微电解-生物膜复合工艺处理含Ba^2＋有机废水

采用微电解-生物膜复合工艺进行了处理含Ba^2＋有机废水的实验研究。在实验过程中，废水中的有机物由生物膜中的好氧微生物与厌氧微生物菌群作为营养源而消耗；Ba^2＋通过电沉积去除一部分，另一部分被生物膜吸收而去除。以不锈钢为阴极，石墨为阳极，pH为7．50时，Ba^2＋平均去除率为54．67％，COD平均去除率为84．91％。两极问的距离影响生化效果及电流密度，电流密度过高影响生化反应。实验结果表明，微电解-生物膜复合工艺可以实现同时降解有机物和去除重金属离子，且效果显著。     

Simultaneous removal of soot and nitrogen oxides from diesel engine exhausts

In this paper, previously reported findings and new results presented here are discussed with the main objective of establishing the reaction mechanism for soot oxidation on different supports and catalysts formulations. Catalysts containing Co, K and/or Ba supported on MgO, La₂O₃ and CeO₂ have been studied for diesel soot catalytic combustion. Among them, K/La₂O₃ and K/CeO₂ showed the best activity and stability for the combustion of soot with oxygen. A reaction mechanism involving the redox sites and the surface-carbonate species takes place on these catalysts. On the other hand, Co,K/La₂O₃ and Co,K/CeO₂ catalysts display activity for the simultaneous removal of soot and nitric oxide. The soot–catalyst contacting phenomenon was also addressed. A synergic La–K effect was observed in which the mechanical mixtures of soot with K–La₂O₃ showed higher combustion rates than those observed when K and La were directly deposited on the soot surface. The effect of the addition of Ba was explored with the aim of promoting the interaction of the solid with NO₂, thus combining the NO_x catalytic trap concept with the soot combustion for filter regeneration. Ba/CeO₂ and Ba,K/CeO₂ were effective in NO_x absorption as shown in the microbalance experiments. However, the formation of stable nitrate species inhibits the soot combustion reaction.     

Ba1-xBix(Ti0.9Zr0.1)O3陶瓷的介电弛豫特征

采用固相反应法制备了Ba1-xBix(Ti0.9Zr0.1)O3(x=0.01,0.02,0.03,0.04)陶瓷,X射线衍射分析表明所有样品均是四方晶体结构,3%mol的Bi3+能够完全溶入钙钛矿晶格中.不同频率下Ba1-xBix(Ti0.9Zr0.1)O3陶瓷的介电温谱显示所有样品均表现出弥散相变的特征,在x≥0....     

液相烧结对Ba(Ti0.91Zr0.09)O3陶瓷介电性能的影响

采用固相反应法制备了添加1wt%CuO-BaO混合物的Ba(Ti0.91Zr0.09)O3铁电陶瓷,借助XRD、SEM、Agilent4284测试仪,讨论了加入CuO-BaO混合物对Ba(Ti0.91Zr0.09)O3铁电陶瓷的烧结温度、相结构、显微组织及介电性能的影响.结果表明:添加1wt%CuO-BaO混合物,能有效降低Ba(Ti0.91Zr0.09)O3的烧结温度,室温介电常数高,介电损耗小.在1MHZ下εTl=3 150,tgδ=0.06,并且伴有介电弛豫现象.     

Subcritical crack growth behavior of a perovskite‐structured Ba0.5Sr0.5Co0.8Fe0.2O3−δ oxygen transport membrane

This paper herein studies subcritical crack growth (SCG) behavior of a perovskite‐structured Ba_0.5Sr_0.5Co_0.8Fe_0.2O_3?δ (BSCF) as an oxygen transport membrane material. The SCG behavior of BSCF is evaluated by a constant load method and constant stress rate method at room temperature (RT) and 800°C in air, respectively. The low crack velocity measurements are carried out by ring‐on‐ring bending tests while the high crack velocity measurements by compact tension tests. The stress rates vary approximately from 0.1012 to 101.2 MPa/min. The fracture stress increases with increasing stress rate at 800°C. The SCG parameter, n, of BSCF is determined to be 24.32 and 13.83 at RT and 800°C in air, respectively. This indicates that BSCF is more susceptible to SCG at 800°C. The strength‐probability‐time (SPT) diagram is constructed for design proposes. The stress for a lifetime of 40 years should not exceed 27.21 MPa at RT or 4.53 MPa at 800°C to assure a failure probability below 1%.     

