摘要： 郭米 进入祁连县扎麻什乡郭米村时,首先是雪山吸引了我.一个一年四季都能看到雪山的人,见到雪山还要大惊小怪,有些不可思议,大约平时所见的雪山也不过是虾米级别的,此时的雪山才算雪山.路追着雪山走,路蜿蜒,或者笔直,雪山都蹲踞天边,岿然不动.路更像雪山甩出的鞭子,灰色细鞭抽在大地上,溅起的是庄廓、羊群和大片森林.可惜森林尚未变绿,草地还在枯黄,云杉的叶子看上去更像黑色的缝衣针.羊身上却是千干净净的白,刚洗过一样,小羊羔跟着羊妈妈啃草,也不知是真的啃还是学学样子.河流在公路一侧.这是黑河的下游,我们向西,河流向东.

关键词： Hybrid membranes   MOF-801   Proton exchange membranes   Structural defects   Sulfonated poly (arylene ether ketone sulfone)  

摘要： Metal-organic frameworks are new kinds of porous crystalline materials. The Zr-based metal-organic framework (MOF-801) is consists of [Zr-6(u(3)-O)(4)(u(3)-OH)(4)](12+) clusters and fumaric acid connectors. MOF-801 has excellent mechanical properties, high chemical stability and high water absorption capacity. There are a large number of hydrophilic functional groups inside MOF-801, which is effective to promote interfacial compatibility between MOF-801 and polymer matrixes. In this work, the MOF-801 with structural defects was synthesized through the solvothermal method by adding excess formic acids as the regulator. These structural defects could confer MOF-801 high surface area (2476.34 m(2) g(-1)) and promote the water absorption capacity. Moreover, structural defects could also expose more open metal sites of MOF-801, thereby increasing the Lewis acidity of MOF-801. Then, the hybrid membranes were synthesized by combining the MOF-801 with structural defects and C-SPAEKS. Dense hydrogen-bond networks formed between the MOF-801 and C-SPAEKS further promote enhance proton conductivity. At the condition of 90 degrees C and 100% relative humidity, the highest proton conductivity of hybrid membranes reached 0.100 S cm(-1), which is similar to that of Nafion 117. Meanwhile, these hybrid membranes showed outstanding chemical and thermal stabilities. These results indicate that these hybrid membranes have potential as proton exchange membranes. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

关键词： Angiogenesis   chemotherapy   chorioallantoic membrane   nanomedicine   radiotherapy   tumor models  

摘要： Introduction: Advancements in cancer management and treatment are associated with strong preclinical research data, in which reliable cancer models are demanded. Indeed, inconsistent preclinical findings and stringent regulations following the 3Rs principle of reduction, refinement, and replacement of conventional animal models currently pose challenges in the development and translation of efficient technologies. The chick embryo chorioallantoic membrane (CAM) is a system for the evaluation of treatment effects on the vasculature, therefore suitable for studies on angiogenesis. Apart from vascular effects, the model is now increasingly employed as a preclinical cancer model following tumor-grafting procedures. Areas covered: The broad application of CAM tumor model is highlighted along with the methods for analyzing the neoplasm and vascular system. The presented and cited investigations focus on cancer biology and treatment, encompassing both conventional and emerging nanomaterial-based modalities. Expert opinion: The CAM tumor model finds increased significance given the influences of angiogenesis and the tumor microenvironment in cancer behavior, then providing a qualified miniature system for oncological research. Ultimately, the establishment and increased employment of such a model may resolve some of the limitations present in the standard preclinical tumor models, thereby redefining the preclinical research workflow.

关键词： Volatilization   Determination method   Auxinic herbicides   Vapor phase   Strata-X (R)  

摘要： The present study aimed to evaluate the Strata-X (R) sorbent, commonly used in cartridges, through analysis by high-performance liquid chromatography coupled with mass spectrometry. Due to the different physical-chemical characteristics of the compounds, different conditions of chromatography and mass analysis were necessary. The developed methods were validated in terms of selectivity, linear range, linearity (coefficient of determination, r(2)), the limit of detection (LOD), the limit of quantification (LOQ), accuracy (recovery, %), and precision (RSD, %). The results allowed us to select efficient extraction methods, using methanol acidified to pH 2 with formic acid, to elute the herbicides 2,4-D and dicamba in both sorbent materials. Besides, the Strata-X (R)) sorbent was efficient in the sorption of analytes;thus, we indicate it for potential use in air sampling as an alternative to XAD-2.

