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1.
介绍了事务处理的基本原理,讨论了.NET中的事务处理,说明了ADO.NET和消息队列中的手动事务处理,以及ASP.NET、XML Web service、.NET Framework类中的自动事务处理,并对.NET中的各种事务处理给出了实施的方法,为利用.NET构建具有事务处理的企业应用提供了参考.  相似文献   

2.
Platycephalus in Chinese sea area has a high commercial value.However,there were mis-identifications in previous records.In this study,we fully distinguished and diagnosed all five species,Platycephalus indicus,P.cultellatus,Platycephalus sp.,Platycephalus sp.1 and Platycephalus sp.2.The results revealed that P.cultellatus was overlooked by previous ichthyologists.Platycephalus sp.1 was misidentified as P.indicus in reality,and Platycephalus sp.2 only existed in the seas of Japan.Furthermore,morphological,especially phylogenetic analysis indicated that Platycephalus sp.from South China Sea differs from all former known species,which might be a new species.We identified all Platycephalus species in China seas for the first time,which will contribute to local species identification,biodiversity conservation and sustainable exploitation of Platycephalus species.  相似文献   

3.
Karenia mikimotoi (Miyake & Kominami ex Oda) Hansen & Moestrup is associated with harmful algal blooms in temperate and subtropical zones of the world. The hemolytic substances produced by K. mikimotoi are thought to cause mortality in fishes and invertebrates. We evaluated the composition of the hemolytic toxin produced by K. mikimotoi cultured in the laboratory using thin-layer chromatography.In addition, we evaluated the effect of co-occuring algae (Prorocentrum donghaiense and Alexandrium tamarense) and the cladoceran grazer Moina mongolica on hemolytic toxin production in K. mikimotoi. The hemolytic toxins from K. mikimotoi were a mixture of 2 liposaccharides and 1 lipid. Waterborne clues from P. donghaiense and A. tamarense inhibited the growth of K. mikimotoi but increased the production of hemolytic toxins. Conversely, K. mikimotoi strongly inhibited the growth of caged P. donghaiense and A. tamarense. In addition, the ingestion of K. mikimotoi by M. mongolica induced the production of hemolytic toxins in K. mikimotoi. Taken together, our results suggest that the presence of other microalgae and grazers may be as important as environmental factors for controlling the production of hemolytic substances. K. mikimotoi secreted allelochemicals other than unstable fatty acids with hemolytic activity. The production of hemolytic toxins in dinoflagellates was not only dependent on resource availability, but also on the risk of predation. Hemolytic toxins likely play an important role as chemical deterrents secreted by K. mikimotoi.  相似文献   

4.
Specimens of a new species of Cerithiidae, Cerithium mangrovum n. sp., were collected during two surveys along the coasts of Hainan and Guangdong Province, China. Usually associated with potamidid snails, this species often occurs in large populations between the mid-high tidal zones in a range of habitats, including mangroves, grass beds, silt, mud, and coral reefs. C. mangrovum n. sp. has a slender and tapering shell and the straight-sided whorl bears three aligned beaded spiral cords. The thick outer lip has a wide posterior sinus. It morphologically resembles C. coralium Kiener, 1841. The shell of C. coralium is usually larger and wider and the spiral cords are not as beaded as in C, mangrovum n. sp. Its radula has a rachidian tooth with a shallow, wide, median basal projection while the rachidian tooth of C. mangrovum n. sp. has a moderately long, median basal projection.  相似文献   

5.
《国土资源》2016,(4):4-9
1968年初,我结束了在北京地质学院8年的学习生活.春节回天津向父母告别后,返回北京.在一个寒冷的夜晚,我挤上了从北京驶往兰州的列车. 列车在朔风怒号中开动了.我此行是前往甘肃省地质局报到.那将是我从事地质工作的新起点.  相似文献   

6.
基于.NET平台的IP网络管理系统的设计与实现   总被引:1,自引:0,他引:1  
首先介绍了IP网管的基本概念、管理框架结构和.NET Remoting等相关内容,然后应用.NET Remoting和XML设计了一个基于.NET平台的IP网络管理系统.  相似文献   

7.
The current study explored Aurelia aurita and Rhopilema esculent um consumption by silver pomfret juveniles, as well as their prey selection between the two jellyfi sh species. Silver pomfret juveniles weighing 1±0.1 g actively preyed on both the species. Their daily A. aurita consumption was 11.6 times their own body weights regardless of the size of A. aurita medusae. Their daily R. esculent um consumption was 13, 9.1, 5, and 4.1 times their own body weights when the R. esculentum medusae were 10, 20, 30, and 40 mm in bell diameter, respectively. The survival rates of the R. esculent um were higher than those of the A. aurita. When the R. esculent um medusae were more than 30 mm in bell diameter, their survival rate exceeded 92%. Silver pomfrets serve as a type of potential predators on A. aurita in coastal waters, and they have little infl uence on R. esculent um with a size exceeding 30 mm. Besides, A. aurita may be able to be used as fi sh prey in silver pomfret artifi cial breeding.  相似文献   

