金鱼淀粉酶性质的初步研究

以金鱼肠及肝胰脏为材料,匀浆抽提离心得粗酶液并对酶性质做初步研究．结果表明：肠淀粉酶与肝胰脏淀粉酶催化淀粉水解的最适pH值分别是6．8,6．2;最适底物浓度分别是0．02％,0．03%最适温度分别是35℃,30℃．并进一步研究一、二价金属离子和重金屑离子对该鱼淀粉酶活力的影响,结果显示。一价金属离子K^＋、Na^＋对酶活力没有影响;二价金属离子Mg^2＋、Ba^2＋对酶活力具有抑制作用,但Ca^2＋对酶活力具有促进作用l重金属离子Hg^2＋、Cd^2＋有明显的抑制作用．     

河蚬蛋白酶法水解工艺的研究

以河蚬为原料,水解度和氮收率为指标,筛选出适合河蚬酶解的蛋白酶,利用二次回归正交旋转组合试验建立水解度与加酶量、酶解温度、酶解时间的数学回归模型,确定河蚬蛋白酶法水解的最佳工艺条件为：液固比3：1,混合酶（Neutrase／Alcalase）组合比例3：1,pH值7．O,加酶量1．3％。酶解温度53℃,酶解时间261rain,此时水解度为46．1％,氮收率81．2％．     

灵芝原生质体制备与再生条件的研究

通过不同酶浓度、酶解温度、酶解时间、渗透压稳定剂及菌龄等对灵芝菌丝原生质体制备与再生的影响的研究 ,结果表明 ,菌龄为 60h的菌丝 ,采用浓度为 2 %的溶壁酶以 0 .6M的甘露醇作渗透压稳定剂于pH6.5,31°C下酶解 2h,当酶解液中湿菌体含量对 0 .1g/ml时 ,其原生质体数可达 2 1 0 7个 /ml,且再生率达8.5%     

蝴蝶兰染色体制片技术流程之探索

应用酶解去壁法制备蝴蝶兰染色体标本,对供试材料的选取、预处理方法、酶解时间和温度加以探索．实验结果显示,换盆后14～20d的盆苗嫩根根尖分裂活性最高、中期分裂相较多．剪取长1cm左右的根尖用O．002M的8-羟基喹啉在18℃预处理4h,卡诺固定液固定2～24h,再用4％纤维素酶和1％果胶酶的混合酶液在25℃下酶解1．5h,能获得高质量的制片,染色体在载玻片上分散良好、形态清晰．     

虎眼万年青皂苷提取工艺研析

以虎眼万年青总皂苷得率为指标,采用正交试验法得出纤维素酶酶解最佳提取工艺．结果为酶解时料液比1：15、用酶量1％、酶解温度50℃、酶解时间30min,得率为0．67％．     

急性肾功能衰竭家兔心肌损伤的体液机制

目的：观察急性肾功能衰竭（ARF）家兔心肌匀浆自由基、一氧化氮的变化，探讨心肌损伤的体液机制。方法：60只家兔均分为四组（n=15）。ARF模型1组：皮下注射1％HgCl2（1．3ml／kg．bw）；ARF模型2组：肌肉注射50％甘油（10ml／kg．bw）；以等量生理盐水代替HgCl2和甘油作为对照1、2组。24h后，所有动物颈总动脉放血备检，并选择固定位置。制备10％心肌匀浆。经Aeroset型全自动生化分析仪测定血清反映肾功能的生化指标。检测心肌匀浆丙二醛（MDA）、超氧化物歧化酶（SOD）、一氧化氮（NO）及其合酶（NOS）的变化。结果：与相应对照组比较，ARF模型1、2组心匀浆SOD活性下降、MDA含量升高（P〈0．05），ARF模型1、2组心匀浆NO含量增强、NOS及iNOS活性增强（P〈0．05～0．01）。结论：ARF家兔心肌损伤的机制与自由基损伤及NO升高有关。     

产壳聚糖酶菌株的初步筛选

利用选择性培养基从土壤中分离具有产壳聚糖酶能力的菌株，获得两株产壳聚糖酶菌株，对其中的一株非芽孢杆菌Yg菌株进行产酶试验并对其酶活性以及酶解最适条件进行测定．结果显示：Yg菌株所产壳聚糖酶具有较强的降解壳聚糖的能力，不同产酶时间所得酶液中，产酶36h所得酶液的酶活力最强；用产酶36h所得酶液降解3％壳聚糖，酶解最适pH值为5．5—6．0，最适温度为50—55℃，10％的酶量完全降解3％的壳聚糖所需时间为30h．     

胰蛋白酶对近江牡蛎的酶解工艺研究

胰蛋白酶在近江牡蛎的酶解工艺中酶解温度、加酶量、底物浓度和pH等因素对水解度影响较大。通过正交试验和从能源、节省时间和操作方便性等角度出发,确定牡蛎酶解的最佳工艺条件为：温度45℃,加酶量1．2％,底物浓度1：2,pH7．0,酶解时间5h。     

