China's distant‐water fisheries in the 21st century

We conservatively estimate the distant‐water fleet catch of the People's Republic of China for 2000–2011, using a newly assembled database of reported occurrence of Chinese fishing vessels in various parts of the world and information on the annual catch by vessel type. Given the unreliability of official statistics, uncertainty of results was estimated through a regionally stratified Monte Carlo approach, which documents the presence and number of Chinese vessels in Exclusive Economic Zones and then multiplies these by the expected annual catch per vessel. We find that China, which over‐reports its domestic catch, substantially under‐reports the catch of its distant‐water fleets. This catch, estimated at 4.6 million t year^?1 (95% central distribution, 3.4–6.1 million t year^?1) from 2000 to 2011 (compared with an average of 368 000 t·year^?1 reported by China to FAO), corresponds to an ex‐vessel landed value of 8.93 billion € year^?1 (95% central distribution, 6.3–12.3 billion). Chinese distant‐water fleets extract the largest catch in African waters (3.1 million t year^?1, 95% central distribution, 2.0–4.4 million t), followed by Asia (1.0 million t year^?1, 0.56–1.5 million t), Oceania (198 000 t year^?1, 144 000–262 000 t), Central and South America (182 000 t year^?1, 94 000–299 000 t) and Antarctica (48 000 t year^?1, 8 000–129 000 t). The uncertainty of these estimates is relatively high, but several sources of inaccuracy could not be fully resolved given the constraints inherent in the underlying data and method, which also prevented us from distinguishing between legal and illegal catch.     

桃蛀螟成虫触角超微结构观察及对玉米花丝挥发物的电生理反应

为了明确桃蛀螟［Conogethes punctiferalis (Guenée)］成虫触角感器类型及形态特征,利用扫描电镜对桃蛀螟成虫触角感器进行观察,并利用触角电位仪分析桃蛀螟触角对5种玉米花丝气味挥发物的反应。发现桃蛀螟触角感器绝大部分位于触角的腹面及侧面,鞭节表皮上有连续的网纹结构,而柄节和梗节上没有。桃蛀螟触角上有7种感器,分别为毛形感器（Ⅰ型、Ⅱ型）、刺形感器、耳形感器、钟形感器、锥形感器、腔锥形感器、栓锥形感器（Ⅰ型、Ⅱ型）。桃蛀螟雌雄成虫对花丝气味挥发物产生明显的触角电位反应,雌性桃蛀螟触角对1-己醇、1-庚醇、β-蒎烯和β紫罗酮反应明显,且随浓度的增加,反应强度增加迅速,尤其对1-己醇的反应尤为明显。雄性桃蛀螟触角对于1-庚醇和1-己醇反应非常明显,反应强度明显弱于雌虫。     

集装箱植物工厂研制与试验

针对植物工厂投入成本高、内部运行成本高和可移动性差等现状,开发了一种集装箱植物工厂。集装箱植物工厂由模块化栽培设施构成,主要包括栽培系统、补光系统、环境调控系统、营养液系统和控制系统等。生菜栽培试验结果表明,集装箱植物工厂可用于蔬菜生产种植,其产量和品质具有一定的提高。      

低碳钢表面渗碳及其耐磨性能研究

土壤耕作部件主要以摩擦磨损失效,为改善耕作部件工作时的耐磨性能,延长其使用寿命,通过对20钢表面渗碳以及淬火和低温回火处理,并使用金相显微镜观察了渗碳层组织以及渗碳层与基体的结合状况,X射线衍射分析渗碳层物相组成,显微硬度计测定了渗碳层硬度,在磨粒磨损试验机上对渗碳层的耐磨性能进行了试验研究。结果表明,20钢渗碳后经过淬火和回火可以得到与基体结合良好的表面耐磨层,组织为回火马氏体,其耐磨性能是不处理的试样的5倍。经过处理以后的低碳钢的耐磨性能不仅取决于材料表层的硬度,而且与材料的韧性相关。20钢表面渗碳后可以作为耕作部件材料得到广泛的推广使用。     

Experimental Warming Effects on Soil Respiration,Nitrification, and Denitrification in a Winter Wheat-Soybean Rotation Cropland

A field experiment was conducted to examine responses of soil respiration, nitrification, and denitrification to warming in a winter wheat (Triticum aestivum L.)–soybean (Glycine max (L.) Merr) rotation cropland. The results showed that seasonal variations in soil respiration were positively related to seasonal fluctuations in soil temperature. Seasonal mean soil respiration rates for the experimental warming (EW) and control (CK) plots were 3.98 ± 0.43 and 2.54 ± 0.45 μmol m^?2 s^?1, respectively, in the winter wheat growing season, and they were 4.59 ± 0.16 and 4.36 ± 0.08 μmol m^?2 s^?1, respectively, in the soybean growing season. There was a marginally significant level (p = 0.097) for mean nitrification rates between EW and CK plots. Soil temperature and moisture accounted for 58.2% and 58.1% of the seasonal variations observed in the winter wheat and soybean plots, respectively.     

