Photoelectrochemical cathodic protection of Cu2O/TiO2 p-n heterojunction under visible light

The Cu2O/TiO2 p-n heterojunction composite photoelectrodes were prepared by depositing Cu 2 O nanoparticles on the surface of TiO 2 nanotubes via anodic oxidation and constant current deposition.Field emission scanning electron microscopy(SEM)and high-resolution transmission electron microscopy(HRTEM)analyses showed that Cu 2 O nanoparticles not only deposited on the surface of TiO 2 nanotube array,but also on the wall of TiO 2 nanotubes.The Cu 2 O deposition amount could be adjusted by changing the deposition time.The photoelectrochemical cathodic protection(PECCP)performance of the prepared photoelectrodes for 316L stainless steel(SS)was tested under visible light.The constant current deposition time had a signifi cant eff ect on the PECCP performance of Cu 2 O/TiO 2-X photoelectrodes and Cu 2 O/TiO 2-20 had the best PECCP performance for the coupled 316L SS.This was attributed to the appropriate amount and thickness of Cu 2 O to form p-n heterojunctions with TiO 2,in which separation of the photogenerated carriers was accelerated and transfer of the photogenerated electrons to 316L SS for PECCP was facilitated.

苯丙氨酸解氨酶合成L-2-氯苯丙氨酸的研究

L-2-氯苯丙氨酸要求旋光对映体过量(ee)≥98%,导致使用化学拆分法合成L-2-氯苯丙氨酸的收率不足50%。为提高收率,文章采用具有立体专一性的苯丙氨酸解氨酶(PAL),催化邻氯肉桂酸与氨合成L-2-氯苯丙氨酸,旋光对映体过量(ee)>99%。通过考察不同形态PAL酶的稳定性,研究得出全细胞冻融法制作的PAL酶稳定性较好,结合氮气保护,反应80 h依然能保留62%的酶活。同时,优化PAL酶催化反应的pH、温度、酶用量,确定最佳条件后,结合分段补料的方式进行酶催化反应,最终使L-2-氯苯丙氨酸的累积量达到了68.5 g/L,转化率达到了97.8%。该技术合成L-2-氯苯丙氨酸的产量和收率较高,有效降低了成本,提升了L-2-氯苯丙氨酸的市场价值。

煤层气开发老区L型加密水平井钻井及排采技术研究

煤层气开发老区L型加密水平井的技术方案,即通过在低产井的井间添加加密水平井,建立起单井之间的有效井间干扰,使整个区域实现整体降压,从而达到提高低产井单井产气量的目的。本文通过从布井、储层保护、钻井及排采四个方面分别提出了老区加密井在具体实施过程中需要注意事项,为煤层气开发老区加密井钻井及排采提供了一个系统的可行的技术方案。

基于语言评价矩阵的L/HIRF防护区域敏感度评级

通过专家对L/HIRF防护区域敏感度等级的影响因素评级打分,采用一种基于语言评价矩阵的群决策方法,确定L/HIRF防护区域敏感度等级。以飞机主起落架为例,确定主起落架的L/HIRF敏感度等级,与查阅文献得到的L/HIRF敏感度等级相符,验证了该方法的可行性,为民用飞机预定维修大纲的制定提供相应的参考。

多电飞机L/HIRF防护系统维修性分析研究

随着飞机对多电技术、复合材料的大量使用,飞机的闪电/高能辐射场防护系统设计也变得越来越重要。根据持续适航的要求,为保证飞机闪电/高能辐射场防护系统在飞机整个寿命中仍能保持正常功能,需要对闪电/高能辐射场防护系统进行维修性分析,制定维修大纲,给出初始计划维修任务。根据MSG-3文件的规定,对闪电/高能辐射场防护系统维修性分析要求、分析方法进行了研究,同时还讨论了维修性工作对飞机设计工作的促进作用。

Neuroprotective effects of vagus nerve stimulation on traumatic brain injury

Previous studies have shown that vagus nerve stimulation can improve the prognosis of trau- matic brain injury. The aim of this study was to elucidate the mechanism of the neuroprotective effects of vagus nerve stimulation in rabbits with brain explosive injury. Rabbits with brain ex- plosive injury received continuous stimulation （10 V, 5 Hz, 5 ms, 20 minutes） of the right cervical vagus nerve. Tumor necrosis factor-a, interleukin-l~ and interleukin-10 concentrations were detected in serum and brain tissues, and water content in brain tissues was measured. Results showed that vagus nerve stimulation could reduce the degree of brain edema, decrease tumor necrosis factor-a and interleukin-1β concentrations, and increase interleukin-10 concentration after brain explosive injury in rabbits. These data suggest that vagus nerve stimulation may exert neuroprotective effects against explosive injury via regulating the expression of tumor necrosis factor-a, interleukin-1 β and interleukin-10 in the serum and brain tissue.

