天然海水河蟹工厂化育苗研究——大水体生产性育苗试验

本文报导了利用对虾育苗设施，进行天然海水河蟹工厂化育苗生产性试验。试验结果令人满意，６９６只亲蟹产出蟹苗１７６４万只。文中讨论了亲蟹的暂养与促产、幼体孵化、幼体培育等主要技术环节。     

马氏珠母贝养殖群体的生长特性研究

从养殖于深圳大亚湾海区的3月龄马氏珠母贝Pinctada martensii养殖群体中挑出较大和较小个体的贝分为2个组,分别命名为大个体组和小个体组,以同样的方式进行养殖,在3—12月龄间每隔1—2月对其生长进行测量;同时取12月龄的贝200个编号进行个体生长测量,到16月龄结束。经t检验,大个体组贝在各个测量阶段4个性状(壳长、高、宽和体重)都显著大于小个体组(p<0.01),大个体组日增长幅度在3—9月龄也大于小个体组;经最小显著差法分析,个体测量的3个亚组间大小存在显著差异(p<0.01),顺序为Ⅰ(Ⅰ’)<Ⅱ(Ⅱ’)<Ⅲ(Ⅲ’),但其日增长量为Ⅰ(Ⅰ’)>Ⅱ(Ⅱ’)>Ⅲ(Ⅲ’),同时显示出初始值较大的个体在后期仍有较大的增长趋势,但个别初始值较小的个体增长快,在生长后期个体也很大。3—9月龄贝的大小平均增长率大于11—16月龄贝,而体重增长要小于11—16月龄贝。该研究结果对选择育种中亲本的选留、珍珠生产中植核贝的选留具有较大的指导作用。     

福建海水鱼类人工繁殖和育苗技术的现状与展望

自90年代以来，福建海水鱼类人工繁殖和育苗技术已向着多品种和批量化方向发展，各特优种类不断增加，人工种苗为海水网箱和池塘养殖提供大量苗源，科研教学单位的多项育苗成果已转化为生产力，开始进入种苗规模化生产的可持续发展阶段。迄今为止，福建海水鱼类人工繁殖和育苗成功的种类至少有14科30种，1999年大黄鱼的育苗量已超过3亿尾，其他年产种苗千万尾以上的海水鱼类有美国红鱼、花鲈、免状黄姑针、真鲷（春季生殖群体）和花尾胡椒鲷；年产种苗数百万尾的有黑鲷、勒氏笛鲷、断斑石鲈、免鱼和斜带髭稠等种类。石首鱼科鱼类已成为人工繁殖和育苗的主要对象。本文还针对福建海水鱼类增养殖的问题，提出今后可持续发展的几点设想。     

Volcaniclastic deposits from the North Arch volcanic field, Hawaii: explosive fragmentation of alkalic lava at abyssal depths

Submarine explosive eruptions are generally considered to become less likely with increasing depth due to the increasing hydrostatic pressure of the overlying water column. Volcaniclastic deposits from the North Arch volcanic field, north of Oahu, have textural characteristics of explosive fragmentation yet were erupted in water depths greater than 4,200 m. The most abundant volcaniclastic samples from North Arch are clast-supported with highly vesicular, angular pyroclasts. They are most likely near-vent pyroclastic fall deposits formed in eruption columns of limited height. Interbedded with highly vesicular pillow lava, they form low (50 to 200 m), steep-sided cones around the vents. Less common are stratified samples with graded bedding; one such sample includes a layer of roughly aligned, platy, bubble-wall glass fragments (resembling littoral limu o Pele) that may have been deposited by density currents. In addition to bubble-wall glass shards, numerous glass fragments with spherical, delicate spindle and ribbon shapes, and Pele's hair-like glass strands occur in the finer size fraction (<0.5 mm) of some samples. They are probably more distal fallout. Another sample, consisting of glass fragments dispersed in a marine clay matrix, was apparently reworked and deposited farther from the vents by bottom currents. Glass compositions include low-(∼0.4-0.6 wt%) and medium-K₂O (>0.6 wt%) alkalic basalt, basanite, and nephelinite. Sulfur and chlorine abundances are high, reaching a maximum of 1,800 and 1,300 ppm, respectively. The ubiquitous presence of limu o Pele fragments, regardless of glass composition, suggests that bursts of Strombolian-like activity accompanied most eruptions. Coalescing vesicles observed in larger pyroclasts and some pillow lava suggests accumulation of volatiles. Since the great hydrostatic pressure makes steam expansion impossible, a volatile-rich, supercritical magmatic fluid probably drove the eruptions. If these volatile-rich magmas had erupted in shallow water or subaerially, tall fountains would most likely have resulted. The great hydrostatic pressure (>40 MPa) limited fountain and eruption column heights.     