Spatial-temporal dynamics of soil chloride distribution in a coastal saline plain: implication for ocean and climate influences

Journal of Soils and Sediments - Restoration of saline soil in coastal areas requires detailed understanding of spatial and temporal soil salt distribution and how the distribution is affected by...     

西瓜复合根际促生菌剂构建与促生效应研究

植物根际促生菌(plant growth-promoting rhizobacteria, PGPR)是微生物肥料的重要菌种资源,在农业生产中起着重要的作用。本实验研究了不同西瓜PGPR分泌激素能力和菌株间的拮抗作用,构建复合菌剂,并研究其对西瓜根系生长的影响。结果表明,12株PGPR均能分泌吲哚乙酸(IAA),Streptomyces CL05分泌量最高达到117.30 mg·L^-1;菌株Sphingomonas CL03、Lysobacter CL02、Microbacterium LS01不产铁载体,菌株Microbacterium LS01、Microbacterium HYL03、Pantoea ananatis HYL01不分泌赤霉素;通过拮抗实验,获得3组复合菌剂,分别为R1、R2和R3。在非灭菌土壤中,与对照相比,复合菌剂R2对西瓜幼苗根长、根表面积、根体积、根尖数和根干质量分别提高了79.0%、46.8%、57.1%、162.7%、49.1%;与对照相比,在灭菌土壤中,复合菌剂R2_S对西瓜幼苗根长、根表面积、根体积、根尖数和根干质量分别提高了191.8%、302.4%、160.0%、206.5%、139.6%,根系平均直径比对照降低了17.5%。复合菌剂R2在灭菌土中的促生效果优于非灭菌土。本研究结果证实,复合菌剂R2对西瓜根系具有明显的促生效应,复合菌剂R2的4株菌分泌赤霉素的能力远远超过R1和R3,这可能是R2促生的机制之一。     

河北省太行山山区中段大枣需冷量界限温度变化特征

利用河北省太行山山区中段11个县的1991—2021逐日平均气温数据和2011—2021逐时气温数据,采用趋势分析、皮尔逊系数等统计方法分析了河北省太行山山区中段大枣进入休眠期7.2℃的界限温度以及休眠期间需冷量的变化规律。结果表明：太行山山区中段气温稳定降至7.2℃终日平均日期为11月10日,最早为11月9日,最晚为11月11日,变化不明显。气温稳定升至7.2℃初日平均日期为3月18日,最早3月15日,最晚3月20日,趋势变化为每10年4.2 d,变化明显;气温稳定降至7.2℃持续日数多年平均日数是128.8 d,最少日数为125.1 d,最多日数为132.3 d,趋势变化为5.1 d/10 a,变化明显。气温稳定降至7.2℃终日中,曲阳、阜平一带开始时间最早;气温稳定升至7.2℃初日中,鹿泉、赞皇一带的开始时间最早。气温稳定降至7.2℃期间的持续日数中,鹿泉、元氏西部、赞皇一带的持续日数最少。曲阳持续日数变化趋势为每10 a减少4.0 d,全区域持续天数每10 a减少前后相差1.9 d;气温稳定低于7.2℃期间的需冷量在鹿泉、赞皇、临城一带存在低值区,需冷量由南向北依次递增;气温在0~7.2℃之间的需冷量在曲阳以及阜平北部存在低值区,需冷量由北向南依次递增。该研究可以对河北省太行山山区中段大枣自然休眠的起止日期、持续时长以及需冷量小时数有更清晰的掌握,为该区域不同品种枣树种植提供科学指导。     

根瘤菌接种方式对复播大豆生长发育的影响

【目的】筛选出适宜新疆南疆复播大豆生长及产量最佳的接种方式及根瘤菌。【方法】采用3种接种方式(拌种、种肥、滴施)和3种根瘤菌剂(SMH12、T6、SN7-2)对大豆品种绥农35进行田间接种试验,采用裂区试验设计,测定大豆农艺性状、光合特性、产量及产量构成因素的变化。【结果】不同接种方式接种根瘤菌均能不同程度促进南疆复播大豆生长及产量。拌种T6处理对大豆平均主茎节数生长最佳;滴施T6处理对大豆平均株高、LAI生长最佳;滴施SN7-2处理对促进大豆茎粗、LAD、单株粒数、单株荚数生长最佳;拌种SN7-2处理对大豆植株Tr、Gs、Pn、单株粒重及产量为最佳。【结论】产量效果最好的组合为拌种-SN7-2,高达5 946.0 kg/hm²。产量较好的组合为滴施-T6达到5 888.6 kg/hm²,种肥-SN7-2为5 461.6 kg/hm²,种肥-SMH12为5 446.6 kg/hm²。