图书馆业务外包的实施策略

业务外包是一种新型的图书馆管理方法。本文介绍了图书馆业务外包的概念、内容、作用，探讨了实施图书馆业务外包的相应策略。     

跨膜蛋白VRAC的结构及生物学功能研究进展

跨膜蛋白是一类位于细胞膜上的重要蛋白质,对于维持细胞稳态和调节细胞的生长发育具有关键作用,因此一直受到广泛研究。本文将介绍一种重要的跨膜蛋白——体积调节阴离子通道（Volume Regulated Anion Channel, VRAC）,并全面综述其分子结构特征和多个生理功能,旨在为后续研究工作提供参考。     

基于YOLOv5s改进模型的小白菜虫害识别方法

小白菜是中国种植面积较广、深受大众喜爱的蔬菜,但真实菜地环境中虫害往往出现在叶片的特定区域,且受环境因素如光照和背景干扰较大,影响对其的智能检测。为提高小白菜虫害的检测效率和准确率,该研究提出一种基于YOLOv5s网络框架改进的YOLOPC小白菜虫害识别模型。首先,引入CBAM（Convolutional Block Attention Module）注意力机制,将其放在CBS（卷积层Convolution+归一化层Batch normalization+激活函数层SILU）的输入端构成CBAM-CBS的结构,动态调整特征图中各个通道和空间位置的权重;使用上采样和1×1卷积操作来调整特征图的尺寸和通道数,实现不同层次特征的融合,增强模型的特征表示能力。同时,改进损失函数,使其更适合边界框回归的准确性需求;利用空洞卷积的优势提高网络的感受野范围,使模型能够更好地理解图像的上下文信息。试验结果表明,与改进前的YOLOv5s模型相比,YOLOPC模型对小白菜小菜蛾和潜叶蝇虫害检测的平均精度（mean Average Precision, mAP）达到91.40%,提高了12.9个百分点;每秒传输帧数（Frame Per Second, FPS）为58.82帧/s,增加了11.2帧/s,增加幅度达23.53个百分点;参数量仅为14.4 MB,降低了25.78个百分点。与经典的目标检测算法SSD、Faster R-CNN、YOLOv3、YOLOv7和YOLOv8相比,YOLOPC模型的平均精度分别高出20.1、24.6、14、13.4和13.3个百分点,此外,其准确率、召回率、帧速率和参数量均展现出显著优势。该模型可为复杂背景下小白菜虫害的快速准确检测提供技术支持。     

辅料和菌剂添加对牛粪堆肥腐熟的影响

为研究不同辅料与菌剂添加对牛粪堆肥过程中堆体理化性质的影响,试验以牛粪为原料,设置7个不同的辅料和菌剂处理, T1(牛粪+玉米秸秆+发酵菌剂)、T2(牛粪+稻草+发酵菌剂)、T3(牛粪+蘑菇菌渣+发酵菌剂)、T4(牛粪+玉米秸秆)、T5(牛粪+稻草)、T6(牛粪+蘑菇菌渣)、CK(牛粪不添加辅料和发酵菌剂)。结果表明,在堆肥过程中,各处理批次的水分含量和C/N均呈下降趋势,pH值先升后降,有机质先降后升,种子发芽指数随堆肥天数的增加而增加。T1和 T2处理堆体升温快、高温期持续时间长,最高温度可达到66℃~67℃,高温期持续30~32天,加速了堆肥腐熟进程,提高了种子发芽指数。堆肥结束时T1和T2处理的种子发芽指数分别达到78.26%和76.48%。隶属函数综合评价表明T1腐熟程度最高,即当牛粪与玉米秸秆配比为4:1时,添加发酵菌剂有利于堆肥腐熟。     

Analysis of regional variation of height growth and slenderness in populations of six urban tree species using a quantile regression approach

Inventory data of six urban tree species from seven cities across Germany were used to model regional variation of height growth, allometric scaling, and slenderness over a wide range of size and age using a quantile regression approach. Variation within and between species and cities was large. Height did not reach an asymptote but declined at higher ages, presumably because of reduction cuts. Allometric scaling and slenderness varied with wind climate, modulus of elasticity, and coefficient of drag. Our data do not support the use of a threshold value of slenderness in tree risk assessment.     

河北省城郊农业发展方向与模式研究

通过对城郊农业特点的分析,提出城郊农业应向二、三产业延伸,实行多功能开发,走观光采摘农业的路子。在实际工作中,通过坚持3个结合、做好5项工作,实现4个功能。     

Life cycle assessment of utilizing freshly cut urban wood: A case study

Large amounts of urban wood resources are generated through tree removals in urban areas. Therefore, there is a growing interest to improve the environmental performance of the urban wood supply chain by quantifying the environmental impacts of creating high-value products from urban tree removals to enhance its utilization. By surveying existing urban wood utilization operations for primary data in two major cities: Baltimore, Maryland, and Milwaukee, Wisconsin, a new life cycle inventory (LCI) dataset per m³ of dry urban hardwood lumber and live edge slabs was created. Incorporating the new LCI data into life cycle assessment method, the total global warming (GW) impact of converting urban trees to kiln-dried lumber was estimated to be 122 kg CO₂ eq and 336 kg CO₂eq per m³ of lumber produced for Baltimore and Milwaukee, respectively. In both cases, the total environmental impact of the product was dominated by the conversion of urban trees to kiln dried lumber at the sawmill processing stage. Using scenario analysis for the source of heat generation used in kiln (force) drying wood, substituting wood fuel from coproducts for natural gas in a boiler for Milwaukee resulted in a substantial reduction in fossil-derived GW impact. Urban and traditional hardwood lumber production follow similar GW impact trajectories over their life-cycle stages with the lumber processing stage having the highest environmental impacts for both. Increasing the overall lumber yield and decreasing kiln (force) drying would substantially improve the environmental performance of urban hardwood lumber and help make it comparable to traditional lumber.     

浅谈自然保护区在湖北生态建设中的地位与作用

随着全国野生动植物保护和自然保护区建设工程的实施 ,自然保护区在我省生态环境建设中的地位与作用越来越重要 ,运用生物多样性管护区的理论指导我省的自然保护区建设将是正确认识自然保护区地位与作用的关键所在。     

GRC构件在建筑装饰业的应用

本文系统地阐述了GRC构件的产品性能,施工工艺及方法、特点,展望未来建筑业外装饰的发展趋势。     

蜜蜂肠道菌群的调节作用及影响因素

近年来, 蜜蜂数量的大量减少导致全球养蜂业面临重要的经济损失,并对农业各个方面造成了严重后果。最新的研究表明肠道菌群与宿主的健康息息相关。综述了肠道菌群的种类和特性,阐述了肠道菌群在蜜蜂等昆虫健康中的调节作用及影响肠道菌群的因素,并对今后的研究方向进行了展望。