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Search Results: 1 - 10 of 122366 matches for " 朱芳宇 "
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百折不挠推进地震预测研究
,
科技导报 , 2012,
Abstract: 地震预测是公认的世界性科学难题,现处于认识过程的初期探索阶段,更多的是感性认识和印象性经验。如果能够同时准确地预测出未来大地震的地点、时间和强度,无疑将可拯救数以万计生活在地震危险区人民的生命;再如果能够预先采取恰当的防范措施,就有可能最大限度地减轻地震造成的损失。
阴极保护用三氧化二铁涂层钛阳极
,
腐蚀科学与防护技术 , 1994,
Abstract: 本文通过电化学测试、扫描电镜与X射线衍射分析研究了Fe2O3/Ti阳极,结果表明该电极在3.5%NaCl溶液中有极化不大,耐高电流密度及消耗率低等优点,是一种很有发展前途的非贵金属阳极,适合在阴极保护和废水处理系统中应用.
A Screen Image Compression Technology Based on Sub-blocking with Dynamic Threshold
基于动态阈值分块算法的屏幕图象压缩技术

,光喜,王曜
中国图象图形学报 , 2003,
Abstract: Compression algorithm for screen images, which comes from the Computer Screen, is an important task in the Screen Share technology. Traditional methods are based on the algorithms such as RLE, LZW or JPEG directly, which cannot meet the requirements of both the quality of recovery image and compression ratio to compress screen image respectively. High compression ratio algorithms (JPEG) result in a low quality of image, while no-distortion algorithm (RLE, LZW) leads to a low compression ratio. In order to resolve this contradiction, an effective compression algorithm based on dynamic threshold sub-blocking is proposed in this paper. Before the image compression, Screen image is divided into four sorts of blocks by certain provided rules first, which are named as Pure-color Blocks, Text Blocks, Icon Blocks, and Image Blocks. Then these blocks are compressed separately depended on their characteristic so as to ensure that the quality of recovery image is the overall best and the compression ratio is the highest. Pure-color Block, Text Block, and Icon Block are compressed with no-distortion compression algorithm, and Image Block is compressed with JPEG algorithm. Result of experiments shows that our algorithm has improved quality of recovery image, higher compression ratio, and higher compressed speed than traditional algorithm.
基于动态阈值分块算法的屏幕图象压缩技术
,光喜,王曜
中国图象图形学报 , 2003, DOI: 10.11834/jig.200309372
Abstract: 计算机屏幕图象压缩一直是屏幕共享技术中的关键问题,而现有算法一般是直接应用传统的RLE,LZW或JPEG算法,但由于这几种算法在对计算机屏幕图象进行压缩时,均无法兼顾恢复质量与压缩比的要求.为此提出了一种基于动态阈值分块的高效压缩算法,该算法首先将屏幕图象按照某种规则划分为纯色块、文字块、图标块和图象块4种特征块,然后针对特征块特点采用相应的压缩算法,以保证压缩算法在恢复质量与压缩比上能同时达到最佳.实验结果表明,该算法图象恢复质量较好,压缩比较大,压缩速度较快,整体性能优于当前现有的屏幕压缩算法,具有广泛的应用前景.
