化工安全生产问题及对策研究

文章根据化工企业普遍存在的装备陈旧落后、工作环境恶劣、员工安全意识低、安全规章制度不健全等问题,从加强安全知识教育、提高全员安全意识、实行科学管理、重视科学技术等方面对化工安全生产策略进行了深入探讨。以期能在化工企业的安全生产工作中有所借鉴,为生产企业、研究学者提供参考。     

制约因素理论及其在生产管理中的应用

作为一种有效的系统全体优化方法，制约因素理论(TOC)在美国、日本得到广泛关注。介绍了制约因素理论的产生及主要内容、方法，对该理论在生产管理中的应用作了解释说明，指出制约因素理论导入后的惊人效果，以期望TOC在中国被广泛了解和应用．     

中国粮食生产环境效率及其影响因素分析

近年来,农业生产带来的环境问题引起日益广泛的关注,而测算环境效率能直观反映农业生产对生态环境的影响,使人们清楚地认识到农业生产所付出的环境代价,进而推动中国农业生产向更具可持续性的方向转变。有鉴于此,本文基于2004-2012年全国农村固定观察点数据,采用超越对数随机前沿分析方法测算了中国农户粮食生产的环境效率,并用Tobit模型考察农户粮食生产环境效率的影响因素。研究结果表明：①全国范围内农户粮食生产的技术效率与环境效率均值分别为0.802和0.489,并且两种效率之间具有较高的相关性;②考虑环境效率后,中国粮食生产的技术效率均值出现了略微的下降趋势,但东部、中部、西部依次递减的趋势没有改变;③环境效率地区间差异明显,呈现出中部、西部、东部依次递减的趋势。而且随着时间变化,各地区的环境效率均呈现出递减趋势;④不同规模农户的粮食生产环境效率也存在差异,具体而言,大规模农户粮食生产环境效率普遍高于中小规模农户;⑤农户特征、农业生产要素、农业技术培训以及土地细碎化等因素均会影响粮食生产环境效率。     

知识型企业的生产可能性曲线及其启示

作为知识型企业的主要投入品,知识所具有的规模经济性、无限复制性、极易变通性,改变了工业企业的生产特点和规律,使知识型企业具有了新型的生产可能性曲线。文章通过知识型企业与工业行企业的对比分析,给出了知识型企业新型的生产可能性曲线形式,并对由此导致的知识型企业的规模经济和范围经济进行了说明,最后认为知识型企业应该立足于做大做强。     

制造分销型企业服务创新的支持平台及工作原理

本文分析了制造分销型企业服务创新的需求、过程和特点,提出了基于平台方法的客户服务创新支持平台,并分析了其工作原理和应用方法,比较了产品平台与服务平台,最后给出了其应用实例和亟需研究的问题。     

论高校产学研及其运行机制

高校产学研工程经过近 10个年头的运行 ,已得到了社会特别是高校的普遍认可 ,从合作主体的关系角度看形成了校内产学研合作模式、双向联合体合作模式、多向联合体合作模式、中介协调型合作模式的运行模式 ,并取得了一定的社会效益与经济效益。由于现行产学研合作各方主体独立 ,合作中必然会出现分歧 ,导致协调困难 ,合作效益低下。为此 ,通过对产学研关系的理论分析 ,针对目前产学研运行机制存在的弊端 ,提出“建立和完善高校科技园 ,组建产学研产业公司 ,以课题或项目为中心强化产学研合作链”新的运行机制。     

Screening of cellulose degradation bacteria from Min pigs and optimization of its cellulase production

BackgroundCellulose as a potential feed resource hinders its utilization because of its complex structure, and cellulase is the key to its biological effective utilization. Animal endogenous probiotics are more susceptible to colonization in the intestinal tract, and their digestive enzymes are more conducive to the digestion and absorption of feed in young animals. Min pigs are potential sources of cellulase probiotics because of the high proportion of dietary fiber in their feed. In this study, the cellulolytic bacteria in the feces of Min pigs were isolated and screened. The characteristics of enzymes and cellulase production were studied, which provided a theoretical basis for the rational utilization of cellulase and high-fiber food in animal production.ResultsIn our study, 10 strains of cellulase producing strains were isolated from Min pig manure, among which the M2 strain had the best enzyme producing ability and was identified as Bacillus velezensis. The optimum production conditions of cellulase from strain M2 were: 2% inoculum, the temperature of 35°C, the pH of 5.0, and the liquid loading volume of 50 mL. The optimum temperature, pH and time for the reaction of cellulase produced by strain M2 were 55°C, 4.5 and 5 min, respectively.ConclusionsMin pigs can be used as a source of cellulase producing strains. The M2 strain isolated from feces was identified as Bacillus velezensis. The cellulase from M2 strain had a good activity and the potential to be used as feed additive for piglets.How to cite: Li F, Xie Y, Gao X, et al. Screening of cellulose degradation bacteria from Min Pigs and optimization of its cellulase production. Electron J Biotechnol 2020;48. https://doi.org/10.1016/j.ejbt.2020.09.001     

