劳动教育是中国特色社会主义教育制度的重要内容,有深厚的理论渊源.高校开展劳动教育既有马克思主义经典作家对劳动重要性的论述作为理论支撑,也符合当前实现中华民族伟大复兴中国梦的现实国情.推进高校劳动教育的着力点在于开展劳动教育之前应当加强学生对劳动教育的认同;在劳动教育的过程中应当完善劳动教育保障机制,在劳动教育完成之后对学生做出正确的评价.以此帮助学生形成正确的劳动价值观,促进学生全面发展.

欧洲板坯连铸供货商为某钢厂建造的宽厚板坯连铸机,在生产中板坯振痕深度较深、铸坯外弧角裂明显,因外弧角裂引起的漏钢事故经常出现,严重影响连铸机的生产秩序和铸坯质量.通过对结晶器和垂直段对弧结构、液压振动、垂直段和弯曲段之间对弧结构等设备的改造以及振动工艺优化,改善了铸坯深振痕、外弧角裂等问题,漏钢事故也基本消失,铸坯质量大幅度提高,铸坯收得率提高0.4％,大大提高了企业的经济效益.

OBJECTIVE: The aim of this study was to investigate the effects of regulation of micro-ribonucleic acid (miR)-146 expression targeting the Notch1 pathway on the repair and regeneration of intervertebral nucleus pulposus cells, and to explore the possible underlying mechanism. MATERIALS AND METHODS: Intervertebral nucleus pulposus cells were harvested from rats and cultured in vitro. All cells were randomly divided into 4 groups, including the normal group, the miR-146 inhibitor group, the miR-146 over-expression group and the negative control group. The cells in the normal group were cultured normally. Meanwhile, the cells in the miR-146 inhibitor group and miR-146 over-expression group were transfected with inhibitor-containing plasmid and miR-146-containing plasmid, respectively. However, the cells in the negative control group were transfected with empty plasmid. 24 h after transfection, the cells were collected for subsequent experiments. The differentiation of nucleus pulposus cells was detected via toluidine blue staining. The relative protein expression levels of Notch1, aggrecan (ACAN) and COL II were detected via Western blotting. Meanwhile, the mRNA expressions of miR-146 and Notch1 were detected via quantitative Polymerase Chain Reaction (qPCR). Furthermore, the apoptosis and proliferation of cells were detected via terminal deoxynucleotidyl transferase-mediated dUTP Nick End Labeling (TUNEL) and Cell Counting Kit-8 (CCK-8; Dojindo, Kumamoto, Japan) assay, respectively. RESULTS: Compared with the normal group, toluidine blue positive staining was significantly increased in miR-146 overexpression group (p<0.05), whereas was significantly decreased in the miR-146 inhibitor group (p<0.05). The results of Western blotting revealed that compared with normal group, the protein expression of Notch1 was markedly decreased in miR-146 over-expression group (p<0.05), whereas the expression levels of ACAN and COL II were notably increased (p<0.05). However, the miR-146 inhibitor group exhibited significantly increased the protein expression level of Notch1 (p<0.05), as well as markedly decreased the expressions of ACAN and COL II (p<0.05). The results of qPCR showed that compared with the normal group, the expression level of miR-146 was significantly increased in the miR-146 over-expression group. However, the mRNA expression level of Notch1 was remarkably decreased (p<0.05). Similarly, the miR-146 inhibitor group exhibited significantly decreased expression level of miR-146, as well as markedly increased mRNA expression level of Notch1 (p<0.05). Compared with those in the normal group, the cell proliferation rate was markedly increased, whereas cell apoptosis was remarkably decreased (p<0.05) in the miR-146 over-expression group. Furthermore, the cell proliferation rate was significantly decreased, while the cell apoptosis was remarkably increased (p<0.05) in the miR-146 inhibitor group. CONCLUSIONS: Regulating miR-146 expression can target the Notch1 signaling pathway, thereby exerting important influences on the repair and regeneration of intervertebral nucleus pulposus cells.

