一种金属多层板的制备方法

ZL201910523204.6一种金属多层板的制备方法-何金燕、焦四海、袁福

Improved Highly Efficient Hydrogen Production from Formic Acid on a Pd/C Catalyst Doped by Phosphorus

以次亚磷酸钠(nAH2PO2)为还原剂,成功地制备出一种新型高效的Pd-P/C催化剂,其对甲酸-甲酸钠混合液分解制氢具有较高催化活性.经过优化后得到的3%Pd-P/C催化剂,在30℃,反应液甲酸和甲酸钠浓度比为1∶5,总浓度为4MOl/l条件下,前1H平均转化频率可达565H-1,该Pd-P/C催化剂的催化活性是传统的以nAbH4还原制得的Pd/C催化剂活性的3.5倍.联合谱学表征结果表明,在Pd粒子的形成生长过程中,P的掺入提高了Pd纳米粒子的分散性,减少了粒子的团聚,最终得到了粒径较小的Pd粒子,从而极大地提高了催化剂的活性.动力学研究表明Pd-P/C催化剂催化甲酸分解的反应活化能为18.63kJ/MOl,相比以nAbH4还原所得催化剂(反应活化能为26.69kJ/MOl),反应活化能更低.A potent phosphorus-doped Pd nanocatalyst(Pd-P/C)for hydrogen generation from the formic acid(FA)-sodium formate(SF)mixtures has been successfully prepared via the reduction of NaH2PO2.Over this 3%Pd-P/C catalyst,the turn-over frequency(Tof)of 565h-1 was observed for a FA-SF mixture with a FA/SF concentration ratio of 1∶5and the total concentration of4mol/L at 30 ℃.Compared with Pd/C synthesized with a NaBH4 reduction method,the activity of Pd-P/C is 3.5times as much.The results of the catalyst characterization demonstrated that the modification with P during the formation and growth of particles resulted in the well-dispersed fine Pd nanoparticles on carbon and enhanced the catalytic performance of the resulted catalyst.Kinetic studies showed that its reaction activation energy was 18.63kJ/mol when utilizing Pd-P/C,much lower than utilizing Pd/C as a catalyst(reaction activation energy of 26.69kJ/mol).国家重点基础研究发展计划(973计划)(2011CBA00500); 福建省自然科学基金(E0510001

黄土丘陵沟壑区主要物种根茎力学特性

植物根茎力学特性影响着植被固定土壤和拦截的能力，是植被抗侵蚀特性研究不可缺少的一部分。在延河 流域选取的６个典型小流域内，对铁杆蒿（Ａｒｔｅｍｉｓｉａ ｇｍｅｌｉｎｉｉ）、茭蒿（Ａｒｔｅｍｉｓｉａ ｇｉｒａｌｉｉ）、达乌里胡枝子（Ｌｅｓｐｅｄｅｚａ ｄａｖｕｒｉｃａ）、阿尔泰狗哇花（Ｈｅｔｅｒｏｐａｐｐｕｓ ａｌｔａｉｃｕｓ）、猪毛蒿（Ａｒｔｅｍｉｓｉａ ｓｃｏｐａｒｉａ）、蒙古蒿（Ａｒｔｅｍｉｓｉａ ｍｏｎｇｏｌｉｃａ）的根 茎进行广泛采样，在测量其根直径、抗拉力、抗拉强度、茎直径、抗弯强度和刚度、木质素和纤维素含量等指标的基础 上，探讨了植物根茎力学特性。结果表明：根系直径与抗拉力呈显著的正相关关系，与抗拉强度呈显著的负相关关系， 且均可用幂函数进行拟合；随着茎的直径增长抗弯刚度不断加强、抗弯强度趋于稳定；猪毛蒿茎平均直径、最大抗压 力和抗弯刚度较其他物种大；达乌里胡枝子的茎抗弯刚度较小，根系抗拉强度和茎抗弯强度却最大；抗弯强度与木质 素含量、纤维素含量和纤维素／木质素均具有显著的相关关系。</p

Study on the genetic stability of expressing His-β~(APC) strain

Genetic stability is essential in the production practice of interest product.Therefore,in order to determine the genetic stability of the genetic strain,plasmid stability was identified through methods of determination of cell growth,plate streaking,enzyme cutting of plasmid DNA,product identification.The experiment shows the following results： the plasmid loss rate of strain His-&beta; was 6% for 5 generation,8% for 10 generation,9% for 15 generation,15% for 20 generation during the subculture on the solid plate with no antibiotics;the size and shape of colony was essentially the same after the strain was transferred of culture on the solid plate for 20 generations;recombinant plasmids did not change before and after subculture through the identification of BamHⅠand HindⅢenzyme cutting;His-&beta; protein in primary and 5,10,15 and 20 generations can be expressed and showed no significant difference after induction.The results showed that the plasmid had structural stability and segregational instability.</p

