三江平原粗饲料体外消化率的测定及品质评价

选取黑龙江省三江平原苜蓿、无芒雀麦、小叶章、稻草、玉米秸、豆秸(不带豆荚),通过常规营养成分分析和两级离体消化法测定了6种粗饲料的体外干物质消化率,估测了粗饲料代谢能,进而由公式计算出GI值。结果表明,这6种粗饲料的GI值存在显著差异(p<0.01),按两个不同纤维(NDF、ADF)指标所得的粗饲料分级指数(GIN、GIA)对六种粗饲料的品质优劣划分次序是一致的,其GIA顺序为苜蓿(2.42)>无芒雀麦(0.56)>小叶章(0.53)>玉米秸(0.34)>稻草(0.28)>不带豆荚豆秸(0.22)。试验证明,运用粗饲料分级指数(GI)能够对不同品质的粗饲料精确分级。     

Subaru telescope observations of Deep Impact

The impact cratering process on a comet is controversial but holds the key for interpreting observations of the Deep Impact collision with comet 9P/Tempel 1. Mid-infrared data from the Cooled Mid-Infrared Camera and Spectrometer (COMICS) of the Subaru Telescope indicate that the large-scale dust plume ejected by the impact contained a large mass (approximately 10(6) kilograms) of dust and formed two wings approximately +/-45 degrees from the symmetric center, both consistent with gravity as the primary control on the impact and its immediate aftermath. The dust distribution in the inner part of the plume, however, is inconsistent with a pure gravity control and implies that evaporation and expansion of volatiles accelerated dust.     

Lignin metabolism regulates lodging resistance of maize hybrids under varying planting density

Hybrids and planting density are the main factors affecting maize lodging resistance. Here, we aimed to elucidate the mechanism of the regulation of maize lodging resistance by comparing two hybrids at various planting densities from the perspective of lignin metabolism. Our results showed that compared to lodging-susceptible hybrid Xundan 20(XD20), lodging-resistant hybrid Denghai 605(DH605) showed a lower center of gravity and culm morphological characteristics that contributed to the higher lodging resistance of this hybrid. Lignin content, activities of key lignin synthesis-related enzymes and G-, S-and H-type monomer contents were significantly higher in hybrid DH605 than in hybrid XD20. Stalk mechanical strength, lignin accumulation and enzyme activity decreased significantly with increasing planting density in the two hybrids. While G-type monomers first decreased with increasing planting density but then remained stable, S-type monomers showed a decreasing trend, and H-type monomers showed an increasing trend. Correlation analysis showed that lodging rate was significantly correlated with plant traits and lignin metabolism. Therefore, maize hybrids characterized by high lignin accumulation, high lignin synthesis-related activities, high S-type monomer content, low center of gravity, high stem puncture strength, high cortical thickness, and small vascular bundle area are more resistant to lodging. High planting densities reduce stalk lignin accumulation, relevant enzyme activities and mechanical strength, thereby, ultimately increasing the lodging rate significantly.     

Gravity field of venus: a preliminary analysis

The line-of-sight gravity field for Venus has been mapped by tracking the Pioneer Venus spacecraft in the vicinity of periapsis for a 45 degrees swath of longitude eastward of 294 degrees . There are consistent and systematic variations in the gravity signature from orbit to orbit, attesting to the reality of observed anomalies. Orbit 93 passes over a large positive topographic feature, the "northern plateau," for which there is no corresponding gravity signature. If this region has no isostatic compensation, the gravity signal would exceed the noise level by a factor of 7. The results of simulation modeling indicate that the northern plateau must be compensated at depths of about 100 kilometers or less. The long-wavelength anomalies seen in the Venus gravity data have been Fourier-decomposed along the orbital tracks and compared to analogous spectra for Earth. The gross power in the two mean spectra is approximately, the same, but systematic variations among the harmonics suggest differences in dynamic processes or lithospheric behavior, or both, for the two planets.     

