多排钢管冲击波压扁行为研究

多排钢管吸能元件在冲击波作用下的大变形问题，对于抗爆结构的吸能装置设计具有重要意义。在单个钢管的动力压扁过程清楚的基础上，根据实验分析了多排钢管受径向冲击塑性行为，建立了八塑性铰机构，描述了钢管压扁位移速度场。给出了塑性铰附近的塑性弯矩值计算方法。     

Calcium Treatment to Maintain Quality of Zucchini Squash Slices

Zucchini squash slices dipped in solutions of CaCl₂ alone or with chlorine were stored at 0°C, 5°C, and 10°C. Slices developed water soaked areas (chilling injury) at 0°C and brown discoloration at 5°C and 10°C, which increased with storage. The amount and severity of chilling injury/browning/decay of water-dipped controls were least at 5°C. Calcium treatments helped in reducing development of decay, rate of total microbial growth, ascorbic acid loss, and shear force decrease of slices stored at 0°C and 10°C but not at 5°C. Addition of chlorine to CaCl₂ seemed to have some benefits at 0°C or 10°C.     

Perspectives on allelopathy in mexican traditional agroecosystems: A case study in tlaxcala

Agroecosystems in Tlaxcala, Mexico, are surrounded by trees and water channels and have a great variety of cultivated and noncultivated plants. The main results of a study carried out on a traditional agroecosystem in Santa Inés, Tlaxcala are presented. Some ecological aspects of polycultures, plant covers (dry leaves ofAlnus firmifolia, Berula erecta, andJuncus sp.), and the allelopathic potential of crops and noncultivated plants (fresh and dry material) were analyzed. The main plants (trees, shrubs, and herbs) present in the agroecosystem were identified. The total number of weeds in plots where plant covers were added was reduced. The number of nodules ofRhizobium phaseoli and the production of bean and squash increased with plant covers. Corn, beans, and squash showed a clear allelopathic effect, as well asChenopodium murale, Tradescantia crassifolia, Melilotus indicus, andAmaranthus hybridus, among other weeds. The contribution of allelopathy in studies of traditional agroecosystems is of great importance for the management of species in space and time. Allelopathy can be the basis of biological control of pests and weeds and of the discovery of new useful substances.     

Studies on the usefulness of Cucurbita maxima for the production of ready-to-eat dried vegetable snacks with a high carotenoid content

Recent research indicates a beneficial influence of a diet rich in β-carotene on human health. For that reason, experiments were undertaken to process winter squash with a high carotenoid content into ready-to-eat dried snacks. Sensory quality and dietary value of chips and crispy cubes made from different cultivars were investigated.The suitability of winter squash for drying purposes depended mainly on the dry matter content in the raw material. Although all the investigated cultivars can be used for producing chips, obtaining high quality porous cubes requires at least 15% of dry matter. ‘Justynka F1’ emerged as the most suitable cultivar for processing; both chips and cubes produced from its fruits were characterized by a high sensory quality and contained significant amounts of beta-carotene (225- 253 μg g-1). Also, the cultivar ‘Amazonka’ could be considered for the production of chips as it allowed us to obtain a product with a high beta-carotene content (200 μg g-1) and good sensory properties. The dried ready-to-eat crispy vegetable snacks made from the new cultivars of winter squash could be exploited as a novel attractive product with the attractive taste and colour to serve as a valuable source of carotenoids in human diet.     

57B线材拉拔后压扁开裂原因分析

针对 5 7B线材生产针布钢丝出现拉拔后钢丝压扁开裂的现象 ,应用理化检验手段 ,对线材、钢丝的化学成分、表面情况、金相组织等进行分析。认为造成钢丝压扁开裂的主要原因是线材表面缺陷及钢丝组织不均匀     

Solution conformation of a synthetic bis-headed inhibitor of trypsin and carboxypeptidase A: new structural alignment between the squash inhibitors and the potato carboxypeptidase inhibitor

The trypsin carboxypeptidase peptide inhibitor (TCPI) whichinhibits both trypsin and carboxypeptidase A has been chemicallyengineered by modification of the Ecballium elaterium trypsininhibitor II (EETI-II). The solution conformation of TCPI, studiedby two-dimensional nuclear magnetic resonance, was shown tobe very close to those of squash inhibitors. Only limited deviationsof the trypsin binding loop compared to its location in theEETI-II/trypsin complex were detected. It was also shown thatthe position of the C-terminal tail did not significantly changefrom the position observed in the complex between carboxypeptidaseA and the potato carboxypeptidase inhibitor (PCI). The conformationof TCPI was carefully compared with the PCI one and a new structuralalignment between the two microproteins is proposed. This alignmentpoints out the very good conservation in the two inhibitorsof a subdomain comprising segments 7–15, 19–22 and25–28. Most importantly, the 2–19 disulfide bridgeof TCPI was not structurally conserved in PCI and appeared tobe rather unimportant for the early folding process of thesemolecules. This result agrees with the recent observation thatthe 2–19 bridge is the last to be formed in the foldingof the squash inhibitor EETI-II and suggests that this is alsothe case during the folding of the potato carboxypeptidase inhibitor.     

THE EFFECT OF TEMPERING-INTERMITTENT DRYING ON QUALITY AND ENERGY OF PLANT MATERIALS

Squash slices were dried in a laboratory scale vibro-fluidized bed in batch operation. The optimal drying condition and degradation mechanism of β-carotene was investigated. A mathematical model was established to simulate and predict the quality protection. The changes of other tissue parameters, such as appearance and rehydration ability of the dried product, were analyzed and discussed. Tempering-intermittent drying is proved to reduce degradation of β-carotene, shorten drying time, and reduce energy consumption.     

笋瓜的腌制技术

为增加腌制笋瓜的品种,介绍了泡笋瓜、糖醋笋瓜、酱笋瓜、鱼油笋瓜和酱清笋瓜的腌制方法.泡笋瓜是将笋瓜切成片,经白矾水浸泡、清水去矾、盐水浸泡和泡制后而成,产品色黄香脆、成辣微甜.糖醋笋瓜是将笋瓜切片后经盐渍、晾晒和糖醋渍等工序制成,产品微咸、酸甜爽口、脆嫩.酱笋瓜是将笋瓜切片后,经腌制、切制、压卤和酱渍等工序制成,产品色红、酱香、脆嫩、鲜甜.鱼油笋瓜是将笋瓜切条,再经腌制、压卤和鱼油渍等工序制成,产品鲜香嫩脆.酱香笋瓜是将笋瓜切片后腌制,再用生抽酱油浸渍而成,产品色浅红或金黄色、肉质鲜嫩.