沙地麻黄育苗试验研究

文章阐述了麻黄（ＥｐｈｅｄｒａｓｉｎｉｃａＳｔａｐｆ）的生物学特性、引种繁殖技术及育苗效果,认为覆膜育苗在生产上有较高的推广价值,可以很好地开发麻黄的药用资源。     

Kamafugitic diatremes: facies characterisation and genesis—examples from the Goiás Alkaline Province, Brazil

This paper describes the internal organisation of two diatremes (Águas Emendadas and Neuzinha) and one small breccia-filled conduit (Tigre) in the central portion of the Late Cretaceous Goiás Alkaline Province (GAP), central Brazil, and explores the criteria for facies recognition. The GAP kamafugitic diatremes are emplaced into Carboniferous sandstones of the Aquidauana Formation, at the northern margin of the Paraná Basin. They are usually elliptical structures, not longer than 900 m, filled with breccia and partially covered by thin kamafugitic to basanitic lava flows. The breccias are dominated by juvenile pyroclasts, with subordinate amounts of cognate fragments and xenoliths. In addition to variations in ash and lapilli proportions, juvenile fragment types may be used to discriminate genetic processes and the corresponding pyroclastic deposits.

An extensive field, textural and compositional dataset was analysed by multivariate statistical techniques. Combined with field observations, this allowed us to define a set of facies for kamafugitic diatremes, and, more importantly, to understand the internal structure of the studied bodies and to cross-correlate them. Seven distinct facies were recognised. The Fluidised Conduit Facies (FCF) represents high-energy, strongly fluidised but only moderately fragmented systems. It occurs in a confined environment, and is typical of deeper parts of the conduit, before the actual diatreme level is reached by the ascending fluidised magma. Large amounts of spinning droplets are formed within this region. The Fluidised Conduit–Diatreme Facies (FCDF) is characteristic of intermediate depths in the conduit, where highly fluidised and highly fragmented systems produce large amounts of ash. Spinning droplets decrease in abundance, ordinary juvenile fragments become very common, and xenoliths from the country rock in the immediate vicinity of the diatreme are present. The Fluidised Fragmented Facies (FFF) and the Magmatic Fluidised Facies (MFF) produce very heterogeneous deposits that dominate the shallower part of the system, making up most of the diatreme-filling materials. The Fluidised Fragmented Facies can be distinguished by much higher degrees of fluidisation, fragmentation and system energy. It occupies the internal part of the diatreme and is characterised by the common presence of tuff pockets, tuff fragments, and accretionary and armoured lapilli. The Magmatic Fluidised Facies typically occupies the outer portion of the diatreme and can be distinguished from the Fluidised Fragmented Facies by the dominance of lapilli over ash and by the presence of abundant wrapped fragments. The Magmatic Facies (MF) and the Coherent Magmatic Facies (CMF) are volumetrically subordinate and represent late stages, when less fluidised and less fragmented material, or even coherent magma erupts relatively passively, in the aftermath of the main explosive stage that generated the diatreme. The Border Facies is defined by the increased abundance of material from the immediate country rock. At Águas Emendadas and Neuzinha this facies is marked by the presence of fragments of peperite-like rock, formed by the interaction of the fluidised magma with friable sandstone.     

