由两部分组成的

According to the demand of high magnetic field power supply, reference is increased with a set ramp rate and stops at a set stable value, so reference system is composed of digital setting and digit to analog converting circuit. But the stability of reference is mostly guaranteed by the performance of D/A circuit, so D/A circuit is particularly studied in reference system. The scheme of D/A circuit, the selection of DAC and its voltage reference, hardware anti-jamming design and PCB design are discussed in detail, and software of remote control and PLC are discussed in brief. Zero-flux DC current transformer well satisfies the demands of the high stability of Load current detection unit, so the principle of zero-flux DC current transformer is analyzed; in the mean time a project which detects the long term stability is designed. During 8 hours, analog signal which is detected with high precision digit multimeter is recorded in computer at 1HZ frequency by GPIB communication. The drift error source and related parameters are explained in the compare-amplify part. Detailed subtraction circuit is designed; also amplifier chip and periphery components are selected and verified according to the theory of error analysis.

根据强磁场电源的需求，参考源应按照软件设定的斜率逐渐上升到设定稳态值，则参考源系统应由数字给定和数模转换电路两大部分组成，而参考源的稳定度主要依靠完成数模转换功能的模拟电路的性能来保证，因此本文对参考源系统的研究以数模转换电路为重点，分别从电路方案的确定、数模转换芯片及其基准电压源的选取和验证、电路板硬件抗干扰和PCB设计几方面进行了论述，然后对数字给定部分的远控组态和PLC程序设计作了简要介绍；采用零磁通原理的直流电流转换器很好地满足了对负载电流检测单元高稳定度的需求，本文详细分析了零磁通检测的原理，并在选定此种类型电流转换器的基础上设计了一套检测长期稳定度的方案，8小时内以1秒为采样周期，通过计算机Labview程序和高精度数字电压表的GPIB通讯，将被高精度数字电压表数字化后的模拟信号采样值连续记录至计算机中；比较放大环节简要阐述了漂移产生的原因和相关参数指标，确定了具体的减法电路形式，并根据误差分析理论对运算放大器和外围元器件进行了选取和验证。

Pike protein consists of S1 and S2 subunit. S1 is head and S2 is rod-shape part, intermolecular effort can bind each other. S1 can bind with host cell epimembranal acceptor. S2 can fix integral Spike protein on the cellular membrane and mediate cell-fusion with virus and host cell. There are significant antigen determinant of virus in Spike protein, genic heterogenesis can effect viral pathogenicity. SARS-CoV Spike protein, which has 23 pieces larvaceous glycosylation sit, consists of 1256 amino acid. Its N-terminals and C-terminals is corresponding conservative.

蛋白是I型膜糖蛋白，介导病毒与宿主细胞膜上的受体结合并与宿主细胞膜相融合。S蛋白由S1和S2两个亚基组成。S1形成球状部分，S2形成棒状部分，两者之间通过分子间的作用力相互结合。S1能与宿主细胞上的受体结合，S2可把整个S蛋白固定在细胞膜上，并介导病毒包膜与宿主细胞膜融合。S蛋白上有重要的病毒抗原决定簇，S基因的突变会影响病毒的致病性。

Either of two large flat bones each forming one of the lateral halves of the pelvis and consisting of the fused ilium,ischium,and pubis.

髋骨构成骨盆侧向部分的两块大而平的骨骼，由合并的髋骨，坐骨和耻骨组成在腰椎下是五个椎骨融合在一起形成的骶骨。

The main components of every ommatidium of compound eye were completed in the larval stages. An ommatidium composed of cornea, four corneagenous cells, four cone cells and retinular cells. The sensitization system of an ommatidium included 11 retinular cells, of which four located at the distal part of the ommatidium; seven formed the proximal main part of the retina. Their structures are different.

小眼的感光系统由11个小网膜细胞组成，且与成体一样，11个小网膜细胞已经分化成4+7两层，其中4个小网膜细胞构成了感光部分的远端，7个小网膜细胞构成感光系统的近端主体，远端和近端的小网膜细胞在结构上也有明显差异。

By the partial purification of Arthrobacter nicotinovorus D-97 endocellular enzymes and the results of enzymatic reaction of enzymes of partition collection, it was found that enzymes related to trehalose synthesis were consisted of Trehalose-forming Enzyme and Trehalose-releasing Enzyme . Trehalose-forming Enzyme could convert maltooligosaccharides into non-reducing maltooligosyl trehalose by intramolecular transglycosylation, and Trehalose-releasing Enzyme could hydrolyze α-1, 4 linkage between the trehalose residue and the maltooligosaccharide residue to release trehalose and maltooligosaccharides with two glucose monomer lesser.

