Estimated Breeding Value in Iranian Buffaloes

This study was conducted from 1992-2002 on 65,534 individual milk records and fat percentage in 473 herds, in six provinces of Khuzestan, Mazndaran, W. Azerbaijan, E. Azerbaijan, Ardabil and Gilan. The data was analyzed by SAS sotfware using GLM procedure. The heritability and breeding value of 1,195 animals were calculated by DFRML procedure. The average milk yield per lactation, days of lactation, fat percentage and LSM of fat percentage were 1,513 kg, 202 days, 5.04 and 6.77, respectively. The estimated heritability of milk was 0.16. The LSM of average milk production in the provinces of Gilan, Mazandaran, E. Azerbaijan, W. Azerbaijan, Khuzestan and Ardabil were： 1,452, 1,586, 1,382, 1,183, 2,135 and 1,189 kg, respectively. These results indicated that Khuzestan province has the highest potential in the field of milk production. The top five highest breeding value bulls have been introduced to artificial insemination＇s station in the city of Uremia.     

浅谈给水排水工程节能节水措施

作者针对给排水系统工程特点并依据多年设计实践,总结了几点节能节水措施;阐明了通过减少不必要的浪费,可以达到节约水资源、节约能源的目的。     

Assessing the sustainability of cropping systems in single- and multi-site studies. A review of methods

The multiple new challenges facing agriculture require the development of innovative cropping systems with high environmental, economic and social performances. Many research programmes are currently focusing on the design of such cropping systems. Some include the multicriteria assessment of cropping systems by diverse methods and approaches. Some of these research programmes are supported by experimental or farmers’ networks, generating new opportunities for data analysis and raising new research and methodological questions. In this article, we provide an overview based on a review of 56 articles, comparing the various methods for sustainability assessment in single- and multi-site studies. Articles were classified according to three characteristics: (i) their objectives, (ii) the study design (single- vs. multi-site), (iii) the type of system assessed (fictitious vs. real). Our analysis was structured around four items: (i) the variables used to describe cropping systems and production situations and the use of these variables in the assessment process, (ii) the criteria and associated indicators assessed, (iii) the methods used to explore multiple aspects of the performance of cropping systems, (iv) the use of reference values. We identified key points to be taken into account in multi-site studies. The application of the proposed guidelines to experimental networks should facilitate the identification of high-performance cropping systems and the identification of the drivers of cropping system performance.     

太阳能辅助闭式热源塔热泵系统冬季制热性能

热源塔热泵系统以空气为冷热源,在冬季制热时其性能会随环境温度的降低而降低。为此研发了可应用陕南地区农村建筑的太阳能辅助闭式热源塔热泵系统,试验研究了冬季工况下系统的制热性能,初步分析了太阳热能与空气热能的互补机理。研究结果表明:系统制热量范围为12.1～15.2 k W,热泵机组性能系数范围为2.3～3.5,系统能效比范围为1.5～2.4,供热温度高于41℃;冷却水温度对压缩机耗电量的影响程度大于防冻溶液温度,冷却水平均温度每升高1℃,压缩要耗电量增加98.1 W,而防冻溶液平均温度每升高1℃,压缩机耗电量减小9.5 W;太阳能辅助热源塔热泵制热模式下,热泵机组通过改变防冻溶液与空气和集热工质换热温差的方法来改变防冻溶液从空气和集热水箱中的吸热量,以实现空气热能与太阳热能的互补。建议在实际应用中应避免供热温度过高以减小压缩机耗电;在集热水箱温度较高时通过降低风机频率减小风机耗电以提高系统综合能效,但应避免风机低频率工作可能给机组安全运行带来的隐患。     

枸骨的药用功效与保健作用

该文系统地综述了枸骨的化学成分和药用价值,并讨论了枸骨资源今后的开发与利用前景。     

江苏盐城首次记录到彩鹮

2020年5月4日在江苏盐城大丰麋鹿国家级自然保护区(120°47′—120°53′E,32°59′—33°03′N)记录到3只彩鹮。栖息地为一处浅滩水塘,3只彩鹮于水中觅食。以往曾宣布彩鹮在国内绝迹,本次记录填补了彩鹮在本地区的分布空白,证实了彩鹮在江苏省仍有分布。这一纪录或许说明本地区栖息地得到了有效的改善。     

