多孔和铸装高能推进剂的燃烧转爆轰

为研究多孔和铸装高能推进剂的危险性能，设计加工了燃烧转爆轰的实验装置，并建立了以光电管为主的测试系统。经实验发现，多孔装药在燃烧向爆轰的转变过程中有冲击波／爆轰波的回传现象，而铸装药则没有

ECAP制备纯Cu的热处理工艺与力学性能

Cu经过等径角挤压(ECAP)变形后,屈服强度达到了约400 MPa,然而加工硬化能力不足导致其在小应变阶段就开始颈缩(≤2%) 。研究发现,可以通过部分再结晶退火调控变形Cu的室温准静态拉伸性能。在275 ℃退火10 min后,其准静态拉伸强度和塑性得到了良好的匹配:在保持屈服强度为330 MPa的前提下,均匀伸长率达5%

Iron and manganese oxides enhance electron output efficiency of Clostridium pasteurianum

[Background] Fermentative dissimilatory metal-reducing bacteria, which are capable of reducing metallic oxides, get energy from fermentation. Little is known about how metallic oxides affect electron output efficiency of fermentative dissimilatory metal-reducing microorganisms. [Objective] This study was conducted to explore the influence of iron and manganese oxides (Fe_2O_3/MNO_2) on electron output efficiency. [Methods] Different concentrations of Fe_2O_3/MNO_2 were added into fermented system containing glucose and inoculated 5% C. pasteurianum. Electrochemical activity of C. pasteurianum was detected. The concentrations of Fe(Ⅱ) and Mn(Ⅱ) were measured by ferrozine spectrophotometry and formaldoxime method. Fermentation substrate and metabolites of C. pasteurianum were detected by gas chromatography and high performance liquid chromatography. Lastly, we calculated the electron output efficiency. [Results] The current density peaked with the value of about 0.93 mA/m~2. The concentrations of Fe(Ⅱ) and Mn(Ⅱ) gradually accumulated. The consumption of glucose was increased by 9.4%/7.7%, Meanwhile, acetate production was increased by 37.5%/25.0%, and butyrate production was increased by 22.7%/6.8%. Additionally, hydrogen production was increased by 21.6%/9.8%, and the total electron output efficiency was increased by 24.27%/10.82%, respectively. The pH values between experimental group and control are no significant difference. [Conclusion] This study shows that iron and manganese oxides can improve the electron output efficiency of C. pasteurianum by increasing glucose consumption and buffering pH value. The results provide evidence for revealing the effects of multivalent metal oxides on the electron output of fermentative dissimilatory metal-reducing bacteria, and further expand our understanding of the interaction mechanism between multivalent metal oxides and fermentative dissimilatory metal-reducing bacteria.</p

The Influence of Magnesium Concentration for the Survival Rate of Bufo melanostictus Tadpoles in the Acidity Water and Alkaline Water