褐色高温单孢菌PE-211纤维素酶的纯化及固定化研究

本研究望能为其在工业、农业、轻工业等方面的应用提供一定的理论依据。研究方法如下：利用摇瓶培养基进行培养,经硫酸铵盐析、2LSephadexG-100柱纯化,用壳聚糖进行固定化。结果是粗酶液被纯化,以戊二醛为交联剂制备固定化酶,得出结论：褐色高温单孢菌PE-211纤维素酶经硫酸铵盐析、2KSephadexG-100柱纯化,粗酶液被纯化47．5倍．比活力为54．15[U／rag,以戊二醛为交联剂制备固定化酶。酶动力学研究表明,固定化酶的最适pH为8．5,最适温度为70℃,且固定化酶在60℃～80℃活力较高;该酶的耐热性很强．而固定化酶的热稳定性比原酶强;以羧甲基纤维素钠为底物。固定化酶的Km为7．19mg／ml,Vmax为0．132mz／ml·min。     

正交实验法优化酶解法制备杨梅酒工艺

以冷冻杨梅鲜果为原料采用酶解浸提法制作杨梅酒,研究果胶酶和纤维素酶对杨梅酒出酒率的影响。通过单因素实验对影响杨梅酒出酒率的酶种类、酶解温度、酶解时间、酶底物比四因素进行考察,并通过正交实验法优化了杨梅酶解工艺参数。结果表明：确定果胶酶为酶解用酶,酶解法制备杨梅酒酶最佳工艺参数为酶解温度35℃、酶解时间4h,酶底物比2％。在此条件下,杨梅酒出酒率为（79．4±0．19）％,比同法不加果胶酶出酒率增加25．4％,并且过滤时间明显缩短。     

卡思卡特城堡

It is worthy of noting that, whilst Crookston Castle witnessed the earlier and happier portion of Mary's variegated life,     

不同的吃喝玩乐

一、吃和喝吃苹果 eat an apple, 吃药 take medicine,吃糖 have some sweets,吃饭 have one's meals,吃馆子 dine out,吃惊 be surprised/     

漏洞百出的教育

Many college freshmen arrive woefully unprepared to do college work, and as disadvantaged populations continue to grow, the share of the American work force that has made it through college is expected to plummet. Many experts blame that educational failure not just on high schools but also on colleges. School & College, a special report by The Chronicle, looks at efforts to fix the system. What reforms would better prepare students for college? What should schools and colleges be doing differently? How should state and federal officials help?     

只要努力,不要后悔

There are numbers of crossroads on our long and unpredictable life journey where we totally have no idea about which direction to choose. No matter what our decision is, we should not turn back, but face the music and go ahead instead. I am this kind of girl who always does try without regretting, one example is how I dealt with my love.     

浅谈移民问题

Migration occurs behind a variety of reasons and has a great effect on the whole world. People may migrate in order to improve their economic situation, or in order to escape civil strife, persecution, and environmental disasters. The impact of migration is complex, bringing both benefits anddisadvantages. This paper briefly talks about the causes of migration, the allocation of benefits, and the ways in which individual countries and the international community deal with this important subject.     

Sister Carrie, an Adherent of Desires

Sister Carrie is one of the most controversial characters in American literature.Thought as a "fallen woman" firstly,she was defined as a "new woman" by some critics later. However, by digging into the motivaton behind the whole process of Carrie's "success", the relationship between Carrie and her creator (the author), the social conditions of then American, it can be found that Carrie has never been free-standing on her thought and she has never found her real-sdf even after becoming a famous actress. In a society dominated by mass consumerism Carrie is only an adherent of her own desires. She also is a representative of all those country girls flooded into cities, a symbol and a sacrifice of the urbanization of America in a time countryside was overcome by cities.     

Improvement of one-cycle controller by use of proportional integral differential controller

1.IntroductionOne-cyclecontrolmethod,whichwasproposedaboutonedecadeago[1],hasbecomeanattractivemethodinspecialfieldssuchaspowerfactorcorrection[2-6],switchingamplifiers[7,8],etc.Themainideaofthiscontrollerisbasedonintegrationofdiodevoltageinone-cycleandforcesittobeexactlyequaltothereferencevalue.Themainadvantageofthiscontrollerisitsrealtimeabilitytorejectthevariationofinputvoltage[1].Despitethisgreatability,ithasnogoodperformancesinrejectingofloaddisturbanceandfollowingreferencecommands.Espec…     

库克斯顿城堡

城堡, 是欧洲典型的建筑之一, 每个城堡都有一个美丽的传说或是一段历史。从本期开始, 我们将推出“城堡之旅”, 带各位读者去浏览、观赏欧洲各地的城堡, 开始一段文化与历史的旅途!     

The Reader Response Approach to Teaching of English Literature

During interview with English majors, it was found that a majority of students expressed disappointment with their experience of English literature classes. Students' dislike of learning English literature appears to be the major problem of teaching English literature in China. Reader response approach is a good way to solve this problem. In this paper, I explain the rationale behind the reader response approach, such as its origin, definition, features, assumptions, and strategies. Then I illustrate how reader response approach works as a teaching strategy by presenting several teaching models. At last I evaluate its usefuiness for teachers and present the advantages of reader response approach in Chinese context.