加味射干麻黄汤与常规西医疗法治疗支气管哮喘的随机对照研究
,维佳,顾娟,
- , 2016, DOI: 10.16781/j.0258-879x.2016.06.0771
Abstract: 目的 分析加味射干麻黄汤在支气管哮喘中的治疗效果,并对比其与常规西医疗法的疗效差别。方法 采用随机对照试验研究方案,选取54例外寒内饮证支气管哮喘患者,随机分为两组,每组27例。中医治疗组采用加味射干麻黄汤治疗,西医治疗对照组采用常规西医疗法,连续治疗2个疗程。采用观察者盲法设计观测两组患者治疗前和治疗后的中医证候积分、肺功能、昼夜呼气峰流速(PEF)变异率、临床疗效及不良反应并进行比较。结果 中医治疗组患者中医证候积分总分及各项指标积分、昼夜PEF变异率与西医治疗对照组相比均下降,差异有统计学意义(P<0.05);中医治疗组患者1 s用力呼气容积占预计值百分比(FEV1%)、用力肺活量(FVC)、呼气峰流速百分比(PEFR%)与西医治疗对照组相比均升高,而昼夜PEF变异率降低,差异均有统计学意义(P<0.05)。中医治疗组和西医治疗对照组患者的总有效率分别为92.59%(25/27)和74.07%(20/27),差异有统计学意义(P<0.05);中医治疗组及西医治疗对照组患者的不良反应发生率分别为3.70%(1/27)和7.41%(2/27),差异无统计学意义(P>0.05)。结论 加味射干麻黄汤治疗相比常规西医疗法可更有效地改善外寒内饮证支气管哮喘患者的症状及肺功能,同时还可减少昼夜PEF变异率,具有较好的临床推广价值,其药理机制和有效成分值得进一步深入研究。
Objective To analyze the clinical effect of Jiawei Shegan Mahuang decoction for bronchial asthma and to compare its effect with that of routine western medicine therapy. Methods This was a randomized controlled clinical trial. Fifty-four patients with bronchial asthma (exterior cold and interior rheum pattern) were included and randomly divided into two groups, with 27 cases in each group. Patients in the control group were treated with routine western medicine therapy and the treatment group adopted Jiawei Shegan Mahuang decoction for two consecutive courses. The TCM syndrome integral, lung function, variation rate of peak expiratory flow (PEF), clinical efficacy and adverse reactions before and after treatment were observed and recorded based on an observer-blinding design. Results Compared with the control group, patients in the treatment group had significantly decreased total scores (and scores for each item) of TCM syndrome integral and variation rate of PEF (P<0.05) and significantly increased scores of forced vital capacity (FVC), FVC in one second (FEV1) and peak expiratory flow rate percentage (PEFR%, P<0.05). The total effective rate was 92.59% in the treatment group, which was significantly higher than that in the control group (74.07%, P<0.05). The incidence rate of adverse reactions in the treatment group was similar to that of the control group (3.70% vs 7.41%, P>0.05). Conclusion Jiawei Shegan Mahuang decoction has better clinical effect in improving the symptom and pulmonary function of patients with bronchial asthma (exterior cold and interior rheum pattern) compared with routine western medicine, and it can decrease the variation rate of PEF, indicating a promising clinical future, with its pharmacological mechanism and key components remaining to be further studied
钠硫电池β″-Al2O3陶瓷管几何参数对其机械强度的影响
张建平,,,祝铭,翔宇
硅酸盐学报 , 2013,
Abstract: 为了有效增强陶瓷管的可靠性,达到大幅度提高钠硫电池使用寿命的目的,根据有限元理论,采用ANSYS软件对钠硫电池关键部件β″-Al2O3陶瓷管的机械强度进行了数值仿真,得出了陶瓷管最大应力随着其几何参数变化的规律。数值仿真结果表明内外壁施压时陶瓷管最大应力随其长度与壁厚比的同比例缩小而增大,但随长度与直径比的同比例缩小而减小,而此时直径与壁厚比的同比例缩小对应力变化几乎没有影响,这为陶瓷管尺寸缩小时机械强度的优化设计提供指导。
海洋细菌Pseudoalteromonas sp.NJ631胶原蛋白酶的克隆与表达
薛春旭,陈威,,
- , 2016, DOI: 10.3969/j.issn.1673-1689.2016.02.011