关键词： 女排   副攻   拦网   效果  

摘要： 随着现代排球的日益发展,攻防转换越来越迅速,副攻手在排球赛场上的攻拦环节主导着重要地位,其拦网的成功率对比赛的胜负起着至关重要的作用。本文以中国女排与前四其他队伍副攻拦网效果为研究对象,利用文献资料法、录像观察法、数理统计法等研究方法,对中国女排副攻与前四名其他队伍副攻在2号位、3号位和4号位的拦网中,对于拦死、拦起、拦回及拦失的效果进行了比较,找出中国女排副攻与四强其他队伍副攻拦网的优劣势,为今后的训练与比赛作参考依据。

关键词： 手足口病   EV71   CoxA16   其他肠道病毒   基因型分析  

摘要： 目的探究2018—2020年平顶山市新华区手足口患儿EV71、CoxA16和其他肠道病毒感染情况及基因型状况。方法选择平顶山市新华区疾病预防控制中心2018年7月至2020年12月收治的104例手足口病患儿作为研究对象,通过患儿粪便及肛拭子标本对患儿病毒核酸进行检测,观察患儿肠道病毒病原学构成情况及分析患儿EV71病毒及CoxA16病毒VP1基因中各基因型同源性,并记录手足口病患儿临床症状表现及外周血白细胞水平。结果104例手足口病阳性样本中,EV71病毒感染54例(51.92%),CoxA16病毒感染7例(6.73%),其他肠道病毒感染43例(41.35%),EV71病毒感染比例高于CoxA16病毒感染比例,差异有统计学意义(P<0.05);CoxA16 VP1基因序列与A、B、C基因型代表株核苷酸同源性为82.6%~82.9%,与D基因型代表株核苷酸同源性为92.7%~99.2%;EV71 VP1基因序列与C4基因型代表株核酸同源性为92.4%~96.8%,与C4a基因型代表株核苷酸同源性为94.3%~96.8%,与C4b基因型代表株核苷酸同源性为92.4%~93.7%;EV71病毒、CoxA16病毒及其他肠道病毒感染组之间发热、皮疹等临床症状所占比例及外周血白细胞水平比较,差异均无统计学意义(P>0.05)。结论手足口病患儿中EV71病毒感染比例相比于CoxA16病毒感染比例更高;且CoxA16及EV71 VP1基因序列均存在高同源性的病毒株;但各病毒株感染后临床症状表现几乎一致。

关键词： 百工   文化身份   游于百工  

摘要： 葛亮“匠传”系列小说《书匠》《飞发》《瓦猫》以《瓦猫》为题结集出版。“书”与“修复”是《书匠》的核心情节;《飞发》借香港理发师技艺、理念之争,继续上海香港南北之争的双城故事;《瓦猫》以西南联大的抗战大历史诠释民间技艺与近代科学精神的融合过程。传统“百工”面临“现代”困境,“百工”而“可游”,意味着传统工艺、民间艺术在现代化、全球化时代的文化适应,昭示出未完成的线性现代性的某种回环路径:在流动、越界中完成代际的精神传承与工艺创新,重建流动时代跨文化社会中,“物”与“人”之关系,思考后物质时代人类的未来。

关键词： Mass timber buildings   Structural robustness   High fidelity model   Progressive collapse   Structural integrity   Component model  

摘要： Multi-storey buildings require mitigation of consequences of unexpected or accidental events, to prevent disproportionate collapse after an initial damage. Cross-laminated timber (CLT) in platform-type construction is increasingly used for multi-storey buildings, however, the collapse behaviour and alternative load paths (ALPs) are not fully understood. A 3D non-linear component-based finite element model was developed for a platformtype CLT floor system to study the ALPs after an internal wall loss, in a pushdown analysis. The model, which accounted for connection failure, timber crushing and large displacements, was calibrated to experimental results and then adapted for boundary conditions corresponding to typical residential and office buildings. Subsequently, five parameters (floor span, connection type, vertical location of the floor, tying level, horizontal wall stiffness) were varied, to study their effects on the ALPs in 80 models. The results showed that three ALPs occurred, of which catenary action was the most dominant. Collapse resistance was mainly affected by the floor span, followed by the axial strength, stiffness and ductility of the floor-to-floor connection, the weight of the level above and the floor panel thickness. This study provides an approach to model ALPs in a platform-type CLT floor system to design disproportionate collapse resistant multi-storey CLT buildings.

关键词： 《洛阳伽蓝记》   异体字   异构字   汉字构形学   佛经  

摘要： 《洛阳伽蓝记》是北魏抚军司马杨衒之在战后重归故都洛阳,因感慨时局变迁物是人非,为追忆昔时佛教盛景所作的一部集佛教、历史、地理、文学于一体的经典著作。由于详细记叙旧时见闻以及对佛教文化,因其所记载内容的详实性使得其在北魏佛教文化研究领域成为第一手资料。文章主要研究《伽蓝记》中的异构字,通过考察其在其他古籍中的使用情况及根据上下文意义,推断出原文本字及产生文字异变的原因。最后认为,《伽蓝记》异文中异构字产生原因多样且数量众多,但具有一定的系统性与可考性,对异构字产生原因的研究和对佛经整理可提供一定参考价值。