增效过磷酸钙的增效机制及其对玉米生长的影响

利用猪毛、风化煤和腐植酸钠的水解液为增效剂制备了一种增效过磷酸钙,探讨了增效过磷酸钙的增效机制及其对玉米生长的影响。结果表明,蒸馏水浸提条件下,增效过磷酸钙能减缓水溶磷的释放,具备较高的pH值缓冲性。与普通过磷酸钙相比,增效过磷酸钙处理的玉米生物量平均增加了41.9%,吸磷量和吸钙量分别增加了61.7%和27.8%,根系活力增加了24.3%。该研究结果对过磷酸钙生产的技术改进具有指导意义。     

过磷酸钙折流混合器的改进

由于绿原化工有限公司过磷酸钙装置生产能力由 6 70 t/ d(实物量 )提高到 84 0 t/ d,折流混合器负荷增大 ,出现折流环磨损加快等问题。采用若干技改措施 :扩大折流环内径、改变折流混合器喷射方向、采用新材料制作折流环 ,使折流混合器能满足 84 0 t/ d过磷酸钙生产的需要     

过磷酸钙含氟尾气处理的新方法

对动态泡沫床处理过磷酸钙含氟尾气的有关技术及费用作了说明 ,指出该方法费用高 ;提出一种新方法 ,该方法不加任何化学助剂 ,采用水作吸收剂 ,只需改变动态泡沫床一些设计参数和选用一种特殊的喷头 (喷头周围设计 1个圆锥形死角区 ,使含氟气体不可能进入该区 )避免了硅胶堵塞。该方法已在湖南浦市化工总厂运行 1年多未发现堵塞 ,同时该法投资少、能耗低、排放尾气达标     

Physical characteristics of sweet potato pulp/polycaprolactone blends

Sweet potato pulp (SSP) obtained as a by‐product from starch extraction was blended with polycaprolactone (PCL) to prepare a biodegradable plastic material. In the blends, PCL was used as a reinforcing agent. The SPP/PCL blends were prepared by compression‐molding under high temperature and pressure, at different SPP/PCL ratios, and the mechanical properties of the molded specimens were tested. Matrix structure and thermal properties were measured by using a Fourier transform infrared (FTIR) spectrophotometer, scanning electron microscope (SEM), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA). Mechanical properties (tensile and flexural properties) were also measured to find the most suitable ratio in a SSP/PCL blend. During compression molding of the SPP/PCL blends under high pressure and temperature, chemical reaction occurred between SPP and PCL, and thus, thermal stability and mechanical strength of the blends increased and water uptake decreased. Also, by increasing the PCL content in the blend, the matrix in the blend became more homogeneous, and consequently, mechanical strength of the molded specimen increased. At 7/3 or 6/4 weight ratio of SSP/PCL, water uptake of the molded specimen became substantially less than that at 8/2. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 861–866, 2004     

A discussion of the methods for comparing the relative effectiveness of phosphate fertilizers varying in solubility

Because various phosphate (P) fertilizers differ widely in their solubility, it is commonly observed that crop response to P fertilizers varies under the same soil and crop conditions. Furthermore, a major problem encountered in the methods for determining the relative effectiveness (RE) of water-insoluble P fertilizer (e.g., phosphate rock) with respect to water-soluble P fertilizers, e.g., single superphosphate (SSP) and triple superphosphate (TSP), is that their growth response curves are usually nonlinear and often do not share a common maximum yield. In this paper, we review and discuss the advantages and disadvantages of the three most commonly used methods for calculating the RE of phosphate rock with respect to TSP (or SSP). The three methods are vertical comparison, horizontal (substitution rate) comparison, and linear-response comparison.     

努力提高过磷酸钙质量

论述以高浓度肥料作为发展方向的今天,过磷酸钙在我国仍应有其一定的地位。介绍扶余化肥厂在以浓酸矿浆法生产过磷酸钙中,采取的一系列技改措施:磷矿配矿使用,增加破碎,提高矿浆细度,定矿调水法磨矿,定浆调酸法混合等,并对磨矿机、混合器、料浆泵、风机等设备进行技改,使产品质量100%达标。     

对网状WDM网中双链路失效的保护算法分析

研究了网状WDM网中双链路失效下共享通路保护(SPP)和共享链路保护(SLP),以及新的保护方式—共享段保护(SSP)的模型,并分析了静态和动态保护算法。动态保护算法可以根据当前网络状态动态调整链路代价,使它们具有较高的资源利用率和较低的阻塞率。     

Polarimetric super-resolution algorithm for radar range imaging via spatial smoothing processing

A full-polarimetric super-resolution algorithm with spatial smoothing processing is presented for one-dimensional (1-D) radar imaging. The coherence between scattering centers is minimized by using spatial smoothing processing (SSP). Then the range and polarimetric scattering matrix of the scattering centers are estimated. The impact of different lengths of the smoothing window on the imaging quality is mainly analyzed with different signal-to-noise ratios (SNR). Simulation and experimental results show that an improved radar super-resolution range profile and more precise estimation can be obtained by adjusting the length of the smoothing window under different SNR conditions.     

Characterizing Strong Stability Preserving Additive Runge-Kutta Methods

Space discretization of some time dependent partial differential equations give rise to ordinary differential equations containing additive terms with different stiffness properties. In these situations, additive Runge-Kutta (additive RK) methods are used. For additive RK methods the curve of absolute monotonicity gives stepsize restrictions for monotonicity. Necessary conditions for nontrivial curves of absolute monotonicity are the nonnegativity of the additive RK coefficients and some inequalities on some incidence matrices. In this paper we characterize strong stability preserving additive Runge-Kutta methods giving some order barriers and structural properties. Research supported by the Ministerio de Educación y Ciencia, Project MTM2005-03894.     

气相色谱法测定过磷酸钙中三氯乙醛

过磷酸钙中的三氯乙醛用异丙醇提取,采用气相色谱法、微电子捕获检测器(ECD)进行测定。该方法具有快速、简单、灵敏度高等优点,适合过磷酸钙中三氯乙醛的测定。