A new pathotype characterization of Daxing and Huangyuan populations of cereal cyst nematode(Heterodera avenae) in China

The cereal cyst nematode（CCN, Heteroder aavenae） causes serious yield loss on cereal crops, especially wheat, worldwide. Daxing population in Beijing City and Huangyuan population in Qinghai Province, China, are two CCN populations. In this study, the CCN pathotypes of Daxing and Huangyuan populations were characterized by tests on 23 standard ＂International Test Assortment＂ with the local species Wenmai 19 as the susceptible control. Tested materials were grouped by three nematode populations＇ virulence on resistant genes（Rha1, Rha2, Rha3, Cre1） and nonresistant genes, varieties and lines. Both Daxing and Huangyuan populations were avirulent to Ortolan（Ha1）. Barley cvs. Ortolan, Siri, Morocco, Bajo Aragon 1-1, and Martin 403-2 were all resistant to both populations. Cultivars Herta, Harlan 43 and wheat Iskamish-K-2-light were all susceptible to Huangyuan population, all of them, however, were resistant to Daxing population. The other five oats were all resistant to the two tested CCN populations. Except Iskamisch K-2-light, all the other wheat cultivars（Capa, Loros×Koga, AUS 10894, and Psathias） were susceptible to Daxing population. Because the pathotypes of the two tested CCN populations in Beijing and Qinghai were not identical to any of the 13 pathotypes previously characterized by the test assortment, we classified Daxing and Huangyuan populations as the new pathotypes, named Ha91.

Site classification of the eastern forest region of Daxing'an Mountains

Based on the plot data from the investigation and the theory of forest ecology and ecological system,the site classification of the eastern forest region of Daxing’an Mountains was made by mean of mathematical method. The main factors were slope, thickness of soil layer, slope position and slope aspect. Grades of slope were used as the division standard for site type group. The slope aspect, slope position and thickness of soil layer were used as the division standards for site type. Altogether 7 site type groups and 15 main site types were determined the region. It provided reliable fundamental basis for the reasonable management and planting design in the area.

Spring habitat selection of sables in Daxing'an Mountains

This paper studies the habitat selection of sables (Martes. zibellina) in spring adopting radio-tracking and GPS (Global Positioning System) in Daxing’an Mountains of China. Sables liked mature and elder forest, but it avoided uncovered and young growth land. In spring sables had strong selection to medium cover-degree forest, but it avoided widen ground and especial high cover-degree forest. On the contrary sables didn’t have the strong selection to shrubs cover-degree, but strong selection to dominant tree species, slope degree and slope direction, especially sable liked medium and lower slope. At the same time, sables had the strong selection to the log’s density and the crown’s cover-degree. Generally it avoided high elevation and lower slope land.

Population Characteristics of Dendrolims Superans in Daxing'an Mountains

Dendrolims superans produced one generation every two years Large larvae and small larvae exist at the sametime. lt broke out in Daxiang an Mountains in 1990. and seriously destroyed growth of Larix gmelum Rupr In order to control D Superans.the population properties of D.superans were stedied from 1991 to 1992 including sex ratio.age distribution. pattern etc.. The sex ratio of D. superans population is The larvae age distrihution indicates that larvaeover 5 instar is less than younger larvae under 4 instar in Yongqing forest farm- but the younger larvae under 4 instar is morethan larvae over 5 instar in Hanjiayuanzi Forest Farm. The population of D. superans in Yongqing Farm has heen declining.and incrcasing in Hanjiayuanzi. Pupae and eggs are mainly distributed in middle and lower crowns layer of trees. respec-tively account for 66% and 59.5%, of total individuals. The pupae in higher cown layer is lightly regular distrihution. andclumping distribution middle and lower crowns layer of trees. The eggs in higher crown is light clumpin1g distribution. andrandom in middle and low crown of tree.

Quantitative dynamics on stimulating regeneration and sowing seedlings of Larix gmelinii in Daxing'an Mountains

To understand the quantitative dynamics and death reason of stimulating regeneration seedlings is significant for stimulating the natural regeneration ofLarix gmelinii and implement of conservation project of natural forest. This paper summarized location observations and directly-seeding simulation experiments of six permanent sample plots that were set up after the seed bumper harvest year ofLarix gmelinii in 1989. The study showed that stimulating natural regeneration seedlings had a large mortality in the first three years, especially in the first year of seedling emergence. After three years seedlings died less and stepped into the stable regeneration stage. A large number of seedlings died of sunscald as the primary death reason. For those areas of good site conditions and rich soil, damping-off would cause seedlings to death in large quantities. The task of stimulating regeneration is mainly to get rid of the litter (forest floor) on burned areas. By means of promoting measures, emergence rate of sown seeds would be several times and dozens of times higher than that of seed shedding on the condition of retention of forest floor. Promoting the regeneration need to select the suitable site against great slope and low-lying lands; at the same time, be careful of the avoidance of frost heaving by depression water.