钒酸盐玻璃陶瓷封接材料的制备及应用

采取熔融-晶化法制备了主晶相为Ba3(VO4)2的玻璃陶瓷,研究了热处理制度对玻璃陶瓷样品析晶情况、热学及力学性质的影响.结果表明:在最佳热处理条件晶化540 ℃,保温2 h下,玻璃陶瓷的转变温度Tg、软化温度Tf、热膨胀系数及硬度均优于基质玻璃,且热膨胀系数为17.81 ×10 -6℃-1与金属铜的热膨胀系数值( 17.7 × 10-6℃-1)临近,能够与之直接封接,将有毒的含铅封接材料取而代之.     

Fabrication of dense barium zirconate fibers by electrospinning with different complex agents

Acetic acid, lactic acid, and trifluoroacetic acid were used as complex agents for the preparation of dense barium zirconate fibers with electrospinning method. The formation of lactate when lactic acid was used as complex agent led to a mild decomposition process which was beneficial for the fabrication of dense barium zirconate fibers. High temperature stable intermediate phase of BaF₂ appeared when trifluoroacetic acid was used. The intermediate phase of BaF₂ was disadvantageous for pure and dense barium zirconate formation. While water vapor preheat treatment for BaF₂ contained fibers was an effective way for the fabrication of pure and dense barium zirconate fibers.     

二氧化钛过渡层对脉冲激光沉积钛酸锶钡薄膜微结构和介电性质的影响

选取极薄Ti02作为过渡层,采用脉冲激光沉积法分别在Si(100)和Pt(111)/Ti/SiO2/Si(100)基底上制备了Bao.6Sro.4TiO3(BST)薄膜,研究过渡层对BST薄膜微结构及电学性质的影响.发现厚度20纳米以内的锐钛矿相结晶TiO2过渡层可使BST薄膜由无规则取向转变为(111)择优取向,而非晶和较厚TiO2过渡层对BST薄膜的取向无影响.结晶的TiO2过渡层也使薄膜的表面颗粒变细.还研究了不同厚度TiO2对BST薄膜电学性质的影响,结果表明BST薄膜在Pt(111)底电极上加入极薄的结晶TiO2过渡层后电学性质有明显改善,薄膜的介电常数和可调谐度提高,而介电损耗降低.加入膜厚约5nm的TiO2过渡层后,测试频率为10 kHz时薄膜相应介电常数、介电损耗及可调谐度分别为513、0.053和36.7%.     

Nd_2O_3掺杂(Sr_(0.9)Ba_(0.1))La_4Ti_4O_(15)陶瓷的结构及微波性能

采用传统的固相反应法制备(Sr_(0.9)Ba_(0.1))La_4Ti_4O_(15)+x%Nd_2O_3(质量分数0≤x≤8,BSN)系微波介质陶瓷,并对其物相组成、晶体结构及微波介电性能进行分析。研究结果表明,Nd_2O_3含量的增加降低了BSN陶瓷的烧结温度,陶瓷的主晶相为SrLa_4Ti_4O_(15)相,并伴随有少量第二相La_2TiO_5的生成。在微波频率下,随着Nd_2O_3含量的增加,BSN陶瓷的介电常数及谐振频率温度系数变化小,品质因数与频率之积(Q×f)值提高,优化出掺杂4%Nd_2O_3的(Sr_(0.9)Ba_(0.1))La_4Ti_4O_(15)陶瓷具有最佳微波介电性能:εr=43.2,Q×f=42 015 GHz(6.024 GHz),τf=-9.6μ℃-1。     

鄂尔多斯盆地长6油层组古盐度研究

以硼、“相当硼”、K+Na含量、K/Na比值、吸附K′+Na′、锶含量以及Sr/Ba比值等地化指标作为古盐度的判识标志,运用亚当斯和科奇古盐度计算公式,对鄂尔多斯盆地长6油层组沉积环境的古盐度进行分析和计算,结果表明长6油层组沉积时湖泊水体的古盐度为0.940%～1.016%,属富钠的微咸-半咸水环境。经分析比较,上述古盐度判识标志中,K+Na含量及K/Na比值与长6油层组的古盐度无明显对应关系,不能作为判识标志;而硼、”相当硼“、吸附K′+Na′、锶含量及Sr/Ba比值等地化指标较为灵敏,对古盐度的判识较为可靠。将多种指标判识的结果作回归分析后,认为科奇公式计算的结果最为可靠。古盐度的确定不仅可以判断湖泊水体类型,而且对了解生油岩系的发育情况和分析浊沸石化作用的钠组分来源都大有帮助。