三维正交纤维增强复合材料箱梁结构机织法与成型工艺研究

本文主要介绍三维正交纤维增强复合材料箱梁结构机织物的织造方法,阐述了纤维增强复合材料在织造过程中形成一向平纹(1/1)一向(1/2)斜纹三维正交织物的织造方法,并在Pro/E软件里建立箱梁结构机织物预制件的几何模型,详细介绍了箱梁结构机织物预制件的成型工艺。为研究箱梁结构复合材料机织物预制件的织造方法、成型工艺和力学特性设计计算打下了良好基础;为开发纤维增强复合材料箱梁结构新产品提供了一个有效途径。

Gliomatosis Cerebri

Gliomatosis Cerebri （GC） is a rare tumor of the central nervous system. It is defined as a diffuse glial tumor that extensively infiltrates the brain, involving more than two lobes. And it is listed as a subtype of astrocytic tumors according to the newest 2007 （4th edition） WHO classification of tumors of the Central Nervous System. GC can be subdivided into Type I and Type II. Clinical findings for patients with GC are usually subtle and nonspecific. The lesions of GC generally show hypo, or isodensity on CT; a poorly defined diffuse hypoor isointense signal on Tl-weighted images, and a scattered diffuse hyperintense signal on T2-weighted images. Histological examination of GC reveals widespread infiltration of neoplastic glial cells with minimal destruction of pre-existing structures. Diagnosis of GC can be ascertained on the basis of a combination of clinical, radiological and pathological data. The treatment of GC includes radiotherapy and chemotherapy; however, the optimal therapeutic strategy is still not well established and prognosis of GC remains poor. This report reviews in detail the aspects of GC mentioned above, and three controversial issues are also discussed in the report.

Inhibition of high-mobility group box 1 expression by siRNA in rat hepatic stellate cells

AIM:To explore the role of high-mobility group box 1 (HMGB1) protein during liver fibrogenesis and investigate the functional effects of HMGB1 gene silencing in hepatic stellate cells (HSCs) using siRNA.METHODS:Hepatic fibrosis in rats was induced through serial subcutaneous injections of dimethylnitrosamine,and expression of HMGB1 was detected by immunohistochemistry.HMGB1 siRNAs were developed and transiently transfected into HSC-T6 cells using Lipofectamine 2000.HMGB1 expression was evaluated by real-time polymerase chain reaction (PCR) and Western blotting analysis.Expression of α-smooth muscle actin (α-SMA) and collagen typesⅠand Ⅲ was evaluated by real-time PCR.Cell proliferation and the cell cycle were determined using the methyl thiazolyl tetrazolium method.Finally,collagen content in HSC supernatant was evaluated by an enzyme-linked immunosorbent assay.RESULTS:The results showed that HMGB1 was upregulated during liver fibrosis and that its expression was closely correlated with the deposition of collagen.siRNA molecules were successfully transfected into HSCs and induced inhibition of HMGB1 expression in a time-dependent manner.Moreover,HMGB1 siRNA treatment inhibited synthesis of α-SMA and collagen types Ⅰ and Ⅲ in transfected HSCs.CONCLUSION:This study suggests a significant functional role for HMGB1 in the development of liver fibrosis.It also demonstrates that downregulation of HMGB1 expression might be a potential strategy to treat liver fibrosis.

Fault diagnosis of rocket engine ground testing bed with self-organizing maps(SOMs)

To solve the fault diagnosis problem of liquid propellant rocket engine ground testing bed,a fault diagnosis approach based on self-organizing map(SOM)is proposed.The SOM projects the multidimensional ground testing bed data into a two-dimensional map.Visualization of the SOM is used to cluster the ground testing bed data.The out map of the SOM is divided to several regions.Each region is represented for one fault mode.The fault mode of testing data is determined according to the region of their labels belonged to.The method is evaluated using the testing data of a liquid-propellant rocket engine ground testing bed with sixteen fault states.The results show that it is a reliable and effective method for fault diagnosis with good visualization property.

Spatial Organization Mechanism of Aircraft Manufacturing

Unquestionably,aircraft industry plays an important part in both economy and security of a nation.However,few of articles have dealt with the spatial development of this industry sector.The purpose of this article is to analyze the dynamics of agglomeration and diffusion of aircraft industry.In a historical view,with some spatial analysis methods,this research discusses the characteristics and patterns of aircraft industry's spatial organization and evolution,globally,nationally and regionally respectively.We find out there is a ‘Matthew effect' in aircraft industry of the world,and the spatial evolution of the industry is consistent with the nation's industrialization process.Then,it concludes that the main agglomeration forces consist of capital,talents,technology and cluster's advantages,and the main diffusion forces include comparative advantages,cost and risk sharing,emerging markets,development policy for backward regions and military requirements.All the factors can be divided into market forces making the spatial development of aircraft industry normal and non-market forces making that irregular.In particular,lessons from the USA and France are expected to be conducive to the rise of China's aircraft industry in the future.

