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1.
本科院校办高职学院是我国 2 0世纪末出现的一个新生事物 ,如何设置专业课程 ,提高教学质量 ,使学生一出校门就能容纳到直接为经济服务当中去 ,结合商务日语专业的具体情况对这个问题进行了思考。  相似文献   
2.
Histological study on the ontogeny of the lymphoid organs, kidney, thymus and spleen of Japanese flounder, Paralichthys olivaceus, from hatching to 40 d was carried out. The pronephric kidney duct appeared early in hatching although the primordial haemopoietic stem cells were observed within a week after hatching. The spleen was first seen after 8d of hatching. The thymus appeared after 15d, situated near the pronephric kidney. Small lymphoid cells appeared during the later phase of the post-larval stage in the sequence of thymus, kidney and spleen. During the 40d of observations, there were no distinct inner or outer zones in thymus and no red or white pulp in spleen. These results suggest that the nonspecific defense immune system plays a very important role in the early larval stage of Japanese flounder.  相似文献   
3.
通过人工调控促使亲本牙鲆(Paralichthys olivaceus)♀×夏鲆(Paralichthys dentatus)♂的性腺发育,人工干法授精获得杂交受精卵。杂交受精卵在温度为16.5~17.5℃,光照为100~400 lx,微充气条件下孵化。对杂交鲆胚胎发育全过程进行连续观察并与牙鲆及夏鲆的胚胎发育进行比较。结果表明:杂交鲆卵裂方式与其他大部分硬骨鱼类一样,属于盘状卵裂。受精后经过2 h 30 min进入2细胞期,7 h 45 min进入囊胚期,15 h 10 min进入原肠胚阶段,25 h 30 min进入神经胚期,49 h左右进入尾芽期。授精后63 h左右发现初孵仔鱼,68h左右50%的仔鱼孵出。在杂交鲆的胚胎发育中,主要有2个发育特征与母本类似而与父本不同:视囊的出现要早于体节的分化;孵化前,仔鱼在卵膜内环绕卵黄囊不到1周。但是在其孵化时间上却与父本相似。  相似文献   
4.
Under artificial LD cycles(6,12,18 L),the elvers of Japanese eel,Anguilla japonica,showed a 24 h cycle of locomotor activity rhythm being most active at light transitions:the eels' activity rose to a primary peak after lights-off,followed by a quiescent period during which they buried into the shelters or lying motionlessly on sand for most of the time,and then reached a secondary peak before lights-on.Elvers could resynchronize their activity rhythm with a new photo cycle within 4 d.Moreover,their activity level at dark phase significantly increased as the light period was prolonged:higher activity levels during shorter dark period.However,the elvers did not display clearly the existence of a circadian rhythm under constant light or dark conditions.The timing of daily activity rhythm evidenced in the Japanese eels may occur through the action of the LD cycles with a weak participation of an endogenous circadian system.In all the LD cycles,over 99% of the activity occurred in the dark phase,indicating that the eels were always nocturnally active no matter what time of day it might be.Under 12 L conditions,the eels' activity level and the time outside sand were significantly elevated both at light and dark phases as temperature increased from 10~15 to 20~25 ℃.The activity rhythm pattern(i.e.,two peaks occurring around light transitions) did not apparently change among temperatures.However,in contrast with the primary activity peaks immediately after lights-off at 20 and 25 ℃,the timing of the primary peaks at 10 and 15 ℃ showed a latency of a few hours following lights-off,indicating the inhibiting effect of low temperature on the eels' activity.  相似文献   
5.
This article examines contemporary Japanese overseas tourism from a supplier‐side perspective using the concept of production systems. We first outline characteristics of the evolving structure of Japanese overseas tourism, with an emphasis on the global spread of Japanese travel companies. This provides a frame for presenting an empirical account of the transactional relationships in the Japanese package tour production system in Whistler, British Columbia, where Japanese tour operators play a pivotal role. We conclude that the recent expansion of Japanese travel companies is fostering the functional integration of the global tourism production system and exhibits increasing reflexivity.  相似文献   
6.