Classification,metallogenesis and exploration of silver deposits in Daxing’anling of Inner Mongolia and its adjacent areas

By the end of 2020,83 silver deposits(or ore occurrences),including four super-large-scale deposits,nine large-scale deposits,33 medium-scale deposits and 37 small-scale deposits or ore occurrences,have been proved.The amount of silver metal exceeds 86000 t with average grade of 100 g/t,which makes Daxing’anling region one of the the most important silver ore belt in China.However,the metallogenic characteristics and metallogenesis need to be clarified.The silver deposits in the study area are classified into three main types,which are magmatic hydrothermal vein type,continental volcano-subvolcanic type and skarn type,respectively.The supergiant deposits include the Shuangjianzishan deposit(silver metal amount of 15214 t with average grade of 138 g/t),the Baiyinchagandongshan deposit(silver metal amount of 9446 t with average grade of 187 g/t),the Huaobaote deposit(silver metal amount of 6852 t with average grade of 170 g/t),and the Fuxingtun deposit(silver metal amount of 5240 t with average grade of 196 g/t).The silver deposits are mainly distributed in the central and south of the Daxing’anling area,and mainly formed in the Yanshanian period.The silver polymetallic deposits in the Daxinganling area are significantly controlled by regional faults and the junction zone of volcanic rock basins and their margins.The north-east trending deep faults are the most important ore-controlling structures in this area.The distribution of silver polymetallic deposits along the main faults is obvious,and the intersection area of multiple groups of faults often form important mine catchments.The Permian is the most important ore-bearing formation in this area,but some important silver polymetallic deposits occur in Mesozoic volcanic basins or pre-Mesozoic strata.The magmatic rocks related to mineralization are mainly intermediate acidic or acidic intrusions,intermediate acidic lavas,pyroclastic rocks,and small intrusions of ultra-shallow or shallow facies of the Yanshanian Period.The mineralization element combination is mainly determined by the elemental geochemical background of surrounding rocks or source layers.In addition,the type of deposit,the distance from the mineralization center,and the degree of differentiation of ore-forming rock mass are also important influence factors.The article analyzes the prospecting prospects of each silver deposit type in the study area,discusses the relationship between mineralization center and deep prospecting,and proposes that porphyry silver deposits should be paid attention to.In the prospecting and exploration of silver deposits,comprehensive evaluation and multi-target prospecting need to be strengthened because silver can coexist or be associated with a variety of metals.

Zircon SHRIMP U-Pb Dating and Geochemical Characteristics of Late Variscan Granites of the Daitongshan Copper Deposit and Lamahanshan Polymetallic-Silver Deposit, Southern Daxing'anling, China

Daxing＇anling （大兴安岭） area is one of the regions that Phanerozoic granites are extremely developed in NW China. At present, the Hercynian granitoid research lags behind the Mesozoic granitoid research. In this article, we have taken systematic petrochemistry and geochronology researches on the Hercynian granitoids in Daitongshan （代铜山） copper deposit and Lamahanshan （喇嘛罕山） silver poly- metallic deposit, which were located at southern section of Daxing＇anling metallogenic belt. Zircon SHRIMP U-Pb dating results show that, the granite aplites in Daitongshan and the gneissic granites inLamahanshan were formed at （265±5）-（268±9） Ma and （252±2）-（252.6±3.4） Ma, respectively, which were both the products of late Herynian tectonic-magmatic events. Samples from Lama- hanshan are characterized by high SiO2 （69.72 wt.%-74.65 wt.%）, high potassium （3.53 wt.%-4.55 wt.%） and low P205 （0.03 wt.%0.12 wt.%）, aluminum saturation index （A/CNK） range from 0.95 to 0.98, Rb, Nd and K are en- riched, whereas the elements such as Nb, Ta, P and Ti are depleted, which belong to I-type grani- toids. Characteristics of samples from Daitong- shan are similar to H-type granitoids. The magmasource may be mostly originated from the lithospheric mantle component which were transformated or affected by the subduction components, and its formation may be closely related with the subduction and orogenesis of the Paleo-Asian Ocean.

