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941.
为了完善提高狐狸繁殖效率的超排技术,探讨了用PMSG、E2、PGF2α和hCG的不同组合处理对诱发初情前雌性蓝狐发情及其对卵巢和子宫发育的影响.EPP组(E2、PMSG和PGF2α组合)和EPPh组(E2、PMSG、PGF2α和hCG组合)分别有2只和3只发情,而对照组未见发情;EPP和EPPh组卵巢指数和有腔卵泡百分率显著高于对照组(P<0.05),而初级卵泡所占百分率则显著低于对照组.此外,EPPh组次级卵泡所占百分率与对照组相比显著降低(P<0.05);当用EPP和EPPh法处理雌性蓝狐后,子宫指数、子宫壁和子宫内膜厚度显著高于对照组(P<0.05).结果 表明,EPP和EPPh处理不仅具有诱发雌性蓝狐发情的功效,而且能够提高初情前雌性蓝狐卵巢指数和增加有腔卵泡数量.  相似文献   
942.
甘薯小象虫是莆田市甘薯最主要害虫,近年来发生为害日趋严重。本文分析了甘薯小象虫在我市严重发生原因和为害特点,并提出以农业防治为主,辅以生物、药剂防治等的综合治理技术和办法,提供生产上参考应用。  相似文献   
943.
本文采集并分析了苏云金杆菌Bacillus thuringiensis发酵后处理技术,揭示了Bt发酵后处理生产膜过滤数据分析、喷雾干燥数据分析和产量的关系,以期对Bt实际生产过程进行高效控制。  相似文献   
944.
As an emerging biotechnology capable of removing contaminants and producing electricity, microbial fuel cells (MFCs) hold a promising future in wastewater treatment. However, several main problems, including the high internal resistance (Rin), low power output, expensive material, and complicated configuration have severely hindered the large-scale application of MFCs. The study targeted these challenges by developing a novel MFC system, granular activated carbon single-chamber MFC, termed as GAC-SCMFC. The batch tests showed that GAC was a good substitute for carbon cloth and GAC-SCMFCs generated high and stable power outputs compared with the traditional two-chamber MFCs (2CMFCs). Critical operational parameters (i.e. wastewater substrate concentrations, GAC amount, electrode distance) affecting the performance of GAC-SCMFCs were examined at different levels. The results showed that the Rin gradually decreased from 60 Ω to 45 Ω and the power output increased from 0.2 W/m3 to 1.2 W/m3 when the substrate concentrations increased from 100 mg/L to 850 mg/L. However, at high concentrations of 1000–1500 mg/L, the power output leveled off. The Rin of MFCs decreased 50% when the electrode distance was reduced from 7.5 cm to 1 cm. The highest power was achieved at the electrode distance of 2 cm. The power generation increased with more GAC being added in MFCs due to the higher amount of biomass attached. Finally, the multi-anode GAC-SCMFCs were developed to effectively collect the electrons generated in the GAC bed. The results showed that the current was split among the multiple anodes, and the cathode was the limiting factor in the power production of GAC-SCMFCs.  相似文献   
945.
Reservoir souring in offshore oil fields is caused by hydrogen sulphide (H2S) produced by sulphate-reducing bacteria (SRB), most often as a consequence of sea water injection. Biocide treatment is commonly used to inhibit SRB, but has now been replaced by nitrate treatment on several North Sea oil fields. At the Statfjord field, injection wells from one nitrate-treated reservoir and one biocide-treated reservoir were reversed (backflowed) and sampled for microbial analysis. The two reservoirs have similar properties and share the same pre-nitrate treatment history. A 16S rRNA gene-based community analysis (PCR-DGGE) combined with enrichment culture studies showed that, after 6 months of nitrate injection (0.25 mM NO3 ), heterotrophic and chemolithotrophic nitrate-reducing bacteria (NRB) formed major populations in the nitrate-treated reservoir. The NRB community was able to utilize the same substrates as the SRB community. Compared to the biocide-treated reservoir, the microbial community in the nitrate-treated reservoir was more phylogenetically diverse and able to grow on a wider range of substrates. Enrichment culture studies showed that SRB were present in both reservoirs, but the nitrate-treated reservoir had the least diverse SRB community. Isolation and characterisation of one of the dominant populations observed during nitrate treatment (strain STF-07) showed that heterotrophic denitrifying bacteria affiliated to Terasakiella probably contributed significantly to the inhibition of SRB. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.  相似文献   
946.
