A revised scheme for mass propagation of Easter Lily

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a modest proposal中英对照

然而我的目的远不止限于救治那些公开宣称的乞丐的孩子，我所说的范围要大得多，包括所有那些在某个年代出生，其父母与那些在街上要求我们大发慈悲的乞丐一样，无力养活他们的幼儿。
As to my own part, having turned my thoughts for many years upon this important subject, and maturely weighed the several schemes of other projectors, I have always found them grossly mistaken in the computation. It is true, a child just dropped from its dam may be supported by her milk for a solar year, with little other nourishment; at most not above the value of 2s., which the mother may certainly get, or the value in scraps, by her lawful occupation of begging; and it is exactly at one year old that I propose to provide for them in such a manner as instead of being a charge upon their parents or the parish, or wanting food and raiment for the rest of their lives, they shall on the contrary contribute to the feeding, and partly to the clothing, of many thousands.

研究生公共英语教材阅读B第3、4、10、11、14课文原文及翻译

Unite 3 Doctor’s Dilemma: Treat or Let Die?Abigail Trafford1. Medical advances in wonder drugs, daring surgical procedures, radiation therapies, and intensive-care units have brought new life to thousands of people. Yet to many of them, modern medicine has become a double-edged sword.2. Doctor’s power to treat with an array of space-age techniques has outstripped the body’s capacity to heal. More medical problems can be treated, but for many patients, there is little hope of recovery. Even the fundamental distinction between life and death has been blurred.3. Many Americans are caught in medical limbo, as was the South Korean boxer Duk Koo Kim, who was kept alive by artificial means after he had been knocked unconscious in a fight and his brain ceased to function. With the permission of his family, doctors in Las Vegas disconnected the life-support machines and death quickly followed.4. In the wake of technology’s advances in medicine, a heated debate is taking place in hospitals and nursing homes across the country --- over whether survival or quality of life is the paramount goal of medicine.5. “It gets down to what medicine is all about, ” says Daniel Callahan, director of the Institute of Society, Ethics, and the Life Sciences in Hastings-on-Hudson, New York. “Is it really to save a life? Or is the larger goal the welfare of the patient?”6. Doctors, patients, relatives, and often the courts are being forced to make hard choices in medicine. Most often it is at the two extremes of life that these difficultyethical questions arise --- at the beginning for the very sick newborn and at the end for the dying patient.7. The dilemma posed by modern medical technology has created the growing new discipline or bioethics. Many of the country’s 127 medical s chools now offer courses in medical ethics, a field virtually ignored only a decade ago. Many hospitals have chaplains, philosophers, psychiatrists, and social workers on the staff to help patients make crucial decisions, and one in twenty institutions has a special ethics committee to resolve difficult cases.Death and Dying8. Of all the patients in intensive-care units who are at risk of dying, some 20 percent present difficult ethical choices --- whether to keep trying to save the life or to pull back and let the patient die. In many units, decisions regarding life-sustaining care are made about three times a week.9. Even the definition of death has been changed. Now that the heart-lung machine can take over the functions of breathing and pumping blood, death no longer always comes with the patient’s “last gasp” or when the heart stops beating. Thirty-one states and the District of Columbia have passed brain-death statutes that identify death as when the whole brain ceases to function.10. More than a do zen states recognize “living wills” in which the patients leave instructions to doctors not to prolong life by feeding them intravenously or by other methods if their illness becomes hopeless. A survey of California doctors showed that 20 to 30 percent were following instructions of such wills. Meanwhile, the hospicemovement, which its emphasis on providing comfort --- not cure --- to the dying patient, has gained momentum in many areas.11. Despite progress in society’s understanding of death and dying, t heory issues remain. Example: A woman, 87, afflicted by the nervous-system disorder of Parkinson’s disease, has a massive stroke and is found unconscious by her family. Their choices are to put her in a nursing home until she dies or to send her to a medical center for diagnosis and possible treatment. The family opts for a teaching hospital in New York city. Tests show the woman’s stroke resulted from a blood clot that is curable with surgery. After the operation, she says to her family: “Why did you bring me back to this agony?” Her health continues to worsen, and two years later she dies.12. On the other hand, doctors say prognosis is often uncertain and that patients, just because they are old and disabled, should