干草原地区土壤~(137)Cs沉积特征

应用１３７Ｃｓ示踪技术研究了半干旱干草原地区土壤风蚀过程和强度．根据不同地貌和植被条件　下土壤剖面中的１３７Ｃｓ沉积特征与背景值样点的对比分析，认为缓起伏草地和半固定沙丘处于轻度风　蚀与堆积状态，蚀积速率小于０．１０８　ｃｍ／ａ；半流动沙丘表面风沙活动强烈，背风坡堆积速率大于１．３５ｃｍ／ａ．

中能重离子碰撞中的局域平衡讨论

在ＢＵＵ框架下，讨论了中能重离子碰撞过程中的平衡过程，以及相关的物理量，如集体流、温度、化学势．研究发现，一定时间以后达到局域平衡，且中心区域最先达到平衡，同时周边碰撞时也发现存在局域平衡．平衡时温度为５一７ＭｅＶ．

Synthesis and magnetic characterization of nickel ferrite nanoparticles prepared by co-precipitation route

Magnetic nanoparticles of nickel ferrite (NiFe2O4) have been synthesized by co-precipitation route using stable ferric and nickel salts with sodium hydroxide as the precipitating agent and oleic acid as the surfactant. X-ray diffraction (XRD) and transmission electron microscope (TEM) analyses confirmed the formation of single-phase nickel ferrite nanoparticles in the range 8-28 nm depending upon the annealing temperature of the samples during the synthesis. The size of the particles (d) was observed to be increasing linearly with annealing temperature of the sample while the coercivity with particle size goes through a maximum, peaking at similar to 11 nm and then decreases for larger particles. Typical blocking effects were observed below similar to 225 K for all the prepared samples. The superparamagnetic blocking temperature (T-B) was found to be increasing with increasing particle size that has been attributed to the increased effective anisotropy energy of the nanoparticles. The saturation moment of all the samples was found much below the bulk value of nickel ferrite that has been attributed to the disordered surface spins or dead/inert layer in these nanoparticles. (c) 2008 Elsevier B. V. All rights reserved.

Beam matching between SFC and SSC

The beam matching status between the two isochronous cyclotrons in the Heavy Ion Research Facility at the Lanzhou-Cooling Storage Ring (HIRFL-CSR) is described. Several methods which can be used to accomplish 100% matching are proposed. By comparing of them, the best method is determined. The advantage due to this method is discussed.

Probing into the catalytic nature of Co/sulfated zirconia for selective reduction of NO with methane

In this work, the structural and surface properties of Co-loaded sulfated zirconia (SZ) catalysts were studied by X-ray diffraction (XRD), N-2 adsorption, NH3-TPD, FT-IR spectroscopy, H-2-TPR, UV-vis diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and NO-TPD. NH3-TPD and FT-IR spectra results of the catalysts showed that the sulfation process of the support resulted in the generation of strong Bronsted and Lewis acid sites, which is essential for the SCR of NO with methane. On the other hand, the N-2 adsorption, H-2-TPR, UV/vis DRS, and XPS of the catalysts demonstrated that the presence of the SO42- species promoted the dispersion of the Co species and prevented the formation Of Co3O4. Such an increased dispersion of Co species suppressed the combustion reaction of CH4 by O-2 and increased the selectivity toward NO reduction. The NO-TPD proved that the loading of Co increased the adsorption of NO over SZ catalysts, which is another reason for the promoting effect of Co. (C) 2004 Elsevier Inc. All rights reserved.

Markov过程在森林资源结构动态预测中的应用──以福建省南平地区的树种结构为例

根据马尔可夫决策过程理论和森林资源连续清查的固定样地调查资料，对南平地区的树种结构进行了预测与调整，结果表明，按现状发展，针阔比例将日趋严重，并且毛竹、经济林的占有率呈下降趋势，最终达到以杉木２８．０５％、马尾松１６．６３％、阔叶树１９．０１％、毛竹５．４３％、经济林２．２６％、其它类２８．７１％的树种结构．经调整后稳定状态的树种结构基本趋于合理，即各树种的占有率分别为杉木１８．７２％、马尾松１３．２４％、阔叶树２６．９８％、毛竹１０．８４％、经济林５．４５％、其它类２４．７７％．

不同氮水平对高油玉米吉油一号籽粒产量及其营养品质的影响

不同氮营养水平对高油玉米吉油一号籽粒产量、蛋白质、氨基酸和油脂的影响的研究表明,不同氮营养水平对高油玉米籽粒产量影响较大,施氮增产10.5%～22.9%。在本试验条件下的经济最佳施氮(N)量为180.3 kg·ha-1。不同施氮水平较不施氮均能明显增加高油玉米籽粒蛋白质及其组分中醇溶蛋白和谷蛋白含量,分别增加7.1%～13.3%(平均10.6%)、22.1%～39.1%(平均29.9%)和25.0%～40.7%(平均35.0%),其中施氮175 kg·ha-1时蛋白质含量最高(10.75%),施氮125 kg·ha-1时蛋白质品质相对较好(谷醇比相对较高,醇溶蛋白占蛋白质比例相对较低)。不同施氮水平较不施氮均能明显增加高油玉米籽粒氨基酸总量和必需氨基酸总量,分别增加11.9%～20.3%(平均17.3%)和12.4%～20.4%(平均17.1%),其中施氮175 kg·ha-1时氨基酸总量(11.50%)和必需氨基酸总量(4.19%)均相对较高。适量施氮能增加高油玉米籽粒油脂含量及不饱和脂肪酸、亚油酸和油酸含量,其中施氮175～225 kg·ha-1时籽粒油分、不饱和脂肪酸、亚油酸和油酸含量均较高,较不施氮分别增加7.0%～7.5%,7.4%～8.3%、7.0%～8.5%和8.1%～8.4%,而过量施氮会明显降低籽粒油分、不饱和脂肪酸、亚油酸和油酸含量。