Cropping patterns in the Canadian Prairies: thirty years of change

Changes in cropping patterns in the Canadian Prairies are examined from the early 1960s to the mid-1990s using census data. Patterns of change within the region are mapped by census division using averaged proportions of land in crops occupied by the main crops for three pairs of census years. Spring wheat and oat have undergone the most significant relative declines. Canola increased dramatically from being the sixth-ranked crop by area in the early 1960s to the third-ranked crop by area by the 1990s. The main change in the Brown soil zone has been a large decline in spring wheat and a compensatory gain in durum wheat. Increases in special crops, especially pulse crops, canola and durum wheat have offset a substantial decline in spring wheat in the Dark Brown soil zone. Barley, tame hay and especially canola have increased at the expense of spring wheat, oat and flaxseed in the Black and Gray soil zones. Prices, transportation costs, changing export markets, crop breeding and local processing all have contributed to these changes.     

军曹鱼生物学特性及苗种规模化繁育技术

简要介绍了军曹鱼(Rachycentron canadum)的形态、分布、食性、生殖、胚胎和仔稚鱼发育过程等生物学特性以及军曹鱼苗种繁育的技术工艺。选择2~3龄鱼作为亲鱼,在海区网箱中采用营养强化结合激素诱导的方法,使其在整个繁殖季节多次成熟产卵。在大亚湾地区其繁殖季节为4~10月,亲鱼繁殖的适宜水温为25~31℃、适宜盐度为30~34,大批量人工催产的受精率为30%~60%、孵化率为55%~82%。采用室外池塘进行种苗大规模培育,初孵仔鱼在水温26~32℃、盐度28~33条件下培育35~40 d,全长8~11 cm,达到商品苗规格。     

集合预报中动态调整的增长模繁殖及其对自由繁殖的改进

用增长模繁殖（BGM）法产生集合预报初始扰动的过程中,对增长模适时的进行调整是有必要的。介绍了动态调整的方法,利用T63L9全球谱模式,通过数值试验考察了在繁殖过程中采用动态调整时增长模的增长和饱和情况,并与自由繁殖试验作了相应的比较。结果表明:动态调整情况下,各层扰动的增长率可以达到一个比较大的数值;在形态饱和方面,动态调整能在很大程度上克服自由繁殖时低层扰动饱和时间滞后的缺陷;综合考虑,动态调整下扰动饱和时间可比自由繁殖缩短1天以上,且饱和特征更加明显。     

小刀蛏室内人工育苗技术研究

本文研究了小刀蛏(Cultellus attenuatus)室内人工育苗技术。在繁殖季节选择壳长7.5cm亲贝,采用铺泥沙蓄养培育,以阴干+维生素浸泡刺激法获得精、卵,幼虫培育中人工控制幼虫密度,D形幼虫到壳顶幼虫前期为5~6个/mL,壳顶幼虫后期为1~2个/mL。进行了不同运输方式和不同底质亲贝蓄养比较试验、不同底质附着基采苗方法试验以及稚贝无底质上升流培育和不同盐度培育试验。研究表明,采用铺细沙加冰的运输方法亲贝成活率最高,干露9h成活率可达90%;以纯海泥底质蓄养的亲贝肥满度和成活率最高;无底质采苗和铺泥采苗对幼虫变态率的影响没有差异;无底质采苗的稚贝,其生长速度明显慢于铺泥采苗;小刀蛏稚贝不宜用上升流进行培育,宜采用铺泥培育的方法;盐度为15时,稚贝培养效果最好,生长速度快、成活率高,盐度为35时培养效果最差。采用上述技术,成功培育出3mm以上的商品苗2000万粒,育苗效果显著。