不同硒源对刺参呼吸代谢的影响

为了研究不同硒源对刺参Apostichopus japonicus特定生长率和呼吸代谢指标的影响,以刺参幼参和成参为研究对象,分别强化投喂硒添加量为0.6 mg/kg的硒代蛋氨酸、硒酸钠和亚硒酸钠饲料,试验周期为60 d。结果表明:硒添加组成参和幼参的特定生长率均显著大于对照组(P<0.05),其中硒代蛋氨酸组最大,且显著大于硒酸钠组和亚硒酸钠组(P<0.05),除硒代蛋氨酸组外,其他各试验组成参的特定生长率均大于幼参;硒添加组成参和幼参的耗氧率均显著大于对照组(P<0.05),其中硒代蛋氨酸组最小,显著小于硒酸钠组和亚硒酸钠组(P<0.05),对应组中,幼参耗氧率大于成参;硒添加组成参和幼参的排氨率均低于对照组,除硒代蛋氨酸组成参显著低于对照组(P<0.05)外,其余硒添加组与对照组均无显著性差异(P>0.05),硒代蛋氨酸组的排氨率最小,对应组中,幼参排氨率大于成参;硒添加组成参和幼参的O/N值均显著大于对照组(P<0.05),其中硒代蛋氨酸组最小,但硒添加组间无显著性差异(P>0.05),对应组中,成参的O/N值大于幼参。研究表明,饲料中添加硒能够提高刺参的代谢率,促进刺参生长,其中有机硒(硒代蛋氨酸硒)的促生长效果好于无机硒(硒酸钠和亚硒酸钠),且硒代蛋氨酸对幼参的促生长效果要好于成参。     

不同硒源对刺参呼吸代谢的影响

为了研究不同硒源对刺参Apostichopus japonicus特定生长率和呼吸代谢指标的影响,以刺参幼参和成参为研究对象,分别强化投喂硒添加量为0.6 mg/kg的硒代蛋氨酸、硒酸钠和亚硒酸钠饲料,试验周期为60 d。结果表明:硒添加组成参和幼参的特定生长率均显著大于对照组(P<0.05),其中硒代蛋氨酸组最大,且显著大于硒酸钠组和亚硒酸钠组(P<0.05),除硒代蛋氨酸组外,其他各试验组成参的特定生长率均大于幼参;硒添加组成参和幼参的耗氧率均显著大于对照组(P<0.05),其中硒代蛋氨酸组最小,显著小于硒酸钠组和亚硒酸钠组(P<0.05),对应组中,幼参耗氧率大于成参;硒添加组成参和幼参的排氨率均低于对照组,除硒代蛋氨酸组成参显著低于对照组(P<0.05)外,其余硒添加组与对照组均无显著性差异(P>0.05),硒代蛋氨酸组的排氨率最小,对应组中,幼参排氨率大于成参;硒添加组成参和幼参的O/N值均显著大于对照组(P<0.05),其中硒代蛋氨酸组最小,但硒添加组间无显著性差异(P>0.05),对应组中,成参的O/N值大于幼参。研究表明,饲料中添加硒能够提高刺参的代谢率,促进刺参生长,其中有机硒(硒代蛋氨酸硒)的促生长效果好于无机硒(硒酸钠和亚硒酸钠),且硒代蛋氨酸对幼参的促生长效果要好于成参。     

非离子氨和氨氮对不同规格史氏鲟幼鱼的急性毒性及安全浓度评价

在水温为(22±1)℃、pH为7.6、DO为7.0⁸.0 mg/L的条件下,对A1(1.7 g±0.2 g)、A2(3.6 g±0.6 g)、A3(10.3 g±1.5 g)3种不同规格的史氏鲟Acipenser schrencki幼鱼进行非离子氨和氨氮的急性毒性及安全浓度评价。结果表明:氨氮和非离子氨对史氏鲟幼鱼的半致死浓度(LC50)和安全浓度均与幼鱼的体质量呈正相关;氨氮对A1、A2、A3组史氏鲟幼鱼的96 h LC50分别为5.30、10.20、12.30 mg/L,安全浓度分别为0.53、1.02、1.23 mg/L;非离子氨对A1、A2、A3组幼鱼的96 h LC50分别为0.13、0.26、0.28 mg/L,安全浓度分别为0.01、0.03、0.03 mg/L。     

