Carbon and Nitrogen Transport during Grain Filling in Rice Under High-temperature Conditions

Rice ( Oryza sativa cv. Koshihikari) seedlings were grown in a sandy dune soil in pots with a basal dressing of N (0.5 g N), P and K. Two N treatments were applied, a +N treatment in which a top dressing of ¹⁵N-labeled 0.5 g N was supplied on July 20 and a −N treatment in which no additional fertilizer was supplied. During the grain-filling stage from August 6 to 13, plants were subjected to one of three temperature treatments; controlled low temperature, LT (day/night 28/23 °C), controlled high temperature, HT (35/30 °C) and uncontrolled glasshouse temperature, UT (day/night averages, 38/26 °C). All plants were then exposed to ¹³CO₂ for 1 h on August 11 in a growth chamber at 25 °C. On August 13, all plants were harvested and the ¹³C and ¹⁵N abundances and starch and sugar concentrations in the ears, shoots and roots were determined. The ¹³C content of the ear was lower in UT than in LT irrespective of the +N or −N treatment. The translocation of ¹⁵N to the ears was also slightly depressed in UT compared with LT. Under high-temperature conditions (HT and UT), the starch content per plant was reduced for −N, but for +N, it was not significantly different among the temperature treatments. A high accumulation of sucrose was observed in all plant parts under UT conditions. It is suggested that extreme high day temperatures during the grain-filling period may reduce starch synthesis in the grains and, especially so under N-deficient conditions. High temperatures also induce an accumulation of sucrose and a decrease in carbon and nitrogen transport from the shoots to the ears via the phloem.     

极端降雨条件下植被恢复流域结构和功能连通性间的关系

探明极端降雨条件下流域水文和泥沙连通性的相互关系，对新形势下黄土高原植被恢复流域水沙调控与水土保持高质量发展具有重要作用。该研究在泥沙连通性指数(index of connectivity,IC)的基础上，采用地形位置指数和植被覆盖因子改进的结构连通性指数(structural sediment connectivity,SC_st)，累计地表径流深因子改进的功能连通性指数(functional hydrological connectivity,HC_fn)，研究了极端降雨和植被恢复对流域水沙连通性的影响及输沙潜力的表征能力。结果表明：植被恢复流域归一化植被指数均值由2000年的0.29剧增到2020年的0.70，显著影响SC_st，其均值由2000年的-6.49下降到2020年的-10.03,Pearson相关系数-0.93；降雨径流显著影响HC_fn，年月尺度上HC_fn均值与降雨径流深的相关系数均大于0.70。HC_fn可动态反映流域径流输沙情况，平水年流域实...     

Surface Armour and Erosion – Impacts on Long‐term Landscape Evolution

The parameterisation of landscape evolution models is key to their reliable use. To determine reliable parameter sets, data collected from many events over a number of years are required. However, for many recently disturbed, degraded and/or rehabilitated sites, this data may not represent the long‐term behaviour of the surface as armouring, weathering, together with vegetation establishment change the erodibility of the surface. Here, we evaluate a new armouring sub‐model within the SIBERIA landscape evolution model. The calibration of the armour model is conducted using 6 years of field data from four plots, each composed of different surface materials and vegetation characteristics. The calibrated model is then tested on an area of the proposed rehabilitated landform of the Ranger Uranium Mine in the Northern Territory, Australia. The SIBERIA model was then run for a simulated period of 100,000 years using parameters representing (i) a surface constructed of fresh waste rock; (ii) a vegetated surface; and (iii) the calibrated armour sub‐model. The results demonstrate that the different parameter sets produce catchments that are unique despite the same starting surface. Surface material properties exert a first‐order control on landscape evolution. Therefore making predictions for the evolution of a landscape requires a reliable understanding of the material properties. This requires a knowledge of what material will be placed where in the catchment. Copyright © 2017 John Wiley & Sons, Ltd.     

