis is a subject of intensive research. Currently, there are no clinically approved drugs that can act as preventive medication. Our previous studies have revealed highly promising antiepileptogenic properties of a compound–myo-inositol (MI) and the present research broadens previous results and demonstrates the long-term disease-modifying effect of this drug, as well as the amelioration of cognitive comorbidities. For the first time, we show that long-term treatment with MI: (i) decreases the frequency and duration of electrographic SRS in the hippocampus; (ii) has an ameliorating effect on spatial learning and memory deficit associated with epileptogenesis, and (iii) attenuates cell loss in the hippocampus. MI treatment also alters the expression of the glial fibrillary acidic protein, LRRC8A subunit of volume-regulated anion channels, and protein tyrosine phosphatase receptor type R, all expected to counteract the epileptogenesis. All these effects are still present even 4 weeks after MI treatment ceased. This suggests that MI may exert multiple actions on various epileptogenesis-associated changes in the brain and, therefore, could be considered as a candidate target for prevention of epileptogenesis.     

分子筛吸附分离混合氯甲苯的研究

本文简要地介绍了用分子筛吸附分离氯甲苯异构体混合物的研究过程及其结果。操作是在以 ZSM——型分子筛为吸附剂的固定床层中进行的,以甲苯为脱吸剂。经小型实验,确定了适宜的操作条件和主要参数。分离后可获得纯度为97%的对氯甲苯。     

Effect of length on the fundamental resonance frequency of arterial models having radial dilatation

The pressure wave moving along an elastic artery filled with blood was examined as a moving Windkessel having a natural oscillation angular frequency nu 0 and a damping coefficient b. The radial directional motion for an element of the wall segment and the adherent fluid was considered. This equation was solved with conditions at both ends of an artery of length L. An external impulse force was applied at one end and a static pressure Po at the other. Analytic solution allowed only certain oscillation modes of resonance frequencies fn, where fn2 = a + cnL-2 with [formula: see text] and V infinity is the high frequency phase velocity. The relationship between f0 and L was examined experimentally for tubes constructed of latex, rubber, or dissected aorta. The effect of raising the static pressure P0 or increasing the tension in the tube was consistent with the prediction. The hypertension that accompanies an augmentation in arterial wall and the association between the heart rate and the mean blood pressure were discussed.     

Spatial and temporal sequence of events in cell adhesion: from molecular recognition to focal adhesion assembly

A new concept that attributes a pivotal role to the pericellular coat in the regulation of the early stages of cell adhesion is presented. Quick, adaptable, and transient adhesion through multiple cooperative weak interactions provides the cell with an additional level of modulation in the decision-making process that precedes the commitment to adhesion at a particular site. Hyaluronan emerges as a modulator of cell adhesion in certain cells, mediating binding or repulsion through its polyelectrolyte character, in addition to its chirality and molecular-recognition properties. The biophysical properties of hyaluronan as well as its ultrastructural organization are analyzed in relation to this proposed function.