[目的]研究野外黑眶蟾蜍(Bufo melanostictus)蝌蚪的生存状况。[方法]研究分别在碱性水(p H 7.5~8.0)以及酸性水(p H 5.5~6.0)2种模拟环境条件下,通过急性毒性试验方法以不同的浓度梯度Mg~(2+)对黑眶蟾蜍蝌蚪进行24和48 h的胁迫试验。[结果]在相同浓度梯度和相同观察时间下,黑眶蟾蜍蝌蚪在碱性水中的存活率低于酸性水;不同p H的水环境与Mg~(2+)的协同作用显著影响黑眶蟾蜍蝌蚪的48 h存活率(F7,32=3.373,P<0.05);黑眶蟾蜍蝌蚪在酸性水环境下适宜生存的Mg~(2+)浓度范围为1 418.41~1 590.54 mg/L,半致死浓度(LC_(50))为2 357.32 mg/L,安全浓度为521.51 mg/L;在碱性水环境下适宜生存的Mg~(2+)浓度范围为1 264.91~1 418.41 mg/L,LC_(50)为1 879.81 mg/L,安全浓度为533.99 mg/L。[结论]该研究可为今后黑眶蟾蜍的保护提供理论依据。[Objective]The aim was to study the survival status of Bufo melanostictus tadpoles in the field.[Method]The regular acute toxicity test was carried out that Bufo melanostictus tadpoles were breed in the alkaline water( p H 7.5-8.0) and acidity water( p H 5.5-6.0)with different Mg~(2+) concentration gradient for 24 and 48 h.[Result]The results showed that the survival rate of Bufo melanostictus tadpoles in the alkaline water was lower than the acidity water in the same condition.Synergistic effects of different p H and Mg~(2+) concentration had a significant effect on the survival rate of Bufo melanostictus tadpoles in the 48 h toxicity experiment( F7,32= 3.373,P < 0.05).In the acidity water environment,48 h toxicity experiment results showed that the optimal Mg~(2+) concentration was 1 418.41-1 590.54 mg / L,the median lethal concentration( LC_(50)) was 2 357.32 mg/L and the safe concentration was 521.51 mg/L.By contract,these three indexes in the alkaline water environment were 1 264.91-1 418.41,1 879.81 and 533.99 mg / L,respectively.[Conclusion] The study can provide theoretical basis for protection of Bufo melanostictus.国家自然科学基金项目(31271124);; 广东省自然科学基金项目(s2013010016062

Breeding high-yield oil-producing strain to use cheap carbon source by UV induced protoplast mutagenesis

【目的】研究并建立利用原生质体紫外诱变技术选育可利用廉价碳源发酵的高产油新菌株的方法。【方法】采用1.5%蜗牛酶和1.0%纤维素酶混合液水解去除细胞壁得到2A00015(近平滑假丝酵母,CAndIdA PArAPSIlOSIS)的原生质体,将其放于紫外灯下诱变及再生壁培养,筛选获得可利用廉价碳源发酵的高产油酵母,并采用气相色谱质谱联用法(gC-MS)测定其脂肪酸组成。【结果】突变效果最好的突变菌株2A00015/25用葡萄糖发酵培养7 d后,其生物量、油脂产率和产油量分别为17.77 g/l、58.12%和10.32 g/l,较原始菌株分别提高了12.45%、23.32%和38.68%;利用废糖蜜发酵培养,其生物量、油脂产率和产油量分别为18.54 g/l、49.44%和9.17 g/l,较原始菌株分别提高了9.09%、21.16%和32.18%。利用废糖蜜培养其产油效率虽低于利用葡萄糖培养,但从环境保护及原材料成本的角度考虑,用废糖蜜作为碳源发酵培养产生油脂更具优势。诱变菌株利用废糖蜜发酵后产生油脂经检测含有8种脂肪酸,其脂肪酸组成与植物油近似,其中不饱和脂肪酸含量占脂肪酸总量的82.4%。【结论】通过利用原生质体紫外诱变技术,成功选育出一株新的可利用廉价碳源的高产油海洋菌株,产油率达到49.4%,提高了21.2%。[Objective] We used UV induced protoplast mutagenesis to study breed a new high-yielding lipid-producing strain which could use cheap carbon source.[Methods] Get the 1.5% glusulase and 1.0% cellulose solution.Hydrolyze to remove the cell wall and obtain the protoplast of 2A00015(Candida parapsilosis).Put it under the ultraviolet lamp for mutagenesis and cultivate regenrated wall.Then screen to get the high oil generated yeast which could be fermented by low-cost carbon source.Determine its fat acid components by gas chromatography with mass spectrometric(GC-MS).[Results] Cultivated the mutant strain with best mutation 2A00015/25 in the glucose.We found that the biomass, oil yield rate and oil production are separately 17.77 g/L, 58.12% and 10.32 g/L, which are separately 12.45%, 23.32% and 38.68% higher than the original strain.We have also cultivated the mutant strain in the waste molasses and found the biomass, oil yield rate and oil production are separately 18.54 g/L, 49.44% and 9.17 g/L, which are separately 9.09%, 21.16% and 32.18% higher than the original strain.The oil yield rate is lower in the waste molasses cultivation than that in glucose cultivation.However, in consideration of environment protection and cost of raw materials, the waste molasses is of much more advantages.It is tested that the fat generated from the waste molasses fermentation consists of eight kinds of fat acid.Its fat acid components are similar to the vegetable oil, in which the content of unsaturated fatty acid comprised 82.4% of the total fatty acid.[Conclusion] Basing on UV induced protoplast mutagenesis, we have successfully bred a new high-yielding oil strain which can make use of the low-cost carbon source, with its oil production rate 49.4% which has increased by 21.2%.深海(微)生物资源勘探与资源潜力评价项目(No.DY125-15-R-01