亚硒酸钠对蛋白核小球藻生长及抗氧化酶活性的影响

为探究不同质量浓度亚硒酸钠对蛋白核小球藻Chlorella pyrenoidosa生长及抗氧化酶活性的影响,试验设计0、2、4、6、8、10、20、40、60、80、100 mg/L共11个亚硒酸钠处理组,定期监测不同处理组小球藻细胞密度、吸光度值及抗氧化酶活性的变化。结果表明:小球藻初始细胞密度为1×10⁶ cells/mL时,添加2、4 mg/L的亚硒酸钠对蛋白核小球藻细胞生长具有显著促进作用(P<0.05),而6～100 mg/L亚硒酸钠对小球藻细胞生长具有显著抑制作用(P<0.05);试验第7天时,6～10 mg/L亚硒酸钠处理组藻细胞恢复生长,至第13天时藻细胞生长速率与对照组无显著性差异(P>0.05),而20～100 mg/L亚硒酸钠处理组小球藻生长速率显著低于对照组(P<0.05),且试验前7 d为负值,第9天开始恢复为正值;蛋白核小球藻含硒量随亚硒酸钠质量浓度的增加而增加;低质量浓度(2～4 mg/L)的亚硒酸钠能诱导小球藻细胞超氧化物歧化酶(SOD)活性显著增加(P<0.05),而高质量浓度(20～100 mg/L)的亚硒酸钠则能够诱导藻细胞谷胱甘肽过氧化物酶(GSH-Px)活性显著增加(P<0.05);用40～100 mg/L亚硒酸钠处理蛋白核小球藻时,藻细胞出现三分裂、四分裂及细胞团的现象。研究表明,低质量浓度硒能促进蛋白核小球藻的生长,而高质量浓度硒具有抑制作用,不同抗氧化酶对硒的敏感性不同,小球藻富硒培养时亚硒酸钠的适宜添加质量浓度为2～4 mg/L,且培养时间应控制在一个月内,以免藻体中毒死亡。     

蛋氨酸硒对刺参生长及消化道指数的影响

为研究蛋氨酸硒对刺参Apostichopus japonicus个体生长和消化道指数的影响,选用体质量为(45±5)g、体长为(10±1)cm的刺参270头,在基础饲料中添加不同量的蛋氨酸硒,使饲料中硒添加量分别为0、0.2、0.4、0.6、0.8、1.0 mg/kg,分6组进行投喂试验,饲养60 d后测定刺参个体生长和消化道指数的变化情况。结果表明:在本试验条件下,随着硒添加量从0增加到1.0 mg/kg,刺参的体长特定增长率从0.11%/d提高到0.34%/d,体质量特定增长率从0.18%/d提高到0.46%/d,均呈上升趋势;肠质量从1.67 g提高到2.21 g;相对消化道质量从0.032 3提高到0.037 0;脏壁比从0.060 8下降到0.051 7。研究表明,蛋氨酸硒可明显促进刺参的消化、生长,且随着蛋氨酸硒含量的增加,促进消化、生长的效果越好。     

饲料中添加蛋氨酸硒对仿刺参幼参存活、生长及免疫指标的影响

在水温为14.0～8.0℃、盐度为31～32和pH为7.5的条件下,将初始体质量为1.30～1.68 g的仿刺参Apostichopus japonicus幼参饲养在塑料水槽(40 L)中,投喂蛋氨酸硒添加量分别为0、0.2、0.4、0.6、0.8、1.0 mg/kg的饲料60 d,每种饲料设3个重复,每个重复组放15头仿刺参。试验结束后饥饿24h,测定仿刺参体质量的特定生长率(SGR),体腔液中过氧化氢酶(SOD)、超氧化物歧化酶(CAT)、酸性磷酸酶(ACP)的活力,体壁干物质和肠干物质中硒的含量。结果表明:各组仿刺参的成活率为100%;当蛋氨酸硒添加量为0.6 mg/kg时,仿刺参幼参的SGR最大,且显著高于对照组(P<0.05),当硒添加量为1.0 mg/kg时,仿刺参幼参的SGR值最小;当硒添加量为0.6 mg/kg时,仿刺参对饲料干物质和粗蛋白的表观消化率最高,且显著高于对照组(P<0.05);各试验组仿刺参体壁干物质中蛋白质含量均显著高于对照组(P<0.05),且当硒添加量为0.4 mg/kg时,蛋白质含量最高;当硒添加量为0.6 mg/kg时,幼参肠中的硒含量最高,且显著高于对照组(P<0.05),但当硒添加量为0.4 mg/kg时,幼参体壁中的硒含量最高,其次为0.6 mg/kg硒组;除硒添加量为1.0 mg/kg外,各试验组仿刺参体腔液中的SOD、CAT值均显著高于对照组(P<0.05),添加量分别为0.8 mg/kg和0.4 mg/kg时达到最高,其次是0.6 mg/kg组;各试验组仿刺参ACP的活性均显著高于对照组(P<0.05),硒添加量为0.4 mg/kg时达到最高。研究表明,仿刺参幼参饲料中蛋氨酸硒的适宜添加量为0.4～0.6 mg/kg。     