基于ArcGIS的菏泽市人口重心迁移研究

通过重心模型相关理论,借助ArcGIS软件技术绘制2003~2012年菏泽市人口重心迁移轨迹,研究人口重心迁移规律,并分析影响其移动的主要因素。研究表明,菏泽市人口重心与菏泽市几何中心相接近;菏泽市总人口的人口重心迁移与菏泽市非农业人口重心、男性人口重心、女性人口重心具有关联性,移动趋势相近;菏泽市人口重心迁移的总趋势是由东南向西北方向移动;人口重心迁移受人口的迁入迁出、人口的自然增长率、菏泽市的社会经济状况等多种因素影响。     

西北太平洋柔鱼洄游重心年际变化及预测

柔鱼(Ommastrephes bartramii)是西北太平洋海域重要的经济头足类,海洋环境决定其资源的空间分布,通过研究其洄游路径的时空变化趋势与海洋环境之间的关系,来推测柔鱼资源的空间分布是当前渔业资源学研究重点,对于实际生产也有重大意义。利用系统聚类分析和神经网络,根据2004年—2015年我国西北太平洋鱿钓生产统计数据和环境数据,包括海表面温度(Sea Surface Temperature,SST)、海表面盐度(Sea Surface Salinity,SSS)和叶绿素浓度(chlorophyll concentration,Chl-a)数据,结合尼诺转化指数(Trans-Ni1o index TNI),分析柔鱼洄游路径的时空变化和海洋环境之间的关系,预测柔鱼在海洋环境的影响下,洄游路径可能发生的变化。结果表明:柔鱼洄游重心的产量占比与洄游重心的离散度在10月和11月呈现出显著的负相关;洄游重心的纬度变化和TNI之间有着显著的正相关,而经度上并未呈现这一关系;研究利用神经网络模型建立了基于海表面温度、盐度和叶绿素浓度的柔鱼洄游路径时空变化的预测模型,预测结果显示,时间跨度在8—11月内,柔鱼洄游重心纬度上呈现南-北-南,经度上呈现出西-东-西的变化趋势,8月和9月预测洄游重心海域的产量占比为64%和68%,10月和11月,柔鱼种群进行产卵洄游。预测产量占比明显提高,预测海域产量占比为83%和89%。     

小麦精选加工效果的探讨

小麦经严格的粒径分级和重力分选,容重和发芽率发生了变化。粒径分级后,随着粒径的增大,容重和发芽率总体上呈增大趋势,但是粒径较大籽粒较易受到雨害,影响其种用品质,而食用品质测试指标变化表现不一致,各粒径区间脂肪酸值基本保持不变,随粒径的增大粗蛋白质含量呈下降趋势,降落数值有一定的增长;再经重力分选后,从1口到5口容重和发芽率依次减小,与未经重力分选样相比,容重测试分选结果较明显,发芽率测试分选结果不明显,同时也表明粒径较大区间段的籽粒其内部籽粒间的比重和种用品质差异性较小,2.6~2.8 mm和2.8~3.0 mm粒径区间重力分选后食用品质测试指标表现不一致。小麦粒径分级和重力分选对食用品质分级效果不明显。     

Dissipation of Planetary Atmospheres

Escape-level density is approximately inversely proportional to gravity and with decreasing mass will tend toward that of interplanetary gas. When this value is reached, dissipation must cease. The minimum possible ground density of lunar air is calculated to be 10(-12) that of the air at normal temperature and pressure. Ionization creates a binding electrostatic charge at the escape level.     