化学气相沉积SiC–B_xC涂层在高温模拟环境中的微观结构

将化学气相沉积在石墨基片上的SiC-BxC复合涂层在O2(8kPa)/H2O(14kPa)/Ar(78kPa)的模拟气氛中,分别加热到700,1000℃和1200℃处理10h。利用扫描电镜、X射线衍射、能谱分析、显微Raman和Fourier变换红外光谱仪研究其微观结构。结果表明:复合涂层中的BxC层在700～1000℃的模拟环境中会被完全氧化成B2O3和H3BO3;在1000～1200℃的模拟环境中,BxC层的氧化产物迅速挥发。经高温模拟环境处理后,复合涂层中生成了硼硅酸盐玻璃,且各氧化产物和SiC层的结晶度随处理温度的升高而下降。基于微观分析结果,对SiC-BxC复合涂层的自愈合抗氧化性能进行了分析

The Intersexual Differences of Sexual Dimorphism,Feeding Habits and Locomotor Performance at Different Temperatures of Southern Grass Lizard(Takydromus sexlineatus) in Zhaoqing,China

通过测量头、尾、体和胃检,研究肇庆南草蜥TAkydrOMuS SEXlInEATuS个体发育过程中两性异形和食性差异。南草蜥成体个体两性大小无显著差异,雄性头部显著大于雌性,两性头部大小异形可能是受到性选择压力的结果。雌雄个体食物生态位重叠度较高,两性生态位差异微弱,食性差异与两性头部异形无明显相关性。通过设计13种不同的环境温度,研究体温变化对南草蜥两性个体运动能力表现的影响。结果显示环境温度通过影响体温而影响南草蜥的运动表现,两性个体疾跑速均具有在低体温范围内随体温升高而加快、在高体温范围内随体温升高而降低的模式。在多数测试温度下,雄体的疾跑速均略大于雌体,但两者平均值在统计上无显著差异。体温对南草蜥的最大持续运动距离和停顿次数的影响显著,两性个体的疾跑速和最大持续运动距离呈显著正相关。雄性和雌性分别在26℃和30℃具有最佳的运动表现。Southern grass lizard( Takydromus sexlineatus) was collected from Zhaoqing,Guandong province to determine the sexual dimorphism and dietary habits by measuring the lengths of head,tail and body,and examining the items in the stomach.The results showed that there was no significant difference in body size.However,male individuals had significantly larger head size than females,which might be due to the divergent sexual selection pressure.A relatively high food niche overlap was observed between the sexes.There was little relationship between food habits and head dimorphism.By designing 13 different ambient temperatures,we determined the relationship between body temperature and locomotor performance of the adults.Ambient temperature affected locomotor performance by influencing the body temperature.Sprint speed increased with increasing body temperature at lower body temperature,while decreasing with increasing body temperatures at higher body temperatures,which was similar between the sexes.However,males ran slightly faster than females in most cases,but intersexual difference of sprint speed was not statistically significant.Body temperature also influenced the maximal move distance and pause times.Sprint speed was positively correlated with the maximal move distance.The optimal temperatures of locomotor performance differed between the sexes: about 26℃ for males and 30 ℃ for females,respectively.国家自然科学基金资助项目(31271124); 广东省自然科学基金(06300177); 广东省高等教育教学改革项目(粤财教[2012]361号); 大学生创新性实验计划项目(DC201316)共同资

