高钾系列复混喷施肥的研制与应用

所研制的高钾系列复混喷施肥其成份以KNO3为主,含微量营养元素。应用试验表明,该喷施肥具有成本低,肥效高,经济效益显著的特点,具有推广应用价值。     

PDSI及sc_PDSI干旱指数在中国西南地区适用性分析

西南地区是中国干旱灾害频发地区,且在全球变暖背景下,干旱发生的频率和程度都有所增加,对农业生产和水资源安全造成威胁。帕默尔干旱强度指数（PDSI,Palmer Drought Severity Index）及在其基础上发展而来的自适应帕默尔干旱强度指数（sc_PDSI,self-calibrating Palmer Drought Severity Index）作为较成熟的干旱监测指标已得到广泛应用。本文利用土壤可含水量（AWC,Available Water Holding Capacity）地理空间模型中土种与AWC的对应关系,反演出西南地区更高分辨率的AWC分布,并采用中国西南70站温度月均值、月累积降水数据,分别计算了PDSI指数及sc_PDSI指数,进而比较分析两种指数的时间变化特征及统计分布性质,探讨二者在西南地区对干旱监测的适用性。结果表明：（1）PDSI与sc_PDSI均反映了西南地区在1965—2010年变干的趋势,但PDSI时间序列振动幅度更大;（2）PDSI的频率分布出现“翘尾”现象,监测到的极端干旱/湿润事件的发生频率高于严重干旱/湿润事件,而sc_PDSI的频率分布则更接近于正态分布;（3）两种指数对2009/2010年西南地区干旱事件的监测结果表明,sc_PDSI对干旱落区和干旱级别的监测均一定程度上优于PDSI,与土壤湿度结果更为接近,而PDSI更易对旱情估计过重;（4）虽然整体上sc_PDSI对PDSI具有一定的调整作用及一定的优越性,但在个别区域（如热带季风气候）并没有体现出调整效果,应用时应当考虑区域因素。     

黄河流域气候变化研究综述

黄河流域从西到东跨越多省,地形复杂,作为中国生态安全战略格局的重要组成部分,是中国气候变化敏感区和生态环境脆弱区。本文主要综述了在气候变暖背景下,黄河流域气候变化特征、影响以及成因和对策建议的最新研究进展：（1）近60年黄河流域气温呈上升趋势,平均升温速率为0.30 ℃/10a,上游升温速率最大,下游次之,冬季升温趋势最显著,夏季最小,降水量上游地区增多,中下游地区减少,蒸散量呈减少趋势。（2）在气候变化和人类活动影响下,黄河流域径流量整体呈下降趋势,源区冰川积雪消融加剧,冻土严重退化,流域植被覆盖整体呈好转趋势,上游脆弱区和中游产沙区水土流失加重,对农业影响利弊皆存,流域病虫害加剧;流域气候变暖,极端天气气候事件增多,对文化遗产安全保存带来巨大挑战。（3）黄河流域气候系统随时间演变的过程不仅受自身内部的动力、热力影响,也受大气环流、海温、青藏高原等外部强迫因子的影响,人类活动造成的大气成分和土地利用覆盖的变化是影响黄河流域局地气候的重要因子。（4）未来黄河流域气温持续上升,降水波动增加,极端天气事件将更加频繁。应对气候变化,重点在于加强黄河流域气候变化科学研究,提升极端天气气候事件的预报预警能力,联合多部门建立气象、水文、生态与数值预报及防控一体化的灾害预报预警系统,同时加强流域水资源的管理调配和有效利用,加强流域生态环境保护,制定科学合理的农业发展战略,推动黄河流域高质量发展。     

Precipitation seesaw phenomenon and its formation mechanism in the eastern and western parts of Northwest China during the flood season

Extending across three major plateaus,namely the Qinghai-Tibetan Plateau,the Inner Mongolia-Xinjiang Plateau and the Loess Plateau,Northwest China has the complex terrain and spatio-temporal climate variations,and is affected by the interactions among different circulation systems,such as the summer monsoon,the westerlies and the plateau monsoon.The understanding of the climate variability,as well as its characteristics and evolution mechanisms in this area has been limited so far.In this paper,the precipitation characteristics and mechanisms in the eastern and western parts of Northwest China during the flood season are compared and analyzed based on the data from 192 national meteorological observational sites in Northwest China in 1961-2016.The results show that,divided by the northern boundary of the East Asian summer monsoon,there are huge differences in the precipitation variation characteristics between the eastern and western parts.The inter-annual variations,interdecadal variations and total trends in the two parts all show a significant seesaw phenomenon.Moreover,it is found that the seesaw phenomenon of precipitation variation is closely related to the opposite variation between the East Asian summer monsoon index(MI) and the westerly circulation index(WI).In addition,the inverse variations on different time scales are only related to the contributions of precipitation at specific grades.Besides,in the two matching patterns of precipitation in the seesaw phenomenon,the middle and high latitudes are occupied by the "high-low-high" wave trains in the precipitation increases in the east of Northwest China(ENWC) and decreases in the west of Northwest China(WNWC) pattern,meaning precipitation increases in ENWC and decreases in WNWC.Whereas the opposite "low-high-low" wave trains at 500 hPa height are observed in the middle and high latitudes in the WH-EA pattern at 500 hPa height,meaning precipitation increases in WNWC and decreases in ENWC.Thus,the atmosphere circulation situation with two wave train types can support both the precipitation seesaw phenomenon and the opposite variation between MI and WI.Moreover,the seesaw phenomenon is shown to be related to the separate or joint effects of the South Asian High,ENSO and the plateau heating on the common but opposite effect on the summer monsoon and the westerlies,in which the South Asian High probably plays a more critical role.This study could deepen the scientific understanding of precipitation mechanisms and improve the weather forecast technology in Northwest China during the flood season.     