中国水稻生产的时空动态分析

【目的】绘制中国南北稻区不同稻作制度下的水稻播种面积和产量重心变动图,分析成因,找出影响现阶段中国水稻总产稳定的关键因素。【方法】利用重心拟合模型对水稻生产的时空动态进行分析,敏感性分析方法找出该变动背景下影响中国水稻总产稳定的关键因素。【结果】新中国成立以来除20世纪60、70年代中国水稻播种面积重心和产量重心向东南和东部发生偏移以外,总体上向东北方向移动。1979-2009年北方稻重心由华北快速移动到了东北松辽盆地。中稻和一季晚稻重心移动方向为先东北后东南与南方稻作制度“双改单”变化顺序由北向南相吻合。早稻和双季晚稻重心移动方向都为西南。南方稻区单季稻比例明显上升,“双改单”现象明显,这是导致中国水稻种植面积下降的主要原因。结合敏感性分析得出播种面积已成为目前最有可能造成中国水稻总产量大幅下滑的关键因素。【结论】市场机制的调控和技术进步是目前影响中国水稻时空变动的两个主要因素。在继续坚持以市场为指导的前提下,依据国情从粮食安全的角度出发,重点对面积呈下滑趋势的早稻和双季晚稻进行调控,同时兼顾水稻总面积,防止其出现较大波动,努力提高水稻单产,是确保现阶段中国水稻总产稳中有升的关键。     

Antarctic Tectonics: Constraints From an ERS-1 Satellite Marine Gravity Field

A high-resolution gravity field of poorly charted and ice-covered ocean near West Antarctica, from the Ross Sea east to the Weddell Sea, has been derived with the use of satellite altimetry, including ERS-1 geodetic phase, wave-form data. This gravity field reveals regional tectonic fabric, such as gravity lineations, which are the expression of fracture zones left by early (65 to 83 million years ago) Pacific-Antarctic sea-floor spreading that separated the Campbell Plateau and New Zealand continent from West Antarctica. These lineations constrain plate motion history and confirm the hypothesis that Antarctica behaved as two distinct plates, separated from each other by an extensional Bellingshausen plate boundary active in the Amundsen Sea before about 61 million years ago.     

内蒙古自治区沙质荒漠化研究

内蒙古自治区已是全国沙质荒漠化最严重、面积最大的省区之一。笔者结合1975、2000、2007年3期遥感影像对内蒙古自治区沙质荒漠化进行遥感信息提取,进而分析近30年来横向空间上、纵向时间上沙质荒漠化从面积变化、空间位置变化、转移方向变化、重心变化出发的变化规律。研究结果表明,内蒙古自治区1975～2000年沙质荒漠化面积变化不大,但整体呈发展趋势,且速率极慢;而2000～2007年沙质荒漠化面积显著地减少,各级沙质荒漠化土地都有不同程度的逆转趋势,逆转速率是极其可观的。     

玉米籽粒比重与灌浆特性的关系

【目的】玉米籽粒比重与容重呈显著正相关,容重偏低一直是中国玉米低商品品质的主要问题之一。论文旨在探讨玉米籽粒比重在籽粒灌浆过程中的建成动态及其与籽粒灌浆特性的关系,以期为提高籽粒比重和容重,改善玉米商品品质提供理论依据。【方法】选用普通型品种农大108（ND108）、硬粒型品种费玉4号（FY4）、高淀粉型品种费玉3号（FY3）和郑单18（ZD18）为供试材料,对授粉后玉米籽粒的干比重、鲜比重、百粒干重、单粒鲜体积和水分含量进行测定,采用回归分析讨论比重与灌浆特性的关系。【结果】籽粒鲜比重授粉后随着籽粒的发育呈上升趋势,到成熟期趋于稳定;而干比重在灌浆前期处于下降趋势,授粉后20-35 d是其增长的快速时期,到灌浆后期基本趋于稳定;成熟期FY4、FY3及ZD18籽粒干比重和鲜比重均大于对照ND108。百粒干重和单粒鲜体积在灌浆前期增长迅速,之后增长速率变缓,至成熟期逐渐趋于稳定,其授粉后的变化趋势均可用Logistic曲线较好的模拟,各回归方程的相关系数在0.986-0.999,均达到显著水平,FY4、FY3和ZD18成熟期百粒干重和单粒鲜体积均大于ND108;授粉后随着干物质的不断积累,籽粒水分含量迅速下降,平均每天下降1.302个百分点。籽粒鲜比重与百粒干重（R²=0.851,P＜0.01）、单粒鲜体积（R²=0.594,P＜0.05）均呈显著正相关,而与水分含量（R²=0.803,P＜0.01）呈显著负相关。以灌浆期的百粒干重,单粒鲜体积和水分含量为自变量x,籽粒干比重为依变量y,用二次曲线方程y=a+bx+cx²对它们之间的回归关系进行拟合,方差分析表明各方程回归系数在0.623-0.748,F检验均达到显著水平（P＜0.01）,其中干比重与籽粒水分含量的关系最为密切（r=0.731,P＜0.01）。当百粒干重、单粒鲜体积和水分含量分别为18.75 g、0.589 cm³和61.5%时,干比重处于最小值,此时对应的各品种授粉后天数分别在24.0-28.1 d、16.3-20.7 d和21.1-23.6 d,均处在籽粒快速增长期,说明在16-28 d内籽粒快增持续期阶段内,是籽粒干比重形成的关键时期。【结论】籽粒干比重在灌浆前期处于下降趋势,之后快速增长到灌浆后期基本趋于稳定;籽粒灌浆快增持续期是干比重形成的关键时期,此期间影响籽粒灌浆将显著影响干比重的大小;干比重与籽粒水分含量的关系最为密切,回归系数达0.731。     