not be denied life-saving therapy. Ethicists also fear that under the guise of medical decision not to treat certain patients, death may become too easy, pushing the country toward the acceptance of euthanasia.13. For some people, the agony of watching high-technology dying is too great. Earlier this year, Woodrow Wilson Collums, a retired dairyman from Poteet, Texas, was put on probation for the mercy killing of his older brother Jim, who lay hopeless in his bed at a nursing home, a victim of severe senility resul ting from Alzheimer’s disease. After the killing, the victim’s widow said: “I think God, Jim’s out of his misery. I hate to think it had to be done the way it was done, but I understand it. ”Crisis in Newborn Care14. At the other end of the life span, technology has so revolutionized newborn carethat it is no longer clear when human life is viable outside the womb. Newborn care has got huge progress, so it is absolutely clear that human being can survive independently outside the womb. Twenty-five years ago, infants weighting less than three and one-half pounds rarely survived. The current survival rate is 70 percent, and doctors are “salvaging” some babies that weigh only one and one-half pounds. Tremendous progress has been made in treating birth deformities such as spina bifida. Just ten years ago, only 5 percent of infants with transposition of the great arteries --- the congenital heart defect most commonly found in newborns --- survived. Today, 50 percent live.15. Yet, for many infants who owe their lives to new medical advances, survival has come at a price. A significant number emerge with permanent physical and mental handicaps.16. “The question of treatment and nontreatment of seriously ill newborns is not a single one,”says Thomas Murray of the Hastings Center. “But I feel strongly that retardation or the fact that someone is going to be less than perfect is not good grounds for allowing an infant to die.”17. For many parents, however, the experience of having a sick newborn becomes a lingering nightmare. Two years ago, an Atlanta mother gave birth to a baby suffering from Down’s Syndrome, a form of mental retardation; the child also had blocked intestines. The doctors rejected the parents’ plea not to operate, and today the child, severely retarded, still suffers intestinal problems.18. “Every time Melanie has a bowel movement, she cries,” explains her mother.“She’s not able to take care of herself, and we won’t live forever. I wanted to save her from sorrow, pain, and suffering. I don’t understand the emphasis on life at all costs, and I’m very angry at the doctors and the hospital. Who will take care of Melanie after we’re gone? Where will you doctors be then?”Changing Standards19. The choices posed by modern technology have profoundly changed the practice of medicine. Until now, most doctors have been activists, trained to use all the tools in their medical arsenals to treat disease. The current trend is toward nontreatment as doctors grapple with questions not just of who should get care but when to take therapy away.20. Always in the background is the threat of legal action. In August, two California doctors were charged with murdering a comatose patient by allegedly disconnecting the respirator and cutting off food and water. In 1981, a Massachusetts nurse was charged with murdering a cancer patient with massive doses of morphine but was subsequently acquitted.21. Between lawsuits, government regulations, and patients’ rights, many doctors feel they are under siege. Modern technology actually has limited their ability to make choices. More recently, these actions are resolved by committees.Public Policy22. In recent years, the debate on medical ethics has moved to the level of national policy. “It’s just beginning to hit us that we don’t have unlimited resources,” says Washington Hospital Center’s Dr. Lynch. “You can’t talk about ethics without talkingethics without talking about money.”23. Since 1972. Americans have enjoyed unlimited access to a taxpayer-supported, kidney dialysis program that offers life-prolonging therapy to all patients with kidney failure. To a number of police analysts, the program has grown out of control --- to a $1.4billion operation supporting 61,000 patients. The majority are over 50, and about a quarter have other illness, such as cancer or heart disease, conditions that could exclude them from dialysis in other countries.24. Some hospitals are pulling back from certain lifesaving treatment. Massachusetts General Hospital, for example, has decided not perform heart transplants on the ground that the high costs of providing such surgery help too few patients. Burn units --- through extremely effective --- also provide very expensive therapy for very few patients.25. As medical scientists push back the frontiers of therapy, the moral dilemma will continue to grow for doctors and patients alike, making the choice of to treat the basic question in modern medicine.1. 在特效药、风险性手术进程、放疗法以及特护病房方面的医学进展已为数千人带来新生。

