基于混沌蚁群算法的冷藏车光伏储能混合制冷系统优化设计

针对冷藏车制冷系统能耗过高和车载光伏发电量不足等问题,设计一种冷藏车混合制冷系统,由光伏发电储能系统作为冷藏车辅助制冷动力来源,在冷藏车长时间停车时供电制冷。建立冷藏车混合制冷系统数学模型,进行样车试验,通过比较试验与仿真数据来验证冷藏车混合制冷系统模型的正确性,并在此基础上,提出将制冷效能系数和光伏发电经济系数作为冷藏车混合制冷系统评价指标,采用乘除法将这2个评价指标统一为目标函数。基于混沌蚁群优化算法,对冷藏车混合制冷系统进行优化设计,优化结果表明:制冷效能系数从0.542降低到了0.402,光伏发电经济系数从0.464升高到了0.840,优化后的冷藏车混合制冷系统更加节能经济。     

农用地整理对碳储量和粮食产能的影响

农用地整理对区域生态系统的空间格局和功能产生的影响需要持续不断的予以关注和调节。该文以福建省建溪流域为例,采用碳储量多源模型和耕地生产潜力模型估算了建溪流域的碳储量和粮食产能,分析了区域尺度农用地整理对碳储量和粮食产能的影响。研究表明:与2010年相比,2016年碳存储总量降低了38.28×10~6 t,为369.29×10~6 t;整理区以1.41%的土地贡献了整个建溪流域1.70%的碳储量减少量,农用地整理对建溪流域生态系统的固碳服务有负作用;2016年建溪流域的粮食产能提高了10.83×10~4t,为124.46×10~4t;农用地整理项目区占建溪流域耕地面积的14.61%,贡献了20.87%的粮食产能提高值,有效提高了建溪流域耕地的粮食产能。农用地整理所产生的碳效应不容忽视,在农用地整理中需要注重生态措施的运用。     

畜禽粪便与秸秆混合发酵及贮藏阶段沼液中碳氮元素变化

为研究沼液从产生到贮藏期间碳氮元素的变化规律,将猪粪、鸡粪和秸秆混合,进行中温厌氧发酵,并在常温下以密闭静置、密闭搅拌、敞口静置、敞口搅拌等4种方式贮藏沼液,跟踪并分析了猪、鸡粪和秸秆混合发酵沼液在厌氧发酵及贮藏期间碳、氮元素的形态和含量变化。结果表明:厌氧发酵阶段,沼液中的总有机碳(TOC)和总氮(TN)浓度均有所增加,增加幅度在15.0%~36.1%之间,其中TOC在第18 d达到最高浓度(6467 mg·L~(-1)),TN在第23 d达到最高浓度(4181 mg·L~(-1))。贮藏阶段,沼液中的TOC、TN浓度均有所降低,TOC先下降后升高,总体降低幅度较小(2.9%~12.0%),降幅顺序为敞口静置敞口搅拌密闭静置密闭搅拌;TN先升高后降低,总体降低幅度较大(4.2%~56.2%),降幅顺序为密闭静置密闭搅拌敞口静置敞口搅拌。综上,厌氧发酵18~23 d的沼液碳氮元素含量最高,采用密闭静置方式并缩短贮藏时间可减少沼液贮藏过程氮元素的损失。     

不同水氮条件对东北寒地黑土直播稻光响应特征的影响

为了揭示寒地黑土直播稻在不同灌水方式和施氮水平下功能叶片光响应特征,以测坑试验水直播水稻为研究对象,采用全面试验方法,设灌水方式和施氮量2个因素,针对水稻分蘖期和抽穗开花期开展了不同水肥条件下直播水稻叶片光响应特征的研究。结果表明:随氮肥施用量的增加,直播稻功能叶片的光响应曲线上升,光强高于600μmol/(m~2·s)时,不同施氮量处理的光响应曲线间距变大。运用非直角双曲线模型建立水稻叶片光合光响应曲线的拟合,得出不同水氮处理下直播水稻叶片的光响应特征参数,结果显示,随着施氮量的增加,最大净光合速率Pnmax、表观量子效率α和光饱和点LSP上升,光补偿点LCP下降;而同施氮量条件下,控制灌溉处理的Pnmax、α和LSP高于淹灌处理,LCP低于淹灌处理。因此,在0~135kg/hm~2的范围内增加施氮量和控制灌溉有助于提升直播稻功能叶片光合作用能力,提高其对光能的利用率和对强光及弱光的适应能力,有效改善叶片光响应特征,提高水稻产量,所以在进行直播水稻栽培研究时,要充分考虑不同水肥条件对其光响应特征的影响。     