The Intersexual Differences of Sexual Dimorphism,Feeding Habits and Locomotor Performance at Different Temperatures of Southern Grass Lizard(Takydromus sexlineatus) in Zhaoqing,China

通过测量头、尾、体和胃检,研究肇庆南草蜥TAkydrOMuS SEXlInEATuS个体发育过程中两性异形和食性差异。南草蜥成体个体两性大小无显著差异,雄性头部显著大于雌性,两性头部大小异形可能是受到性选择压力的结果。雌雄个体食物生态位重叠度较高,两性生态位差异微弱,食性差异与两性头部异形无明显相关性。通过设计13种不同的环境温度,研究体温变化对南草蜥两性个体运动能力表现的影响。结果显示环境温度通过影响体温而影响南草蜥的运动表现,两性个体疾跑速均具有在低体温范围内随体温升高而加快、在高体温范围内随体温升高而降低的模式。在多数测试温度下,雄体的疾跑速均略大于雌体,但两者平均值在统计上无显著差异。体温对南草蜥的最大持续运动距离和停顿次数的影响显著,两性个体的疾跑速和最大持续运动距离呈显著正相关。雄性和雌性分别在26℃和30℃具有最佳的运动表现。Southern grass lizard( Takydromus sexlineatus) was collected from Zhaoqing,Guandong province to determine the sexual dimorphism and dietary habits by measuring the lengths of head,tail and body,and examining the items in the stomach.The results showed that there was no significant difference in body size.However,male individuals had significantly larger head size than females,which might be due to the divergent sexual selection pressure.A relatively high food niche overlap was observed between the sexes.There was little relationship between food habits and head dimorphism.By designing 13 different ambient temperatures,we determined the relationship between body temperature and locomotor performance of the adults.Ambient temperature affected locomotor performance by influencing the body temperature.Sprint speed increased with increasing body temperature at lower body temperature,while decreasing with increasing body temperatures at higher body temperatures,which was similar between the sexes.However,males ran slightly faster than females in most cases,but intersexual difference of sprint speed was not statistically significant.Body temperature also influenced the maximal move distance and pause times.Sprint speed was positively correlated with the maximal move distance.The optimal temperatures of locomotor performance differed between the sexes: about 26℃ for males and 30 ℃ for females,respectively.国家自然科学基金资助项目(31271124); 广东省自然科学基金(06300177); 广东省高等教育教学改革项目(粤财教[2012]361号); 大学生创新性实验计划项目(DC201316)共同资

中国大陆民办高校的分类与评估

大陆民办高等教育经历了二十多年的快速发展 ,与公办高校相比 ,目前民办高校不仅表现在类型上的多样化 ,其发展特性也有所不同。按大陆相关法规规定 ,公办和民办高校的认证标准是一样的 ,但民办高校各自的质量保障及评估控制体系仍然有着区别。本文对大陆民办高校类型与评估进行了调研及分类分析 ,并指出了民办高校发展亟待解决的尖锐问

Micro-CT analysis of high temperature creep damage of 2D C/SiC composites

利用显微CT针对自愈合2dC/SIC复合材料高温蠕变试验前后的内部孔隙率进行了分。析结果表明,显微CT技术能较好地探测高温蠕变前后2dC/SIC复合材料内部孔隙率变化,从孔隙率的变化初步证实了bXC组元对2dC/SIC复合材料有一定的自愈合作用。利用显微CT技术证实了高温下的拉伸应力不会导致2dC/SIC复合材料中新的裂纹产生。We report a micro-CT experiment that permits us to assess void growth and microstructure development in self-healing 2D C/SiCcomposites subjected to high temperature creep.The results reveal that the micro-CT is a promising facility to detect the evolution of voidsin 2D C/SiC composites,and the BxC composition plays a positive role in the self-healing behavior of the composites subjected to hightemperature.In addition,the results show that high temperature creep will not lead to new cracks in the composites,which may be caused bythe self-healing of matrix cracks.国家自然科学基金重点项目(90405015