Palaeozoic and early Mesozoic fish faunas of the Japanese Islands   总被引:2,自引:0,他引:2  
MASATOSHI GOTO 《Island Arc》1994,3(4):247-254
Abstract In recent years, many fish teeth and scales have been found from the Palaeozoic and Mesozoic age strata of the Japanese Islands. This study is a compilation of the Japanese fish record from the Palaeozoic and early Mesozoic age deposits. Based on the published and unpublished data, the fossil fishes from the Palaeozoic and Early Mesozoic of Japan can be classified into 27 genera and 33 species, that is, one species of Devonian placoderms, 19 species of Permian to Jurassic elasmobranchs, three species of Permian cochliodonts, seven species of Carboniferous to Permian petalodonts, and three species of Triassic to Jurassic osteichthyans.  相似文献   
7.
In order to study characteristics of horizontal crustal strains, we divide the Japanese Islands into 14 tectonic provinces consistent with the suggestion given byMatsuda (1990). We calculate frequency distribution of strain rates using the results of the Precise Control Survey initiated by the Geographical Survey Institute in 1973. This survey is a revision of old first- and second-order triangulation networks by trilateration. The principal axes and principal strains inside all the geodetic triangles are deduced from the comparison of the old triangulation and the new trilateration networks. The maximum shear strain rates are calculated by dividing the accumulated strains with the time intervals. The frequency distribution of strain rates is counted for each tectonic province and for the entire Japanese Islands. It is proved that the maximum shear strain rate with highest frequency ranges from 0.10–0.15 microstrain/a for 4409 data in the Japanese Islands. The mean value of the strain rates throughout the Japanese Islands is deduced to be 0.18 microstrain/a. We also calculated a mean value of strain rates for each tectonic province. Comparison is made between mean geodetic strain rates in the provinces and Quaternary strain rates estimated by geomorphic data. It is found that 0.3–0.4 microstrain/a of the highest order strain rate is now prevailing in the Izu province, the south Fossa-Magna collision zone, and some special provinces along the eastern part of the Japan Sea coast.  相似文献   
8.
This paper describes a rockfall event in the Daisekkei Valley of Mount Shirouma-dake (2,932 m), the northern Japanese Alps. The rockfall occurred on a steep cliff comprising well-jointed felsites and produced debris of ≥8,000 m3. Most debris was deposited on an elongated snowpatch located immediately beneath the cliff, and it caused casualties among people who were trekking along a trail on the snowpatch. Additionally, a large rock block slipped 1 km on the snowpatch. The rockfall could have been due to the differential retreat of the rockwall, which contains areas of high- and low-density joints. Seasonal and diurnal freeze–thaw activities and snow avalanches and wash appear to be important factors responsible for the retreat. Although some rock blocks that can collapse further remain on the rockwall, the position of the mountain trail in the Daisekkei Valley is fixed. Fundamental reform of tourism systems for climbers, including education on natural hazards, is required.  相似文献   
9.
本文从日本沿岸选取了28个验潮站及联测的GPS站,利用奇异谱分析(Singular Spectrum Analysis,SSA)和SSA+自回归滑动平均(Auto Regression Moving Average,ARMA)方法预测了2014—2018年的近海海平面变化和地壳垂直变化.并用同时段的验潮及GPS的实际测量值进行验证,结果显示,SSA+ARMA预测的相对海平面精度为0.0357~0.0607 m,地壳垂直运动的精度为0.0049~0.0077 m,绝对海平面的精度为0.0433~0.0683 m,且三者SSA+ARMA的预测结果均优于只用SSA预测的结果.在此基础上本文利用SSA+ARMA预测了日本沿岸2019—2023年的近海绝对海平面变化,结果显示,2019—2023年的平均海面高较往年(2014—2018)升高0.0353 m,2003—2023年绝对海平面的变化率为0.0039 m·a-1,预测结果较为理想.  相似文献   
10.
文中总结单舰航线水文气象保障业务的特点、难点,并结合航线水文气象保障的现状提出一些个人的建设性建议。  相似文献   
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