乡村道路重大交通事故致因分析——两则典型案例剖析

在论述乡村道路重大交通事故个案分析价值及其统计学意义的基础上,对两则典型案例的事故致因进行剖析,发现交通安全意识淡薄和道路通行状况恶劣是乡村道路重大交通事故的主要原因,并就事故原因背后的乡村道路建设的规范和乡村客运制度的完善以及交通普法和安全意识的培养阐述有关观点。     

把握新形势开创监理工作新局面——陕西省宝鸡市扶风县农机监理工作记实

本文结合当地实际情况,为更好地贯彻《道交法》提出行之有效的方法并采取了措施,取得成效。     

Evaluation on the irrigation and fertilization management practices under the application of treated sewage water in Beijing, China

Irrigation and fertilization management practices play important roles in crop production. In this paper, the Root Zone Water Quality Model (RZWQM) was used to evaluate the irrigation and fertilization management practices for a winter wheat–summer corn double cropping system in Beijing, China under the irrigation with treated sewage water (TSW). A carefully designed experiment was carried out at an experimental station in Beijing area from 2001 to 2003 with four irrigation treatments. The hydrologic, nitrogen and crop growth components of RZWQM were calibrated by using the dataset of one treatment. The datasets of other three treatments were used to validate the model performance. Most predicted soil water contents were within ±1 standard deviation (S.D.) of the measured data. The relative errors (RE) of grain yield predictions were within the range of −26.8% to 18.5%, whereas the REs of biomass predictions were between −38% and 14%. The grain nitrogen (N) uptake and biomass N uptake were predicted with the RE values ranging from −13.9% to 14.7%, and from −11.1% to 29.8%, respectively. These results showed that the model was able to simulate the double cropping system variables under different irrigation and fertilization conditions with reasonable accuracy. Application of RZWQM in the growing season of 2001–2002 indicated that the best irrigation management practice was no irrigation for summer corn, three 83 mm irrigations each for pre-sowing, jointing and heading stages of winter wheat, respectively. And the best nitrogen application management practice was 120 kg N ha⁻¹ for summer corn and 110 kg N ha⁻¹ for winter wheat, respectively, under the irrigation with TSW. We also obtained the alternative irrigation management practices for the hydrologic years of 75%, 50% and 25%, respectively, in Beijing area under the conditions of irrigation with TSW and the optimal nitrogen application.     

子午线轮胎磨损的计算机仿真

轮胎的磨损直接关系到轮胎的使用寿命.计算机仿真技术能够比较精确地模拟轮胎的磨损变形情况,为此采用ANSYS软件建立了子午线轮胎的三维有限元模型,通过分析轮胎的各个模态得到了轮胎各部位的变形和应力情况, 从而为降低或避免轮胎的磨损提供了一定的理论依据.     

糖皮质激素对肉鸡骨骼肌糖摄取能力的影响及机制探讨

利用同位素双标法,测定在NO供体硝普钠（SNP）、NO合酶（NOS）抑制剂N^G-硝基、L-精氨酸甲酯（L-NAME）和糖皮质激素皮质酮（corticosterone）存在条件下,基础状态或胰岛素诱导的肉鸡离体腓骨长肌的2-脱氧葡萄糖（2-DG）转运速率。结果表明：①SNP引起肌肉基础状态和胰岛素诱导的2-DG转运速率增加,表明NO是调节骨骼肌糖代谢的一个重要细胞因子。②皮质酮引起静态肌肉2-DG转运速率增加,可能与其破坏肌纤维膜的完整性有关。③皮质酮引起肌肉胰岛素诱导的2-DG转运速率下降,加入SNP后,胰岛素机能明显改善,表明应激早期,机体NO浓度的下降,可能与糖皮质激素诱发的胰岛素抵抗有一定关系。④与体内研究不同的是,没有观察到L-NAME对离体骨骼肌2-DG转运速率的影响,表明血液动力学因素在骨骼肌糖摄取机制中同样起着非常关键的作用。     

槲皮素促进拟南芥生长素极性运输的研究(英文)

Study on the role of quercentin in polar auxin transportation. Arabidopsis was cultured on medium supplemented with quercetin to observe the growth of hypocotyls,14C-IAA transport assays were conducted to measure the auxin transport activity. The results showed that Arabidopsis mutant aux1 which had been deficient in auxin influx transportion obviously recovered the ability after cultured on the medium with quercetin. The polar auxin transport was promoted by the addition of quercetin. These results indicated that quercetin could promote polar auxin transport in vivo.     

Quercetin Promotes Auxin Transport in Arabidopsis thaliana

Study on the role of quercentin in polar auxin transportation. Arabidopsis was cultured on medium supplemented with quercetin to observe the growth of hypocotyls,14C-IAA transport assays were conducted to measure the auxin transport activity. The results showed that Arabidopsis mutant aux1 which had been deficient in auxin influx transportion obviously recovered the ability after cultured on the medium with quercetin. The polar auxin transport was promoted by the addition of quercetin. These results indicated that quercetin could promote polar auxin transport in vivo.