加强山西省农产品质量安全监督管理策略

随着社会经济的不断发展，人们的生活水平也日益得到提高，农产品的安全质量愈发受到人们的关注。农产品的质量安全直接关系社会稳定，以及人们的身体健康，更是政府发展人本理念的重要体现。然而就当前的发展形势来看，在实际的农产品质量安全监督管理过程中仍然存在些许问题，农产品安全风险隐患仍相对较大。为此，如何加强农产品质量安全监管，对于保障农产品质量安全具有十分重要的意义。以山西省为探究对象，分析了山西省农产品质量安全现状及其监管过程中存在的问题，提出了加强质量安全监管的有效对策。      

Putative Identification and Adduct Formation of Reference Materials for Cotton Secondary Metabolite using UPLC-ESI-MS Analysis

[Objective] The aim of this study is to establish an method for cotton metabolites identification by ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS) analysis, and to investigate the adduct types, dominant adducts and appropriate ESI ion modes of cotton secondary metabolites under the determined UPLC and ESI conditions. [Method] UPLC-ESI-MS was employed to analyze 18 cotton metabolite standards, Online XCMS software was used to extract the nontargeted mass spectrum data, and MATLAB software was used to prepare calculation programs for the identification method of cotton metabolite standards. [Result] A high-throughput identification method of cotton secondary metabolite, named POSid and NEGid separately for the positive and negative ESI modes, was established based on the calculated accurate molecular weight. In the determined UPLC condition and positive and negative ESI mode, 14 cotton metabolite standards were correctly identified. There found 6 adducts including [M+H]⁺, [M+Na]⁺, [M+NH₄]⁺, [2M+NH₄]⁺, [2M+Na]⁺ and [2M+H]⁺ in positive ion mode, and 8 adducts including [M-H]^-, [2M-H]^-, [M+Cl]^-, [M+FA-H]^-, [3M-H]^-, [M+Na-2H]-, [M-H₂O-H]^- and [M+TFA-H]^- in negative ion mode, while 1 to 6 adducts were observed in the mass spectrum of a single standard, and each metabolite standard had a dominant adduct of a preference for ESI mode. Melibose was suitable for ESI positive ion mode detection, gossypol was suitable for both ion modes detection; and 12 compounds were suitable for negative ion mode detection due to mass spectrum signals of their dominant adduct stronger in negative ion mode than positive ion mode. [Conclusion] Based on the accurate molecular weight, the established identifying method can identify the 18 cotton metabolite standards with their nontarget mass spectrometry data. Under the determined UPLC and ESI condition, the dominant adducts of cotton secondary metabolites have the preference of ESI mode. These results provide technical and theoretical data support for further study of cotton metabolomics.     

Gelatin-walled microencapsulated diet for larval shrimp (Penaeus japonicus Bate) manufactured using the fluidized bed coating process

The gelatin-walled microencapsulated feed for larval shrimp (Penaeus japonicus) was produced using the fluidized bed coating process. The microencapsulated diet showed no significant agglomeration in the coating process and the diameters of the microdiet were in a normal distribution. Scanning electron microscopy microphotographs showed the appearance of a microencapsulated diet with a uniform surface and a continuous film around the core. The retention efficiency of vitamin C was 88.2% in the coating process. The inclusion efficiency, lipid encapsulation efficiency and nitrogen retention efficiency of the microdiet were 92.2 ± 1.6%, 76.8 ± 4.1% and 60.6 ± 5.2% respectively. The mysis α of P. japonicus were reared for 20 days to the later larval stage. The wet weight of larval shrimp increased 300.0% in the microdiet from 10 up to 30 day after hatching. The wet weight and the total length of larvae were greater in co-feeding compared with the control (P<0.05), but there was no significant difference in larval survival between co-feeding and control (P>0.05). There were significant differences (P<0.05) in the wet weight, total length and survival in the microdiet compared with the control. The results indicated a huge potential for the use of the gelatin-walled microencapsulated diet for the partial and total replacement of live food for larval shrimp.     

条石鲷的生物学及养殖生态学研究进展

条石鲷是一种具有较高经济价值和观赏价值的海产鱼类.文章简述了国内外对条石鲷生物学及养殖生态学的研究进展,并提出了条石鲷的养殖生态学研究方向和前景.     

小型甘蔗收割机多用途配套机具抽水机组的研制

本文针对甘蔗田间人工灌溉作业效率低、劳动强度大、生产成本高的生产实际,设计了一种新型的田间灌溉机械,经性能试验和测试表面,研制的小型甘蔗收割机多用途配套机具抽水机组操作便利,整机工作可靠,且该机实现了一机多用,满足了农机通用化的技术要求,设计达到了预期目标。     

神经转换较慢犬如何进行鉴别训练

<正>警犬鉴别训练难度甚大,特别是神经转换较慢犬的鉴别训练,难度更大。笔者结合实际,就神经转换较慢犬在鉴别训练中易出现的问题及解决办法作以下浅谈。     

加强教学档案管理 为学校内涵发展服务

本文通过对教学档案实例分析,反映了教学档案在本科教学评估中发挥的作用,展示了教学工作取得的成效和学校科学发展的成果,进一步强调教学档案管理和利用的重要性,提出了加强教学档案管理与研究,为学校发展服务的思路和措施。     

宁夏生态移民科技帮扶工程实施效果评价

"四个全覆盖"工程是宁夏针对生态移民实施的一项科技帮扶工程.本文通过构建评价指标体系,运用因子分析法对"四个全覆盖"工程实施效果进行评价,对分析工程实施过程中存在的问题,提出了一些对策性建议,使"四个全覆盖"工程实施效果更加显著.     

北京山地森林的土壤养分状况

森林土壤是维持林木健康生长的基质,其肥力特征影响并控制着林木的健康状态(Fisher et al.,2000)。森林退化与土壤肥力的衰退有密切的联系(La Mannaetal.,2004)。因此,对森林土壤特征的了解,可及时为森林健康经营提供依据。随着生态环境问题的日益突出以及森林健康理念的发展,世     

4YM-110型前悬挂式亚麻收获机的研制

针对目前亚麻人工收获劳动强度大和效率低的生产实际情况,研制了适应亚麻机械化收获的4YM-110型前悬挂式亚麻收获机;解决了亚麻的拔取、输送和有序铺放等问题。经田间试验和生产考核表明,该机具有操控方便、生产率高、拔净率高及可靠性高等显著特点。