从对立到融合：日本的都农关系及都市农业演变研究

把空间概念“都”与产业类别“农”融于一体的“都农关系”,是日本近70年来社会经济发展的重要议题之一。基于对中国城市化发展进入都市化高级阶段,以及乡村振兴亟需多类型化实施的认识背景,对日本都农关系的演变进行历史梳理,划分出都农分离、都农共生和都农融合3个阶段,并从社会经济宏观背景变化的视角说明阶段递进的原因。同时把都市农业视为都农关系的表征,分析其在农户结构、种植结构和功能结构上的系列响应。在此基础上,援引制度学派的基本原理,探索日本都农关系从对立走向融合的制度变迁机理。本文认为,都农融合是不可逆转的潮流,因此有必要把“都农关系”转化为中国的政策性概念,强化从都市区视角处理城乡融合创新发展问题。建设具有中国特色的都农融合和都市农业发展体系,需要一系列的制度创新,也亟需学术界主动的理论探索。     

AVHRR 1B定位数据经验插值模型的误差分析

确定像元地理坐标是几何纠正及卫星数据应用的基础。经验插值方法常用于计算高分辨率辐射计AVHRR1B定位数据,研究插值模型的定位误差具有重要意义。该文分析了AVHRR像元空间位置和像元大小,利用AVHRR扫描线的圆心角θ表示像元的位置,建立了像元位置θ和像元大小Δθ的表达模型;根据分段线性插值模型,计算插值后的像元位置θafter和像元大小Δθafter,获得分段线性插值模型的像元位置和大小的误差模型。     

河北省地震局行政值班管理系统的设计与实现

近年来,各级党委政府全面推进机关事业单位值班工作制度化、规范化和标准化,地震系统行政值班人员数量、频次、要求越来越高,责任越来越大.针对河北省地震局行政值班工作的人工管理现状,科研人员结合当前值班规则与工作需求,设计开发一套河北省地震局行政值班管理系统,通过模块实现在线自动排班换班、实时更新排班情况与值班次数统计等功能...     

Influence of Spatial-Temporal and Environmental Factors on Larimichthys polyactis,Octopus variabilis,and Species Aggregated Set-Net CPUEs in Haizhou Bay,China

Set-nets are common alongshore fishing gear used in Haizhou Bay, which rely on flow to catch fish. The catch per unit effort(CPUE) of set-net is affected by spatial-temporal and environmental factors but no research has been conducted on this subject. In this study, we used generalized additive models(GAMs) to explore the influence of spatial-temporal and environmental factors on CPUEs of species aggregated, small yellow croaker(Larimichthys polyactis), and octopus(Octopus variabilis) based on logbooks investigations conducted at 4 stations in an alongshore area of Haizhou Bay from 2011 to 2012. The results showed that all CPUEs exhibited significant spatial-temporal differences at various scales. Aggregated CPUE was high when the sea surface temperature(SST) was 15-18℃ and 20-23℃, which was mainly determined by life history traits of the octopus and small yellow croaker(optimal SSTs 14-17℃ and 19-24℃, respectively). Chlorophyll-a concentration had significant influences on the aggregated, small yellow croaker and octopus CPUEs at optimal ranges of 3.8-6.2 mg m~(-3), 4.2-4.8 mg m~(-3) and 4.5-5.5 mg m~(-3), respectively. Flow through the net had positive relationships with CPUEs. The approximate logarithmic trends in regression curves had a critical point of 2.5 Mm~3 d~(-1), which was the dividing point that differentiated whether the major factor affecting CPUEs was the flow velocity or the fishery resource. Our results from this study will help guide fishery production and improve catch rate of set-net fishing in Haizhou Bay.     

刺参中皂苷组分蒸发光散射-高效液相特征图谱研究

采用高效液相色谱-蒸发光散射(HPLC-ELSD)法建立了刺参皂苷的特征图谱.方法:色谱柱为Symmetry C18(150 mm×4.6 mm,5 μm),采用0.2% 乙酸水溶液-乙腈进行梯度洗脱,流速1.0 mL/min;柱温30 ℃;漂移管温度70 ℃;载气压力25 psi.结论:方法具有良好的专属性,可以作为刺参类产品是否含有刺参皂苷的评价方法.     