基于延安市不同植被类型NDVI对气象因子影响及空间异质性

利用Google Earth Engine平台,以Landsat数据集为数据源,采用Slope+Manna-Kendall非参数检验方法,分析全区和不同植被覆盖类型区NDVI_max与气象因子时间变化特征,并应用重心迁移模型分析其空间变化特征,最后应用最小二乘法(OLS)和时空地理加权回归模型(GTWR)进一步揭示不同植被覆盖类型区内NDVI_max分异特征及其驱动力。结果表明:1）1993-2017年延安市年NDVI_max呈现增长趋势,平均年际变化率达到0.008/a(P<0.01),不同植被覆盖类型年NDVI_max也呈现增长趋势,其中针叶林增加幅度最大,为0.009 1/a;2）1993-2017年延安市镶嵌林地重心迁移速率最高（166.31 m/a）,落叶阔叶林重心迁移速率最低（27.04 m/a）;3）延安市全区NDVI与气象因子（平均气温、总降水、平均最高温度和平均最低温度）之间没有显著相关性,但在不同植被覆盖类型情况下,气象因子对NDVI_max存在显著性作用;4）基于GTWR拟合不同植被类型NDVI_max与不同气象因子的效果明显高于OLS,且不同气象因子对于不同植被类型NDVI_max均有影响,各因子之间回归系数存在空间差异性。     

1961—2010年云南省气候变化特征分析

为了研究云南气候变化特点,利用1961—2010 年云南25 个站点的平均气温、最低气温和最高气温、降水量资料,分析研究云南近50 年来的气候变化。结果表明：（1）云南升温趋势明显,升温率达0.24℃/10 a;（2）一年四季中,冬季升温的趋势最明显,春季、夏季和秋季的升温幅度大致相等;（3）年降水量呈略减少趋势,长期变化趋势不显著。年降水量呈周期性的波动变化,且年际变化较大;（4）年平均降水日数变化总体呈下降趋势,其中下降最显著的是小雨日数,中雨日数略为下降,而大雨和暴雨日数却略为增加;（5）年降水强度总体呈上升趋势。     

Effect of Zn application methods on Zn distribution and bioavailability in wheat pearling fractions of two wheat genotypes

Pearling is an effective method for evaluating the distribution of chemical components in wheat grain. Five pearling fractions(representing approximately 20% of the original sample weight) of wheat grain were obtained using the JNMJ3 rice polisher for two cultivars with different methods of Zinc(Zn) application; the residual portion(approximately 80%) was ground as flour. Results showed that foliar or soil+foliar Zn application methods effectively increased Zn concentrations and bioavailability in whole grain and pearling fractions, but soil Zn application was ineffective in field conditions. In addition, the concentrations of Zn, Fe, Mn and Cu within wheat grain showed a diminishing trend from the outer layer to the inner portions of the wheat grain as the pearling level increased. These results clearly showed the distribution of minerals in wheat grain, especially in the outer part of the grain(bran). The results also suggest that precise milling techniques combined with foliar Zn application could improve the Zn and Fe nutritional qualities of consumed flour and mitigate human Zn and Fe deficiencies.     