将食尼古丁节杆菌D-97胞内酶部分纯化并对各收集组分进行酶反应，发现其海藻糖合成酶系由海藻糖生成酶(Trehalose-forming Enzyme，TFE)和海藻糖释放酶(Trehalose-releasingEnzyme，TRE)组成，前者分子内转糖基将直链麦芽寡糖转化为没有还原性的麦芽寡糖基海藻糖，后者专一切割麦芽寡糖基海藻糖分子上麦芽寡糖基与海藻糖连接的α-1，4糖苷键，从而释放出海藻糖和减少了两个葡萄糖单体的麦芽寡糖。

Most of the confidences were unsought—frequently I have feigned sleep, preoccupation, or a hostile levity when I realized by some unmistakable sign that an intimate revelation was quivering on the horizon; for the intimate revelations of young men, or at least the terms in which they express them, are usually plagiaristic and marred by obvious suppressions.

绝大多数的隐私都不是我打听来的——每逢我根据某种明白无误的迹象看出又有一次倾诉衷情在地平线上喷薄欲出的时候，我往往假装睡觉，假装心不在焉，或者装出不怀好意的轻佻态度。因为青年人倾诉的衷情，或者至少他们表达这些衷情所用的语言，往往是剽窃性的，而且多有明显的隐瞒。（第1－2页）辨析原文只有一句话，由三个部分组成，有两层递进关系。

Study the bioactivity of the n-HA/PA66 composite and the effects it would be to body's metabolism of calcium and phosphorus ion in vivo.(3) Study the osteo-conductivity and the ability to repair bone defect of the porous n-HA/PA66 composite and the feasibility use it as the scaffold of bone tissue engineering. Objects and Methods as follows: 1.To evaluate the biocompatability of nano-hydroxyapatite crystals and polyamide composite (n-HA/PA66) with the L929 cells.To proceed the morphological observation and take pictures of L929 cells after 1d,2d,4d,and 7d of co-cultured with extract of n-HA/PA66 ,and direct contact with n-HA/PA66.To determine light absorbtion value of every hole under 500 nm with enzyme linked immunity instrument after 1 d,2 d,4 d,and 7 d of contact of n-HA/PA66 extract with L929 cells,and direct contact with n-HA/PA66.In the meanwhile calculate the relative multiplication rate of cells,and evaluate them by six degree tests for cytotoxicity. To investigate the acute and chronic toxic reaction on the whole body induced by the new nano-hydroapatite crystals and polyamide composite(n-HA/PA66)after implanting in vivo and its effects on partial constitution of animal organs after implanting in vivo,and evaluate the potential and degree of subcuticular stimulation reaction.

本实验主要由以下三部分组成：一、n-HA/PA66 复合材料在动物体内、体外的生物相容性及生物安全性评价二、n-HA/PA66 复合材料植入动物体内的生物活性及近期对机体钙、磷代谢影响的实验研究三、网孔 n-HA/PA66 复合材料作为支架修复兔桡骨节段缺损的动物实验研究主要研究目标及方法如下：参照 GB/T16886.5-1997-ISO 10993-5：1992《医疗器械生物学评价细胞毒性试验体外法》之评价标准和要求，采用规定的 L929 细胞(小鼠结缔组织成纤维细胞)，分别经直接接触和材料浸提液与细胞共培养等方式对 n-HA/PA66 复合材料进行细胞毒性测试，采用细胞形态观察法观察两种细胞各组在 24h、48h、72h、5 天后各时相点的细胞形态学变化，并在显微镜下照相，从而对细胞与材料的生物相容性进行定性评价；同时采用细胞生长抑制法，以酶标仪定量测定评价各组 1，2，4，7 天 L929 细胞的相对增殖率，以定量测定并判别材料对细胞的毒性程度。

The fleet that take on the convoying mission is comprise of guided missile destroyer Haikou and Wuhan and a integrated depot ship "Weishan Lake", including two shipborne helicopters and partial navy special operations troops.

担任此次护航任务的中国海军编队由&武汉&号导弹驱逐舰、&海口&号导弹驱逐舰、&微山湖&号综合补给舰组成，并搭载两架舰载直升机和部分海军特战队员。

The Chinese formation carrying on the mission of convoy is made up of "WuHan" Missile chaser,"Haikou"Missile Chaser,"Huishan Hu" comprehensive depot ship and they load the two helicopters by ship and part of navy members .

担任此次护航任务的中国海军编队由&武汉&号导弹驱逐舰、&海口&号导弹驱逐舰、&微山湖&号综合补给舰组成，并搭载两架舰载直升机和部分海军特战队员。

The Chinese navy to carry out this convoy task is made up of the missile chaser named "WuHan", the missile chaser named "the sea", and the comprehensive depot ship named "WeiShan lake", and with 2pcs of the fleet helicopter and some special naval soldiers.

担任此次护航任务的中国海军编队由&武汉&号导弹驱逐舰、&海口&号导弹驱逐舰、&微山湖&号综合补给舰组成，并搭载两架舰载直升机和部分海军特战队员。

In the United States, chronic alcoholism and hepatitis C are the most common ones.

在美国，慢性酒精中毒，肝炎是最常见的。

If you have any questions, you can contact me anytime.

如果有任何问题，你可以随时联系我。