间伐对油松人工林碳储量的长期影响

间伐不仅能改变人工林林木生长状况,还会影响整个森林碳储量,研究间伐对人工林碳固存的长期影响,有助于准确评价人工林的碳汇功能,为人工林的科学经营管理提供参考。2016年8月,以黄土高原森林区营造于1962年,间伐于1985年的4种(强度间伐、中度间伐、轻度间伐、对照)油松人工林为对象,保留密度分别为800,1 500,2 200,2 900株/hm~2,研究了间伐对油松人工林不同植被层、叶凋落物、粗木质残体和土壤有机碳库的影响。结果表明:轻度和中度间伐下油松人工林系统碳储量较对照显著提高了28.54%和21.33%,强度间伐碳储量(154.66t/hm~2)与对照(169.26t/hm~2)无显著差异。乔木层是油松人工林的主要碳库,占人工林总碳储量的64.85%~74.62%。不同处理下乔木层树干碳储量所占比例最高(52.05%~56.43%),树根和树枝次之(22.27%~22.60%和17.73%~18.32%),树叶最低(3.56%~7.01%)。中度和强度间伐下在提高林下灌草多样性的同时,总的灌草碳储量分别比对照高24.27%和25.24%。间伐显著降低了叶凋落物碳储量,其中,强度间伐下的叶凋落物只有对照的48.15%。土壤碳库的变化主要是由土壤表层0—20cm有机碳变动所引起,中度和强度间伐土壤表层碳储量较对照分别减少了17.68%和33.76%,而轻度间伐(51.23t/hm~2)与对照(50.96t/hm~2)无显著差异。土壤表层碳储量与植物多样性和基础呼吸呈显著负相关。轻度和中度间伐有助于森林生态系统碳固定,其中轻度间伐不仅有利于地上植被碳固定,而且还有助于土壤碳库的维持。     

Response of yield increase for dryland winter wheat to tillage practice during summer fallow and sowing method in the Loess Plateau of China

Soil moisture is the most critical limiting factor impacting yields of dryland winter wheat(Triticum aestivum L.) and it is strongly affected by tillage practice and sowing methods. This study was to assess the link between sowing method and tillage practice during summer fallow and their subsequent effect on soil moisture and grain yield. Furthermore, we sought to identify a more appropriate farming management practice for winter wheat production in Loess Plateau region of China. The experiment was conducted from 2011 to 2013, using a two-factor split plot design, including subsoiling(SS) or no tillage(NT) during summer fallow for main plots, and conventional drill sowing(DS) or plastic film drill sowing(FM) for subplots. Results showed that the maximum soil water storage(SWS) was under SS×FM treatment with values of 649.1 mm(2011–2012) and 499.4 mm(2012–2013). The SWS during the 2011–2012 growing season were 149.7 mm higher than that in the 2012–2013 growing season. And adoption of SS×FM significantly increased precipitation use efficiency(PUE) and water use efficiency(WUE) compared to other treatments for both seasons. Moreover, adoption of SS×FM significantly increased yield by 13.1, 14.4, 47.3% and 25.9, 39.1, 35.7% than other three treatments during the two growing seasons, respectively. In summary, combining subsoiling during summer fallow with plastic film drill sowing(SS×FM) increased SWS at sowing and effectively improved WUE, thus representing a feasible technology to improve grain yield of dryland winter wheat in the Loess Plateau of China.     

Influence of protein characteristics and the proportion of gluten on end-use quality in Korean wheat cultivars