Superior mechanical properties and deformation mechanisms of heterogeneous laminates under dynamic shear loading

High-strain rate response of low C steel/304 stainless steel (SS) laminates was characterized by hat-shaped specimen using Hopkinson-bar technique at a strain rate of about 7 x 10(4) s(-1). Better dynamic shear properties were observed in the laminates, compared to the plain low C steel plate and the plain 304 SS plate. The laminates were found to postpone the nucleation of adiabatic shear band (ASB) in the hard zone and to delay the propagation of ASB from the hard zone to the soft zone. The conventional maximum stress criterion on ASB nucleation was found not valid any more in the laminates. The hardness difference between the hard zone and the soft zone in the laminates was found to have great influence on the patterns of ASB evolution. Nanotwins were formed in the 304 SS and grain refinement was observed in the martensite low C steel for strain hardening under dynamic shear loading. The mechanical incompatibility across the interfaces was observed to result in strain gradient and geometrically necessary dislocations at the interfaces under dynamic shear loading, contributing to extra strain hardening. The extra hardening was also found to be triggered at the propagation tip of ASB, which helps for achieving better dynamic ductility in the laminates

Catalysis of Decomposition of Formic Acid by Au/Al_2O_3 Promoted by Carbon Nanotubes

利用碳纳米管(CnTS)作为添加剂,研发出一种高效新型的Au/CnTS-Al2O3催化剂,其对甲酸分解脱氢具有较高催化活性.经过优化后的Au/CnTS-Al2O3催化剂,在甲酸和甲酸钠摩尔比为7∶3的条件下,363k时甲酸分解的转化频率可达356H-1,比没有掺杂CnTS的Au/Al2O3基底催化剂的活性提高了71%,比直接使用CnTS作载体的Au/CnTS催化剂提高了236%.利用气相色谱检测分解后的气体产物,发现其中CO的体积分数小于0.01%,保证了分解得到的氢气的清洁与干净.联合谱学表征结果表明,CnTS的加入不仅增大了载体的比表面积,而且高度分散了催化剂表面Au粒子使其粒径保持在2nM左右,另外还提高了催化剂表面活性物种Au0的比例.同时,CnTS的高吸氢、储氢能力,也有助于活性位上甲酸分子解离下来的氢物种向CnTS溢流、扩散,从而促进了甲酸脱氢的活性.A type of highly efficient Au/Al2O3 catalyst doped with carbon nanotubes(CNTs)for decomposition of formic acid was developed,which displayed relatively high activity.Using the Au/CNTs-Al2O3 catalyst under the reaction conditions of 363 Kand a mole ratio of formic acid to sodium formate of 7∶3,the turn-over frequency(Tof)of formic acid decomposition reached 365h-1,71% higher than using the Au/Al2O3 catalyst without CNTs and 236% higher than using the Au/CNTs catalyst.We measured the gas products from decomposition of the formic acid by GC-9160 chromatography and found that the fractional volume of CO was less than 0.01%,which ensured the decomposed hydrogen clean and pure.The results of the catalyst characterization demonstrated that the addition of CNTs not only increased the specific surface areas of supporters,highly dispersed Au particles on the surface of the catalyst to around 2nm,but also enhanced the proportion of active species Au0 on the catalyst surface.Meanwhile,CNTs with high hydrogen absorption and hydrogen storage capacity would be conducive to scattering hydrogen-species produced from dehydrogenation of formic acid molecules at the active Au sites and transferring them to the CNTs,followed by diffusion,thus promoting the dehydrogenation of formic acid.国家重点基础研究发展计划(973)项目(2011CBA00500); 福建省自然科学基金(E0510001

Understanding Chitosan-mediated Synthesis of Au/Carbon Nanotube Nanohybrids and Its Catalytic Performance

