共查询到20条相似文献,搜索用时 125 毫秒
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阐述国产复合(混)肥与进口复合肥的差距,复合(混)肥结块的原因,国产防结块剂与进口防结块剂的对比。建议使用国产防结块剂,可取得与进口防结剂相同效果,并可降低生产成本。 相似文献
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影响化肥结块的因素有多种。一般认为贮存温度、贮存压力、粒度、颗粒强度和湿含量是影响结块的主要因素。除了在化肥生产、包装、贮运过程中采取措施外,向化肥中添加防结块剂是最有效的防结块方法。目前常用的防结块剂有惰性粉末、无机盐、表面活性剂和非表面活性剂[1]。表面活性剂能改变固体和液体之间的表面张力。根据表面活性剂的极性结构,表面活性剂可分为2类:离子表面活性剂和非离子表面活性剂。离子表面活性剂有阳离子表面活性剂和阴离子表面活性剂2种。表面活性剂的作用是防止吸湿,改善结晶习性,抑制晶体的溶解和重结晶,减弱颗粒间… 相似文献
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蒙增辉 《中国现代应用药学》2006,(1):39-40
分析影响磷酸二铵产品结块的主要因素:包装温度高(设计≤50℃;实际≥60℃);细小颗粒(1~2mm)较多;水分含量高(2.2%~2.5%);抗结剂效果欠佳等。介绍为降低包装温度和产品水分、改善粒度状况所采取的工艺措施,并进行了抗结剂的优选试验。DAP结块情况有所缓解。 相似文献
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采用比浊法考察结块干燥培养基的质量。结果表明,结块干燥培养基对微生物的生长繁殖有一定的影响,并认为比浊法快速、简便、灵敏度高。 相似文献
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针对过磷酸钙肥料存在的易结块,熟化期长的问题开展了对过磷酸钙生产工艺进行优化的研究。该文公对添加活化疏松剂筛选试验和应用情况作一介绍。试验结果表明,根据不同矿种和条件,加入合适的活松剂后,鲜肥转化率较对比样,可提高3%-15%,生产出的疏松过磷酸钙鲜肥堆积重压35天后仍不结块。 相似文献
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1997年下半年,我公司根据市场情况恢复了硝酸磷肥双系统生产,取得了较好的经济效益。但由于全国化肥市场转入疲软,产品开始销售不畅,淡季出现积压,用户对产品结块问题反映日益强烈,影响产品的生产与销售,必须予以解决。1产品结块的原因 产品结块是由于颗粒内部的少量水分扩散到表面,或颗粒吸潮时盐类之间发生缓慢的化学反应,或盐类的离解和再结晶,从而在颗粒表面之间形成晶体桥,晶体桥与颗粒间存在凝聚力,使产品颗粒聚结成块。我公司硝酸磷肥产品含游离水≤1.2%(质量分数,下同),主要成分是硝铵和磷铵,临界相对湿… 相似文献
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分析复合肥产生结块的影响因素,时主要因素进行正交实验.根据正交实验各因素极差分析.温度、压力(码放高度)、粒度、存放时间各因素对NPK复合肥结块的影响程度为:温度压力(码放高度)粒度存放时间. 相似文献
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剖析了高氮复合肥"长毛"结块的原因,主要是由溶解度较大的尿素在温度梯度和水分的作用下,在复合肥颗粒表面逐渐生成的一种针状放射型半透明体所引起。通过实验,提出复合肥颗粒表现"蛋壳"化(指喷淋一种表面活性剂溶液于复肥表面)是解决高氮复合肥"长毛"结块问题的最有效途径。 相似文献
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目的探讨肺内结块的病理基础及在良、恶性鉴别诊断中的价值。方法搜集经手术切除经病理证实的肺内结块,肺癌(24例)、结核瘤(3例)、炎性假瘤(6例)、具有毛刺CT征结块33例,均采用螺旋CT扫描并结合组织学病理所见,观察和评价毛刺CT征。结果 33例毛刺征按其长度通常一般可分为两类:①短毛刺征(25例),其中(22例)为恶性,3例为良性病变。②长毛刺征8例,其中6例为良性病变,2例为恶性。结论毛刺征是诊断肺恶性肿瘤的征象之一,尤以短毛刺征诊断价值最为重要,该征出现若结合结块的其他特征和临床表现,则可提高对肺恶性肿瘤的诊断的准确率。 相似文献
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Atypical antipsychotic agents seem to be effective treatments for bipolar disorder, especially as adjunctive treatments. They may be a safer and more effective alternative to the common practice of maintenance adjunctive treatment with traditional antipsychotic agents in patients with bipolar disorder. However, currently available research studies are limited methodologically mainly to open-label, uncontrolled designs. Further research is required before the definitive efficacy of these agents in bipolar disorder is established. If randomized or double-blind data support the open-label data reviewed here, atypical antipsychotic agents may possess an important role in the adjunctive treatment of bipolar disorder. 相似文献
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《Journal of drug targeting》2013,21(3):167-174
AbstractSuperparamagnetic agents in magnetic resonance imaging: physico-chemical characteristics and clinical applications.Superparamagnetic agents have been the subject of extensive research over the last decade. They consist of iron oxide nanoparticles which are highly effective in Magnetic Resonance Imaging (MRI). The particle size varies widely and influences their physico-chemical and pharmacokinetic properties.Their main present and future applications by the parenteral route are: imaging of gastrointestinal tract, liver and spleen, lymph nodes.Ultrasmall superparamagnetic iron oxide particles (USPIO) are also blood pool agents which could be used for perfusion imaging (i.e. brain or myocardial ischemic diseases) as well as for imaging of vessels in Magnetic Resonance Angiography.These agents open up an important field of research into more specific agents adapted to clinicians' needs in diagnostic imaging. 相似文献
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Narayanan A Bailey C Kashanchi F Kehn-Hall K 《Expert opinion on investigational drugs》2011,20(2):239-254
INTRODUCTION: the search for effective inhibitors to multiple infectious agents including influenza, smallpox and hemorrhagic fever viruses is an area of active research as many of these agents pose dramatic health and economic challenges to the human population. Many of these infectious agents are not only endemic threats in different parts of the globe, but are also considered to have the potential of being used as bioterrorism agents. AREAS COVERED: this review focuses on inhibitors that are currently in use in the research community against specific emerging infectious agents and those that have bioterrorism potential. The paper provides information about the availability of FDA approved drugs, whenever applicable, and insights into the specific aspect of the agent life cycle that is affected by drug treatment, when known. EXPERT OPINION: the key message that is conveyed in this review is that a combination of pathogen and host-based inhibitors may have to be used for successful control of viral replication to limit the development of drug resistance. 相似文献