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9.
Algal allelopathy is an ecological/physiological phenomenon that has focused attention on the interactions among algae and the production of algal toxins. We investigated the allelopathic interactions between the dinoflagellate genus Prorocentrum micans and diatom genus Skeletonema costatum and between P. micans and dinoflagellate genus Karenia mikimotoi using bi-algal cultures. Because the effects were species-specific and size-dependent, we evaluated the effect of different initial densities. At low densities of P. micans and high densities of S. costatum inoculated into the same medium, the growth of P. micans was weakly restrained, whereas the growth of S. costatum was significantly suppressed. S. costatum and K. mikimotoi were strongly inhibited by P. micans, in both the bi-algal cultures and enriched filtrates. Direct cell-to-cell contact was not necessary to gain a competitive advantage, thus, our results suggest that P. micans inhibited the growth of S. costatum and K. mikimotoi by the release of allelochemical(s). Last, a mathematical model was used to simulate growth and interactions between P. micans and S. costatum and between P. micans and K. mikimotoi in bi-algal cultures.  相似文献   

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正优秀基层所(站)1.许昌县新元国土资源分局2.许昌县河街国土资源所3.襄城县湛北乡国土资源管理所4.鄢陵县陈化店国土资源所5.长葛市增福庙国土资源所6.长葛市后河国土资源所7.禹州市国土资源局小吕国土资源所8.禹州市国土资源局梁北国土资源所9.许昌县陈曹国土资源所10.禹州市国土资源局鸿畅国土资源所6月25日,许昌市国土资源局召开全市国土资源系统"优秀基层所(站)"和"莲城国土卫士"表彰大会。  相似文献   

12.
Three new species of fossil woods are reported from the Upper Jurassic to Lower Cretaceous in southeastern Mongolia,including Protaxodioxylon mongolense sp. nov. Circoporoxylon mongolense sp. nov. Protocircoporoxylon mongolense sp. nov. The anatomical characters of three new species are described in detail.  相似文献   

13.
Vibrio anguillarum is an important bacterial pathogen of aquatic organisms and a significant problem in aquatic farming.The rapid detection and identification of V.anguillarum,and other pathogens that infect marine organisms,is crucial to effective disease management.In this study,we developed a loop-mediated amplification (LAMP) assay to detect V.anguillarum in an hour in a single tube without the need for thermal cycling.Conserved regions of the metalloproteinase (empA) gene of V.anguillarum served as the targets for primer design.A fragment of the empA gene was amplified at 65°C in the presence of the primer mixture and Bst DNA polymerase.In the optimized LAMP assay,6.7 pg of V.anguillarum DNA could be detected.Six strains of V.anguillarum and 17 strains of non-V.anguillarum bacteria were used in this study to evaluate the species specificity of the primers.The six V.anguillarum strains gave a positive result in the LAMP assay.This method was also validated in V.anguillarum-infected fish.This LAMP method is more sensitive than PCR in the detection of V.anguillarum and shows good species specificity.The LAMP assay is therefore an effective method for the quick detection of V.anguillarum both in the laboratory and in the field.  相似文献   

14.
【Title】

【Author】

【Addresses】1

The tree root distribution pattern and biomass of seventeen year old trees of Grewia optiva, Morus alba, Celtis australis, Bauhinia variegata and Robinia pseudoacacia were studied by excavation method. B. variegata roots penetrated to a maximum depth of 4.78 m, whereas, M. alba roots were found down to 1.48 m depth. Lateral spread was minimum in B. variegata (1.10 m)and maximum inR. pseudoacacia (7.33 m). Maximum root biomass of 6.30 kg was found in R. pseudoacacia and minimum (2.43 kg) was found in M. alba. For four species viz.,G. optiva, M. alba, C. australis andR. pseudoacacia, 68%-87% root biomass occurred within top 0-30 cm soil depth, but forB. variegata this was only45%. The soil binding factor was maximum in G. optiva and minimum in B. variegata. Soil physico-chemical properties also showed wide variation. The study suggests thatB. variegata with a deep root system is the most suitable species for plantation under agroforestry systems. R. pseudoacacia and G. optiva with deep root systems, more lateral spread and high soil binding factor are suitable for plantation on degraded lands for soil conservation.  相似文献   

15.
Prorocentrum minimum is a bloom-forming, planktonic mixotrophic dinoflagellate, and can cause stress in shrimp ponds. In this study, healthy Exopalaemon carinicauda were exposed to 5 × 10^4 cells mL^-1 P. minimum for 72 hours to investigate the adverse effect of P. minimum on shrimps. Elevated superoxide dismutase(SOD) activity and malondialdehyde(MDA) content, reduced total antioxidant capacity(T-AOC) and catalase(CAT) activity, and regulatory glutathione peroxidase(GPX) activity were found in the hemolymph of E. carinicauda after exposure to P. minimum. In this study, P. minimum exposure induced oxidative stress and caused significant oxidative damage to E. carinicauda. P. minimum exposure increased the expression of HSP70 gene in the hemocyte, gills and hepatopancreas. Compared with the enhanced level of caspase-3 gene mR NA in the hemocyte and gills, the up-regulation of caspase-3 gene in the hepatopancreas was only observed from 3 to 6 h, and then the mRNA level of glutathione-S-transferase(GST) gene increased. These results indicated that GST might be involved in the shrimp hepatopancreas’ defense against P. minimum exposure. The present study demonstrates that exposure to P. minimum could induce oxidative stress and apoptosis in E. carinicauda. The SOD activity, HSP70 and GST(in the hepatopancreas) were evoked to protect cells from oxidative stress and apoptosis. This study will provide new insights into the toxic mechanism of P. minimum on shrimps.  相似文献   

