一种片内硬件调试支持单元设计

该模块通过AHB总线接口监听总线通信内容并将其实时记录于缓冲器中,用户可以通过该缓冲域观察系统运转;它支持在断点/观察点以及处理器陷阱等条件下通过挂起处理器进行系统诊断,同时其内部多级地址译码机制可以对所有片上控制存储单元进行定位,方便用户进行调试。通过专用的调试通信链路,用户可以方便地对嵌入式系统进行远程调试。     

化学自生热压裂液技术研究进展

化学自生热压裂液在低pH值或高温下发生热化学反应生成对地层低伤害的盐溶液和气体,并放出大量的热量,具有生热量大、返排快、储层伤害小等特点,能够有效克服压裂液对地层冷伤害和低温破胶不完全等问题。介绍了氯化铵与亚硝酸钠的生热机理,分析了p H值、反应物浓度、初始温度对压裂液生热量和生热反应速度的影响;根据不同交联剂类型将化学自生热压裂液分为了硼交联胍胶压裂液、酸性交联压裂液和黏弹性表面活性剂压裂液,总结了不同压裂液体系的性能和优缺点,介绍了压裂施工工艺和现场应用,并从压裂液配方和工艺方面对化学自生热压裂液研究进行了展望。     

基于A位元素置换策略合成新型MAX相材料Ti3ZnC2

MAX相材料是一类兼具金属和陶瓷特性的三元层状材料, 在高温导电、耐磨、耐腐蚀和耐辐照损伤等方面性能优异。目前已经合成出的MAX相材料已有70余种, 但A位元素一直局限在ⅢA和ⅣA主族元素, 如Al、Si、Ga等, 而以副族元素占据A位的MAX相鲜有报道。本研究以Ti₃AlC₂为前驱体, 利用熔盐中的A位置换反应, 制备出了A位为Zn元素的全新MAX相材料Ti₃ZnC₂。结合X射线衍射、扫描电子显微镜和透射电子显微镜等分析手段对Ti₃ZnC₂的成分和结构进行了确认, 并通过密度泛函理论对Ti₃ZnC₂的结构稳定性和晶格参数进行了确定。进一步通过热力学计算对Fe、Co、Ni、Cu等几种元素的A位置换反应进行了预测, 发现采用这几种元素的氧化物进行置换反应在热力学上也都具有可行性。本研究所提出的元素置换策略是在保持MAX相六方层状晶体结构的基础上, 利用Al、Zn在高温下形成共晶产物实现Zn原子向A层内的迁移, 而熔盐介质的存在促进了反应动力学。本方法巧妙地避免了MAX相传统合成过程中竞争相的形成, 如M-A合金相, 因此可以用于探索更多未知的MAX相材料。     

~(137)Cs示踪法研究黄土丘陵区坡面侵蚀空间变化特征

利用放射性同位素示踪技术,对黄土丘陵区不同坡长坡面土壤剖面中137Cs含量测定与分析,研究了坡面土壤侵蚀强度的空间变化特征.结果表明,坡长对坡面侵蚀强度的空间分布有重要影响,坡面侵蚀强度呈波动变化趋势.小流域全坡面水流汇集过程中,净泥沙流失强度随流程的增加先增加后减少.     

D1 and D2 dopamine receptor mediation of amphetamine-induced acetylcholine release in nucleus accumbens

To assess the interaction of dopamine and acetylcholine systems in the rat nucleus accumbens in response to direct D-amphetamine administration, in vivo microdialysis measures of acetylcholine were used during reverse dialysis of amphetamine alone and in combination with D1 and D2 receptor antagonists SCH 23390 and sulpiride, respectively. During a 15-min exposure to amphetamine (50 microM) in the nucleus accumbens, acetylcholine increased to 33% above pre-infusion levels, became maximal at 15 min post-infusion (+41%) and gradually returned to baseline levels by 60 min post-amphetamine. Conversely, amphetamine (1 mM) administration caused a biphasic change in acetylcholine release with a trend toward a decrease (-14%) during exposure followed by a significant increase (+36%) at 30 min post-amphetamine that returned to baseline levels by 60 min after infusion. The increases observed during amphetamine (50 microM) exposure and during recovery from amphetamine (1 mM) were both blocked by co-administration with the D1 antagonist, SCH 23390 (10 microM), but not with the D2 antagonist, sulpiride (10 microM). Co-infusion of sulpiride eliminated the trend toward reduced acetylcholine release observed during 1 mM amphetamine whereas co-administration of SCH 23390 potentiated this decrease. A possible tonic D1 facilitation of nucleus accumbens acetylcholine release was indicated by the consistent reductions in acetylcholine release observed during infusion of SCH 23390. These results suggest that amphetamine administration in the nucleus accumbens induces a bidirectional change in acetylcholine release that is dependent on dose and opposing effects of nucleus accumbens D1 and D2 activation. In general, relatively low doses of amphetamine administered into the nucleus accumbens caused an increase in acetylcholine release that was dependent on dopamine D1 receptors whereas higher doses of amphetamine resulted in a D2-mediated decrease.     