几种中草药对刺参幼参的急性毒性试验

为探究刺参Apostichopus japonicus对中草药的毒性反应,在水温13¹5℃下采用水生生物急性毒性试验方法对体质量为(2.36±0.41)g的刺参幼参进行了5种中草药急性毒性试验。结果表明:单方中草药对刺参幼参的毒性大小依次为五倍子>乌梅>石榴皮>黄芩>甘草;五倍子、乌梅、石榴皮、黄芩和甘草对刺参幼参的48 h半致死浓度分别为0.340、2.027、2.149、2.234、4.900 g/L,安全浓度分别为0.055、0.272、0.166、0.271、0.605 g/L;6组复方药物中毒性最大的是五倍子+甘草,其次是五倍子+黄芩、甘草+黄芩、石榴皮+五倍子,乌梅+石榴皮、五倍子+乌梅两组复方的毒性最低。研究表明,在安全浓度范围内,单方中草药五倍子、乌梅,复方五倍子+乌梅、石榴皮+乌梅可用作刺参细菌性疾病的防治药物。     

两种典型表面活化剂SDS和NP对刺参幼参的急性毒性效应研究

为评价典型表面活性剂对大型海洋底栖动物的风险,采用静水毒性试验法,以十二烷基硫酸钠(SDS)和壬基酚(NP)两种典型表面活化剂对刺参Apostichopus japonicus幼参(体质量为0.15 g±0.05 g)分别进行单一的急性毒性试验,SDS试验浓度设为0、5.00、6.47、8.38、10.81、14.00 mg/L,NP试验浓度设为0、500、594、708、841、1000μg/L。结果表明:SDS对幼参72、96 h的LC_(50)分别为10.927、9.834 mg/L,而NP对幼参72、96 h的LC_(50)分别为1.12、0.80 mg/L;两种表面活性剂对幼参的安全浓度(SC)则分别为0.983 mg/L(SDS)和0.08 mg/L(NP);SDS的毒性效应主要体现在刺激幼参排脏吐肠,而NP的毒性效应则主要体现在引起体壁严重化皮。研究表明,SDS和NP两种表面活性剂对刺参幼参均存在较高的毒性效应,本研究结果可为表面活性剂的生物毒性预测和养殖水质风险评估提供基础数据参考。     

两种典型表面活化剂SDS和NP对刺参幼参的急性毒性效应研究

为评价典型表面活性剂对大型海洋底栖动物的风险,采用静水毒性试验法,以十二烷基硫酸钠(SDS)和壬基酚(NP)两种典型表面活化剂对刺参Apostichopus japonicus幼参(体质量为0.15 g±0.05 g)分别进行单一的急性毒性试验,SDS试验浓度设为0、5.00、6.47、8.38、10.81、14.00 mg/L,NP试验浓度设为0、500、594、708、841、1000μg/L。结果表明:SDS对幼参72、96 h的LC_(50)分别为10.927、9.834 mg/L,而NP对幼参72、96 h的LC_(50)分别为1.12、0.80 mg/L;两种表面活性剂对幼参的安全浓度(SC)则分别为0.983 mg/L(SDS)和0.08 mg/L(NP);SDS的毒性效应主要体现在刺激幼参排脏吐肠,而NP的毒性效应则主要体现在引起体壁严重化皮。研究表明,SDS和NP两种表面活性剂对刺参幼参均存在较高的毒性效应,本研究结果可为表面活性剂的生物毒性预测和养殖水质风险评估提供基础数据参考。     