Abstract: 对交替假单胞菌Pseudoalteromonas sp.NJ631基因组中潜在的胶原蛋白酶基因进行克隆与表达,并鉴定重组蛋白PNJC的酶活力。根据NJ631基因组序列草图,利用基因组信息发掘方法获得胶原蛋白酶功能提示的编码基因,进而利用高效表达质粒pET28a构建重组表达系统。经IPTG诱导表达、亲和层析纯化获得重组蛋白纯化产物。以不溶性Ⅰ型胶原蛋白为底物,测定胶原蛋白酶酶活力。对Pseudoalteromonas sp.NJ631基因组信息挖掘,从中发现一条疑似编码胶原蛋白酶的基因序列,命名为Pnjc。该基因全长1 359 bp,GC含量45.62%,编码由452个氨基酸残基组成的约51 000大小的胶原蛋白酶。SDS-PAGE 检测表明,胶原蛋白酶PNJC在0.2 mmol/L的IPTG诱导下得到高效表达。经过亲和层析获得纯化重组蛋白PNJC,蛋白质质量浓度约为1 mg/mL。酶活检测表明,PNJC的酶活力为160.34 U/mg,为标准品的70.48%。PNJC高酶活力表明,Pseudoalteromonas sp.NJ631来源的胶原蛋白酶具有重要的研究价值与工业开发潜力。
The gene encoding collagenase from Pseudoalteromonas sp.NJ631 was cloned and expressed in E.coli cells. Subsequently,the bioactivity of recombinant protein,named PNJC,was assessed. The gene sequence encoding a putative collagenase,designed Pnjc,was obtained from the genome of Pseudoalteromonas sp. NJ631 using a genome mining approach. The Pnjc coding region was amplified and cloned into pET-28a Vector. The plasmids harboring the assembled full-length sequence encoding PNJC were transformed into the E.coli cells for the expression of the PNJC protein. The expression and purification of the recombinant protein were carried on according to manufacturer's instruction. Finally,the enzymatic activity of collagenase was assessed by using recombinant protein decomposing the type I collagen as substrate. The 1359-bp open reading frame with 45.62% GC was obtained from the genome of Pseudoalteromonas sp. NJ631,which was encoded of a protein of 452 amino acids and shared significant homology with the collagenase from the other genera. The PNJC was highly expressed by adding 0.2 mM IPTG. The assay of enzyme activity showed that the enzyme activity of PNJC was 160.34 U/mg,70.48% of the standard,confirming that the Pnjc gene encoded a functional collagenase. This is the first report of the cloning the expression of collagenase from marine bacteria Pseudoalteromonas sp. The PNJC encoded by Pnjc gene from NJ631 showed high bioactivity on decomposing the type I collagen,which are of potential value for the commercial exploitation
中国沿海拟穴青蟹群体遗传多样性的微卫星分析
舒妙安?,,,赵晓枫?,郭晓令?
水产学报 , 2011, DOI: 10.3724/SP.J.1231
Abstract: 利用17对微卫星引物对我国沿海7个拟穴青蟹野生群体(杭州湾、三门湾、闽江口、东山湾、珠江口、北部湾、清澜港)进行了遗传多样性分析。结果表明,17个位点在所有青蟹群体中均为高度多态(pic>0.5),共检测到253个等位基因;7群体的平均等位基因数(a)为9.41~10.94,平均有效等位基因数(ne)为5.42~6.87,平均杂合度(h)为0.511~0.563,群体遗传多样性水平较高。分子方差分析(amova)结果显示,94.13%的遗传变异存在于群体内,5.87%的遗传变异存在于群体间,两两群体间fst值为0.0355~0.0817(p<0.01),表明群体间遗传分化水平中等偏低。hardy-weinberg平衡检测表明,7群体普遍存在杂合子缺失现象。青蟹群体间遗传距离为0.2530~0.5719,upgma聚类分析表明,杭州湾与三门湾群体首先聚在一起,再与闽江口群体、东山湾群体聚为一支;珠江口群体与清澜港群体聚为另一支;两分支最后与北部湾群体聚类在一起。
基因组结构揭示的根瘤菌系统发育群
郑君 刘桂荣,万孚 周光 刘树林
中国科学 生命科学 , 2003,
Abstract: 阐明根瘤菌之间的系统发育关系, 可使人们更有效地利用这些自然资源, 因而对农业生产和环境保护具有重大意义. 通过Ⅰ-CeuⅠ酶切表明64株根瘤菌的基因组结构特征, 揭示根瘤菌的系统发育关系. 结果表明, 64株根瘤菌依据基因组结构特征可聚为21个系统发育群, 这些群与16S rRNA分子聚群结果大致相符, 但与现行的根瘤菌分类体系所得结果有较大差异.
Ti ANODE WITH OF Fe_2O_3 COATING FOR CATHODIC PROTECTION
阴极保护用三氧化二铁涂层钛阳极

YAN Yumin,ZHU Zufang,
,

腐蚀科学与防护技术 , 1994,
Abstract: Anode Fe2O3/Ti was studied by electrochemical measurement,scanning electronic micro scope and X-ray diffraction.The results show that the electrode in 3.5% NaCl has the advantages of small polarization,good resistance to high current density density and low loss rate.The elecctrode Fe2O3/Ti is a promis sing anode made of non-noble metals and can be used in cathodic protection and waste water processes.
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