纳米Fe3O4负载酸改性炭对水体中Pb2+、Cd2+的吸附

为探讨纳米Fe₃O₄负载联合硝酸改性椰壳炭对Pb²⁺、Cd²⁺单一及复合溶液的吸附特性，通过静态吸附实验，针对吸附剂的表面特性、投加量、溶液初始pH、吸附时间、重金属初始浓度等影响因素进行了探讨，应用等温吸附模型及吸附动力学模型对吸附特性进行了研究。结果表明，纳米Fe₃O₄负载酸改性炭比表面积较未改性椰壳炭增加了221.03 m²·g^-1，表面含氧官能团如O-H、C=O、C-O-C增加，芳香性增强，等电点提高至5.68。从经济效率角度考虑5 g·L^-1为合理吸附剂用量，pH为5.0时，吸附效果最好，吸附在4 h达到平衡。准二级动力学模型对吸附的拟合度更高，吸附主要是化学吸附，吸附由快速外扩散和颗粒内扩散共同作用，Pb²⁺、Cd²⁺的吸附分别更符合Langmuir和Freundlich等温吸附模型。纳米Fe₃O₄负载酸改性椰壳炭对Pb²⁺、Cd²⁺的最大吸附量（Q_m）分别达42.54 mg·g^-1和25.79 mg·g^-1，为未改性椰壳炭的1.87倍和2.23倍，复合溶液中Pb²⁺、Cd²⁺的Q_m分别为单一溶液的65.16%和54.21%，这揭示了离子共存条件下的吸附竞争现象。研究表明，纳米Fe₃O₄负载联合硝酸改性提高了椰壳炭对Pb²⁺、Cd²⁺的吸附能力，且Pb²⁺的吸附性能及吸附竞争性优于Cd²⁺。     

拖拉机姿控飞轮防侧翻系统卸载能量回收试验研究

拖拉机侧翻事故是农业生产过程中最严峻的安全问题之一，现有主、被动安全手段均未能从根本上解决该问题。在前期利用飞轮—电机加速旋转时产生的反向力矩进行姿态调节实现失稳态拖拉机姿态回稳的基础上，为进一步避免姿控飞轮卸载过程造成能量浪费，本文基于1∶16比例模型试验平台设计搭建了飞轮卸载能量回收电路，并通过模型试验对其回收效果进行了验证。试验结果表明，当模型拖拉机以0.2m/s速度行驶于路面不平度较高的G级、H级路面出现侧翻趋势并实现姿态回稳时，整机侧向姿态角降至10°后能量回收系统可介入工作，此时回收电压出现峰值0.97V（H-B轨迹），随后其数值变化趋势与姿控飞轮转速的降低趋势相似，直至飞轮卸载完成后回收电压归零。试验过程中，飞轮—电机系统在对不同的整机侧翻趋势做出响应时，能量回收系统完成的电量回收不同，但均完成了对飞轮卸载能量的部分回收，提高了整机能源的利用效率。     

南瓜新品种科栗1号的选育

科栗1号是以S31-1为母本、S4-1为父本配制而成的南瓜一代杂种。植株蔓生,长势中等;分枝较少,叶小,节间短;第1雌花节位第9节左右;嫩瓜扁圆形,瓜皮绿色覆绿色斑点和浅色纵条斑纹,老瓜皮墨绿色。嫩瓜单瓜质量0.5~1.5kg,果实横径9cm左右,纵径13cm左右,糯性好,粉质,品质佳;春季露地和秋季设施栽培嫩瓜产量1500~2000kg·(667m2)-1,早春设施栽培嫩瓜产量3000kg·(667m2)-1左右。适宜浙江省及栽培条件相似的地区推广种植。