几种中草药对刺参幼参的急性毒性试验

为探究刺参Apostichopus japonicus对中草药的毒性反应,在水温13~15℃下采用水生生物急性毒性试验方法对体质量为(2.36±0.41)g的刺参幼参进行了5种中草药急性毒性试验。结果表明:单方中草药对刺参幼参的毒性大小依次为五倍子>乌梅>石榴皮>黄芩>甘草;五倍子、乌梅、石榴皮、黄芩和甘草对刺参幼参的48 h半致死浓度分别为0.340、2.027、2.149、2.234、4.900 g/L,安全浓度分别为0.055、0.272、0.166、0.271、0.605 g/L;6组复方药物中毒性最大的是五倍子+甘草,其次是五倍子+黄芩、甘草+黄芩、石榴皮+五倍子,乌梅+石榴皮、五倍子+乌梅两组复方的毒性最低。研究表明,在安全浓度范围内,单方中草药五倍子、乌梅,复方五倍子+乌梅、石榴皮+乌梅可用作刺参细菌性疾病的防治药物。     

An improved sodium carbonate-Based extinguishant for sodium fires

Laboratory-scale experiments were conducted in an attempt to improve a noncorrosive sodium fire extinguishing agent consisting mainly of sodium carbonate.     

天然钠基膨润土干法提纯研究

通过中试和1:1工业试验对天然钠基膨润土原矿进行干法提纯.确定了最佳工艺生产条件.试验证明,提纯后产品的性能较原矿有较大的提高,各项指标可达到膨润土防水毯产品原料的标准要求.     

Suppression of sodium fires with liquid nitrogen

Sodium has unusual fire hazards, including autoignition when heated in air or exposed to liquid water. Owing to limitations of existing suppression agents for sodium pool fires, suppression using liquid nitrogen (LN₂) is examined here. Sodium pools of 5–80 g were heated in stainless steel beakers. At about 290 °C, pool surface autoignition occurred and caused a rapid pool temperature increase. Vapor phase combustion occurred when the pools reached 320–450 °C, ultimately leading to pool temperatures up to 700 °C. For suppression tests, LN₂ delivery (at 2.7 g/s) began when the fires became fully-developed, near a pool temperature of 600 °C. Liquid nitrogen was found to be an effective suppression agent. The minimum amount of LN₂ required to suppress a fully-developed sodium pool fire was found to be about three times the initial sodium pool mass.     

Enhancement of PCBs biodegradation by sodium ligninsulfonate

Various mixtures of commercial PCBs (Aroclors) were rapidly biodegraded by Pseudomonas sp. 7509. The rate of biodegradation could be greatly enhanced by growing the cells in a stable PCB-ligninsulfonate emulsion. Microscopic examinations and growth studies suggested that biodegradation mainly took place at the PCB-water interface; the use of ligninsulfonate in the growth medium apparently allowed the cells to overcome the substrate limiting factor of surface area which, otherwise, might govern the subsequent rate of PCB degradation. Sodium ligninsulfonate was not degraded significantly in the PCB biodegradation process. Analyses of the culture broth, by gas chromatography, revealed that P. sp. 7509 could degrade 300 ppm of Aroclor 1254 after 18 days incubation. This degradation rate could be further enhanced by the addition of a small amount of Aroclor 1221 to the growth medium. A kinetic study, using resting cells, indicated that Aroclor 1221 was degraded much faster (980 μg h⁻¹ mg cell dry wt⁻¹) than the higher chlorinated Aroclor 1254 (43 μg h⁻¹ mg cell dry wt⁻¹). This finding was supported by manometric data which showed that regardless of the type of PCBs mixture used to grow the cells, the lower chlorinated PCBs were always oxidized faster than the higher chlorinated PCBs. The level of chlorination in a PCBs mixture therefore appears to be one of the major factors in determining its relative persistence to biodegradation.     

硫酸钠溶液和硫酸钠盐渍土的冻结温度及盐晶析出试验研究

为了探索硫酸钠盐渍土的盐胀与冻胀机理,对硫酸钠溶液分别在环境温度-20℃和变环境温度-5℃～-10℃下进行降温试验;并对硫酸钠盐渍土在环境温度-20℃下进行降温试验,通过试验研究了硫酸钠溶液和硫酸钠盐渍土中芒硝的析出规律及各自的冻结温度。试验表明：在相同外界环境温度下,浓度大的溶液,芒硝更容易析出;具备一定浓度的溶液,在环境温度变化缓慢条件下更容易析出但溶液的冻结温度的趋势一致;相同浓度硫酸钠盐渍土的冻结温度均低于硫酸钠溶液的冻结温度,随着含盐量增加,其冻结温度降低;在相同外界环境温度下,盐晶在土体中更容易析出。     

