The catfishes (Teleostei: Siluriformes) of central Sumatra

The freshwater and estuarine catfishes of central Sumatra draining to the Indian Ocean and between the Rokan and Batang Hari drainages are reported on the basis of literature records, museum material, and recent collections. Eighty-two species in 10 families are recorded from central Sumatra. Hemibagrus velox and Nanobagrus stellatus are described here as new species. Akysis macronema and Clarias olivaceus are redescribed here.     

A new Odonata family from the Jurassic of Central Asia (Odonata: Epiproctophora)

The new damsel‐dragonfly family Paragonophlebiidae is described based on a new genus and two new species from the Middle‐Late Jurassic of Central Asia.     

Some helminths of the volcano rabbit Romerolagus diazi,including a description of the nematode Teporingonema cerropeladoensis gen. nov., sp. nov. (Trichostrongylidae: Libyostrongylinae)

Some helminths are recorded from volcano rabbits Romerolagus diazi, originally captured in Mexico, which died at the Jersey Wildlife Preservation Trust. Teporingonema cerropeladoensis, a new genus and species of trichostrongylid nematode, is described and its position within the Libyostrongylinae discussed.     

Emersion behaviour and foraging ecology of the common Chilean clingfish Sicyases sanguineus (Pisces: Gobiesocidae)

The present study is the first to correlate information on emersion behaviour and foraging ecology of Sicyases sanguineus, a common clingfish of the Chilean coast. Individuals smaller than 15 cm in total length were frequently found at the highest points in the inter-tidal zone and consumed inter-tidal animals and seaweeds. Fish larger than 23 cm were infrequently observed emersed in the lower inter-tidal zone, but were collected sub-tidally by divers. These large clingfish ate mainly benthic animals occurring in the low inter-tidal and sub-tidal zones. Size-dependent factors, dessication and wave impact restrict the area of action of S. sanguineus to certain areas of the rocky inter-tidal and shallow sub-tidal zone. However, the fish can be locally very abundant, consuming a great diversity of prey items including both direct primary space users and mobile animals able to affect community structure through grazing. We argue, therefore, that S. sanguineus may be important in structuring communities in some areas of the rocky inter-tidal and shallow subtidal zones of Central Chile.     

Notes on Bombyliidae (Diptera) from the southern borderlands of the Sahara with descriptions of new species

The paper is a review of the genus Pellenes (s. lat.) in the fauna of Central Asia and the Caucasus. The genus Pellenes(s. lat.) is redefined and subdivided into four subgenera according to the structure of genitalia: Pellenes(s. str.), Pelpaucus subgen. nov., Pelmultus subgen. nov. and Pelmirus subgen. nov. Altogether 23 species have been treated, of which nine are described as new to science: Pellenes amazonka sp. nov. (female), P. badkhyzicus sp. nov. (male), P. borisi sp. nov. (female), P. karakumensis sp. nov. (male), P. bonus sp. nov. (male), P. pamiricus sp. nov. (male and female), P. pseudobrevis sp. nov. (male and female), P. sytchevskayae sp. nov. (male and female) and P. turkmenicus sp. nov. (male and female). Five species are newly synonymized: P. maderianus Kulczyński, 1905 with P. epularis (O. P.-Cambridge, 1872); P. kulabicus Andreeva, 1976 and P. simoni (O. P.-Cambridge, 1872) with P. geniculatus (Simon, 1868); and P. albomaculatus Peng and Xie, 1993 with P. denisi Schenkel, 1963; P. tauricus (Thorell, 1875) is removed from synonymy with P. simoni (O. P.-Cambridge, 1872) and is shown to be a junior synonym of P. nigrociliatus (Simon in L. Koch, 1875). A lectotype is designated for Pellenes brevis Simon, 1868. P. campylophorous (Thorell, 1875) is recognized to be nomen dubium. Pellenes calvus (Simon, 1868) is excluded from the Central Asian fauna of Pellenes. Evarcha lapponica (Sundevall, 1832), comb. nov. (ex Pellenes), is proposed. Some morphological terms, e.g. the median septum, the epigynal flaps, the central blindending pocket and the newly proposed ‘compound terminal apophysis’, are discussed in relation to their homology.     