RMSG-3下民用直升机L/HIRF分析

从工程应用的角度出发,采用基本理论研究的研究方法,深入研究了RMSG-3标准在民用直升机的L/HIRF分析的应用。分析了L/HIRF防护退化模式,建立了L/HIRF敏感度评估体系,确定了重要维修项目确定原则,采用矩阵法制定了维修间隔期,确定了维修任务判断方法。为今后民用直升机L/HIRF分析工作及预防性维修任务的确定提供帮助。

Change in Activities of Protective Enzymes in New Strains of Cichorium intybus L. Mutated in Outer Space under Water Stress

[Objective] This study aimed to investigate the effects of space mutation on the activities of protective enzymes in different strains of Cichorium intybus L. and provide theoretical basis for screening drought-tolerant plants in southern karst area. [Method] C. intybus seeds were sent into outer space by ＇Shijian No.8＇ seed- breeding satellite. The new strains and original variety of C. intybus L. were used as experimental materials to determine the activities of catalase （CAT）, peroxidase （POD）, superoxide dismutase （SOD）, and malondialdehyde （MDA） content. [Result] The results showed that MDA content in PA-82, Puna chicory and PA-43 increased gradually with the increase of water stress duration, which was enhanced by 0.575, 0.72 and 0.844 μmol/g respectively at 12 days. In addition, the activities of SOD, POD and CAT increased rapidly; at 9 days, the activities of SOD in PA-82, Puna chicory and PA-43 were enhanced by 878.9, 809.2 and 711.1 U/g, with the increas- ing range of 139.1%, 136.7% and 121.1%, respectively; the activities of POD were enhanced by 4 397, 3 754 and 2 767 U/（g ·min）, with the increasing range of 265.84%, 257.65% and 204.06%, respectively; the activities of CAT were enhanced by 402.1, 277.1 and 170.9 KU/L, with the increasing range of 73.08%, 39.69% and 26.20%, respectively; subsequently, the activities of these three protective enzymes were reduced significantly; at 12 days, the activities of SOD in PA-82, Puna chicory and PA-43 were reduced to 1206.5, 1144.7 and 1108.6 U/g, respectively; the activi- ties of POD were reduced to 3 145, 2 876 and 2 753 U/（g·min） , respectively; the activities of CAT were reduced to 587.2, 698.1 and 584.1 KU/L, respectively. [Con- clusion] According to the results of comprehensive evaluation, drought resistance in three C. intybus varieties exhibited a descending order of PA-82 〉 Puna chicory 〉 PA-43.

Transfer of PUFA fatty acid protected and carnitin precursor on the ration of chemical composition of milk dairy goat

The experiment was conducted to investigate the effect of transfer of PUFA protected and carnitin precursor on the ration of chemical composition of milk dairy goat. In total, 10 female dairy goats of 2 - 4 years old Peranakan Etawah (PE) with body weight of 25 - 45 kg were used in this experiment. The feed material included a basal diet (control) based on yellow corn, rice bran, soya bean meal, coconut meal, tuna fish oil and lemuru fish oil. The method of the research was experimental in vivo using Randomized Completely Block Design (RCBD). There were 5 treatments in each experiment and 2 replications. The treatment consisted of P0 = control ration, P1 = P0 + 200 ppm L-carnitine on the ration, P2 = P1 + soya bean oil, P3 = P1 + protected tuna fish oil 5 ml or equal with 4% in the ration, and P4 = P1 + protected lemuru fish oil 5 ml or equal with 4% in the ration. The measured variable is chemical composition of milk dairy goat. The results of variance analysis showed that the effect of transfer of PUFA fatty acid in the rations contained 200 ppm L-carnitine significantly

Hepatic Protective Effects of <i>S</i>-Allyl-L-Cysteine (SAC) in Rats with Carbon Tetrachloride (CCl₄) Induced Liver Injury

