排序方式： 共有27条查询结果，搜索用时 296 毫秒
1.
针对复杂大规模可编程器件的特点,提出了一种新的数字频率计的实现方法。在MAXPLUSII开发软件环境下,采用硬件编程语言VHDL,实现了数字频率计的设计。经过仿真,并下载验证,能够实现测频功能。 相似文献
2.
以文献标题中的英—中、中—英翻译为素材，对文献标题翻译概念信息传递中的单词术语与多词术语进行了比较和探讨。 相似文献
3.
Peanut-like hematite has been prepared by a new facile hydrothermal method and applied in the adsorption removal of As(V). The structural features of the as-prepared hematite were characterized systematically by X-ray diffraction, X-ray photoelectron spectroscopy, Brunauer–Emmett–Teller, scanning electron microscopy, energy-dispersive X-ray spectroscopy mapping, Fourier transform infrared spectroscopy, and transmission electron microscopy. Results showed that the morphologies of hematite could be tuned to spindle-like, oval-like, and cantaloupe-like shapes by adjusting the hydrothermal conditions. The peanut-like hematite formation followed a five-step route. At pH = 3, the adsorption amount of As(V) over peanut-like hematite reached 13.84 mg/g, and the adsorption kinetic process corresponded to the pseudo-second-order kinetic model. The peanut-like hematite also showed partial selectivity over As(V) in the hydrosphere. This method can be a reference for the preparation of other architectural metal oxide materials. 相似文献
4.
To improve separate effect of binary heterogeneous azeotrope in the magnetic field with different magnetic induction intensity, the influence of magnetic field on the rectification process of binary heterogeneous azeotrope was investigated with l-butanol-water system. The results show that the composition of liquid-liquid phase equilibrium of l-butanol-water system has definitely changed, the composition of l-butanol in light phase （l-butanol layer） increases by 1. 17%-1.63% and the composition of water in heavy phase （water layer） increases by 1.21%-1.58% under the influence of magnetic field. By separation of magnetization, the composition of l-butanol increases by 0.8%-1.2% and the recovery ratio of 1 -butanol increases by 1.6%-2.5%. Magnetic field has positive effect, however, the magnetized effect is not in proportion to magnetic induction intensity and has an optimum condition, in the range of 0.25 T-0. 3 T. 相似文献
5.
实现林业可持续发展,首先要更新观念;然后要选准主攻方向,明确建设重点,因地制宜地实施;还要建立一整套保障体系。 相似文献
6.
7.
为解决传统的情感分析方法中存在的语义理解能力不足和情感分析不充分问题,本文从语义的角度,运用构建模糊情感本体的方法,对中文在线评论情感分析进行研究.引入情感空间模型,并将传统的在线评论情感分析细分为特征评价和情绪表达两方面.基于已建立的模糊情感本体,对产品(服务)的特征、情感类和强度、程度词、否定词、修辞方法和标点等语义元素进行标注,构建从句子层到文档层的情感计算方法.选取有代表性的评论语料进行实验,结果表明建立的情感分析方法具有优良的准确性和应用性,进一步分析发现不同评论语料中情感具有不同的表达形式和关联关系. 相似文献
8.
9.
Schwertmannite(Sh), a poorly crystalline iron(hydr)oxide that usually appears in acid mine drainage, plays a significant role in the immobilization of As(V). In this study, the effects of UV irradiation and oxalate on the dissolution of Sh with structurally incorporated As(V) [Sh-As(V)] and the subsequent mobilization of As(V) were investigated at pH 3.0. In the dark, more total dissolved Fe was produced(the maximum value was 33.2 mg/L) in the suspensions of Sh-As(V) with oxalate than in those without oxalate. UV irradiation slightly enhanced the mobilization of As(V) for the system of Sh-As(V)-1 and Sh-As(V)-2 in the absence of oxalate compared with that in the dark. However, in the presence of oxalate, UV irradiation caused the concentration of mobilized As(V) to decline by 630-875% compared with that in the dark. This study enhanced our understanding of the mobilization of As(V) and demonstrated that UV irradiation could contribute to the immobilization of As(V) on Sh in aqueous environments containing oxalate. 相似文献
10.