磷化氢与烯烃反应的原位NMR谱研究

本文应用加压原位(in-situ)核磁共振技术,在反应温度70～75℃,压力1.0～2.0MPa,氘代苯为溶剂,偶氮二异丁腈(AIBN)为引发剂的条件下探索了磷化氢与丙烯腈,4-乙烯基吡啶,烯丙基胺,丙烯酰胺,氨基吡啉和N-乙烯基咔唑的自由基加成反应,结果表明除氨基吡啉之外的其它五种含氮化合物均能与磷化氢发生反应,从而找到合成含氮有机膦的良好路线。     

Simulation of plasma flow in toroidal solenoid filters

An improved drift approximation model with an added radial electrostatic field has been successfully developed. Our model provides a computationally efficient way of quantitatively describing the plasma motion and predicting the plasma behavior in the toroidal solenoid in a filtered cathodic vacuum arc (FCVA) system. Storer's (1989) experimental results have been successfully simulated by this model. A good quantitative fit is obtained for our simulation results to the measured ion currents versus distance along the torus for various B field strengths, the attenuation length, and the wall current. The model describes the change of plasma density along the torus and provides the value of the electron-ion collision frequency at various conditions. The effect of the magnetic field and radial electric field on the plasma transportation can be assessed by the simulation and various plasma parameters can be determined. It is found that the radial electric field confines the 3-directional drift of the ions and is one of the most important parameters in determining the ion throughput. For any given B field strength and plasma parameters, there is a peak ion output corresponding to an optimal potential difference which can be obtained by the simulation. Over three times more ion output can be achieved when the torus wall is appropriately biased     

微分简易示波伏安法测定分子筛中微量钴的研究

微分简易示波伏安法是一种新的示波分析方法．与经典示波计时电位法相比，具有灵敏度高、去极剂峰高易于测定等优点．本文研究了CO－4（2一毗院偶氮）间苯二酚钠（PAR）体系的示波特性并探讨了应用微分简易示波伏安法测定微量钻的可能性．试验发现，在O．2mol／LHAc－0·2mol／LNaAc－2·5X10－’mol／LPAR底液中，钻离子在iFE曲线的阴极支上电位为一1．68V处产生一尖锐峰，其峰高与钻离子浓度在1．5X10’～1·2X10－‘mol／L范围内呈线性关系，检测灵敏度为5．OXIO－’mol／L‘以此拟定了测定微量钻的新方法．与光度法相比，该…     

对过程e~＋e~－→J／ψ→γ＋X（J~（PC），X→BB（重子，反重子）的角分布和共振态X的自旋－宇称分析

用螺旋度角分布方法对过程ｅ＋ｅ－～Ｊ／ψ→γ＋Ｘ（ＪＰＣ）→ＢＢ（重子，反重子）进行了分析，得到了Ｘ具有不同自旋─—宇称时角分布及投影角分布的形式，从而可以通过对实验数据的分析来确定共振态Ｘ的自旋性质．     

Detection and study of Rb I Rydberg states

We describe the details of an experiment using an atomic beam of rubidium which allowed us to detect by field ionization techniques the np Rydberg states from n = 28 up to n = 78, to detect also ns and nd states using a Stark mixing, and for all of these detected states to check the classical law E_c = [16n^*4]^?1 concerning the critical ionizing electric field E_c. It turns out that for n as high as 65 this law is quite well verified.     

Barium ferrite (BaFe12O19) thin films prepared by pulsed laser deposition on MgO buffered Si substrates

Barium ferrite (BaFe₁₂O₁₉) thin films have been deposited by pulsed laser deposition (PLD) on Si substrates with MgO underlayers. The films were deposited in oxygen atmosphere by excimer laser (=248 nm, pulse duration=23 ns) in the temperature range 750–900 °C. The experiments showed that the substrate temperature has remarkable effect on the films magnetic and structural properties. The BaFe₁₂O₁₉ films deposited at 900 °C in 200 mTorr oxygen showed some perpendicular orientation, with a perpendicular squareness of 0.5 and an in-plane squareness of 0.3. Such thin BaFe₁₂O₁₉ films have platelet grains with a size of about 300 nm. The perpendicular saturation magnetization and coercivity are 185 emu/cm³ and 1.4 kOe, respectively. PACS 81.15.Fg.; 75.70.Ak; 75.50.Pp; 68.55.j     

Room temperature diluted magnetic semiconductor synthesized by dual beam laser deposition

Diluted magnetic semiconductor Co-doped ZnO film has been synthesized by a dual beam pulsed laser deposition method. The magnetic, electrical, and optical properties of the Zn_0.985Co_0.015O_0.67 film are studied in this paper. The film shows ferromagnetic behavior with a coercivity of about 300 Oe at room temperature, and semiconductor behavior with carrier concentration of 2.2×10¹⁸ cm^-3, and a resistivity of 102 mcm. Structural investigations indicated that the film has similar lattice constants to that of ZnO. It is shown that the film exhibits excellent optical properties with a band gap energy of 3.31 eV, which is close to that of ZnO. The origins of the magnetism are also discussed. PACS 81.15.Fg; 75.50 Pp; 61.72.Vv