S-allyl-L-cysteine (SAC) is an organosulfur compound derived from aged garlic extract (AGE). Studies have reported that AGE possesses bioprotective capacity, including antidiabetic, antimicrobial, antioxidant, and antitumor effects. The present study examined the protective effects of SAC against carbon tetrachloride (CCl4) induced hepatotoxicity in rats. Ten male Wistar rats aged 11 - 12 weeks were randomly divided into two groups (five rats/group) as control and SAC groups. All rats had ad libitum access to water, and the SAC group received water containing SAC intragastrically (200 mg/kg) once daily for five consecutive weeks. In the fifth experimental week, 50% CCl4 in olive oil (1 mL/kg) was administered intraperitoneally three times a week to induce liver injury in both groups. Rats were sacrificed at 24 hours after the last CCl4 injection, and liver tissues were excised for histopathological, immunohistochemical and antioxidant analyses. The rats in the SAC group did not show abnormal behavior, such as decreased water intake or food consumption, during the experimental period. Body weights in all groups did not change significantly over the experimental period. Histopathological analysis showed that the percentage of hepatic steatosis was lower in the SAC group at 12.75% ± 3.74% compared to 24.64% ± 5.29% in the control group (p < 0.05). The percentage of cytochrome P4502E1 (CYP2E1) distribution area in the SAC group was also lower at 19.61% ± 6.18% compared with 25.22% ± 6.21% in the control group (p < 0.05). These results suggest that SAC can alleviate CCl4-induced liver damage by decreasing hepatic steatosis and reducing CYP2E1 expression in rats.

蓝靛果多酚提取物保肝、保肾的药效研究

研究蓝靛果多酚提取物对四氯化碳(CCl_(4))、顺铂诱导的急性肝损伤、急性肾损伤小鼠的保护作用,为蓝靛果多酚提取物保肝保肾作用以及蓝靛果相关健康产品的研发与临床应用提供理论依据.选择CCl_(4)诱导小鼠肝损伤、顺铂诱导小鼠肾损伤动物模型,灌胃蓝靛果多酚提取物,检测各组小鼠组织形态学、脏器指数、血清中肝、肾功能指标和氧化应激指标的变化.结果表明,与模型组相比,蓝靛果多酚提取物能够降低肝、肾损伤小鼠的组织损伤程度,改善肝、肾细胞病理现象,调节肝、肾相关功能,提高抗氧化指标.因此,蓝靛果多酚提取物具有保肝、保肾的作用,对于健康产品开发和临床应用具有重要意义.

飞机高强度辐射场(HIRF)防护分析

首先通过对HIRF引起的飞行事故的介绍,提出研究HIRF防护的必要性,接着介绍了HIRF防护条款在国内外的发展及相关要求,在此基础上研究了飞机HIRF合格审定方法,最后对比了实施HIRF防护适航条款前后的费效比,指出实施HIRF防护条款后有更大收益,对我国在HIRF防护领域开展相关研究具有借鉴意义。

基于R-L模型误差的自适应距离保护

为了描述R-L模型的准确性,提出了R-L模型误差的概念。仿真显示,R-L模型误差与测量电抗误差有明确的关系。目前基于R-L模型算法的距离保护一般采用反时限动作特性,针对其保护范围的开放很保守、不利于中远端故障快速切除的缺陷,提出了基于R-L模型误差的自适应距离保护。故障后,实时计算R-L模型误差,并根据R-L模型误差与测量电抗误差的关系自适应地调整电抗值。仿真结果表明,所提出的自适应方案能有效防止暂态超越,并能显著提高末端故障时的动作速度,整体性能较反时限动作特性距离保护有了很大提高。

N-叔丁氧酰基-O-烷基-L-酪氨酸甲酯的合成工艺研究

以L-酪氨酸为原料,经由羧基、氨基保护后,对其侧链酚羟基进行修饰,得到两个未见文献报道酪氨酸的衍生物Ia,Ib,其总收率分别为74.5%,75.6%,合成方法简便,成本低廉,具有较高的商业应用价值.化合物结构经MS,IR,1H NMR和13C NMR的验证.

