不同品性冬小麦籽粒灌浆特性研究

为揭示冬小麦干物质积累过程的动态变化,利用不同品种冬小麦分期播种的灌浆速率资料,建立了Logistic模型,定量分析了不同播期条件下不同品性冬小麦的灌浆特性,并探讨了冬小麦灌浆特性对气象因子的响应情况。结果表明,籽粒灌浆质量与开花后天数的关系符合Logistic生长曲线方程。基于Logistic模型求算的各次级参数能够较好地表征冬小麦籽粒灌浆特性,半冬性品种较春性品种灌浆高峰期出现时间早;春性品种的粒重渐增期和粒重快增期持续时间一般长于半冬性品种的;半冬性品种的平均活跃灌浆期较春性品种的短;早播和正常播种条件下,春性品种最大和平均灌浆速率均高于半冬性品种的,而迟播条件下春性品种最大和平均灌浆速率均低于半冬性品种的,适期晚播更利于春性品种灌浆和千粒重增加。灌浆特性的变异系数分布总体呈春性品种大于半冬性品种的,表明播期对春性品种的影响更大。不同籽粒灌浆特性对气象因子的响应不同,其中孕穗—成熟期内的平均气温、孕穗—乳熟期内的降水量、播种—乳熟期内的日照时数与冬小麦灌浆特性相关密切,基于灌浆特性与气象因子建立的逐步回归方程决定系数为0.507～0.875,均通过了0.01的显著性检验。     

Retrospection on the Conclusions of Earthquake Tendency Forecast before the Wenchuan M_S8.0 Earthquake

The reason for the failure to forecast the Wenchuan M_S8.0 earthquake is under study, based on the systematically collection of the seismicity anomalies and their analysis results from annual earthquake tendency forecasts between the 2001 Western Kunlun Mountains Pass M_S8.1 earthquake and the 2008 Wenchuan M_S8.0 earthquake. The results show that the earthquake tendency estimation of Chinese Mainland is for strong earthquakes to occur in the active stage, and that there is still potential for the occurrence of a M_S8.0 large earthquake in Chinese Mainland after the 2001 Western Kunlun Mountains Pass earthquake. However the phenomena that many large earthquakes occurred around Chinese Mainland, and the 6-year long quietude of M_S7.0 earthquake and an obvious quietude of M_S5.0 and M_S6.0 earthquakes during 2002～2007 led to the distinctly lower forecast estimation of earthquake tendency in Chinese Mainland after 2006. The middle part in the north-south seismic belt has been designated a seismic risk area of strong earthquake in recent years, but, the estimation of the risk degree in Southwestern China is insufficient after the Ning’er M_S6.4 earthquake in Yunnan in 2007. There are no records of earthquakes with M_S≥7.0 in the Longmenshan fault, which is one of reasons that this fault was not considered a seismic risk area of strong earthquakes in recent years.     

Characteristics of the Zhengzhou Laoyachen Fault Revealed by Seismic Exploration Data

Exploration and research of fault activities are the fundamentals of earthquake prediction and prevention and disaster reduction. In order to determine the location, characteristics and activities of the Zhengzhou-Laoyachen fault, shallow seismic prospecting with different exploration depth across the Laoyachen fault was carried out in the northern suburbs of Zhengzhou city in 2006. The images of the subterranean structure and tectonics at depths of 30m～6000m have been available by applying the combined methods of explosive seismic sources and vibrator seismic sources, as well as the combination of diverse observation systems with different parameters. The outcome indicates that the Laoyachen fault is a normal fault running NW and dipping NE, which offsets stratums ahead of Neogene (N). However, no fault displacements are found in the interior stratums of Q+N.     

Thermal Anomalies and Earthquakes： Evidence from Wenchuan, China

Earthquake prediction is a difficult problem in Earth sciences.Unsuccessful predictions one after another urged people to explore more synthetic and comprehensive methods for earthquake prediction.The Lithosphere-Atmosphere-Ionosphere(LAI)coupling theory pays great attention to the processes taking place within the near ground layer of atmosphere.It has achieved great results recently,and can enlighten us about the nature of an earthquake's precursor.Based on the NCEP reanalysis dataset,this paper attempts to track the anomalies of the surface's upward long wave radiation flux(ULWRF),the temperature at the depth of 10cm～20cm below ground surface layer(BGL)and the air temperature at 2 meters above ground surface(AIR)around the time of the strong Wenchuan earthquake.Thermal anomalies were observed before and after May 12,2008,the time of the Wenchuan earthquake.Perhaps the thermal anomaly that occurred prior to the earthquake can be taken as indicators of the earthquake,but in view of the complexity of the earthquake phenomena,using thermal anomaly as a precursor should be done with caution.     