The effects of protein characteristics and the proportion of gluten on end-use quality in 13 Korean wheat cultivars for three years were verified in this study. Year, cultivar, and the interaction between the year and the cultivar influenced protein characteristics, the proportion of gluten except for γ-and ω-gliadin using RP-HPLC(reversed-phase high-performance liquid chromatography), and end-use quality. Protein characteristics and the proportion of gluten in Korean wheat cultivars were between those of Australian standard white(ASW) and hard wheat(AH). Korean wheat cultivars exhibited a higher average α+β gliadin proportion than imported wheat, a γ-gliadin proportion similar to that of dark northern spring wheat, and the same ω-gliadin proportion as AH. They showed a bread-loaf volume intermediate between those of ASW and AH and a texture of cooked noodles similar to that of soft white wheat, but less springiness than imported wheat. The cookie diameter of Korean wheat cultivars was similar to that of hard red winter wheat. There was a correlation between bread-loaf volume and protein characteristics, except for the protein content in Korean wheat cultivars. Springiness and cohesiveness of cooked noodles were not correlated with protein characteristics, while hardness was correlated with the protein content and water absorption of a mixograph. Cookie diameter was negatively correlated with the sodium dodecyl sulfate(SDS) sedimentation volume and water absorption of a mixograph. The end-use quality was not correlated with any proportion of gluten composition. Principal component analysis(PCA) showed that the proportion of gluten was not related to the quality of the bread(both PCs, 81.3%), noodle(77.7%), and cookie(82.4%). PCA explained that Keumkang is suitable for superior bread, while Uri is good for cooked noodles and cookies.     

Relationship of chemical properties of different peanut varieties to peanut butter storage stability

This study examined the effect of peanut quality on the storage stability of peanut butter. The quality of 17 varieties of peanuts was analyzed, and each was used to prepare peanut butter. For different storage temperatures and durations, stability of the peanut butter was measured according to three indicators: peroxide value, acid value, and centrifugal rate. The correlation between peanut components and peanut butter storage stability was also investigated. The results indicated significant differences in fatty acid composition between different varieties of peanut. Peanut butter prepared with high oleic peanuts (Kainong 17-15) had a significantly longer shelf life than that of other varieties. The significant correlation between the stability of peanut butter and peanut quality suggests that oleic acid and linoleic acid were the main influencing factors on stability. This study finds that the high oleic peanuts (HOP) is the most suitable variety for making peanut butter, which can allow farmers and processors to choose the specific variety for better product and shelf life.     

乙烯与1-MCP处理对伯谢克辛甜瓜采后生理品质的影响

【目的】 研究乙烯与1-MCP处理在7℃冷藏条件下对伯谢克辛甜瓜采后生理品质的影响,为甜瓜采后贮藏保鲜提供理论依据。【方法】 以伯谢克辛甜瓜为原料,分别采用500 mg/L的乙烯和2 μL/L 1-MCP对甜瓜进行处理,每隔24 h测定甜瓜果实硬度、呼吸强度、细胞膜渗透率、可溶性固形物、可溶性糖、还原糖、VC、可滴定酸等品质指标。【结果】 与CK相比,1-MCP可以明显降低甜瓜果实呼吸强度、细胞膜渗透率,保持甜瓜果实硬度,抑制可溶性固形物、还原糖、总糖、可滴定酸、VC含量下降,乙烯处理降低果实硬度,促进果实中可溶性固形物、糖、酸含量和VC含量的下降。【结论】 伯谢克辛甜瓜为乙烯敏感性果实,1-MCP处理能够抑制甜瓜采后呼吸作用,减缓甜瓜果实营养物质的流失,较好的保持甜瓜品质,乙烯处理提高了甜瓜的呼吸强度和细胞膜透性,降低果实硬度,加速了果实采后品质劣变及软化衰老进程。     

短期封育对博乐绢蒿荒漠群落特征和碳密度的影响

【目的】研究封育对荒漠草地群落特征和物种多样性影响,分析生态系统碳库对草地封育的响应规律,为退化荒漠草地的修复和科学管理提供科学依据。【方法】以新疆博乐绢蒿荒漠为研究对象,采用野外调查和室内分析相结合的方法,对封育4 a的荒漠草地群落数量特征、物种多样性和生态系统碳库(生物量碳库,凋落物碳库和土壤碳库)测定分析。【结果】(1)与自由放牧区(FG)相比,封育4 a后博乐绢蒿荒漠草地的植被高度、盖度、密度、多样性指数、均匀度指数和丰富度指数降低了6.2%~48.4%(P>0.05)。(2)封育不利于生物量的积累,茎、枯落物和地下(0~100 cm根系)生物量封育后显著下降了18.6%~31.1%(P<0.05),但根冠比没有显著变化。(3)封育降低了博乐绢蒿荒漠草地地上生物量碳密度、表层土壤有机碳含量,且土壤上层(0~50 cm)有机碳密度降低幅度为53.5~233.6 g/m²。【结论】短期封育不利于博乐绢蒿荒漠草地生物多样性的维持和生态系统碳库的积累,在封育措施的基础上配合施肥、补播等其他恢复措施。