应变速率对8090Al-Li合金拉伸性能的影响

用动态拉伸的方法研究了应变速率对 80 90 Al— L i合金拉伸性能的影响 ,应变速率的范围为 10 - 3～ 10 3s- 1。结果表明 ,合金的强度和塑性随应变率的增加而增加。试样的 SEM和 TEM分析发现 :准静态下的断裂为沿晶断裂 ;随着应变率的增加 ,断裂从穿晶准解理断裂过渡到由显微空穴聚集而成的韧窝断裂。高应变率下80 90 Al- L i合金强度和塑性的提高与其变形机制和晶界无沉淀区 (PFZ)的变化有关     

Fe3Al合金的高温变形行为

用载荷松弛法对Ｆｅ－２８Ａｌ－２Ｔｉ合金在较高温度下的变形行为进行了研究．测定了Ｆｅ－２８Ａｌ－２Ｔｉ合金在高温变形时的载荷松弛曲线、应力减小因子Ｙ及激活能值,并对试样进行了显微结构观察．结果表明,Ｆｅ－２８Ａｌ－２Ｔｉ合金的高温变形是一个亚晶界吸收位错,而且不断向大角晶界转变的过程．     

链条锅炉模糊控制研究

针对链条锅炉的运行特点,提出一套基于模糊控制理论的链条锅炉控制方案。链条锅炉滞后时间长、惯性大,采用传统控制方法控制效果不理想,但采用模糊控制方法可以取得良好的控制效果。本控制系统由负荷控制和燃烧控制子系统构成。控制系统通过调节供入的燃料量和合理组织炉内燃烧,提高了锅炉的运行效率。针对不同的调节对象,分别设计了不同的模糊控制器,改善了控制系统的整体控制效果。该系统已经成功地应用于北京市德宝锅炉房。     

地下水咸淡水混合带动态特性试验研究

应用电导率法,通过大型移流弥散砂槽模型试验,成功地测到了混合带,并对混合带及其动态特性进行了观测、分析和研究,在总体水头的水平梯度方向与浓度的水平梯度方向（弥散的反方向）相反的条件下,得到了咸水入侵进慢退快、混合带发展演化过程中有回咸现象以及介质分层、高浓度等试验的部分规律。部分成果对滨海地区水资源的规划、管理和海（咸）水入侵的预防、治理以及移流弥散问题的物理模型、数学模型的研究有参考意义和实际应用价值。     

美东地区罗德河流域地下水中铝形态分布的化学平衡模式计算

美东地区的罗德河流域遭受着严重的酸沉降侵蚀．在酸性条件下,铝从土壤中大量溶解并迁移到水环境中．地表水中升高的铝浓度对鱼类产生毒害,监测地表水和土壤水中的铝形态及浓度变化已成为问题的关键．本文报导了用化学平衡模式计算法分析美东地区罗德河流域地下水中的铝形态分布,获得了有价值的结论     

A massive phytoplankton bloom induced by an ecosystem-scale iron fertilization experiment in the equatorial Pacific Ocean

The seeding of an expanse of surface waters in the equatorial Pacific Ocean with low concentrations of dissolved iron triggered a massive phytoplankton bloom which consumed large quantities of carbon dioxide and nitrate that these microscopic plants cannot fully utilize under natural conditions. These and other observations provide unequivocal support for the hypothesis that phytoplankton growth in this oceanic region is limited by iron bioavailability.     

Molecular evidence for increased hematopoietic proliferation in the spleen of the b/b laboratory rat

The splenomegaly and the appearance of a significant number of CFU-E (erythroid colony-forming units) and BFU-E¹ (erythroid burst-forming units) in the Belgrade laboratory rat (b/b) spleen prompted us to analyse further the molecular evidence for increased hematopoietic proliferation in the b/b spleen. Messenger RNAs (mRNAs) specific for globins, proteins for iron transport and deposition and the band 3 protein were used in rat erythropoietic tissues as markers for proliferation and erythroid differentiation. In the b/b spleen, all mRNAs analysed display an erythroid-specific pattern of expression. This analysis also revealed an enhanced level of mRNA for ferritin in the +/b spleen, whereas erythrocyte-specific mRNA production was normal.     

