沈阳市河流生态建设项目实施建议

近年来,因干旱少雨等自然灾害影响及人类生产活动对环境的破坏,致使一些中小河流生态功能遭到不同程度的破坏。结合沈阳市近年来河流生态建设的实施情况,从工程措施和生物措施两方面详细介绍了针对不同河流状况的生态建设措施,对今后类似工程建设提供借鉴。     

Correlation analysis of mineral element contents and quality traits in milled rice (Oryza stavia L.)

The relationships among potassium (K), calcium (Ca), sodium (Na), magnesium (Mg), iron (Fe), zinc (Zn), copper (Cu), and manganese (Mn) contents in milled rice (Oryza stavia L.) of 274 genotypes and the relationships between these mineral element contents and other rice quality traits including 3 cooking quality traits, 17 amino acid contents, and protein content were investigated. The results showed that there were significant correlations among most of mineral element contents. Mg, Fe, and Mn contents were significantly correlated with most of the other mineral element contents, while Cu content had significantly negative associations with the K and Mg contents of rice. The relationships between mineral element contents and cooking quality traits showed that gel consistency (GC) was significantly correlated with K, Cu, and Mn contents of rice. Amylose content (AC) was significantly associated with K, Na, Mg, Cu, and Mn contents. The alkali spreading value (ASV) had closely positive relationships with Ca, Mg, and Mn contents. In addition, 8 mineral element contents had obvious correlations with different amino acid contents. Mg, Ca, and Zn contents were significantly correlated with most of the 17 amino acid contents, but Na content did not correlate with amino acid contents except aspartic acid of rice. Furthermore, significant associations were found between protein content and Na, Mg, Zn, Cu, or Mn content. Six principal components were extracted to explain 84.50% of the total variances and contained the information provided by the original 29 variables according to the principal component analysis.     

Evaluating reclamation levels of coastal saline soil using laboratory hyperspectral data

Considerable proportions of coastal saline tidelands in China have been reclaimed for agricultural land uses in the past 30 years. This study aims to investigate the potential utility of laboratory hyperspectral data for evaluating the reclamation levels of those saline lands. A coastal region of Shangyu City (Zhejiang Province) was used as the study area, which was then grouped into four subzones according to the reclamation history. Soil samples were collected at each subzone, and they were characterized by high electrical conductivity and sand content and low organic matter; the longer the saline lands have been reclaimed, the lower the electrical conductivity and sand content are and the higher the organic matter content is. These changing trends of the soil chemical and physical properties can be indicated by the laboratory reflectance spectra of the soil samples. Stepwise discriminant analysis (SDA) was applied to select and identify six salient spectral bands at 488, 530, 670, 880, 1400, and 1900 nm. Using derived discriminant functions, saline lands with different historical years of reclamation were classified with an overall accuracy of 86.6% in a self-test and 89.3% in a cross validation. Finally, this study suggests that remotely sensed hyperspectral data serve as promising measures to assess the reclamation levels of coastal saline soil, as opposed to time-consuming field investigations. Published in Russian in Pochvovedenie, 2007, No. 10, pp. 1226–1233. The text was submitted by the authors in English.     

珠三角农业休闲旅游发展现状与开发建议

近年来,农业休闲旅游已成为我国旅游业发展的一个新亮点和农村经济的新增长点,需要政府和旅游行业与企业加强引导,促进其健康有序发.文章基于珠三角农业休闲旅游发展现状与开发进行探讨.     

东北玉米主产区不同培养料配方对平菇产量的影响研究

研究我国东北玉米主产区平菇栽培过程中不同培养料配方对菌袋的发菌速度、菌丝长势、出菇过程、子实体产量的影响.结果表明:玉米芯的新、陈对发菌速度和菌丝长势影响显著,直接关系到产品的产量与质量;栽培料中新、旧玉米芯各占一半,其他辅料正常添加,可以节省蔗糖和维生素等辅料;选用新玉米芯作为栽培主料效果也很好,但需要添加一定量的蔗糖、维生素等辅料,以保证栽培效果.     

拖拉机自动增力式盘式制动器压盘球槽加工方案的优化

本文以拖拉机制动器压盘五球槽的加工为例,通过对普通铣床、数控铣床及组合铣床三种典型设备的加工方案分析,并对三种方案进行比较和优化,最终得出最佳的加工方案。本案例对类似零件的加工具有一定的指导和借鉴作用。     

磴口县生态网络多情景模拟研究

复杂生态网络是近年来区域生态环境可持续研究的热点。以2016年磴口县的遥感影像数据、DEM数据等为研究素材,提出生态库伦力的概念并基于力导向算法构建生态网络多情景模拟模型,结合最小累积阻力面模型设置多个情景模式对磴口县现状生态网络的演化进行研究。研究结果表明:随着(1.0,0)模式到(0,1.0)模式的转换,生态源地斑块栅格逐渐消失,骨架廊道逐渐出现断裂;在(0,1.0)模式下生态网络遭到极大破坏,现状条件下若进行大规模土地经济开发会对生态网络造成极大的破坏;但在(0.9,0.1)模式下,虽沙漠边缘处出现破坏,但是在样圆内部生态网络却出现扩张,在现有自然资源的约束下,磴口县仍有发展经济的空间,但空间不大。本研究所提出的多情景模拟模型适用于生态网络的演化分析。     

抗病优质大白菜“秋白70”的选育

优质、抗病的大白菜新品种——秋白70是利用天津青麻叶为母体，进行游离小孢子培养，并结合人工接种鉴定技术于2002年育成功。该品种长势旺，成熟期70d，株型较直立，株高48cm，开展度51cm，外叶8片，叶形长倒卵形，叶色深绿，叶面多皱，绿帮；叶球长筒形，颜色绿，叶球内叶颜色浅黄，心叶拧抱，舒心；叶球高44cm，直径14cm，单球重2.2kg左右，净菜率82.3%。品质优良，口味佳。较抗霜霉病和病毒病。平均产量10.8kg/m2。     

Measurement and Analysis of Prestressed Concrete Flat Beam- Waffle Slab System During Prestressing

During the pre - stressing of the unbonded prestressed concrete wide flat beam - waffle slab system, the displacements and strains of slab and the prestressed concrete beams were site - measured and the results were analyzed. The prestressing construction was simulated by finite element program. The prestressing efficiency of the unbonded prestressed concrete wide flat beam - waffle slab system was discussed. It indicates that the prestressing efficiency was affected by the in -plane stiffness of slab.     

Structural Analysis and Discussion of Wide -stayed Bridge Basket

Based on a cable -stayed bridge girder as an example, the structure and function, the operating principle and calculation model of the main elements of the Basket of wide - stayed bridge were described in detail. A further discussion was carried out on the Basket of Cantilever construction of the main beam in the structure.