Objective To examine the influence of mesenchymal stem cell (MSC) intrathecal transplantation on spinal cord phosphorylate extracellular signal-regulated kinases 1/2 (pERK1/2) expression and neural function in rats with spinal cord ischemia/reperfusion injury (SCII). Methods Fifty SD rats were subjected to SCII. They were divided into 5 groups (n=10):① SCII without additional treatment. ② SCII with intrathecal microinjection of PBS. ③ SCI with intrathecal transplantation of MSC in PBS. ④ SCII with intrathecal transplantation of MSCs in PBS+intravenous injection of U0126 (200 μg/kg) in dimethyl sulfoxide (DMSO). ⑤ SCII with intrathecal transplantation of MSC and intravenous injection of DMSO. Two days after SCII, neural function was assessed with Basso, Beattie & Bresnahan locomotor rating scale (BBB) and somatosensory potentials evoked by lower limb stimulation. After assessment, pERK1/2 expressions in the spinal cord were assayed with immunohistochemistry and western blot. Results Intrathecal transplantation of MSC elevated the levels of pERK1/2 in the spinal cord, and improved BBB scores, and improved incubation period and amplitude of somatosensory evoked potential (SSEP). However, ERK1/2 specific inhibitor U0126 blocked ERK1/2 phosphorylation, and attenuated recovery of spinal cord function after intrathecal transplantation of MSC. Conclusions Intrathecal transplantation of MSC may an effective therapeutic strategy to improve recovery of spinal cord function after SCII. pERK1/2 may involve in circuit interaction of MSC with spinal cord.

BACKGROUND We investigated whether an intrathecal transplantation of mesenchymal stem cells (MSCs) activates extracellular adjusting protein kinase1 and 2(ERK1/2) in the spinal cords of rats following an ischemia-reperfusion injury, resulting in improved spinal cord function and inhibition of apoptosis. MATERIAL AND METHODS We observed the relationship between the activation of ERK1/2 in the rat spinal cord and intrathecal transplantation of MSCs, as well as the effect of U0126, a MEK1/2 (upstream protein of ERK1/2) inhibitor, on a spinal cord ischemia-reperfusion injury model in rats using Basso Beattie Bresnahan (BBB) scoring, somatosensory evoked potentials (SSEPs), immunohistochemistry, and Western blot analysis. RESULTS After transplantation of MSCs, the lower limb motor function score increased, and the incubation period of SSEPs and amplitude were improved. Moreover, following transplantation of MSCs, Bcl2 expression increased, whereas Bax expression decreased after reperfusion. Transplantation of MSCs significantly enhanced pERK1/2 expression in the spinal cord, as well as pERK1/2 in immunoreactive cells located in the grey matter of the L4/5 levels of the spinal cord, following ischemia reperfusion injury in rats. The effective dose of U0126 required to inhibit pERK1/2 expression was 200 µg/kg. Bcl-2 decreased and the level of Bax expression increased in the spinal cord after ischemia reperfusion injury, and the protective effects of MSCs were attenuated. CONCLUSIONS Our findings suggest that intrathecal transplantation of MSCs activates ERK1/2 in the spinal cord following ischemia reperfusion injury, partially improves spinal cord function, and inhibits apoptosis in rats.

In order to realize the efficient development of shale gas reservoirs,hydraulic fracturing has been obtained the widespread application in the development process of shale gas reservoirs. However,the reservoir is difficult to be completely open in practice because the thickness of the shale gas reservoir is always large. Therefore,according to the characteristics of desorption,diffusion and seepage,a productivity model of partial open fractured wells in shale gas reservoirs has been established.And the productivity model was calculated by using Laplace transform,Fourier transform and the principle of Duhamel in combination with Stehfest numerical inversion algorithm. The productivity decline curves of partial open fractured wells in shale gas reservoirs were plotted. The influences of the open degree,the desorption coefficient,the dimensionless storativity ratio,the dimensionless desorption time and the center position of the crack on the productivity decline curves were analyzed. The study shows that the larger the open degree is,the larger the output of a partial open fractured well is,and the larger the desorption coefficient is,the larger the desorption quantity is,the slower the output degression speed of a partial open fractured well in a shale gas reservoir becomes. The starting time of desorption depends on the magnitude of the dimensionless desorption time. The smaller the dimensionless desorption time is,the earlier the starting time of desorption becomes. The center position of the crack has influence on the productivity decline curves of partial open fractured wells in shale gas reservoirs. The smaller the distance between the center position of the crack and the center position of the reservoir is,the slower the output degression speed of a partial open fractured well becomes. Therefore,it is important for implementing the hydraulic fracturing to increase the open degree and make the center position of the crack near the center position of the reservoir.

