Catalytic behavior of YBa2Cu3O7-x in the partial oxidation of methanol to formaldehyde

The partial oxidation of methanol to formaldehyde was studied over YBa₂Cu₃O_7-x catalyst in a flow reactor. The structural change of YBa₂Cu₃O_7-x before and after the reaction was measured by means of XRD and iodometric titration method. The catalytic characteristics of YBa₂Cu₃O_7-x for the partial oxidation of methanol to formaldehyde was due to copper ions. It was found that Cu⁺² was responsible for the higher selectivity for formaldehyde.     

Relationship of a dystrophin-associated glycoprotein to junctional acetylcholine receptor clusters in rat skeletal muscle

The relationship of a member of the transmembrane dystrophin-associated glycoprotein (DAG) complex to acetylcholine receptors (AChRs) was investigated using immunofluorescence techniques at rat neuromuscular junctions (NMJs) viewed en face. These results were compared with those from a similar previous study of dystrophin and an autosomal homologue (utrophin or dystrophin-related protein, DRP) (Bewick et al. Neuro Report 1992; 3: 857-860). The region of highest 43 K DAG (43DAG) labelling projected beyond the AChRs by approximately 0.3 microns, as does that for dystrophin. By contrast DRP labelling precisely co-localizes with the AChRs. These results suggest that at the NMJ, the region of high 43DAG concentration encompasses the area of highest intensity labelling for both DRP and dystrophin.     

The rank one mixed μ problem and ‘kharitonov-type’ analysis

The general mixed μ problem has been shown to be NP hard, so that the exact solution of the general problem is computationally intractable, except for small problems. In this paper we consider not the general problem, but a particular special case of this problem, the rank one mixed μ problem. We show that for this case the mixed μ problem is equivalent to its upper bound (which is convex), and it can in fact be computed easily (and exactly). This special case is shown to be equivalent to the so-called ‘affine parameter variation’ problem (for a polynomial with perturbed coefficients) which has been examined in detail in the literature, and for which several celebrated ‘Kharitonov-type’ results have been proven.     

New Environment-Friendly Approach for Bastnasite Metallurgic Treatment (I): Extraction of Tetravalent Cerium from Sulphuric Acid Medium with Di(2-ethylhexyl) Phosphoric Acid

Bastnasiteisamainsourceofrareearthproducts inwhichCeO2/REOisabout50%.Atpresent,a cidity leachingcombinedwithalkali conversion method[1]iscommonlyusedinthebastnasitetreat ment.Thismethodisunfriendlytotheenvironment becausetheradioactiveelementofthoriuman…     

Formation of C4 species in the deactivation of a Pd/SiO2 catalyst during the selective hydrogenation of acetylene

The deactivation characteristics of Pd/SiO₂ in the selective hydrogenation of acetylene were correlated with changes in the amount of the C4 species produced. The amounts of butenes produced changed in parallel with the catalyst activity, indicating that the rate limiting step for butene production was the same as that for acetylene hydrogenation. On the other hand, the amount of 1,3-butadiene produced changed, showing a maximum with catalyst deactivation because 1,3-butadiene is an intermediate in the sequential reaction process which involves both the production and consumption of 1,3-butadiene. This was verified by a simultaneous TG/reaction experiment showing that 1,3-butadiene was a precursor of green oil. The catalyst showed a self-regenerative behavior in its activity and the amounts of C4 species produced during the early stage of deactivation because two opposite factors, which contributed to either the lowering or the promotion of activity, were involved in the process. A specific type of polymer species, produced during the initial period of deactivation, is proposed to be responsible for the promotion of catalyst activity.     

Growth hormone response to growth hormone-releasing factor in selected and control Holstein heifer calves

Holstein heifer calves from selected and control lines were treated with growth hormone-releasing factor to determine whether the magnitude of the pituitary growth hormone response is associated with genetic potential for milk yield. Cows in the selected line were bred to highest Predicted Difference milk sires available each year, while control line cows were bred to bulls that were average for 1964 milk production. Eight calves from each line of similar age (206 to 210 days) and weight (205 kg average) were injected intravenously with .1 microgram/kg growth hormone-releasing factor. Dams' first lactation 305-day mature equivalent records were 10,192 +/- 495 kg for selected calves and 6,908 +/- 376 kg for control calves. Before treatment, GH tended to be higher in selected than control calves (mean +/- SE: selected = 7.5 +/- 1.8, control = 4.6 +/- .4 ng/ml). After injection, peak GH were reached within 20 min and were similar in selected and control calves, averaging 66 +/- 16 and 73 +/- 13 ng/ml, respectively. Results indicate that the magnitude of the growth hormone response to growth hormone-releasing factor is not related to future performance of dairy calves.     

负载化非茂单活性中心催化剂乙烯聚合的研究

在硅胶上负载了双(N-环己基-3-叔丁基水杨醛亚胺基)二氯化锆配合物,得到负载化非茂单活性中心催化剂。该催化剂用于乙烯聚合,考察了配合物用量、共聚单体1-己烯用量、聚合温度、聚合压力、聚合时间、三乙基铝用量对乙烯聚合性能的影响及对聚合物的相对分子质量、相对分子质量分布、熔体流动指数和密度的影响。实验结果表明,负载化非茂单活性中心催化剂保持了原均相催化剂的乙烯聚合性能;该催化剂在淤浆聚合工艺中聚合平稳,所得聚合物的颗粒形态良好。     

Use of Fiber Bragg Grating Sensors for Determination of a Simply Supported Rectangular Plane Plate Deformation

A measurement method has been developed to determine the full-field deformation of a simply supported plane plate under transverse load. The method utilizes strain information provided by a set of four fiber Bragg grating sensors mounted on the plate in a way that all sensors measure strains along one certain direction. The sensors were interrogated using a wavelength swept fiber laser. Utilizing the strain information and the first four terms of Navier solution of simply supported rectangular plate, the necessary parameters for determining the deflection could be computed. By substituting the values of x- and -y- coordinates of each position on the rectangle plate, the full-field deformation information can be obtained. Single-point loading tests were experimentally performed to verify the accuracy of the method.     

La2（MoO4）3：Eu均-花瓣状微／纳米结构的构筑及其荧光性能

在表面活性剂十二烷基硫酸钠（SDS）的作用下，采用温和的水热方法，成功制备了Eu掺杂的花瓣状L丑2（MoO4）3：Eu纳米微结构。这些形貌新颖的微米绒球的直径约3μm，由厚度30nm左右的纳米片次级结构单元自组装构筑而成，分散性良好，形貌规整、大小均一。通过XRD、SEM、TEM测试技术，研究了形貌的形成机理。由于具有良好的结晶度，这些花瓣状La2（MoO4）3：Eu纳米微结构显示出良好的发光性能。