增稠剂对特一粉冷冻面团拉伸特性的影响

以特一粉冷冻面团为研究对象,通过质构仪,研究添加黄原胶、卡拉胶、瓜尔豆胶、聚丙烯酸钠对冷冻面团拉伸特性的影响,通过单因素试验进行响应面分析。结果表明,当添加黄原胶为0.33%,瓜尔豆胶为0.90%,卡拉胶为0.61%,聚丙烯酸钠为0.05%时,得出最大拉伸面积,对冷冻特一粉面团品质有很好的改良作用。     

谷朊粉对冷冻面团的流变学性质及发酵能力的影响

探讨了添加不同比例的谷朊粉,对冷冻面团流变学特性及发酵能力的影响。结果表明,添加谷朊粉可以优化冷冻面团的流变学特性,改善冷冻面团的质量,谷朊粉添加量为2％时,冷冻面团的质量最优。谷朊粉还提高了冷冻面团的产气力,改善了冷冻面团的发酵能力,谷朊粉添加量为1％时,冷冻面团的发酵能力最高。     

甜高粱茎秆在冷冻条件下含糖量的变化研究

采用15个甜高粱作为研究材料,分别对收获时及冷冻153、0和45 d的茎秆含糖量进行研究。结果表明：甜高粱的茎秆在冷冻条件下45 d内对甜高粱茎秆的含糖量没有显著影响,在生产加工过程中可以采用冷冻的方式进行贮藏。     

乳清粉对冷冻面团的流变学特性及发酵能力的影响

探讨添加不同比例的乳清粉对冷冻面团流变学特性及发酵能力的影响。结果表明,添加乳清粉可以优化冷冻面团的流变学特性,改善冷冻面团的质量,乳清粉添加量为2%时,冷冻面团的质量最优。乳清粉还可提高冷冻面团的产气力,改善冷冻面团的发酵能力,乳清粉添加量为2%时,冷冻面团的发酵能力最高。冷冻时间不超过21d的冷冻面团的拉伸特性较优,产气力较好。     

祁连山区春季冻土深度特征及对春小麦发育期的影响

为了分析祁连山冻土深度对春小麦发育期的影响,利用祁连山区11个站春季冻土深度及张掖和武威站春小麦发育期资料,采用回归分析、相关性检验、F检验等方法,分析了冻土深度的时空变化特征以及春季冻土深度对祁连山区春小麦发育期的东西部影响差异。结果表明：冻土深度最大出现在祁连站,以此为中心,向低海拔区域呈逐渐减小趋势;春季冻土深度随时间变化呈现明显的减小趋势,减小主要出现在1985年以后,1961—1984年变化幅度较小,这与春季明显的增温时段基本同步。春季冻土深度对祁连山东部代表站点武威春小麦的发育期影响效果显著,先后影响到了春小麦的播种、出苗、三叶、拔节、孕穗、抽穗以及成熟,冻土深度增加,则发育期延迟,延迟速率为0.5～2.4天/10cm;然而,春季冻土深度对西部代表站点张掖春小麦的影响并不显著,只对出苗和三叶产生一定的影响。     

科尔沁沙坨地-草甸地冻融期地温与最大冻结深度的变化规律

[目的]探究科尔沁沙坨地—草甸地土壤温度与冻结深度的变化规律,为合理指导该区农工生产和建设提供支持。[方法]基于2007—2015年冻融期人工观测数据,对比分析科尔沁沙坨地与草甸地冻融期多年土壤温度与最大冻结深度变化规律。[结果]研究区100cm处沙坨地与草甸地多年土壤温度的标准差变化规律基本一致,草甸地要小于沙坨地,但融解后期由于草甸地融解期历时较长,其标准差大于沙坨地;同时考虑土壤温度和土壤水分对最大冻结深度的影响时,沙坨地在200cm处和草甸地在140cm处的R2分别为0.959和0.788。[结论]研究区内沙坨地先冻结与先融解,沙坨地最大冻结深度较草甸地深,同时考虑土壤温度与土壤水分的最大冻结深度的拟合优度最好,沙坨地与草甸地中最大冻结深度与土壤温度和土壤水分均呈负相关关系。     

使用便携式X射线荧光（PXRF）法原位区分酸性和非酸性冻土带

Frozen soils or those with permafrost cover large areas of the earth’s surface and support unique vegetative ecosystems. Plantsgrowing in such harsh conditions have adapted to small niches, which allow them to survive. In northern Alaska, USA, both moistacidic and non-acidic tundra occur, yet determination of frozen soil pHs currently requires thawing of the soil so that electrometric pHmethods can be utilized. Contrariwise, a portable X-ray fluorescence (PXRF) spectrometer was used in this study to assess elementalabundances and relate those characteristics to soil pH through predictive multiple linear regressions. Two operational modes, SoilMode and Geochem Mode, were utilized to scan frozen soils in-situ and under laboratory conditions, respectively, after soil sampleswere dried and ground. Results showed that lab scanning produced optimal results with adjusted coefficient of determination (R²) of0.88 and 0.33 and root mean squared errors (RMSEs) of 0.87 and 0.34 between elemental data and lab-determined pH for Soil Modeand Geochem Mode, respectively. Even though the presence of ice attenuated fluoresced radiation under field conditions, adjusted R² and RMSEs between the datasets still provided reasonable model generalization (e.g., 0.73 and 0.49 for field Geochem Mode). Principalcomponent analysis qualitatively separated multiple sampling sites based on elemental data provided by PXRF, reflecting differences inthe chemical composition of the soils studied. Summarily, PXRF can be used for in-situ determination of soil pH in arctic environments without the need for sample modification and thawing. Furthermore, use of PXRF for determination of soil pH may provide highersample throughput than traditional eletrometric-based methods, while generating elemental data useful for the prediction of multiplesoil parameters.     