膦甲酸钠氯化钠注射液联合泛昔洛韦片治疗头面部带状疱疹的临床观察

观察静滴膦甲酸钠氯化钠注射液联合口服泛昔洛韦片对治疗头面部带状疱疹的临床疗效及安全性。本文将98例头面部带状疱疹患者分为对照组48例与治疗组50例,观察口服泛昔洛韦片(对照组)和口服泛昔洛韦片联合静滴膦甲酸钠氯化钠注射液(治疗组)治疗头面部带状疱疹的临床疗效及安全性。根据复诊或随访比较两组患者的疗效评价参数,分析得出治疗组总有效率(96.0%)明显优于对照组(79.2%,P<0.05);治疗组在止痛、结痂、脱痂时间方面显著优于对照组(P<0.05)。在治疗头面部带状疱疹中,应用膦甲酸钠氯化钠注射液联合泛昔洛韦片,可较快使得疼痛缓解、皮损减少,安全性高且疗效佳,值得临床推广。     

葡萄糖酸钠改性萘系高效减水剂的研究

通过接枝改性合成葡萄糖酸钠改性萘系高效减水剂,阐述了该减水剂的合成工艺,分析了合成产品的红外光谱并比较改性前后萘系减水剂在流动度、表面张力、表面吸附量、坍落度、减水率和抗压强度等性能的差别。实验结果表明,通过接枝改性,使改性后的萘系减水剂的减水率提高3.39%,2 h坍落度损失率减小41.49%,克服了传统萘系减水剂坍落度损失大的缺点,同时提高了混凝土的早期抗压强度。     

Toxicity of sodium selenite to rainbow trout fry

In a study designed to examine the long-term effects of inorganic selenium (IV) on early life stages of rainbow trout (Salmo gairdneri), survival was significantly reduced at selenium concentrations of 47 and 100 μg l⁻¹ after 90 days of exposure. Length and weight were significantly reduced after 90 days of exposure to 100 μg l⁻¹. Whole-body residues of selenium increased with increasing exposure concentrations but appeared to decline between 30 and 90 days of exposure. Analyses of trout backbone indicated little change in bone development with exposure to selenium (IV) with one exception; calcium concentrations were significantly decreased in fish exposed to 12 μg l⁻¹ of selenium. Results of our study indicates that a recommended safe level of 10 μg l⁻¹ for inorganic selenium would not significantly affect growth and survival of rainbow trout; however, concentrations of selenium near this level can reduce the levels of calcium in the backbones of trout.     

Sol-gel法制备铌酸钠棒

采用溶胶凝胶法,以氢氧化铌为铌源,以柠檬酸为络合剂,乙二醇为酯化剂,添加PVP(聚乙烯吡咯烷酮)改性来制备铌酸钠棒。采用TG/DTA对干凝胶热解成份进行分析,用XRD对样品的结晶结构进行表征,用扫描电镜观察样品的特征结构,并用EDS检测样品中元素的组成,研究了形成棒状铌酸钠所需的最佳条件。     

Adsorption of sodium lauryl sulfate onto arsenic-bearing ferrihydrite

Ferrihydrite is an excellent adsorbent for binding trace toxic contaminants such as arsenic, and precipitate flotation of the arsenic-bearing ferrihydrite has been studied. Anionic surfactants such as sodium lauryl sulfate (SLS) and sodium oleate (NaOL) are suitable collectors for the flotation. The adsorption of SLS both alone and after the subsequent addition of NaOL on these precipitates at pH 4-5 was measured. It has been shown that the synergistic effect of the two surfactants on flotation is dependent on their addition order. The presence of NaOL before SLS in the conditioning stage can prevent the adsorption of SLS because of the electrostatic shielding of adsorption sites on the precipitates. The post addition of NaOL to the SLS-bearing precipitates can promote the flocculation of the precipitates and enhance entrainment of SLS for better flotation. The SLS adsorption data fit better with the modified Frumkin isotherm than the Langmuir isotherm. Thermodynamic parameters (-delta Gads0,delta Hads0, and delta Sads0) have been derived from the analysis of the adsorption isotherms. The results suggest that the adsorption of SLS on AFH is physical and exothermic.