16.
2008年度的矿山储量动态监测工作,业已结束.通过对矿山的储量动态监测,各地暴露出诸多新问题.给我们的矿政管理带来新困惑.本文就此作一分析、探讨,努力促使我市的矿政管理更加规范、科学和合法. 一、概述 今年参加矿山储量动态监测的矿山共有30多家.根据各县(市、区)反映的情况,主要存在以下几类问题.一是采矿权有效期已届满但累计总量未采完,故矿山企业仍然在生产.二是采矿权有效期未满但企业提前采完核定资源量,矿山仍然在生产.三是采矿权有效期未满,法定储量也未采完,但有越界开采现象.四是采矿权有效期未满,划定资源量也采完,存在越界现象.五是采矿权有效期已届满,划定资源量也采完.且有越界现象.六是矿山企业超年度规模开采矿产资源.  相似文献   

17.
To clarify the confusion surrounding species identification and state intraspecific variations, this research studied the morphological taxonomy of five species, Kentrophyllum cf. setigerum Petz et al., 1995; Zosterodasys shumerica Aliev, 1990; Frontonia tchibisovae Burkovsky, 1970; Neourostylopsis orientalis Chen et al., 2013; and Apoholosticha cf. sinica Fan et al., 2014, which were collected from Chongming Island's marsh wetlands. Kentrophyllum cf. setigerum possesses less somatic kineties than K. setigerum(19–26 right and 18–25 left kineties vs 35–40 right and 30 left kineties). Whether Z. shumerica is identical to Z. transversa Foissner et al., 1994, which was presented in a previous report, was negated. The improved diagnosis for the species is provided. Frontonia tchibisovae was confirmed to have three or four micronuclei, and the number of kinetosome rows in its peniculus 3 varied between China and Russia populations. The new population of N. orientalis bears cortical granules, which differs from the original population that has an arrangement of rows across the dorsal bristles. For A. cf. sinica, there are colorless cortical granules on the ventral side of the new population, whereas in the previously reported populations bright orange, spherical granules were clustered around dorsal cilia. Additionally, we sequenced the small-subunit(SSU) rRNA genes of K. cf. setigerum, N. orientalis, and A. cf. Sinica, and compared the new and reported populations. For the first time, we also provide a species list, including 33 ciliates collected from the wetlands based on living observation and silver staining.  相似文献   

18.
We evaluated the feeding ecology of largehead hairtail (Trichiurus lepturus) and hairtail (T. margarites). We collected specimens from fishing ports in the Beibu Gulf (Gulf of Tonkin) from October 2008 to September 2009 and analyzed their gut contents. We collected 857 T. lepturus and 666 T. margarites samples. The number of stomachs examined in this study was sufficient to describe the monthly and ontogenetic diet shifts for the two species, as indicated by the trophic diversity curves. T. lepturus was a general omnivore, feeding primarily on Bregmaceros rarisquamosu, Decapterus maruadsi, and Acetes chinensis. Conversely, T. margarites preyed primarily on D. maruadsi, B. rarisquamosus, B. nectabanus, and A. chinensis. Both species exhibited distinct ontogenetic diet shifts. Although the two hairtail specie fed on similar sources in the same habitat, the diet overlap was relatively low. Our results suggest that hairtail play an important role in controlling small pelagic and benthic fish populations in the gulf. This trophic correlation shall be used for developing a marine ecosystem model for the Beibu Gulf.  相似文献   

19.
20.
From June 2003 to June 2004, an investigation on the life cycle, production and trophic basis of dominant species of macrozoobenthos community in a second-order river of the Hanjiang River basin, Hubei, China was carded out. The results showed that the dominant species Leptophlebia sp. and Ephemera sp. appeared to develop two generations per year, and there was a small overlap in the two generations of both species. The pupation of Leptophlebia sp. mainly occurred in autumn and winter, while pupation of Ephemera sp. mainly took place in summer and winter. The standing stocks of the Leptophlebia sp. population and Ephemera sp. population had two peaks in a year. The cohort production and cohort P/B ratio of the Leptophlebia sp. population estimated by size frequency method were 19.018 1 g/m^2.a and 5.7 respectively, while its annual production and P/B ratio were 38.036 2 g/m^2.a and 11.4. The cohort production and cohort P/B ratio of the Ephemera sp. population were 38.015 9 g/m^2.a and 5.9, while its annual production and P/B ratio were 76.031 8 g/m^2.a and 11.8.  相似文献   

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