Key technological innovations in the construction of the main terminal of Beijing Daxing International Airport

Beijing Daxing International Airport,a major landmark project in China and a new driver for national development,will represent the direction for the development of civil aviation airports in China.The airport,situated in the junction of Nangezhuang,Daxing District,Beijing City and Gu’an County,Hebei Province,has seen its north terminal area and north terminal built in the first phase,covering a total construction area of about 1.4 million m2.The north terminal area is designed to have an annual throughput of 45 million passengers.

儿童原发性肾上腺皮质功能减退的临床特征和基因突变研究

目的分析儿童原发性肾上腺皮质功能减退患者的临床特征及其DAX1、SF1基因突变的发生率,探讨导致该病可能的分子机制。方法选择原发性肾上腺皮质功能减退的男性患儿25例,观察患儿的临床特征并行辅助检查。抽提外周血基因组DNA,对DAX1基因2个外显子(外显子1和2)的PCR扩增产物进行测序分析;无突变者行SF1基因(外显子2~7)突变筛查。结果患儿均有不同程度的皮肤色素沉着、乏力、恶心、呕吐及脱水等表现;18例曾出现肾上腺危象;8例有明确家族史。15例达到青春发育年龄的患儿中,8例(53.3%)伴性发育不良。DAX1基因检测共发现8种突变,包括1种错义、6种移码和1种无义突变;其中6种(c.291delC、c.332-333delCT、p.E137X、c.605delG、c.731delG和c.838delG)为新发现突变,余为已报道过的突变:2例为p.L262P(表兄弟),1例为c.652-653delCA;未发现SF1基因突变存在。DAX1基因突变率为40%(10/25),伴性发育不良患儿突变率为62.5%(5/8),有明确家族史患儿DAX1基因突变率为100%(8/8);DAX1基因突变患儿的发病年龄不同,...

荧光定量PCR检测牛性别相关基因DAX1表达的标准质粒和标准曲线的构建

本研究根据GenBank中登录的剂量敏感的性别反转-先天性肾上腺发育不良基因1(dosage-sensitive sex reversal,adrenal hypoplasia critical region,on chromosome X,gene 1,DAX1)设计引物,构建包含DAX1基因cDNA片段的质粒,作为中国荷斯坦牛DAX1基因mRNA定量检测的标准品,建立了DAX1基因mRNA表达实时荧光定量PCR检测方法。结果表明,该方法特异性好,检测灵敏度达102拷贝,线性范围为102～106拷贝,阈值循环数(Ct)与PCR体系中起始模板量的对数值间有着良好的线性关系(r=0.99975),扩增效率高(E=100%),可以作为检测牛DAX1基因mRNA定量检测方法。

基于MIDAS的DAX网络发布技术在油田WebGIS中的应用研究

提出了基于 MIDAS的 DAX网络发布技术在Web GIS中的设计方法。该方法在一个共享的中间层上封装了商业规则 ,集中的实现了应用服务器所要实现的功能 ,使客户程序将重点放在显示数据和与用户交互上。将这项技术应用于油田中的地质图绘制方面 ,解决了油田中多层分布式异构数据库的访问、管理和地质图件的动态生成问题。研制开发的“基于 Web GIS地质图绘制软件包”在大庆油田推广使用 ,取得了良好的效果。

Gamma generalized linear model to investigate the effects of climate variables on the area burned by forest fire in northeast China

The purpose of this study was to determine a suitable model for investigating the effects of climate factors on the area burned by forest fire in the Tahe forest region, Daxing＇an Mountains, in northeast China. The response variables were the area burned by lightning- caused fire, human-caused fire, and total burned area. The predictor variables were nine climate variables collected from the local weather station. Three regression models were utilized, including multiple linear regression, log- linear model （log-transformation on both response and predictor variables）, and gamma-generalized linear model. The goodness-of-fit of the models were compared based on model fitting statistics such as R2, AIC, and RMSE. The results revealed that the gamma-generalized linear model was generally superior to both multiple linear regressionmodel and log-linear model for fitting the fire data. Further, the best models were selected based on the criteria that the climate variables were statistically significant at at = 0.05. The gamma best models indicated that maximum wind speed, precipitation, and days that rainfall greater than 0.1 mm had significant impacts on the area burned by the lightning-caused fire, while the mean temperature and minimum relative humidity were the .main drivers of the burned area caused by human activities. Overall, the total burned area by forest fire was significantly influenced by days that rainfall greater than 0.1 mm and minimum rela- tive humidity, indicating that the moisture condition of forest stands determine the burned area by forest fire.