Al胁迫下油菜生物量Al积累及保护酶系统的响应

采用水培法，研究了油菜湘杂油二号（耐Al型）和浙双758（Al敏感型）的生物量、根尖Al含量及叶片保护酶活性、叶片MDA和Pro含量对Al胁迫的响应。结果表明，胁迫7d时，湘杂油二号根系、地上部和总生物量下降率（13％～36％、13％～36％、5％～17％）均小于浙双758（30％～53％、12％～20％、16％～28％）。胁迫14d生物量下降比胁迫7d时明显，根冠比也随Al^3＋浓度增加和时间延长而下降；同时，株高变化趋势与生物量变化趋势基本一致。胁迫7d下，湘杂油二号根尖A1含量在3．94～5．88μg·g^-1之间，浙双758在4．96—7．54μg·g^-1之间，胁迫14d时根尖Al积累进一步增加。Al^3＋对叶片SOD、CAT和POD具有激活效应，SOD上升幅度较为明显，胁迫7d和14d时，200μmol·L^-1。Al^3＋浓度下湘杂油二号分别增加2．50倍和2．03倍，浙双758分别增加2．02倍和1．83倍，Al^3＋对CAT和POD的诱导效应小于SOD；从时间差异看，SOD、CAT的绝对活性和增幅在胁迫14d时小于胁迫7d，POD相反。叶片MDA和脯氨酸含量均随Al^3＋浓度增加和时间延长而升高，MDA含量在湘杂油二号中低于浙双758，而脯氨酸含量是湘杂油二号高于浙双758。研究认为，湘杂油二号根尖排斥A1的能力较强，且叶片能够维持较高的保护酶活性和较高的脯氨酸含量，因而其耐Al性强于浙双758。

补充L-精氨酸对力竭性游泳导致的小鼠骨骼肌氧化性损伤的保护作用

目的探讨补充L-精氨酸对小鼠力竭性游泳后骨骼肌氧化应激和抗氧化防御系统的保护作用。方法将29只断乳10天的雄性昆明种小鼠随机分为对照组、L-精氨酸组、力竭性游泳组、L-精氨酸+力竭性游泳组;对照组和力竭性游泳组每天灌胃生理盐水20ml,L-精氨酸组和L-精氨酸+力竭性游泳组每天灌胃1.2g/kg的L-精氨酸溶液20ml;灌胃14天后,力竭性游泳组和L-精氨酸+力竭性游泳组进行一次性力竭游泳,测定力竭游泳后即刻小鼠骨骼肌组织MDA、SOD、T-AOC、NOS活性、NO含量及力竭游泳时间。结果力竭性游泳运动前补充L-精氨酸减轻了小鼠骨骼肌氧化性损伤和增强了小鼠骨骼肌抗氧化系统并使运动时间延长。结论,可能的机制是补充L-精氨酸引起NOS活性和NO形成,从而抑制脂质过氧化增殖反应。

L-茶氨酸对产肠毒性大肠杆菌引起的免疫应激小鼠肝脏的保护作用研究

以SPF级Balb/c雌性小鼠为实验动物,对其适应性饲养3 d后连续30 d灌喂不同剂量L-茶氨酸,然后腹腔注射产肠毒性大肠杆菌E44813诱导免疫应激,5 h后取样,分析研究了各组小鼠肝脏与脾脏系数,血清谷丙转氨酶(Alanine aminotranferease,ALT)与谷草转氨酶(Aspartate aminotransferase,AST)含量,肝组织匀浆丙二醛(Malondialdehyde,MDA)水平与谷胱甘肽过氧化物酶(Glutathione peroxidase,GSH-PX)、过氧化氢酶(Catalase,CAT)、超氧化物歧化酶(Superoxide Dismutase,SOD)活性,肝组织病理学变化,以及血清中γ-干扰素(γ-Interferon,IFN-γ)、白细胞介素-4(Interleukin-4,IL-4)的表达量,以探明L-茶氨酸对产肠毒性大肠杆菌免疫应激小鼠肝脏的保护作用。结果表明,不同剂量的茶氨酸干预处理均能明显降低由大肠杆菌E44813感染引起的肝脏、脾脏系数的升高,降低血清ALT、AST及肝组织匀浆MDA水平,提高肝组织匀浆SOD、CAT、GSH-PX活性,减少IFN-γ、IL-4表达量,改善肝脏组织病理损伤,其中以300 mg·kg-1剂量组效果最好,说明茶氨酸干预对产肠毒性大肠杆菌诱导的免疫应激小鼠肝损伤具有保护作用,而且可能是通过减少IFN-γ与IL-4的表达、降低炎症反应、提高抗氧化能力等途径达到保护肝脏的作用。