Oesophageal intramural pseudodiverticulosis: a cause of dysphagia in a 10-year-old boy

We report a 10-year-old boy who presented with a piece of chicken stuck in his throat. He had similar episodes in the past that resolved spontaneously. The foreign body was removed and oesophagoscopy revealed no abnormality. Post-operative barium swallow showed oesophageal intramural pseudodiverticulosis.     

Ozone therapy of diffuse peritonitis in the early postoperative period

The functional status of the oxidative-antioxidative system was studied in 72 patients after vast cancer operations. Traditional surgical treatment and its combination with intraoperative irradiation were shown to lead to tense antioxidative defense and to suppressed T-cell immunity and to call for antioxidative and immunomodulating therapy. High intraoperative blood loss complicated by hemorrhagic shock injured the oxidative-antioxidative system greatly. The magnitude of this damage correlated with the rate of prehypoxia. Addition of the potent antioxidant Ceruloplasmin to the drug regimen normalized a recovery period, helped to correct posthypoxic multiorgan insufficiency, to recover oxidative-antioxidative balance, and to decrease the incidence of pyoinflammatory complications. Patients with endogenous intoxication showed activated lipid peroxidation, decreased functional activity of antioxidative defense components and of T-cell immunity in homeostasis. The use of Ceruloplasmin and Laprot had pronounced antiinflammatory and detoxifying effects on the patient's body and activated its antioxidative defense.     

Antibacterial ability and biocompatibility of fluorinated titanium by plasma-based surface modification

Biomaterial surfaces with satisfied antibacterial activity and appropriate cytocompatibility are a pressing clinical need for orthopedic and dental implants.Fluorinecontaining biomaterials have been demonstrated to obtain antibacterial activity and osteogenic property,while the effect of fluorine chemical compositions on antibacterial property and cytocompatibility is rarely studied.To this end,the coatings with different fluorine chemical compositions on titanium surface were prepared by plasma treatment to verify the antibacterial ability and cytocompatibility of fluorinated surfaces.Their antibacterial ability was evaluated by using Staphylococcus aureus,and the cell compatibility was investigated with MC3T3-E1 cells in vitro.The results show that both fluorocarbon coating and metal fluorides coating exhibited a hydrophilic and nano-scaled roughness.Rather than the fluorocarbon coating,the coating composed of metal fluorides presented satisfied bactericide effect and excellent cytocompatibility.The antibacterial mechanism is associated with the metal fluorides and released fluoride ion.This work would provide novel sight in optimizing the surface modification method of fluorinated biomaterials for biomedical applications.     

气相色谱法测定氟虫腈中残留乙醇、甲苯含量

以DB-624毛细管色谱柱(94%二甲基聚硅氧烷和6%氰丙基硅氧烷)为分离要素,使用FID检测器,建立高效快速的气相色谱法,实现了农药氟虫腈中残留溶剂乙醇、甲苯的含量的测定与控制.实验结果表明,该方法灵敏度高,线性范围宽,测定结果准确可靠.     

黏度法测定超高分子量聚乙烯分子量的研究

为验证ASTM D4020–2011和GB/T 1632.3–2010是否适合测定我国常用超高分子量聚乙烯(PE-UHMW)的黏均分子量以及探讨奥氏黏度计能否代替乌氏黏度计测定PE-UHMW的黏均分子量,研究了黏度法测定PE-UHMW分子量的影响因素,包括黏度计与毛细管内径的选择、溶液浓度与溶剂的选择、抗氧剂的作用、实验温度的控制以及数据处理方法等。实验结果表明,十氢萘是配制PE-UHMW溶液的较佳溶剂,PE-UHMW溶液的浓度与毛细管流出时间分别控制在0.008～0.050 g/(100 mL)与80.0～140.0 s较为合适,加抗氧剂能有效防止PE-UHMW的氧化降解,选用毛细管内径为0.55 mm的奥氏黏度计可满足使用要求。