不同降雨强度下黄土区冻土坡面产流产沙过程及水沙关系

为了明确降雨对冻土坡面侵蚀的作用机理,探讨冻土和未冻土在不同水力条件下侵蚀之间的差异。通过室内模拟降雨试验,采用3种降雨强度(0.6,0.9,1.2 mm/min)对比定量研究冻土坡面和未冻土坡面产流产沙过程及水沙关系。结果表明:在0.9、1.2 mm/min雨强下,冻土坡面的产流时间相对对照坡面提前了18.7,6.4 min。冻土坡面径流量、侵蚀量均远大于对照坡面,在0.9,1.2 mm/min雨强下径流量分别是对照坡面的1.16,1.19倍,侵蚀量分别是对照坡面的10.40,6.40倍。随着降雨进行,坡面产生不同程度的细沟,其中,冻土坡面相比对照坡面细沟出现时间分别缩短了18 min,22 min,且冻土坡面细沟侵蚀量占总侵蚀量的79%～92%,此比例大于同雨强下的对照坡面。两种坡面的累计径流量与累计产沙量之间满足y=kx+b的线性关系,在细沟间侵蚀阶段,冻土坡面的k值是对照坡面的8.48～9.02倍,而在细沟侵蚀阶段,则为对照的3.68～7.50倍。研究结果表明细沟侵蚀是冻土坡面土壤侵蚀率增大的主要原因,而冻结层的阻水作用是导致坡面上细沟出现时间提前的最重要因素。该研究可以为完善土壤侵蚀机理研究提供一定的参考价值。     

冰鲜杂鱼和人工配合饲料对大口黑鲈肌肉品质及健康状况影响的评价

本试验通过测定血清生化指标和肌肉营养成分,评价冰鲜杂鱼和人工配合饲料对大口黑鲈肌肉品质及健康状况的影响。养殖过程中冰鲜组大口黑鲈全程投喂冰鲜杂鱼,饲料组大口黑鲈全程投喂大口黑鲈专用人工配合饲料。在商品鱼上市前,冰鲜组和饲料组各随机采集6尾用于测定血清生化指标,再各随机采集6尾用于测定肌肉营养成分。结果显示:饲料组大口黑鲈血清中谷草转氨酶(AST)活性显著高于冰鲜组(0.01≤P0.05),血清中碱性磷酸酶(ALP)活性极显著高于冰鲜组(P0.01),血清中总蛋白(TP)和白蛋白(ALB)含量极显著低于冰鲜组(P0.01)。冰鲜组大口黑鲈肌肉中总氨基酸(TAA)含量显著高于饲料组(0.01≤P0.05),且肌肉中各种氨基酸的氨基酸评分(AAS)和化学评分(CS)以及必需氨基酸指数(EAAI)均高于饲料组。饲料组大口黑鲈肌肉中亚油酸(C18∶2)含量极显著高于冰鲜组(P0.01)。结果表明,本试验条件下,冰鲜组大口黑鲈肌肉营养品质特别是蛋白质品质及氨基酸组成要优于饲料组,且健康状况也优于饲料组,但饲料组大口黑鲈肌肉中亚油酸含量较冰鲜组极显著升高。因此,大口黑鲈的人工配合饲料配方还需要进一步的优化,来满足消费者对大口黑鲈的营养需求。     

Study on Technology of Black Silkies Chicken Semen Freezing by DMA Pellet

The aim was to explore the effects of different kinds of dilution and thawing devices on the N,N-dimethylformamide (DMA) pellet frozen semen of Black Silkies. Firstly,the motility and fertility of the frozen semen thawed by different dilutions were compared;Then,the motility of the frozen semen was compared when the pellets were thawed using different tube and different number.Finally,the motility and fertility of the sperm thawed by three kinds of thawing devices (thermostat water bath,hotfunnel and hotplate ) were tested. The results showed that:①There was similar order of the sperm motility and fertility in the different dilution groups (LR > F > B > L),and there was significant difference among those groups (P < 0.05).②The motility was the best when the frozen semen was thawed with large thin-wall glass tube at 60℃.③The best temperature range of the 3 devices was different. The highest motility for thermostat water bath was 50 to 60℃ (0.51 to 0.59),and thermostat hotfunnel was 40 to 45℃ (0.42 to 0.46),while thermostat hotplate was 50 to 55℃ (0.61 to 0.63).There was no significant difference of the motility in the optimum temperature range for each device (P > 0.05).④The fertility of the different devices in their best thawing temperature was 26.91% (55℃,thermostat hotplate),23.08% (60℃, thermostat water bath), 20.93% (40℃, thermostat funnel),respectively,and there was no significant differences among those groups (P > 0.05).Therefore,the efficiency thawing condition for the Black Silkies frozen semen was the LR diluent,DMA cryoprotectant,pellet freezing,thawed in the thermostat hotplate at 54.9℃.