Structural effects of three-dimensional angle-interlock woven composite undergoing bending cyclic loading

This paper reports the structural effects of three-dimensional(3-D)angle-interlock woven composite(3DAWC)undergoing three-point bending cyclic loading from experimental and finite element analysis(FEA)approaches.In experiment,the fatigue tests were conducted to measure the bending deflection and to observe the damage morphologies.By the FEA approach,a micro-structural unit-cell model of the 3DAWC was established at the yarn level to simulate the fatigue damage.The stress degradation at the loading condition of constant deformation amplitude was calculated to show the degradation of mechanical properties.In addition,the stress distribution,fatigue damage evolution and critical damage regions were also obtained to qualitatively reveal the structural effects and damage mechanisms of the 3DAWC subjected to three-point bending cyclic loading.

Study on the Mechanism of Xiaotan Sanjie Recipe for Inhibiting Proliferation of Gastric Cancer Cells

Objective:To explore the mechanism of Xiaotan Sanjie Recipe (XtSjR, Recipe for dissolving phlegm to eliminate stagnation) in inhibiting proliferation of gastric cancer cells. Methods: The nude mouse human gastric cancer MKN-45 in situ transplantation tumor model was established by use of OB glue, and 40 model mice were randomized into 5 groups, model group, low-dose XtSjR group, middle-dose XtSjR group, high-dose XtSjR group, and 5-Fu group, 8 rats in each group. Human gastric cancer MKN-45 telomerase reverse transcriptase (hTERT) protein and mRNA expressions were assayed by immunohistochemical method and real-time fluorescence quantitative RT-PCR, and influences of XtSjR on the expressions of hTERT protein and mRNA were investigated in the nude mouse human gastric cancer MKN-45 in situ tumor transplantation model. Results: 1) There were significant differences in the mean tumor weight between the low-, middle-, high-dose XtSjR groups and the model group (all P<0.01); 2) There were significant differences in the hTERT positive expression rate between the middle-and high-dose XtSjR groups and the model group (P<0.05 or P<0.01); 3) There were significant differences in the hTERT mRNA content between the middle-and high-dose XtSjR groups and the model group (P<0.05 or P<0.01). Conclusion: 1) XtSjR has a marked inhibitory effect on the growth of gastric cancer cells; 2) XtSjR inhibits telomerase activity by down-regulating the expressions of hTERT protein and mRNA, shortening the length of cancer cell telomeres gradually, losing the ability to infinitely proliferate, and finally inhibiting the growth and proliferation of tumor cells.

Functional mechanism of Pingchuanning Decoction on adjustment of clara cell secretory protein in airway remodeling of asthmatic rats

OBJECTIVE:To study the functional mechanism of Pingchuanning Decoction in treatment of airway remodeling in asthmatic rats.METHODS:Eighty healthy Wistar male rats were randomized into eight groups(n=10 rats each):Normal group,Asthma model group,Dexamethasone group,Guilong Kechuanning group,Xiaoqinglong Decoction group,and Pingchuanning Decoction low-,middle-,and high-dose groups.The rats of all but the Normal group were made into asthma models through intraperitoneal injection and aerosol inhalation of ovalbumin.All treatments were administered at the first stimulation of asthma onset(third week of modeling),and the rats were killed after stimulating asthma attacks for 4 weeks.The general conditions of rats and pathomorphological changes of the lung tissues were observed.The expression of nerve growth factor(NGF) of the lung tissues was measured with immunohistochemical methods,and the content of Clara cell secretory protein(CCSP) mRNA was determined with RT-PCR.RESULTS:Compared with the Normal group,the contents of NGF and CCSP mRNA in the lung tissues of the Model group were significantly changed(P<0.01).Compared with the Model group,the indices of Pingchuanning Decoction and other treatment groups were improved to some extent(P<0.05 or P<0.01).CONCLUSIONS:Pathological changes of airway inflammation and remodeling were present in these rat asthma models.Pingchuanning Decoction had an intervention effect on these experimental models.Its functional mechanism may be related to multiple factors,including alleviation of airway inflammation,relief of bronchial smooth muscle spasm,and inhibition of airway remodeling.