Denitrificationis the ability of bacteria to use nitro-gen oxides(NO3-and NO2-)as electron acceptorsto pro-duce gaseous nitrogen,mainly N2.The oxidation of or-ganic material coupled to reduction of oxygen leads to ahigher energy yield than reduction of nitrate.Oxygen iscommonly accepted to be the first choice as electron ac-ceptor[1].Therefore,denitrifying is generally thought toonly occur under almost anaerobic conditions.Anefficientwastewater treatment toremove nitrogen components relieson…  相似文献   
947.
NaCl对中华补血草叶片盐腺发育及其泌盐速率的影响   总被引:6,自引:0,他引:6  
丁烽  王宝山 《西北植物学报》2006,26(8):1593-1599
以中华补血草(Limonium sinenseKuntze)为实验材料,研究了不同浓度NaCl处理对其生长、盐腺发育及泌盐速率的影响.结果显示:(1)随着NaCl浓度的升高,植株干重和鲜重均先显著升高后逐渐下降,当NaCl处理浓度为100 mmol/L时,植株干、鲜重达到最大;(2)与对照相比,300 mmol/L NaCl处理下盐腺的分泌细胞及平均直径差异不显著,而在1002、00 mmol/L的NaCl处理下显著增大;(3)随着NaCl浓度的升高,盐腺密度显著升高且叶片上表面盐腺总数明显高于对照,单个盐腺的泌盐速率和叶片整体泌盐速率均显著升高.结果表明,100~200 mmol/L NaCl处理可显著促进中华补血草盐腺的发育及泌盐能力,300 mmol/L以上NaCl处理对盐腺的直径影响不显著,但可显著促进盐腺的泌盐能力.  相似文献   
948.
对作者实验室分离到的3种酵母菌混合处理味精生产废水的条件进行了研究,结果表明最佳处理条件为:pH值4.0、温度28℃、时间20h、接种量10%,COD去除率可达到82.9%。并对处理后的酵母菌菌体进行了饲料评价,发现混合菌体含有丰富的蛋白质、脂肪含量小等优点。该技术作为预处理应用于实际工程中将取得较好的处理效果并产生一定的经济效益。  相似文献   
949.
养殖刺参附着期“化板症”病原菌的分离鉴定及来源分析   总被引:1,自引:0,他引:1  
摘要:【目的】查明养殖刺参附着期“化板症”的病原及其来源,并获得该病的治疗药物。【方法】分别对化板症状较为典型的3家育苗场的发病幼体进行病原学分析,对可疑病原进行人工回接感染并进行形态学、生理生化和16S rDNA序列分析鉴定,对各养殖场育苗系统,包括水源、养殖池水、池底污物、附着基板和饵料进行细菌学分析,对病原菌进行药敏测试。【结果】从所有病参中分离得到1种优势菌株,人工回接感染证明它对健康刺参有较强的致病性,且感染病参与自然发病刺参的症状相同。鉴定出“化板症”的病原为弧菌Vibrio sp.。养殖系统中除水源的细菌浓度没有超标污染 (<50 cfu/mL)外,其余均检出了大量细菌 (>1 × 105 cfu/mL);病原来源较复杂:水源、养殖池水、池底污物、附着基板和饵料均发现了病原菌,但病原菌浓度以饵料中最多,附着基板次之,水源中最少。萘啶酸等12种常用抗生素可有效抑制该病原菌的生长。【结论】“化板症”的病原为弧菌Vibrio sp.;饵料可能为“化板症”病原的主要来源;萘啶酸等12种常用抗生素可用于该病的防治。  相似文献   
950.
1. Fish community structure and habitat distribution of the abundant species roach, perch and ruffe were studied in Lake Nordborg (Denmark) before (August 2006) and after (August 2007) aluminium treatment to reduce internal phosphorus loading. 2. Rapid changes in fish community structure, abundance and habitat distribution occurred following a decline in in‐lake phosphorus concentrations from 280 to 37 μg P L?1 and an increase in Secchi depth transparency from 1.1 to 1.9 m (August). The proportion of perch in overnight gill net catches increased, whilst roach decreased, and the average weight of all key species increased. 3. The habitat distribution of perch and roach changed from a high proportion in the upper pelagic and littoral zones in 2006, towards enhanced proportions in the deeper pelagic and profundal zone in 2007. The abundance of large‐bodied zooplankton increased and the abundance of benthic invertebrates decreased in the same period, suggesting that the habitat shift was not induced by food limitation. 4. Ruffe shifted from the littoral and upper profundal zones towards the deep profundal zone, likely reflecting an increased predation risk in the littoral zone and better oxygen conditions in the deep profundal. 5. Our results indicate that enhanced risk of predation in the upper pelagic and the littoral zones and perhaps improved oxygen concentrations in the deeper profundal zone at decreasing turbidity are responsible for the observed habitat shift. The results indicate that fish respond rapidly to changes in nutrient state, both in terms of community structure and habitat use.  相似文献   
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