By establishing evaluation indexes of optimal exhaustion of coal resource,the paper calculated and evaluated depletion condition of coal resource in China from 1999 to 2008 using DEA.The result can provide some valuable information for decision-makers.

神华宁夏煤业集团羊场湾煤矿6.2 m大采高工作面煤层倾角达8°～20°,走向起伏角为8°～12°;其工作面赋存条件之复杂在国内外大采高开采领域很少见.根据工作面生产布局和开采现状,综合考虑了设备因素、经济因素及安全等因素.通过建立长度优化力学模型并运用非线性规划法和工程类比法手段初步对大采高工作面长进行了论证和分析.结果表明,大采高工作面最佳优化长度在经济上存在的合理值并非越大越好,在采高为6.2 m的条件下,工作面长度选取300 m较为合理.

Safety benefit has been analysed and it has been considered that should be acounted in coal mining rights valuation. After estimated appreciation benefit,social benefit and environmental benefit using the method of contribution rate of technological progress and AHP,we have drawn a conclusion that the safety benefit taken into account in coal mining rights valuation is 3.4% of coal GDP.

In continues casting steel process the distortion of the water cooling mould inner wall followed the metal superplasticity distortion theory. The thrust force of hydraulic cylinder for the online mould width adjustment was calculated according to the metal superplasticity distortion theory,and the mathematical model of the speed of the mould width adjustment was proposed. The functional relations between the casting speed and the speed of mould width adjustment and the method of calculating the force of hydraulic cylinders for the online mould width adjustment were obtained.

The water inrush coefficient related to the 5 holes drilled to the Ordovician was obtained at Jingfu Ba chigou coal mine,through analysis of hydrogeologic conditions and numerical calculation made by water inrush coefficient theory.According to the statistical analysis of national wide mine-water inrush information,and the geological conditions of underground aquifuge at Bachigou coal mine,the 0.1 MPa/m critical water inrush coefficient is determined,and hence a conclusion is reached,that is,the 8-2 coal seam floor has water inrush risks during mining.Based on the coefficient figures of the 5 holes,the 8-2 coal seam could be divided into two areas,that is,the safe area and the dangerous area.

<等温线分析与实验>针对imJRWS砼绝热温升试验系统的具体结构,根据设计要求,进行了大量反复实验,对于数据进行了全面系统分析。其结论是,实验数据表明,设计原理正确,是符合DL/T5150-2001的试验规范,由该理论制造的imJRWS601砼绝热温升试验系统可以广泛用于混凝土热特性参数的测定。

currently some obvious defects can be found in existing double flat thermal conductivity instrument such as long time measuring,complicated operation etc.To solve these problems,we developed a new instrument with ARM as its MCU,which can achieve full automatic controlling,data collection,processing and calculating thermal conductivity coefficient,as well as displaying and printing measuring results by using embedded real time operation system OS C/OS-Ⅱ and friendly interface.The measuring precision of this instrument meets the requirements of the nation standard,and the intelligent instrument also shows its superiority in measuring time,accuracy,automatic degree and size aspects,which contributes itself capable of broad use in heat-resistant and preservation materials companies,relevant quality assessment departments,colleges and research institutes.

The choice of proper parameters and structure contributes to the heat diffusion and mechanical strength of the concaster mould.This paper presents the chief parameters of slab concaster mould and proposes the optimum design of the relevant equipment.It provides scientific basis for the design and operation of the concaster mould.

This article introduces the existing problems of the No.1 slab caster mould at Meishan Iron Steel Co.,Ltd.some revamping methods are introduced,and the mould structure characteristics,cooling and sealing effect of the mould before and after the revamping are presented and compared.

本文探讨了防紫外布料的测试方法,从大气的紫外特性及皮肤对紫外的生理反应出发,提出了防紫外布料的特征参量,为抗紫外布料定标提供依据.