蔷薇红景天总黄酮提取物对Aβ_(25-35)诱导PC12细胞损伤的保护作用及其活性部位筛选

目的考察蔷薇红景天总黄酮提取物(TFE)对β淀粉样蛋白25-35(Aβ_(25-35))诱导的PC12细胞损伤的保护作用及其活性部位筛选。方法采用20μmol·L^(-1)Aβ_(25-35)诱导PC12细胞损伤,经AB-8大孔吸附树脂色谱法分离蔷薇红景天TFE,得水及20%、40%、60%、80%、95%乙醇洗脱物(即TFE-0%、TFE-20%、TFE-40%、TFE-60%、TFE-80%和TFE-95%)。计算不同体积分数乙醇洗脱物浸膏得率(赋予0.3权重),紫外分光光度法检测不同体积分数乙醇洗脱物总黄酮含量(赋予0.7权重),综合评价不同体积分数乙醇洗脱物。MTT法检测不同体积分数乙醇洗脱物对损伤后PC12细胞活力的影响;采用倒置显微镜观察细胞形态;采用2,4-二硝基苯肼显色法检测乳酸脱氢酶(LDH)的活性;采用黄嘌呤氧化酶法检测超氧化物歧化酶(SOD)的含量;酶联免疫测定(ELISA)法分别检测细胞上清中白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)、环氧合酶-2(COX-2)和白细胞介素-1β(IL-1β)的分泌水平。结果TFE-40%总黄酮浓度和浸膏得率的综合得分高于其他不同体积分数乙醇洗脱物。与空白组比较,模型组细胞间隙变大,数目减少,出现细胞碎片,突触明显减少,存活率和SOD水平明显降低(P<0.05),LDH水平明显升高(P<0.05);与模型组比较,TFE-40%、TFE-60%洗脱物和盐酸多奈哌齐组细胞形态均有一定程度改善,数目增多,突触增加,细胞形态较完整;TFE-40%、TFE-60%、TFE-80%及TFE-95%组的细胞上清液中IL-6、TNF-α、COX-2和IL-1β的水平均明显降低(P<0.05)。结论蔷薇红景天TFE-40%洗脱物对Aβ_(25-35)诱导的PC12细胞损伤具有较好保护作用,为最佳活性部位,其机制可能与拮抗Aβ_(25-35)的神经毒性和抑制细胞炎症的发生有关。

水稻穗型突变体cl的鉴定、保护与遗传分析

通过神州八号飞船搭载广东省常规优质稻主导品种粤农丝苗获得一个稳定遗传的穗型突变体cl,中文名为粤花占1号,2015年完成农业部植物新品种权的申请工作(申请号:20151728.8,公告号:CNA014491E)。该突变体农艺性状与野生型极为相似,熟色好,产量高,但表现出异常的花序结构,一次枝梗数增加,二次枝梗、小穗梗长度严重缩短,枝梗顶端小穗3粒簇生在一起。进一步的细胞学观测发现,差异主要源自幼穗分化的第3期到第4期发育异常所致。遗传分析表明该性状由非完全显性单基因控制,BSA性状定位法初步将该基因定位于染色体6,命名为CL-6。本研究的结果为进一步精细定位和克隆CL-6基因、找到控制水稻幼穗枝梗伸长缩短的功能基因或调控因子奠定基础,同时为培育理想穗型水稻和观赏农业提供优良种质。

基于电子式互感器微分输出的改进R-L模型距离保护算法

以基于罗氏线圈的电子式电流互感器和基于电容分压原理的电子式电压互感器为例,推导电子式互感器的微分输出原理。通过对传统R-L模型算法进行改进,可直接利用电子式互感器输出的微分信号进行故障测距并实现距离保护功能,在保证可靠性的基础上缩短了保护动作时间。通过对过渡电阻的影响进行分析,证明改进R-L模型算法本身具有较好的抗过渡电阻能力。通过仿真实验、动模实验以及对算法动态特性的分析,验证了基于改进R-L模型算法的故障测距及距离保护方案的可行性和有效性。