【正文】 課題確定主題概念 在計算機(jī)信息檢索之前，對待檢課題進(jìn)行深入的分析，找出課題中包含的主要概念以及明確最終的檢索目的。還要明確所需信息的類型是文獻(xiàn)型還是數(shù)值型、事實型；是全文型、還是文摘型、是專利型還是一般資料。例如：檢索 AIDS與 HIV感染方面的文獻(xiàn)。其關(guān)鍵詞是 AIDS和HIV與感染 步驟 2 選擇檢索方式和數(shù)據(jù)庫 : 選擇合適的數(shù)據(jù)庫和檢索方式是計算機(jī)信息檢索成功的關(guān)鍵。一般來說，網(wǎng)絡(luò) 數(shù)據(jù)庫的數(shù)據(jù)更新速度要比光盤數(shù)據(jù)庫快得多。要根據(jù)待檢課題的學(xué)科專業(yè)范圍、主題內(nèi)容、檢索要求和目的，選擇收錄文獻(xiàn)種類、專業(yè)覆蓋面、年代跨度和更新周期對口的數(shù)據(jù)庫及檢索方式。例如：接上例，經(jīng)過分析例子屬于醫(yī)學(xué)范疇，可以選擇SCI或 IM數(shù)據(jù)庫 步驟 3 確定檢索途徑 如果檢索課題的研究范圍和內(nèi)容比較寬廣惡和系統(tǒng)時，多采用分類途徑方法。如果檢索課題的研究范圍和內(nèi)容比較專深時，往往采用主題檢索方法。同時，要注意檢索詞的選用。使用主題詞還是使用自由詞檢索。例如：接上例，可以利用主題途徑＋副主題詞進(jìn)行檢索。 步驟 4 編制檢索策 略（檢索式） 編制檢索策略是指在正確分析課題主題的基礎(chǔ)上，把選擇好的檢索詞或檢索標(biāo)識按檢索系統(tǒng)規(guī)定或允許的運算符或檢索規(guī)則連接起來，形成檢索策略，并提交計算機(jī)檢索進(jìn)行處理的全過程。 常用的運算符有：⑴布爾邏輯運算符―― (and 、 or 、 not) 表達(dá)檢索詞之間的邏輯關(guān)系的算符。⑵位置算符―― (with 、near 、 pre ) 適用于兩個檢索詞在同一篇命中文獻(xiàn)中需要指定間隔距離或出現(xiàn)順序的檢索表達(dá)式。⑶字段限定符―― (in 、 =)將檢索詞限制在文獻(xiàn)特定字段中出現(xiàn)的檢索。⑷截詞算 符―― （ *、 ?）是指截取檢索詞中的一部分進(jìn)行文獻(xiàn)檢索的方式。例題：接上例，檢索式可以是 AIDS and HIV and infect 步驟 5 檢索策略的反饋調(diào)整 檢索策略輸入檢索系統(tǒng)之后，初步檢索的結(jié)果有時不一定能滿足課題的要求，例如，檢索的輸出文獻(xiàn)較多，而且不相關(guān)文獻(xiàn)所占比例較大時，檢索式應(yīng)作相應(yīng)的調(diào)整。反之，亦然。如有必要，應(yīng)對檢索式進(jìn)行多次的反饋修改和調(diào)整，直到檢索結(jié)果滿意為止。 名詞解釋 1 知識 2 情報 3 文獻(xiàn) 4 核心期刊 5 專利 6 知識產(chǎn)權(quán) 7 專利文獻(xiàn) 8 同族專利 9 引文 10 來源著者 11 倒排文 檔 12 參考數(shù)據(jù)庫 13 聯(lián)機(jī)檢索 14 脫機(jī)檢索 15 記錄 16 光盤 17 二次檢索 18URL 19 綜述 20 文獻(xiàn)信息調(diào)查研究 。 簡答題 ⒈什么是檢索語言，其作用是什么 ⒉主題語言有幾種？簡要闡述其特點和區(qū)別 ⒊什么是查全率和查準(zhǔn)率，二者之間有何關(guān)系 ⒋簡述《中文科技資料目錄》（醫(yī)藥衛(wèi)生）分類途徑的檢索步驟 ⒌ 《醫(yī)學(xué)主題詞表》（ MeSH）字順表的參照系統(tǒng)有哪幾種？舉例說明其意義 6 依據(jù)我國專利法保護(hù)對象專利有哪幾 種類型？各種類型的專利有效期為多少 ⒎ 簡述知識產(chǎn)權(quán)的特點 ⒏簡述授予專利權(quán)的條件 ⒐ SCI 的作 用有哪些 ⒑ 簡述引文分析法的作用 ⒒ 簡述計算機(jī)信息檢索系統(tǒng)的構(gòu)成 ⒓ 照國際上通用的分類方法，數(shù)據(jù)庫通常分為哪些類型 ⒔簡 述數(shù)據(jù)庫的結(jié)構(gòu) ⒕ 計算機(jī)檢索系統(tǒng)中常用的運算符或檢索規(guī)則有哪些 ⒖ 簡述光盤的類型和特點 ⒗ 簡述 Inter 能提供的服務(wù) ⒘ 簡述電子郵件地址的組成 18報道性文摘與指示性文摘的區(qū)別 論述題 ⒈科技文獻(xiàn)根據(jù)加工層次劃分為幾種類型，各類型有何特點？ ⒉試述文獻(xiàn)檢索的基本方法、途徑和步驟。 ⒊ 述國內(nèi)醫(yī)學(xué)文獻(xiàn)檢索刊物的類型和特點。 ⒋試述《醫(yī)學(xué)主題詞表》（ MeSH）的四個組成部分的作用 ⒌試述 IM主題索引的編排規(guī)則以及使用該索引檢索文獻(xiàn)時應(yīng)如何選準(zhǔn)主題詞 ⒍試述 SCI各種檢索途徑的用途和使用方法 ⒎結(jié)合實例說明計算機(jī)檢索的基本步驟。 ⒏舉例說明計算機(jī)文獻(xiàn)檢索中檢索策略的反饋調(diào)整手段 ⒐試述計算機(jī)檢索系統(tǒng)中常用的運算符或檢索規(guī)則 ⒑試述因特網(wǎng)搜索引擎的概念、類型及意義 ⒒試述網(wǎng)上生物醫(yī)學(xué)信息資源的類型和特點 ⒓試述文獻(xiàn)信息調(diào)研的基本步驟 、類型及意義 4 請您刪除一下內(nèi)容， O(∩ _∩ )O 謝謝?。?！ 2021 年中央電大期末復(fù)習(xí)考試小抄大全，電大期末考試必備小抄，電大考試必過小抄Acetylcholine is a neurotransmitter released from nerve endings (terminals) in both the peripheral and the central nervous systems. It is synthesized within the nerve terminal from choline, taken up from the tissue fluid into the nerve ending by a specialized transport mechanism. The enzyme necessary for this synthesis is formed in the nerve cell body and passes down the axon to its end, carried in the axoplasmic flow, the slow movement of intracellular substance (cytoplasm). Acetylcholine is stored in the nerve terminal, sequestered in small vesicles awaiting release. When a nerve action potential reaches and invades the nerve