Dissection of the pheromone-modulated flight of moths using single-pulse response as a template

The upwind flight of male moths to conspecific females is mediated by the chemical and structural characteristics of a pheromone plume. We describe the reaction of maleCadra cautella, the almond moth, to the interception of single pulses of sex pheromone, the smallest structural units of odour plumes. Following loss of a pheromone plume, males cast, that is fly a crosswind course without progressing upwind. The response of casting males to interception of a pulse of 0.25 s duration was, after a delay of 0.21±0.07 s, to turn and briefly fly straighter upwind, resulting in average net upwind displacements of 18 cm in a 50 cm s^–1 wind. Upwind progress in the single-pulse response was the result of steering more upwind and an increase in airspeed, although average ground speed remained unchanged. During the last third of the surge, males turned crosswind, returning to casting flight. These behavioural reactions to pheromone contact and loss support the phasic-tonic model of odour-modulated flight, in which an underlying tonic counterturning rhythm, expressed upon pheromone loss, is briefly overridden by phasic upwind surges, expressed upon interception of the pheromone filament. The surge portion of the cast-surge-cast response was diminished and more crosswind if individual pulses were shorter (0.02 s), probably due to sub-optimal contact with pheromone. The cast-surge-cast response to interception of a single 0.25 s pulse was used as a template to interpret the form of flight tracks in plumes of known structure. The template matched portions of flight tracks of males flying in plumes of low pheromone pulse frequency, thus reflecting the male's pattern of pulse encounter. In plumes ensuring a high frequency of pulse interception, only the upwind surge portion of the template was expressed, resulting in nearly straight upwind flight tracks. Similar nearly straight upwind flight tracks occurred in flights along plumes of low pulse frequency with large volume. Thus flight tracks of maleC. cautella to point sources of pheromone depend on both the frequency and the size of filaments encountered.     

2-Carboxyethylgermanium sesquioxide,a synthetic organogermanium compound,as an inducer of contrasuppressor T cells

2-Carboxyethylgermanium sesquioxide (Ge-132), a synthesized organogermanium compound with immunomodulaing activities, was shown to be an inducer of anti-suppressor T cells in normal mice. The suppressor cell activity of T6S cells, a clone of burn-induced CD8⁺ IL-4-producing suppressor T cells, was clearly inhibited when a mixed lymphocyte-tumor cell reaction of the clone was conducted with splenic mononuclear cells from mice treated orally with a 100 mg/kg dose of Ge-132. The activity of anti-suppressor cells was demonstrated in spleens of mice 2 days after treatment with Ge-132 and reached its peak on day 3. The anti-suppressor cells induced by the compound were of a contrasuppressor T cell-linage, because they were characterized as CD4⁺ CD28⁺ TCR/⁺ Vicia villosa lectin-adherent T cells. These cells produced IFN- but did not produce IL-2, IL-4, IL-6 or IL-10 in their culture fluids. CD4⁺ anti-suppressor T cells induced by Ge-132 may be different from other subsets of CD4⁺ T cells because Th1 and Th2 cells generated in our laboratory did not adhere toVicia villosa lectin-coated petri dishes, and each produced specific cytokines. Th1 cells produced IFN- and IL-2 while Th2 cells produce IL-4 and IL-10 in vitro. These results suggest that Ge-132 may be useful as an inducer of contrasuppressor T cells in immunocompromised individuals bearing suppressor T cells. To eliminate suppressor T cells from immunocompromised hosts may result in improved resistance from various opportunistic infections.     

The use of cyclophosphamide as an enhancer of the vaccine against foot-and-mouth disease

The immunization of biungulate animals with killed foot-and-mouth disease virus (FMDV) requires periodic vaccinations due to a low vaccine immunogenicity. Therefore, FMDV antigens need to be combined with adjuvants such as aluminum hydroxide, saponin or oil emulsions. Animal handling for periodic inoculations, and the repeated doses of vaccines that have to be administered increase the commercialization costs. Moreover, the use of adjuvants may induce adverse effects.In the present work we show that it is possible to increase the life span of neutralizing antibodies in serum when a single dose of cyclophosphamide (Cy) is administered four days before vaccination with aluminum hydroxidesaponin FMDV vaccine.