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目的:从文献角度评价我国抗抑郁药的研究,促进其在我国的发展。方法:用文献计量学方法对PubMed数据库1998年1月1日~2008年10月31日收录的抗抑郁药文献进行分析。结果:共收录抗抑郁药文献17784篇,总数量增长缓慢;来源于中国的文献共96篇,近几年呈现快速增长的趋势;在1998~2007年被收录的74篇文献中34篇是英文语种,40篇是中文语种,涉及56个研究机构和51种杂志,且来自北京地区的文献最多。结论:我国应继续加强抗抑郁药科研的投入和规模。 相似文献
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抗乙型肝炎病毒药物的研究进展 总被引:2,自引:0,他引:2
慢性乙型肝炎病毒感染是一个全球性的健康问题,开发抗乙型肝炎病毒药物一直是个热点。本文通过检索相关医药文献,对近几年来此类药物作一比较和评价,尤其对核苷类药物的研究进展进行着重介绍。 相似文献
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药物缓释、控释制剂的研究开发现状及发展趋势 总被引:5,自引:0,他引:5
近年来国内外研制成缓释、控释制剂的主要有片剂、胶囊剂、微球剂、滴眼剂、注射植入剂等。目前缓释、控释制剂技术发展迅速,其研制开发有广阔的市场和临床前景。 相似文献
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Development of antidotes: problems and strategies 总被引:1,自引:0,他引:1
Antidotes against chemical warfare agents are "orphan drugs" given that these poisonings are rare. Therefore, they are of limited interest to the pharmaceutical industry. For this reason, and recognizing the increasing threat of terrorist or asymmetrical use of chemical warfare agents, the responsibility for research into medical countermeasures against these weapons is of primary interest to armies. Accordingly, the research activities of the Bundeswehr Institute of Pharmacology and Toxicology are dedicated to improving diagnosis, prophylaxis and therapy of individuals who are exposed to a chemical agent. Here, antidote development and testing are a high priority in the research program, particularly with respect to organophosphorus (OP) nerve agents and sulphur mustard. The Institute has been coordinating research activities undertaken in house and in collaboration with external researchers. The research program aims to develop primarily in vitro models to minimize the sacrifice of animals, using strategies, which involve human material early in antidote testing. An animal model using isolated mouse diaphragm demonstrated the correlation between AChE activity and neuromuscular function. A similar relationship was found between erythrocyte AChE and neuromuscular function in patients with acute OP pesticide poisoning. In vitro rate constants of the various reactions that are involved in enzyme inhibition and reactivation using human material were used for prediction of what would happen in vivo. This prediction could be confirmed in a patient with acute OP pesticide poisoning. Finally, computer models are being established to estimate the therapeutic effect of an antidote in various human poisoning scenarios. This approach is necessary to compensate for the lack of human clinical pharmacodynamic studies that are usually required for drug regulatory approval, given the obvious ethical issues preventing human volunteer studies with these agents. 相似文献
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The development of oncological therapeutic agents is a complex and risky process and it is mainly pursued by research-based pharmaceutical companies. Academic and public research institutions, however, have contributed to the finding and evaluation of basic scientific knowledge, which were transferred to the industry for co-development. Since 1960 increasing regulatory demands have caused a prolonged development time and dramatical multiplication of costs. Oncological research in Germany began shortly after the end of war, when Bayer worked on the ethyleneimino compounds with agents like E39 and trenimon for therapeutical use. Early in the fifties this focus of research changed to Asta-Werke, Bielefeld (later ASTA Medica, Frankfurt) where cyclophosphamide (Endoxan, Cytoxan), ifosfamide (Holoxan, Ifex) and trofosfamide were developed as worldwide leading alkylating cytotoxic agents. The detection of mesna (Uromitexan, Mesnex) used for the organospecific detoxification of urotoxic metabolites caused a further increase of the cancerotoxic selectivity and an improved safety of oxazaophosphorine therapy. There has been ongoing research on alkylating agents (mafosfamide, glufosfamide), and new therapeutic principles like miltefosine (Miltex) or hormonal agents like cetrorelix (LHRH-antagonist) are in development. 相似文献