利用循环伏安法,结合其他谱学表征技术,如SEM/HrTEM,Xrd和XPS对Au/碳纳米管复合材料合成过程中壳聚糖和碳纳米管的协同作用进行了探讨.研究结果表明,壳聚糖不仅提高了碳纳米管在水溶液中的分散性和稳定性,锚定Au纳米粒子于碳纳米管载体表面以防止他们迁移/聚结,更重要的是,其还能够通过降低碳纳米管的还原电势来促进Au3+的自发还原.谱学表征结果表明,相对于纯碳纳米管而言,壳聚糖缠绕的碳纳米管上形成了一种还原电位更低的新还原位,从而使Au离子与碳纳米管间的还原电势差值明显增大,由此引发了壳聚糖与碳纳米管对Au3+的协同还原效应.该类Au/碳纳米管复合材料进一步的应用研究结果表明,其对在水溶液中催化nAbH4还原对硝基苯酚反应表现出很高的活性.The synergistic effect of chitosan and carbon nanotube in synthesis of Au-carbon nanotube nanohybrids were investigated by cyclic voltammograms measurement,combined with various characteristic techniques,such as SEM/HRTEM,XRD and XPS.The present results reveal that the role of chitosan is not only just to disperse CNTs steadily in aqueous solution as well as to anchor Au nano-particles preventing them from migrating/agglomerating on the carbon nanotubes support,but also to adjust carbon nanotubes reduction potential responsible for reduction of Au ions.Those results in addition provide solid evidence that the formation of a new active site,located on the surface of chitosan wrapped carbon nanotubes,is directly related to such cooperative effect.The markedly down shifting of reduction potential of the new active site results in the increasing difference in reduction potential between Au ions and carbon nanotubes,hence,improving spontaneous deposition of Au ions.Moreover,the Au-carbon nanotube nanohybrids has also shown highly effective catalytic performance for reduction of 4-nitrophenol by sodium borohydride in aqueous solution.国家重点基础研究发展计划(973)项目(2011CBA00500); 国家基础科学人才培养基金项目(J1210014); 福建省自然科学基金项目(E0510001

Behavior changes of rats with syndrome of stagnation of liver qi and spleen deficiency after injecting microcrystalline BDNF in bilateral DG areas and regulation of active fraction of Xiaoyao Powder

目的:从行为学角度探讨逍遥散有效部位治疗肝郁脾虚证的调节机制。方法:60只雄性SD大鼠随机等分为5组:正常组、模型组、假手术组、脑源性神经营养因子(BDNF)组、逍遥散组。以21d慢性束缚应激方法塑造大鼠肝郁脾虚证模型,在此基础上,运用脑立体定位仪埋管微量注射BDNF塑造BDNF组。逍遥散组造模方法和BDNF组尽可能相似,突出逍遥散有效部位和BDNF二者干预的可比性,第1、7、14、21天分别比较BDNF组和逍遥散组反映行为变化的各项指标变化趋势是否一致。结果:模型组大鼠逐步呈现肝郁脾虚证表现;假手术组大鼠开始呈现焦躁状态,第14-21天,逐步和模型组行为表现趋同;BDNF组起到干预治疗作用,大鼠焦躁状态得到抑制;逍遥散组大鼠表现自然,逍遥散有效部位起到较好的调节作用。排除了手术创伤等混杂因子,逍遥散组和BDNF组经过21d治疗后穿格数、站立次数、修饰次数变化趋势逐步相似。结论:逍遥散有效部位和BDNF可能有一条作用通路相似,即可能均通过BDNF信号通路来治疗肝郁脾虚证。Objective: To explore the mechanism of active fraction of Xiaoyao Powder in treating rats with syndrome of stagnation of liver qi and spleen deficiency. Methods: Sixty SD male rats were randomly divided into 5 groups as control group, model group, sham-operation group, BDNF group and Xiaoyao Powder group. The rat models with syndrome of stagnation of liver qi and spleen deficiency were established by using method of chronic immobilization stress(CIS) for 21 days. On the basis, rats in BDNF group received injection with microcrystalline BDNF in bilateral DG areas with the help of stereotaxic apparatus. The model establishing methods of Xiaoyao Powder and BDNF groups were as similar as possible, in order to highlight the comparability in intervention between active fraction of Xiaoyao Powder and BDNF. The variation trend of behavior indicators of rats in Xiaoyao Powder group and BDNF group was compared on the 1st, 7th, 14 th, and 21 st day. Results: The symptoms of ‘syndrome of stagnation of liver qi and spleen deficiency' appeared progressively in rats of the model group. Rats in shamoperation group were in anxiety states at the beginning, and the symptoms were basically the same with model group from the 14 th to 21 th day. Anxiety state of rats in BDNF group was inhibited. The behaviors of rats in Xiaoyao Powder group were nature, which showed that active fraction of Xiaoyao Powder could play a good adjustment effect. Eliminating the influence of surgical trauma, the crossing times, standing times, and licking frequency of rats in Xiaoyao Powder group and BDNF group after treating for 21 days were basically the same. Conclusion: From the above results of behaviores, it concludes that there is a similar action pathway between active fraction of Xiaoyao Powder and BDNF, and both might treat syndrome of stagnation of liver qi and spleen deficiency by BDNF signaling pathway.国家自然科学基金青年基金项目(No.81302960)~