LOESS IN THE LONGXI BASIN OF GANSU PROVINCE

The Nuanquangou loess section in the Longxi Basin has been examined in terms of stratigraphic investigation,. including 14C dating, paleomagnetic polarity, spore-pollen diagram, and mineral and chemical analyses. The results indicate that the section is one of the ancient loess sections with a continuous sedimentation and composed of homogeneous materials with abundant carbonate. The Brunhes / Matuyama boundary and the Jaramillo event were recorded in the section. Stratigraphically,this section can be divided into the Holocene and the Pleistocene loess. The latter includes Malan, Lishi and Wucheng loess in descending order. They were developed at about 1.2 Ma ago, whereas the Nuanquangou loess section possesses some local characteristics different from those observed in other areas.     

对铬铁磨球组织选择的理论探讨

通过对磨球运动、受力状况和磨损机制及其影响因素的分析，提出了对磨球使用性能的要求；应用材料科学基本理论，重点探讨了铝铁磨球组织选择的方法、原则和依据。结论是：根据磨球的工况条件，准确判断磨球的磨损机制是合理选择磨球组织的前提。     

地震沉积学在大庆长垣密井网条件下储层精细描述中的初步应用

文中针对大庆油田特高含水期精细调整挖潜,需要精细精确刻画储层的要求,充分利用大庆长垣油田密井网条件下储层精细描述成果及高密度三维地震资料,建立了处理-解释一体化高保真地震处理、大密度合成记录精细标定及地层切片优选方法;针对不同类型砂体分布特点,给出了利用地层切片采用"砂中找泥"和"泥中找砂"的单一河道识别分析方法,形成了"地震趋势为引导,井点相控"的井震结合储层精细刻画方法;实际应用证明对剩余油的分析认识更具针对性,应用点坝识别成果指导了D区水平井方案设计,取得了较好的钻遇效果。     

汶川8.0级地震彭州现场调查及灾害成因分析

2008年5月12日14时28分发生的汶川8．0级大地震对我国四川省西部及西北部县市造成了特别严重,甚至是毁灭性破坏。本文是对地震灾区,主要是极重灾区彭州龙门山镇的现场调查情况的总结,包括灾区的地表破裂、崩塌滑坡地质灾害及建筑物破坏等情况。在此基础上,结合其他的分析成果,对此次地震灾害的主要成因进行了分析。分析表明,本次地震灾害的主要成因包括：震级大、震源浅、断层破裂区域广、影响范围大：地表地质灾害严重,大面积的崩塌、滑坡、泥石流造成了大量的人员伤亡;农村建筑物缺乏必要的抗震设防,乡镇建筑物抗震性能存在差异。     

汶川M_S8.0地震彭州灾区典型震害与成因初步分析

2008年5月12日14时28分汶川发生的8.0级大地震对我国四川省西部及西北部县市造成了特别严重,甚至是毁灭性破坏.基于现场调查资料,分析了彭州灾区的灾害空间分布,描述了典型建筑物破坏和大型滑坡体等地质灾害现象,并结合彭州地区房屋抗震设防情况,对此次地震灾害的主要成因进行了分析.结果表明,本次地震灾害的主要成因包括震级大、破坏力强,滑坡崩塌等地震地质灾害严重,农村建筑物缺乏必要的抗震设防措施等.在未来的规划与建设中,应避开断层、滑坡危险区域,并加强对农村地区建筑物的抗震设防指导.     

二十二万年以来东亚夏季风的千年尺度变化及其在不同时期的差异

本文采用游离铁和全铁的比值,建立了0．220MaB．P．以来长武黄土-古土壤序列的高分辨率古风化强度序列,揭示出0．220MaB．P．以来黄土高原古环境发生了一系列千年尺度的变化,且多数在同一剖面的磁化率记录上没有明显反映或反映较弱。由于该地区冬季土壤温度低于0℃,化学风化的强度主要受控于夏季的温度和降水。据此我们认为,这种千年尺度的波动是东亚古夏季风强度变化的信号。此指标与格陵兰GRIP冰芯δ¹⁸O记录对比发现,二者在末次冰期有较好的吻合性,而夏季风在末次间冰期(深海氧同位素阶段5e)及以前的变化要平缓得多。因此,本文的结果显示出：0．220MaB．P．以来,东亚夏季风在千年尺度上的大幅度变化在末次冰期最为显著,此前则表现为一种较为稳定的模式。