Effects of Molasses-Urea Supplementation on Weight Gain,Ruminal Fermentation and Major Microbe Populations of Winter-Grazing Sheep in Inner Mongolia

The present experiment was conducted to determine the effects of Molasses-Urea Supplementation （MUS） on weight gain, ruminal fermentation and major microbial populations in sheep on a winter grazing regime in Inner Mongolia. Total 40 sheep, allowed free consumption of MUS after grazing, served as a treatment group, while 30 sheep, fed only by pasture grazing, served as a control group. Ruminal fermentation parameters, consisted of pH, Bacterial Crude Protein （BCP） and ammonia nitrogen （NH3-N） were measured. In addition, numbers of five symbiotic bacteria were investigated. The results showed as follows： the average daily weight gain, concentration of NH3-N and numbers of protozoa were significantly higher （p〈0.05） in the treatment group than those in the control group. Contrastingly, no significant difference was found in BCP concentration and pH between the two groups. At the end of the experiment, the populations of Selenomonas ruminantium, Anaerovibrio lipolytica, Fibrobacter succinogenes, Ruminococcus flaveciens and Ruminococcus albus in the treatment group were significantly higher than those of the control group （p〈0.05）. These results demonstrated that greater weight gain could be induced during winter in Inner Mongolia by improved nutritional status through promotion of microbial populations using urea and sugar.

伊犁黄土的磁学性质及其与黄土高原对比

近20多年来黄土高原的黄土磁学性质与古气候研究取得了重要进展,极大地推动了东亚古季风演化、亚洲内陆干旱化及过去全球变化的研究,但对亚洲内陆天山地区的黄土磁学性质知之甚少.选择天山伊犁盆地黄土剖面进行了系统的磁性测量,包括磁化率、无磁滞磁化率、高低温磁化率和磁滞参数等,并与黄土高原进行了对比,开展了伊犁黄土的X射线衍射矿物学分析,初步探讨了伊犁黄土磁化率增强的机制.结果表明,伊犁黄土磁性矿物的总含量要远远低于黄土高原,但磁性矿物类型与黄土高原黄土基本类似,以磁铁矿、磁赤铁矿和赤铁矿为主,部分样品还有钛铁矿等.在磁性矿物中磁赤铁矿占的比例总体上要比黄土高原黄土低,而磁铁矿和赤铁矿占的比例比黄土高原黄土要高.磁性矿物的粒度要比黄土高原粗,以准单畴(PSD)和多畴(MD)为主.成壤作用产生的细粒超顺磁体对磁化率的贡献非常有限,粒径为PSD和MD的磁铁矿和磁赤铁矿为伊犁黄土磁化率的主要贡献者.伊犁黄土磁化率增强既有风速论模式(阿拉斯加或西伯利亚黄土成土模式),又有黄土高原超细颗粒成壤模式,但以前一种模式为主导.伊犁黄土磁化率增强除与源区的原生磁性矿物有关以外,还与当地的地形气候环境和地质背景有关.伊犁黄土磁化率增强的机制十分复杂,将磁化率应用古气候的解释时要慎重.

Loess magnetic properties in the Ili Basin and their correlation with the Chinese Loess Plateau