terminal, a shower of acetylcholine vesicles is released into the junction (synapse) between the nerve terminal and the ?effector‘ cell which the nerve activates. This may be another nerve cell or a muscle or gland cell. Thus electrical signals are converted to chemical signals, allowing messages to be passed between nerve cells or between nerve cells and nonnerve cells. This process is termed ?chemical neurotransmission‘ and was first demonstrated, for nerves to the heart, by the German pharmacologist Loewi in 1921. Chemical transmission involving acetylcholine is known as ?cholinergic‘. Acetylcholine acts as a transmitter between motor nerves and the fibres of skeletal muscle at all neuromuscular junctions. At this type of synapse, the nerve terminal is closely apposed to the cell membrane of a muscle fibre at the socalled motor end plate. On release, acetylcholine acts almost instantly, to cause a sequence of chemical and physical events (starting with depolarization of the motor endplate) which cause contraction of the muscle fibre. This is exactly what is required for voluntary muscles in which a rapid response to a mand is required. The action of acetylcholine is terminated rapidly, in around 10 milliseconds。 an enzyme (cholinesterase) breaks the transmitter down into choline and an acetate ion. The choline is then available for reuptake into the nerve terminal. These same principles apply to cholinergic transmission at sites other than neuromuscular junctions, although the structure of the synapses differs. In the autonomic nervous system these include nervetonerve synapses at the relay stations (ganglia) in both the sympathetic and the parasympathetic divisions, and the endings of parasympathetic nerve fibres on nonvoluntary (smooth) muscle, the heart, and glandular cells。 in response to activation of this nerve supply, smooth muscle contracts (notably in the gut), the frequency of heart beat is slowed, and glands secrete. Acetylcholine is also an important transmitter at many sites in the brain at nervetonerve synapses. To understand how acetylcholine brings about a variety of effects in different cells it is necessary to understand membrane receptors. In postsynaptic membranes (those of the cells on which the nerve fibres terminate) there are many different sorts of receptors and some are receptors for acetylcholine. These are protein molecules that react specifically with acetylcholine in a reversible fashion. It is the plex of receptor bined with acetylcholine which brings about a biophysical reaction, resulting in the response from the receptive cell. Two major types of acetylcholine receptors exist in the membranes of cells. The type in skeletal muscle is known as ?nicotinic‘。 in glands, smooth muscle, and the heart they are ?muscarinic‘。 and there are some of each type in the brain. These terms are used because nicotine mimics the action of acetylcholine at nicotinic receptors, whereas muscarine, an alkaloid from the mushroom Amanita muscaria, mimics the action of acetylcholine at the muscarinic receptors. Acetylcholine i