要素区际流动影响及对策初探--以产业结构为例

文章在分析生产要素国际流动对产业结构影响的基础上,探讨了生产要素区际流动对区域产业结构的影响,提出了削弱要素区际流动对经济落后地区不利影响的对策,即建立和完善我国的各类要素市场,减少要素区际流动成本;完善财政转移支付制度;发挥政策性银行的作用,实行有差别的金融政策,完善中西部非银行全融机构体系：增加向中西部地区的投入以改善其基础设施和投资环境,等等。     

LXYL-P1-2 immobilized on magnetic nanoparticles and its potential application in paclitaxel production

BackgroundLXYL-P1-2 is the first reported glycoside hydrolase that can catalyze the transformation of 7-β-xylosyl-10-deacetyltaxol (XDT) to 10-deacetyltaxol (DT) by removing the d-xylosyl group at the C-7 position. Successful synthesis of paclitaxel by one-pot method combining the LXYL-P1-2 and 10-deacetylbaccatin III-10-β-O-acetyltransferase (DBAT) using XDT as a precursor, making LXYL-P1-2 a highly promising enzyme for the industrial production of paclitaxel. The aim of this study was to investigate the catalytic potential of LXYL-P1-2 stabilized on magnetic nanoparticles, the surface of which was modified by Ni²⁺-immobilized cross-linked Fe₃O₄@Histidine.ResultsThe diameter of matrix was 20–40 nm. The K_m value of the immobilized LXYL-P1-2 catalyzing XDT (0.145 mM) was lower than that of the free enzyme (0.452 mM), and the k_cat/K_m value of immobilized enzyme (12.952 mM s⁻¹) was higher than the free form (8.622 mM s⁻¹). The immobilized form maintained 50% of its original activity after 15 cycles of reuse. In addition, the stability of immobilized LXYL-P1-2, maintained 84.67% of its initial activity, improved in comparison with free form after 30 d storage at 4°C.ConclusionsThis investigation not only provides an effective procedure for biocatalytic production of DT, but also gives an insight into the application of magnetic material immobilization technology.How to citeZou S, Chen TJ, Li DY, et al. LXYL-P1-2 immobilized on magnetic nanoparticles and its potential application in paclitaxel production. Electron J Biotechnol 2021;50.https://doi.org/10.1016/j.ejbt.2020.12.005     

Isolation and identification of a cellulolytic bacterium from the Tibetan pig's intestine and investigation of its cellulase production

BackgroundThe Tibetan pig is a pig breed with excellent grazing characteristics indigenous to the Qinghai–Tibet plateau in China. Under conditions of barn feeding, 90% of its diet consists of forage grass, which helps meet its nutritional needs. The present study aimed to isolate and identify a cellulolytic bacterium from the Tibetan pig's intestine and investigate cellulase production by this bacterium. The study purpose is to provide a basic theory for the research and development of herbivore characteristics and to identify a source of probiotics from the Tibetan pig.ResultsA cellulolytic bacterium was isolated from a Tibetan pig's intestine and identified based on morphological, physiological, and biochemical characteristics as well as 16S rRNA analysis; it was designated Bacillus subtilis BY-2. Examination of its growth characteristics showed that its growth curve entered the logarithmic phase after 8–12 h and the stable growth phase being between 20 and 40 h. The best carbon source for fermentation was 1% corn flour, while 2% peptone and yeast powder compound were the best nitrogen sources. The initial pH during fermentation was 5.5, with 4% inoculum, resulting in a high and stable amount of enzyme in 24–48 h.ConclusionsThe isolated BY-2 strain rapidly grew and produced cellulase. We believe that BY-2 cellulase can help overcome the shortage of endogenous animal cellulase, improve the utilization rate of roughage, and provide strain sources for research on porcine probiotics.     

我国气象前科技成果阶段管理实施的现状、问题及对策

论述了我国气象行业前科技成果管理阶段的现状及存在的主要问题,提出了在前科技成果阶段如何通过科学的管理方法提高科研项目管理的整体质量,使科研成果满足经济、社会和气象事业发展的需要,全面提高气象科技成果的观点.     

Polymorphism of bovine lipocalin-2 gene and its impact on milk production traits and mastitis in Holstein Friesian cattle

