Synergistic Effect of Nonionic Surfacants(Nonethoxylated Sorbitan Esters)on Herbicides in Paddy Fields

An uneven herbicide distribution can lead to reduced efficacy,and the release of herbicide residues and their transformation products into the environment through runoff increases their potential use risk.Understanding the water distribution dynamics of commonly used paddy field herbicides,for example,oxadiazon,is imperative for the long-term management of weeds in paddy fields.To clarify the diffusion and sedimentation ability of oxadiazon with the addition of a nonionic surfactant—diffusion and settling agent(DSA)for subsequent commercial use in paddy field water layers,the synergistic mechanisms of DSA with butachlor and bensulfuron-methyl in paddy fields were studied.Bioassays,instrumental analysis and field experiments were conducted in this research to provide a relevant basis for improving the efficacy of paddy field herbicides.The field experiment results indicated that DSA could increase the plant and fresh weight control effects of oxadiazon(450 g a.i.·hm^(-2)),butachlor and bensulfuron-methyl to different degrees.These findings demonstrated that DSA could not only effectively improve oxadiazon diffusion and settling in water layers and significantly increase the control effects of butachlor and bensulfuron-methyl,but also promote crop growth and development to different degrees.

火焰喷涂高熵合金增强铜基复合涂层的组织和耐磨性研究

为了研究AlCoCrFeNi高熵合金(HEA)的加入对铜基复合涂层形貌、显微硬度和耐磨性的影响,以火焰喷涂法在40Cr钢表面制备了AlCoCrFeNi/Cu复合涂层,并采用X射线衍射仪、显微硬度计、扫描电镜和高速摩擦磨损试验机等对涂层的组织及耐磨性进行了测试表征。结果表明:高熵合金(HEA)由BCC和FCC双相固溶体组成。AlCoCrFeNi/Cu复合涂层呈层状结构。随着高熵合金含量的增加,复合涂层的显微硬度增加,当AlCoCrFeNi高熵合金达到最大加入量40%时,显微硬度达到最高值490.8 HV,磨损量达到最低值1.06 mg,比未添加高熵合金时降低94.9%,摩擦系数随高熵合金含量的增加而逐渐增大。

Genomic and transcriptomic insights into cytochrome P450 monooxygenase genes involved in nicosulfuron tolerance in maize(Zea mays L.)

Postemergence application of nicosulfuron for weed control in maize fields can cause great damage to certain maize inbred lines and hybrids. Two maize genotypes, tolerant inbred(HBR) and sensitive inbred(HBS), were found to significantly differ in their phenotypic responses to nicosulfuron, with the EC50(50% effective concentration) values differed statistically(763.6 and 5.9 g a.i. ha–1, respectively). Pre-treatment with malathion, a known cytochrome P450 inhibitor, increased nicosulfuron injury in both HBR and HBS. Our results support the hypothesis that nicosulfuron selectivity in maize is associated with cytochrome P450 metabolism. Further analysis of the maize genome resulted in the identification of 314 full length cytochrome P450 monooxygenase(CYP) genes. These genes were classified into 2 types, 10 clans and 44 families. The CYP71 clan was represented by all A-type genes(168) belonging to 17 families. Nine clans possessed 27 families containing 146 non-A-type genes. The consensus sequences of the heme-binding regions of A-type and non-A-type CYP proteins are ‘PFGXGRRXCPG’ and ‘FXXGPRXCXG’, respectively. Illumina transcriptome sequence results showed that there were 53 differentially expressed CYP genes on the basis of high variation in expression between HBS and HBR, nicosulfuron-treated and untreated samples. These genes may contribute to nicosulfuron tolerance in maize. A hierarchical clustering analysis obtained four main clusters named C1 to C4 in which 4, 15, 21, and 13 CYP genes were found in each respective cluster. The expression patterns of some CYP genes were confirmed by RT-q PCR analysis. The research will improve our understanding of the function of maize cytochrome P450 in herbicide metabolism.

Effect of False Ragweed (Iva Xanthifolia Nutt) Seed Extracts on Plants

Bioassay method was used to study the biological activity of different polar solvent extracts of False ragweed seed. Specially, water extracts of False ragweed has an effect on plant germination and root length. The study found that False ragweed seed extracts had different degrees of inhibition on many plant seed germinations, and inhibited the germination of cucumber seeds best, the maximum inhibition rate was 79.5%, for cabbage, sorghum and maize seed germination inhibition rate was more than 30%. False ragweed seed extracts also had strong inhibition on cucumber and many other plant root length, and inhibited the root length of cucumber best followed by red beans. The result showed that False ragweed seed extracts contained some materials that could inhibit germination and growth of some plants.

Effects of Methylated Soybean Oil Adjuvant on Fomesafen Efficacy to Weeds

Tank-mix adjuvant has the potential to improve the weed control efficacy of post-emergence herbicides. In order to study the synergistic effect of adjuvant, the effects of different rates of fomesafen alone or applied methylated soybean oil adjuvant（MSO） were sprayed on redroot pigweed, abutilon and black nightshade under greenhouse condition. The results showed that fomesafen had different performance on the three weeds, and MSO adjuvant could effectively increase the control. The nightshade control was lower than other two weeds with all the fomesafen doses from 131.25 to 506.25 ga.i. · hm-2 with or without adjuvant. The control of abutilon was between the black nightshade and the redroot pigweed, and had better control at 375 ga.i. · hm-2 with adjuvant or 506.25 ga.i. · hm-2 alone or with adjuvant respectively. The results indicated that mixing adjuvant with fomesafen improved the control on weeds, especially at the low rate. Black nightshade was more difficult to control. The redroot pigweed had the most susceptibility to fomesafen alone or with adjuvant.

基于图像识别的证书分拣盖章机器人机械手智能原点搜寻

针对工业机器人编码器掉电等情况,造成原点丢失以后,机械手需要工程师手动操作建立原点的情况,本文提出一种通过给机械手加装摄像头,利用图像比较识别的方法,让机器人通过学习,能够智能避障,自动找回原点的方法。

互联网普及与国际贸易——基于出口方视角的研究

文章选取69个经济体作为样本,利用中介效应模型Bootstrap法、随机前沿分析、动态因子分析等方法对双边贸易中出口方互联网普及与制造业产品贸易的关系进行研究。结果表明,出口方互联网普及率越高,制造业产品贸易规模越大,且对于技术密集型产品、资本密集型产品、中级技术产品、高新技术产品、化学制品及相关产品以及机械及交通设备等产品来说,两者的关系更加显著。出口方互联网普及可通过提升生产效率、贸易便利化程度、贸易效率、扩大贸易市场规模以及降低贸易多边阻力扩大制造业产品贸易规模。上述结论在考虑零贸易值、异质性、指标测度、时滞因素、贸易惯性以及内生性等因素后依然稳健。

感应加热对AlCoCrFeNi-Cu复合涂层组织及耐磨性的影响

采用氧-乙炔火焰喷涂在40Cr钢表面制备了AlCoCrFeNi-Cu复合涂层,为了进一步降低涂层的孔隙率,提高涂层的硬度和耐磨性,将所得涂层进行感应加热处理,研究了感应加热工艺对涂层相组成、微观形貌、显微硬度和摩擦磨损性能的影响。结果表明:经过感应加热后,涂层中高熵合金没有发生氧化和分解,涂层的孔隙率最高下降了41.29%,涂层最高硬度为510 HV,磨损量最低为0.69 mg,具有较好的摩擦磨损性能。