Ka波段毫米波云雷达对青藏高原东南缘降水回波的分析

利用丽江站新建的Ka波段毫米波云雷达获得的高时间分辨率的垂直观测资料,结合同址的地面自动气象站和雨滴谱的分钟数据、常规探空数据和附近C波段天气雷达的强度回波,分析了两次降水过程前后云雷达反射率因子Z、径向速度V_r、速度谱宽S_w的垂直变化规律。分析表明:在发生弱降水时,云雷达Z在垂直方向的变化不明显;但V_r、S_w值在0℃层稍低位置有一个明显的分界层(融化层),粒子通过融化层后V_r、S_w都是快速变大,这个变化主要是粒子的相态由固态变成液态引发的,可以通过V_r、S_w突变值的位置来识别0℃层亮带的高度。从C波段天气雷达回波强度、剖面图及云雷达位置的时间-高度图看,对毛毛雨和小雨的回波,强度和高度差异比较明显,毛毛雨比小雨回波高度低、强度弱,与云雷达相比C波段雷达对高一些的云观测不到,对距离较远的弱降水回波无法观测到;由于相同粒子对不同波长电磁波的散射不一样,造成两种雷达垂直方向观测到的Z变化不同。对比弱降水回波,云雷达在...     

Geochemical and Isotopic Techniques Constraints on the Origin, Evolution, and Residence Time of Low-enthalpy Geothermal Water in Western Wugongshan, SE China

Geothermal resources are increasingly gaining attention as a competitive, clean energy source to address the energy crisis and mitigate climate change. The Wugongshan area, situated in the southeast coast geothermal belt of China, is a typical geothermal anomaly and contains abundant medium- and low-temperature geothermal resources. This study employed hydrogeochemical and isotopic techniques to explore the cyclic evolution of geothermal water in the western Wugongshan region, encompassing the recharge origin, water–rock interaction mechanisms, and residence time. The results show that the geothermal water in the western region of Wugongshan is weakly alkaline, with low enthalpy and mineralization levels. The hydrochemistry of geothermal waters is dominated by Na-HCO3 and Na-SO4, while the hydrochemistry types of cold springs are all Na-HCO3. The hydrochemistry types of surface waters and rain waters are Na-HCO3 or Ca-HCO3. The δD and δ18O values reveal that the geothermal waters are recharged by atmospheric precipitation at an altitude between 550.0 and 1218.6 m. Molar ratios of major solutes and isotopic compositions of 87Sr/86Sr underscore the significant role of silicate weathering, dissolution, and cation exchange in controlling geothermal water chemistry. Additionally, geothermal waters experienced varying degrees of mixing with cold water during their ascent. The δ13C values suggest that the primary sources of carbon in the geothermal waters were biogenic and organic. The δ34S value suggests that the sulfates in geothermal water originate from sulfide minerals in the surrounding rock. Age dating using 3H and 14C isotopes suggests that geothermal waters have a residence time exceeding 1 kaBP and undergo a long-distance cycling process.     

磁铁矿与黄铁矿双向交代研究及意义

在华北盆地南缘早古生代碳酸盐岩中,发现了包括交代假象和交代残余枯内的一系列足以支持磁铁矿与的矿之间发生双向交代作用的确凿矿物学证据,甚至在同一个磁性矿物颗粒内,还辨认出方向完全相反而且是先后发生的２种交代现象。磁铁矿（铁磁性矿物）和黄铁矿（顺磁性矿物）之间有双向交代会直接干扰古地磁数据,并影响以此为基础而开展的地块运动分析和古地理的重建。     

储层原始含油饱和度计算方法研究

储层原始含油饱和度是评价储层的重要指标 ,它的计算方法有 :岩心直接测定方法、间接确定法和毛管压力曲线计算方法。简要地讨论了这几种方法 ,重点探讨了利用毛管压力曲线计算储层原始含油饱和度的方法 ,针对该方法目前使用中存在的问题进行了改进 ,并在该方法的理论基础上 ,结合新疆塔里木盆地北部的实例 ,提出一种便于利用毛管压力曲线计算储层原始含油饱和度的适用方法     

冻结粘性土的变形分析

通过三轴压缩试验条件下冻结粘性土变形分析,发现冻结粘性土的体应变明显不为零,随荷载的变化而变化。加荷初期试样体积收缩。但随着荷载的进一步增大而变为膨胀;轴向应变则随偏应力的增大而磁大,表现出明显的粘塑性特征。应力－应变曲线上的准弹性段、屈服处和粘塑性段刚好分别对应体变曲线上的体缩段、体缩量大处和膨胀段。根据冻结粘性土变形曲线。给出了考虑体变形的应力－应变关系。