硫代基夫碱叠氮基糖原料中间体的合成

利用亚硝酸盐介导的Lattrell-Dax羟基翻转反应,合成了硫代基夫碱的叠氮基糖原料3,并探讨了不同邻位保护基对翻转反应的影响.结果表明:邻位羟基用三苯甲基(Tr)保护,化合物可以成功实现Lat-trell-Dax羟基翻转反应,得到单一构型产物.

Estimation of gases emitted by forest fires based on remote sensing data

Forest fire, an important agent for change in many forest ecosystems, plays an important role in atmo- spheric chemical cycles and the carbon cycle. The primary emissions from forest fire, CO2, CO, CH4, long-chained hydrocarbons and volatile organic oxides, however, have not been well quantified. Quantifying the carbonaceous gas emissions of forest fires is a critical part to better under- stand the significance of forest fire in calculating carbon balance and forecasting climate change. This study uses images from Enhanced Thematic Mapper Plus （ETM＋） on the Earth-observing satellite LANDSAT-7 for the year 2005 to estimate the total gases emitted by the 2006 Kanduhe forest fire in the Daxing＇an Mountains. Our results suggest that the fire emitted approximately 149,187.66 t CO2, 21,187.70 t CO, 1925.41 t CxHy, 470.76 t NO and 658.77 t SO2. In addition, the gases emitted from larch forests were significantly higher than from both broadleaf-needle leaf mixed forests and broadleaf mixed forests.

The effects of humus moisture content on underground fires in a Larix gmelinii plantation

Underground fires are a smoldering combustion with a slow spread rate, low temperatures and no flame. They can last from days to several months, and can even become overwintering fires. They are difficult to find, leading to considerable damage to the forests. The moisture content of combustible fuels is an important factor in the occurrence and persistence of underground forest fires. The Daxing’an Mountains are a hot spot for underground fires in China. This paper looks at the influence of different moisture contents on underground fire characteristics using simulation combustion experiments in the laboratory. The study showed that peak temperature and spread rate fluctuation of humus at different moisture levels increased with humus depth. Peak temperature and spread rate fluctuation of humus at different depths decreased with increased moisture;moisture content and depth of humus had a significant effect on peak temperature and spread rate fluctuation;peak temperature at different depths decreased with increased moisture;the spread rate in upper layers increased with moisture content, while the spread rate in the lower layers decreased with increased moisture content.

DAX1基因突变所致先天性肾上腺发育不全1例并文献复习

患儿,男,4岁。主因发现口唇、牙龈变黑2年2012年3月8日入院。出生情况正常,皮肤偏黑,外生殖器无畸形。无吐奶、喂养困难。走路说话与同龄儿相仿。2年前,家人发现其口唇及牙龈变黑,易疲劳。1年前患者无明显诱因出现频繁呕吐、腹痛,不能进食,不伴有发热、腹泻,于当地医院查：血电解质：钾5.1～5.91mmol/L,钠100～109mmol/L,

Dax1与胚胎干细胞多能因子Oct4、Sox2、Nanog及Esrrb相互作用的研究进展

胚胎干细胞(ESCs)的自我更新能力和多能性的维持依靠Oct4、Sox2、Nanog及Esrrb等转录因子形成的庞大、复杂的转录调节网络,而Dax1也能参与ESCs特性调节。Dax1与Oct4、Sox2、Nanog和Esrrb等核心因子相互作用,参与维持ESCs特性并抑制ESCs分化。Dax1还能在诱导产生诱导多能干细胞(IPSCs)过程后期产生与Nanog相似的促进作用。研究Dax1在ESCS转录调节网络和诱导产生IPSCs过程中的作用、功能、地位和与其他转录因子相互作用的具体机制,可为干细胞机制研究和临床治疗转化研究助力。目前,Dax1在胚胎干细胞中作用的相关研究较少。本文综述了已有研究成果,以期为胚胎干细胞进一步研究及临床治疗转化研究提供参考。

DAX——一种新型多媒体软件

九十年代一个最引人注目的计算机应用领域是交互式通信。开发交互式通信系统是一项既有趣又有益的工作。这些系统可以实现与外界交流信息,查找信息,回签问题,留言和发送信息等。DAX为开发这些系统提供了一个良好的平台。一、DAX的组成 DAX的名称来源于三个不同领域的名称字首的合成: D表示数据库(Dutabases)——信息的组织者,用来查找和读写信息. A表示声音文本(Audiotext)——对语音信息进行处理。