基于农户尺度的鄱阳湖平原水稻多熟种植现状及其驱动因素分析

该文以多熟种植典型区域——江西省鄱阳湖地区为例,基于农户问卷调查资料和Logistic回归模型,分析了该地区水稻熟制的现状特征及其影响因素.研究结果表明:(i)在研究区内约66.47%的受访农户选择多熟种植的耕作模式且存在明显的地域差异;(ii)农户水稻多熟种植模式的选择主要受灌溉条件、地块面积、家庭规模、微地貌类型、农户对农业补贴的评价、非农总收入、旱灾等因素的影响;(iii)灌溉条件、地块面积、家庭规模、微地貌类型、农业补贴与农户水稻熟制的选择呈显著正相关,而不断爆发的旱灾频度和非农总收入的增多对水稻的多熟种植具有明显的抑制作用;(iv)未来政府应加强水利设施建设,加大政策扶持力度,因地制宜地引导农民进行多熟种植,以保障区域粮食安全.     

“一带一路”视域下中国与中亚五国贸易影响因素研究——基于随机前沿引力模型的实证分析

基于2001—2017年中国与中亚五国的贸易数据,采用随机前沿引力模型分析影响双边贸易流量的核心因素,并引入贸易非效率模型进一步探究贸易非效率因素,找出贸易阻力。研究表明,经济规模是中国与中亚五国双边贸易的促进因素,人口规模和地理距离对双边贸易的抑制作用明显;贸易非效率因素对双边贸易流量的干扰大,关税、区域贸易协定和交通基础设施水平是贸易非效率的主要构成因素,影响了贸易潜力的发挥。据此,为"一带一路"倡议下,推进中国与中亚五国双边贸易提出对策建议。     

河北平原生态环境用水量估算

生态环境用水是指为维护生态环境不再恶化并逐渐改善所需要消耗的水资源总量。河北平原属重度缺水地区,水资源短缺已成为影响和制约河北省社会经济、环境可持续发展的主要因素。在21世纪应在保证生态用水的前提下,合理规划和保障社会、经济的用水。本文估算了河北平原近期及远期目标所需生态环境用水量,估算结果:2010年、2020年的生态环境用水量分别是59.61亿m~3,60.15亿m~3,这将为河北省水资源可持续利用与社会、经济可持续发展提供科学依据。     

2015—2021年采暖季华北平原污染过程气象条件分析

华北平原是中国三大平原之一，特殊的地理位置、较多的重工业企业及采暖季相对更高的污染排放，导致采暖季极易出现大范围、长时间的污染过程，PM_2.5浓度明显高于周边区域。为了更好地了解天气系统及气象要素对采暖季华北平原城市空气质量的影响，以北纬32°—40°、东经114°—120°华北平原地区50个城市为研究对象，分析2015—2021年采暖季(11月至次年3月)气象条件对华北平原采暖季大范围重污染过程的影响。研究表明，华北平原发生重污染时，高空500 hPa环流曲率减小，环流相对更加平直，垂直方向逆温出现概率增大，水平及垂直方向更加静稳，污染物扩散能力减弱，近地面山东中南部、河南异常偏南风导致区域升温、增湿，有利于颗粒物吸湿增长及二次转化，河北中西部异常偏东至东北风，导致污染物受太行山山脉影响，在太行山东侧堆积，易在山前形成大范围污染过程，且与山东中南部、河南的异常偏南风形成区域风场辐合，污染物扩散条件不利。分析2021年1月20日至28日一次污染过程发现，污染发生期间华北平原高空大气环流相对平直，地面以均压场控制为主，多静风辐合，湿度持续较大，整体污染扩散条件不利，...     

改进的KNN实时校正方法在山区中小流域的应用

为提高山区中小流域实时洪水预报精度,提出了一种基于历史洪水学习的KNN实时校正方法(KNN-H法),并选择陕北黄土高原地区2个山区中小流域为研究区域,将其与传统KNN法和AR法进行对比,验证该方法的校正效果。结果表明:KNN法和KNN-H法的校正精度总体高于AR法；KNN法和AR法不能有效降低预报结果的峰现时间误差,而KNN-H法校正结果峰现时间误差比校正前有明显降低；KNN-H法通过对历史洪水预报误差的学习,可有效解决KNN法在实时校正中因为预热期资料不足导致的校正精度不高问题；当预报洪水过程处于涨洪或退水阶段时,KNN-H法能够快速定位到历史洪水的相同阶段,分析历史预报误差后迅速对当前预报值做出校正；总体上KNN-H法校正精度高于传统KNN法。