BackgroundMastitis is one of the most serious diseases of dairy cattle, causing substantial financial losses. While predisposition to reduced somatic cell count in milk has been considered for in cattle breeding programs as the key indicator of udder health status, scientists are seeking genetic markers of innate immune response, which could be helpful in selecting cows with improved immunity to mastitis. Lipocalin-2 (LCN2) is a protein involved in the response of the immune system by eliminating iron ions which are necessary for the growth of pathogenic bacteria, so LCN2 may be considered as a natural bacteriostatic agent and could become a marker of infection.ResultsA total of five SNPs were identified in LCN2 gene (one in the promoter, three in exon 1, and one in intron 1). A single haplotype block was identified. The locus g.98793763G > C was found to have a significant impact on protein levels in milk, and alleles of this locus were identified to have a significant positive dominance effect on this trait. None of the four analysed loci had a statistically significant impact on the milk yield, fat levels in milk or the somatic cell score. LCN-2 gene had no significant impact on the incidence of mastitis in the cows.ConclusionsAlthough the identified SNPs were not found to have any impact on the somatic cell count or the incidence of mastitis in cows, it seems that further research is necessary, covering a larger population of cattle, to confirm the association between lipocalin-2 and milk production traits and mastitis.How to cite: Pokorska J, Piestrzyńska-Kajtoch A, Kułaj D, et al. Polymorphism of bovine lipocalin-2 gene and its impact on milk production traits and mastitis in Holstein Friesian cattle. Electron J Biotechnol 2019;40. https://doi.org/10.1016/j.ejbt.2019.04.004     

新疆兵团棉花生产技术效率及影响因素分析

生产技术效率是影响农业生产的重要因素之一。以新疆生产建设兵团棉花种植户为研究对象,通过相关数据统计,运用随机前沿分析方法 (SFA)探讨兵团棉花种植过程中的生产技术效率及其影响因素。研究结果表明,纵观10余年的兵团棉花生产,其生产过程中存在着一定程度的技术效率损失;进一步分析发现,棉花种植过程中的用工数量、投入的直接费用和相关的时间变量对兵团职工种植过程中的生产技术效率都具有显著的正效应,而棉花机采比重、种籽费用的相关投入比率和政策性的影响因素虽然对技术效率有正的影响,但影响不显著。进而提出应加强兵团棉花种植过程中的农技推广与田间管理、加大对兵团农业的补贴力度、推广棉花种植过程中的全程机械化、完善现有的兵团管理制度、发展兵团特色的可循环绿色环保棉花产业等政策性建议。     

农业保险的要素配置效应及其作用机制——基于助力现代农业发展视角

在巩固脱贫攻坚成果同乡村振兴有效衔接目标背景下,农业保险是否具有影响生产要素配置进而助力现代农业发展的“造血”功能亟待研究。本文基于山东与甘肃583份农户调研数据,兼顾小农户与新型农业经营主体,就助力现代农业发展视角下农业保险保障水平对农业生产要素配置的影响及作用机制进行分析。研究发现：①农业保险保障水平与经营规模、资金投入、技术投入存在先正向激励后负向抑制的“倒U型”关系,与农业绿色生产水平存在线性正向关系。②农业保险保障水平对小农户和新型农业经营主体的生产要素配置影响存在差异,对小农户而言,农业保险保障水平与资金投入、技术投入存在“倒U型”关系,与农业绿色生产水平存在线性正向关系;对新型经营主体而言,农业保险保障水平仅与经营规模、资金投入及技术投入存在“倒U型”关系。③农业保险保障水平主要通过促进土地流转来扩大经营规模,通过增强农险信贷协同效应来提高资金投入,通过加强农业技术培训来提升技术投入,进而助力现代农业发展。据此,提出了全面提高保障水平、增强补贴政策指向性、缓解农业信贷约束、抑制道德风险问题等政策建议。     

中国区域建筑产业生产效率变动的差异与空间趋同研究

中国区域建筑产业发展呈现出较大的差异性,这种差异性的长期存在和过分扩大不仅会影响到建筑产业发展的整体效率,也不利于资源的有效配置。据此,本研究将随机前沿生产函数模型与σ趋同检验方法结合,探索进入新世纪后中国建筑产业生产效率变动的区域差异及其背后的影响机制,并进行各地区建筑产业生产效率的收敛性实证分析。研究发现,中国建筑产业生产效率由东到西依次呈现出梯次发展趋势,区域科技投入状况、建筑市场开放度、市场的所有权结构和产业发达程度四个控制变量极大地促进了中国建筑业生产效率的提升;而建筑业人力资本和区域金融业发展状况两个控制变量对建筑业生产效率的提升带来了负面效应。区域间与区域内建筑产业生产效率的差异化程度均存在着严重的"拉大"趋势。最后,从有效遏制地方保护、规范竞争秩序、深化国有企业改革、吸引外资企业和完善创新机制五个方面提出相应的对策建议。     

SCI与科研成果评价探讨

近年来,SCI评价标准作为评价科研成果的一种标准,引起了学术界的广泛关注。本文从分析SCI评价标准的应用情况入手,探讨SCI自身的局限性、过度强调SCI评价标准的危害性以及如何合理地利用SCI评价标准。     

模块化下的产品创新战略

本文认为模块化为产品快速、持续的创新搭建了一个平台。一方面,模块化技术下生产出的产品由相互独立的功能模块所组成,方便了企业通过混合与匹配功能模块来实现产品的多样化;另一方面,在模块产品的松耦合构架下,相同功能模块可能存在多个相似的生产者,竞争关系为产品创新带来持续的动力。