On the Riemann–Hilbert problem of the matrix Lakshmanan–Porsezian–Daniel system with a $$4\times4$$ AKNS-type matrix Lax pair

Theoretical and Mathematical Physics - The initial-boundary value problems for the matrix Lakshmanan–Porsezian–Daniel system are studied by utilizing the Fokas unified transform...     

Analysis of cement and cement raw meal by atomic absorption spectrophotometry using a new fusion agent

A new fusion agent is proposed for the analysis of cement and cement raw meal using AAS. In the described method, 0.8 g of the fusion agent, consisting of equal portions of oxalic acid, lithium carbonate and lithium tetraborate, was mixed with 0.2 g of the sample, and the mixture was fused for 10 min at 925 degrees C in a platinum crucilbe. The fusion cake was dissolved with dilute hydrochloric acid (1 + 10) and diluted to 500 ml for the determination of Si, Al, Fe, Ti, Na and K expressed as SiO(2), Al(2)O(3), Fe(2)O(3), TiO(2), Na(2)O, and K(2)O respectively. For the determination of Ca and Mg (expressed as CaO and MgO respectively), 10 ml of the previous sample solution were mixed with 4 ml of 6% (m/v) lanthanum nitrate solution and the solution was diluted to 100 ml. The method was found to have good accuracy and precision. The time required to determine the eight elements was around 80 min for each sample.     

Theoretical Study on the Mass Transfer of Metal Ions in Ion Exchange Process

The kinetics of ion exchange between Ca2 , Mg2 , Co(Ⅱ), Cu(Ⅱ),Ni(Ⅱ), Fe(Ⅲ), y3 or Sm3 , respectively, in 0.50 mol/L HC1 and H on macrorecticular sulfonic ion exchange resin and the kinetics of the same reactions (M -H exchange) when Mn(Ⅱ) coexisted in resin phase as accelerating ion were studied. The accelerating effect manifested and its rule are consistent with the accelerating effect theory based on the concept concerned with adsorption electrical double layer which has been suggested in a previous paper published.     

A New Dimeric Phthalide from Angelica sinensis

Angelica sinensis (Oliv.) Diels (Umbelliferae), known as Danggui in Chinese, one of the most important traditional Chinese medicines, is used for tonifying blood and treating female irregular menstruation and amenorrhoea. It is also used for treatment of …     

High-performance liquid radiochromatography: Its application for stability study of [3H] stobadin

An HPLC method was developed for studying the stability of [³H] stobadin stored in physiological saline or buffers at various pH. Optimum conditions for the separation of degradation products were elaborated. A high-performance liquid chromatograph equipped with a radioactivity detector was used.     

An example of applications of the elementary catastrophe theory in Hamiltonian systems

The convection in atmosphere discussed in ref. [1] is rigorously treated by considering the variation of environmental temperature with the height. This represents an example of applications of the elementary catastrophe theory in Hamiltonian systems.     

2型糖尿病患者血清钙镁与甲状腺激素含量变化及临床意义

为了监测 2型糖尿病人血清钙、镁和甲状腺激素含量 ,分析其临床意义及相关性 ,应用放射免疫分析法测定了 1 1 5例 2型糖尿病及 1 5 0例健康人血清甲状腺激素含量。同时用美国杜邦RXL自动生化仪测定了其血清钙、镁含量。结果表明 ,在 2型糖尿病伴有明显并发症者血镁、FT3水平明显降低 (P <0 0 5 ) ,钙镁两种元素与甲状腺激素水平无明显相关性。 2型糖尿病患者适当补镁对预防其并发症是有益的 ,测定FT3 等可作为判断 2型糖尿病严重程度和估计预后的参考指标。