Study of Paleoearthquakes by Excavation of Grouped Trenches on the Zemuhe Fault in Daqingliangzi,Xichang,Sichuan

Uncertainties are common in the dating of paleoearthquakes.To improve the credibility of the dating of paleoearthquakes,analysis was done on fault activity,sedimentary environment and seismo-geomorphology to investigate paleoearthquakes along the Zemuhe active fault zone.Grouped trenches were excavated near Daqingliangzi,which revealed three palaeoearthquake events aged 160a,3100a and 5500a～8900a,respectively,including recurrence intervals of about 3000a.Sedimentary processes related to strike-slip fault type earthquakes were discussed,and a sedimentary model was put forward for strike-slip faults at hillsides where drumlin and reverse scarp developed.     

Preliminary Research on the Characteristics of the M_S8.0 Wenchuan Earthquake Hazard

The M_S8.0 Wenchuan earthquake on May 12, 2008 caused heavy casualties and economic loss. According to the field investigations, the characteristics can be described as follows: The meizoseismal region with an intensity of XI shows an obviously zonal distribution and suffered serious destruction from the earthquake, and the destruction perpendicular to the earthquake surface rupture decreased sharply. At the same time, the intensity X and IX regions perpendicular to the rupture are narrow and therefore their coverage area is small. The intensity on both sides of the rupture attenuates rapidly, but intensity VII and the VI regions are wide, the latter covering about 240,000 km~2. In intensity VI region, the damage area perpendicular to the rupture in the southern part is much larger than that of the northern part. Also, much new understanding about destruction types and destructive modes for all kinds of buildings, landforms and terrain is achieved in this paper.     

新元古代“雪球”事件对海水碳、硫同位素组成的影响

在新元古代晚期地球上曾发生过全球性的冰川作用，一些学者称之为“雪球”事件。在新元古代“雪球”事件前后，古海水的C、S同位素组成都出现了非常大的变化，在“雪球”之前海水中的碳酸盐非常富集^13C，在“雪球”期间和紧随其之后贫^13C，然后δ^13C值出现了高达10‰的正漂移；在“雪球”开始之前古海水硫酸盐的δ^34S值呈逐渐降低的变化特征，紧随“雪球”之后古海水硫酸盐的δ^34S值出现了超过20‰的正漂移，达到地质史上的最高值，同期形成的硫化物具有异常高的δ^34S值。“雪球”事件前后古海水C、S同位素组成的大幅度变化，是由“雪球”前后全球环境的剧烈变化引起的。“雪球”前后海水C、S同位素的大幅度变化是与“雪球”有关的特殊环境条件作用的结果，也是“雪球”事件存在的有力证据。     

美味系猕猴桃越冬冻害指标

通过对1991-2020年越冬期灾害调查、历史灾情查阅和专家评估,初步建立美味系猕猴桃越冬冻害症状及对应指标的3级评价标准.基于对美味系猕猴桃陕西及河南4个主栽县28例灾害个例致灾因子的主成分分析和K-means聚类分析,构建了美味系猕猴桃越冬冻害的综合指标及分级标准,并用3个主栽县资料进行验证.结果 表明:美味系猕猴...     

OTC-1型开顶式气室的臭氧发生、控制与测量系统及物理性能评价

1　 OTC-1型开顶式气室的臭氧发生、控制与测量系统(1 )臭氧发生系统　 OTC-1型开顶式气室是利用臭氧发生器作为气源 ,本试验选用的发生器为 QHG-1型高频臭氧发生器 .该发生器通过将纯氧通入高频放电单元产生臭氧 .放电单元由玻璃管和插在里面的不锈钢管组成 ,两管形成一个环状放电间隙 ,高压极是不锈钢管 ,玻璃管外壁用水冷却 ,同时冷却水作为地极 .臭氧生成的化学过程先是电晕中高自由能电子将氧分子离解成氧原子 ,接着 ,通过三体碰撞反应形成臭氧 .即 :e- 1 O2 → 2 O e- 1 ,　　O O2 M→O3 M式中 M是气体中任何其它气体分…     

我国近40年温度的变化及对农业生产的影响

利用１９５１－１９９０年全国大体分布均匀的３５０个站点的温度资料，分析了近４０年年平均气温，最冷月，最热月平均气温的时空分布特点及各时段（以１０年为一时段）温度距平场的变化。并分析了温度变化对农业生产的影响。