锰结核中硅,铝,铁,镁,磷,钾,锰,钛的XRFA

本文叙述了用XRF分析锰结核中Si、Al、Fe、Mg、P、K、Mn和Ti的方法。按照通常锰结核的主次成分制备6个人工合成标准,根据Sherman方程计算了已知成分(二元系统)的相对强度。用L-T方求得了互致元素校正的理论α系数(基本的、混合的、修正的),用DATAFLEX151B计算机以BASIC语言汇了“PRA,APU”计算机程序。然后进行非线性回归分析了锰结核样品得到了满意的结果。     

Synthesis of Diethyl Oxalate by a Coupling-Regeneration Reaction of Carbon Monoxide

This article describes a process for the synthesis of diethyl oxalate by a coupling reaction of carbon monoxide, catalyzed by palladium in the presence of ethyl nitrite. The kinetics and mechanism of the coupling and regeneration reaction are also discussed. This paper presents the results of a scale-up test of the catalyst and the process based on an a priori computer simulation.     

一种新型温湿度测量系统的设计

为了解决传统温湿度测量系统存在的标定和校准过程复杂而引起的精度不高的问题,文中介绍了一种新型的温湿度测量系统。该系统由瑞士SENSIR ION公司新生产的SHT11数字式温湿度传感器和日本NEC公司生产的78F9177Y单片机为核心组成,具有电路简单、免标定、精度高和可靠性好等优点。     

光谱痕量分析的检出限问题

本文研究了光谱分析中的检出限问题。对目前文献中提出的一些检出限的公式进行了归纳和推导。讨论了ＩＵＰＡＣ和Ｌｏｎｇ检出限公式的一些实际应用。     

Comparison of Different Cartridges of Solid Phase Extraction for Determination of Polyphenols in Tobacco by UPLC/MS/MS and Multivariate Analysis

The comparison of solid phase extraction(SPE) for the preconcentration and isolation of polyphenols in tobacco samples was carried out by ultra-high performance liquid chromatography/tandem mass spectrometry (UPLC/MS/MS) and multivariate analysis.Several adsorbing materials of SPE(C18,NH2,SAX and OASIS) were investigated.It was found that the C18 and OASIS cartridges can not only speed up the purification process,but also simplify the SPE operation.A UPLC/MS/MS was used for the determination of polyphenols ...     

Nachweis und colorimetrische Bestimmungsmethoden des Molybd?ns

Ohne Zusammenfassung     

远红外契伦柯夫FEL的动力学理论

契伦柯夫自由电子激光可以产生远红外相干受激辐射。本文建立了契伦柯夫自由电子激光的动力学理论并详细研究了初始信号频率,电子束电压和束—介质膜间隙对器件性能的影响。与自由电子激光,回旋自谐振脉塞比较,指出了短波契伦柯夫自由电子激光的几个显著特点。     

Search for a bound trineutron with the 3He(π−pgr;+)nnn reaction

A search for the production of a bound trineutron state has been performed using the reaction ³He(π⁻,π⁺)nnn at incident pion energies of 65, 75, and 120 MeV. No evidence for the existence of the ³n was found, and an upper limit for the production cross section of approximately 30 nb/sr (2σ confidence level) was obtained. Received: 22 October 1998     

Determination of sulfur anions by ion chromatography-postcolumn derivation and UV detection

A novel method for determination of formaldehyde sulfoxylate,sulfite,thiocyanate,and thiosulfate in foodstuffs by ion chromatography separation with postcolumn derivation and UV detection has been developed.All species are separated at Dionex IonPac AG22A and AS22A with mobile phase of a mixture of 4.5 mmol/L sodium carbonate and 0.8 mmol/L sodium bicarbonate at a flow-rate of 1.0mL/min.The postcolumn derivation solution was 0.24%iodine in 0.2%phosphate acid and the detection wavelength was set at 288 nm...