Over the past two decades, magnetoclimatological studies of loess-paleosol sequences in the Chinese Loess Plateau (CLP) have made outstanding achievements, which greatly promote the understanding of East Asian paleomonsoon evolution, inland aridification of Asia, and past global climate changes. Loess magnetic properties of the CLP have been well studied. In contrast, loess magnetic properties from outside the CLP in China have not been fully understood. We have little knowledge about the magnetic properties of loess in the Ili Basin, an intermontane depression of the Tianshan (or Tien Shan) Mountains. Here, we present the results of rock magnetic measurements of the Ili loess including mass magnetic susceptibility (χ) and anhysteretic remanent magnetization (ARM), high/low temperature dependence of susceptibility (TDS) and hysteresis, as well as X-ray diffraction (XRD) for mineral analysis. Based on the comparison with loess-paleosol sequences in the CLP (hereafter referred to as the Chinese loess), we discuss the possible magnetic susceptibility enhancement mechanism of the Ili loess. The results show that 1) the total magnetic mineral concentration of the Ili loess is far lower than that of the Chinese loess, though they have similar magnetic mineral compositions. The ferrimagnetic minerals in the Ili loess are magnetite and maghemite, and the antiferromagnetic mineral is hematite; XRD analysis also identifies the presence of ilmenite. The ratio of maghemite is lower in the Ili loess than in the Chinese loess, but the ratios of magnetite and hematite are higher in the Ili loess than in the Chinese loess. 2) The granularity of magnetic minerals in the Ili loess, dominated by pseudo-single domain (PSD) and multi-domain (MD) grains, is generally much coarser than that of the Chinese loess. Ultrafine pedogenically-produced magnetic grains have a very limited contribution to the susceptibility enhancement. Rather, PSD and MD particles of magnetite and maghemite are the main contributors to the enhancement of susceptibility in the Ili loess. 3) The susceptibility enhancement mechanism for the Ili loess is complicated and superimposes both a wind velocity/vigor model (Alaskan or Siberian model) and the in situ ultrafine grain pedogenic model; the former might play an important role in the Ili loess. 4) Magnetic susceptibility enhancements of the Ili loess are related not only to the eolian input of the source area, but also to the local climate, landform, and geological background. Therefore, great care should be taken when reconstructing paleoclimate using magnetic susceptibility data from the Ili loess.

Magnetostratigraphy of Late Tertiary sediments from the Chinese Loess Plateau and its paleoclimatic significance

The Late Tertiary red clay/bed sediments underlying the Quaternary loess-paleosol in the Chinese Loess Plateau possesses high-resolution paleoclimatic changes related to the uplift of the Tibetan Plateau. Magnetostratigra-phy and susceptibility measurements are discussed in this paper. The paleomagnetic results show that the red clay/bed began to accumulate at about 8.1 Ma, which represents the oldest Late Tertiary deposit continuously in the central Loess Plateau. The magnetic susceptibility curves show stepwise increases since the initiation of red clay, superimposed on several peaks. Moreover, the magnetic susceptibility increased abruptly since 3.8 Ma, which probably indicates the inception of the modern East Asia monsoon system. Between 3.8 and 2.6 Ma, the stepwise increases of susceptibility may imply progressively intensified East Asia summer monsoon activity related with the stepwise uplift process of the Tibetan Plateau.

Estimation of herbage intake and digestibility of grazing sheep in Zhenglan Banner of Inner Mongolia by using n-alkanes

To reveal the seasonal dynamics of herbage intake, diet composition and digestibility and clarify the relationship of those with herbage nutrient and botanical composition of grazing sheep in Zhenglan Banner of Inner Mongolia, the n-alkane technique was used to test in sheep grazed during June, August and December. The results showed that the sheep mainly ate Fringed sagebrush, Stipa krylovii and Carex in proportions of 33.5,17.9 and 21.2%, respectively, in spring. In summer, the sheep consumed cleistogenes,Potentilla tanacetifolia, Thyme, etc; the intake of Fringed sagebrush, Carex and Stipa declined. In winter,Fringed sagebrush accounted for 50.1% of herbage intake, and the intakes of Cleistogenes and Stipa krylovii increased to 15.3 and 18.4%, respectively. Herbage intake by the sheep in spring was 1.8 kg DM/d, and digestibility was 71.4%. Herbage intake and digestibility decreased slightly to 1.7 kg DM/d and 68.4%during the summer, respectively and decreased significantly to 1.2 kg DM/d and 36.4% in winter. There were significant correlations between diet composition and CP content in winter, diet composition and botanical composition in summer. A highly positive correlation between herbage intake and digestibility was observed in grazing sheep.

Estimating camera parameters from starry night photographs

We propose an efficient, specific method for estimating camera parameters from a single starry night image. Such an image consists of a collection of disks representing stars, so traditional estimation methods for common pictures do not work. Our method uses a database, a star catalog, that stores the positions of stars on the celestial sphere. Our method computes magnitudes(i.e., brightnesses) of stars in the input image and uses them to find the corresponding stars in the star catalog. Camera parameters can then be estimated by a simple geometric calculation. Our method is over ten times faster and more accurate than a previous method.