A network of superconducting gravimeters detects submicrogal coseismic gravity changes

With high-resolution continuous gravity recordings from a regional network of superconducting gravimeters, we have detected permanent changes in gravity acceleration associated with a recent large earthquake. Detected changes in gravity acceleration are smaller than 10(-8) meters seconds(-2) (1 micro-Galileo, about 10(-9) times the surface gravity acceleration) and agree with theoretical values calculated from a dislocation model. Superconducting gravimetry can contribute to the studies of secular gravity changes associated with tectonic processes.     

Moon: two new mascon basins

Lunar gravity data and orbital photography indicate that there is a mascon basin approximately 1000 kilometers in diameter on the farside of the moon and that Mare Marginis is the flooded fraction of a mascon basin approximately 900 kilometers in diameter.     

山东省粮食生产时空格局演变及安全评价

采用重心迁移模型、探索性空间数据分析和波动指数等方法,对1995—2015年山东省粮食生产时空格局变化及粮食安全状况进行研究。结果表明:1)1995—2015年,山东省粮食总产经历了从波动下降到稳步上升2个阶段,而粮食单产整体呈上升趋势;在主要粮食作物中,小麦的总产量和播种面积占比最高,玉米次之,而甘薯和大豆占比呈持续下降的趋势;2)山东省粮食生产存在明显的空间差异,鲁西地区大部分县(市、区)已发展为全省主要粮食高产区,粮食生产重心向西迁移;粮食生产空间集聚态势增强,鲁西地区成为大规模稳定性热点,鲁北、鲁中山区以及鲁东沿海地区成为稳定性冷点;3)从粮食安全状况看,山东省粮食生产能力逐渐提高,粮食安全状况整体趋于好转,但粮食供给稳定性较差,形势依然严峻。     

Lunar gravity: the first farside map

A global lunar gravity field has been determined from data on the long-term motion of the Apollo 15 and Apollo 16 subsatellites and Lunar Orbiter 5. The nearside gravity map resolves major mascon basins and, in general, is in excellent agreemnent with the results of Muller and Sjogren. The farside gravity map is characterized by broad positive gravity in the highland regions with interspersed, localized, negative anomalies corresponding to major ringed basins. A comparison between global gravity and topography indicates that a thicker farside crust could be responsible for these gravitational differences between the two lunar hemispheres.     

阿拉伯海域围网渔场时空分布及其与海表环境因子的关系

为了解阿拉伯海海表环境因子对围网作业渔场的影响,采用2016-2017年中国印度洋拖围网生产数据和同期海表温度、叶绿素浓度、表层海流和海面高度数据,统计分析了围网作业重心变化,以及围网CPUE与海表环境因子关系,并利用频次分析和经验累积分布函数计算出最适宜的海洋环境区间。结果表明:阿拉伯海的海表环境、围网作业和渔场重心受印度洋季风影响明显,围网渔场渔汛主要在东北季风期间,渔场重心移动方向与表层季风相似。东北季风期间,围网作业渔场的海表温度呈现由高到低再到高的小幅波动趋势。CPUE随着叶绿素浓度高值区域南北收缩,呈现南北移动纬向特征;且CPUE呈径向分布在西边界流速较大的海域右侧,多出现在海流最大值和最低值中间区域。东北季风期间,围网渔场适宜海表温度在25.5～28℃,叶绿素浓度在0.2～0.5 mg/m~3,表层海流在0.05～0.25 m/s,海表高度0.20～0.35 m。