A Suggestion for a Fast Multiplier

14
IEEE TRANSACTIONS ON ELECTRONIC COMPUTERS
February
A Suggestion for a Fast Multiplier*
C. S.
WALLACEt
2) Acceleration of the formation of summands; 3) Accelerationห้องสมุดไป่ตู้of the addition of summands.
Summary-It is suggested that the economics of present largescale scientific computers could benefit from a greater investment in hardware to mechanize multiplication and division than is now common. As a move in this direction, a design is developed for a multiplier which generates the product of two numbers using purely combinational logic, i.e., in one gating step. Using straightforward diode-transistor logic, it appears presently possible to obtain products in under 1 ,sec, and quotients in 3 1sec. A rapid square-root process is also outlined. Approximate component counts are given for the proposed design, and it is found that the cost of the unit would be about 10 per cent of the cost of a modern large-scale computer.

大百合鳞片诱导不定芽的影响因素研究

大百合鳞片诱导不定芽的影响因素研究摘要以大百合鳞片为外植体材料，研究确定诱导鳞片形成不定芽的影响因素。

结果表明：大百合鳞茎的中层鳞片启动与分化能力强，是最佳的外植体；以MS+6-BA 1.0mg/L+NAA 0.20mg/L的培养基诱导启动效果最好，启动率为86.7%，能培养具有较强分化能力的不定芽5.3个。

关键词大百合；鳞片；不定芽植株再生；诱导大百合（Cardiocrinum giganteum）是百合科大百合属珍贵的多年生鳞茎花卉，因其植株粗壮高大，显著区别于百合属植物而得名[1]。

大百合健美挺拔，花朵洁白硕大，美丽芳香，栽植群体的观赏效果极为壮观，在欧洲首次亮相就引起轰动，获得了“百合王子”的美誉[2]。

然而，长期以来，这种极具观赏价值的野生花卉，却一直未受到世人的重视。

近几年，经过引种驯化和人工栽培，已成为一种优良的观赏栽培植物[3]。

大百合常规的繁殖方法是分球（新鳞茎）繁殖，但这种繁殖方法会导致鳞茎逐年变小退化，且繁殖速度极为缓慢，不宜频繁分栽。

采用组织培养快速繁殖的方法，可以加快繁殖速度，对保护这一珍贵野生花卉种质资源以及在园林绿化中大规模推广应用具有重要意义。

1材料与方法1.1材料试验材料为大百合的更新鳞茎，取自中科院植物研究所华西亚高山植物园。

1.2方法1.2.1外植体消毒。

将大百合的更新鳞茎置于冰箱内4℃下贮藏30d后取出，去掉最外面一层腐烂、褐化的鳞片，将根系切除。

先用湿纱布轻轻地洗净鳞茎表面，然后将鳞瓣剥下，放入洗衣粉溶液中浸泡5min，流水冲洗2h，置于超净工作台上，先用75%的酒精消毒10s，再用0.1%的升汞消毒10~12 min（中间更换2次消毒液），无菌水冲洗4~5次后，将鳞瓣纵切成1.0cm2大小，再放入无菌水中冲洗掉渗出液，用无菌滤纸吸干表面水分，置于超净工作台上备用。

1.2.2诱导培养。

将外植体以腹面向上和向下两种方式接种到MS培养基上进行培养，附加不同浓度的BA、KT和NAA。

英文外刊，抗击疟疾的科学家们，陷入了生物伦理学的争论

英文外刊，抗击疟疾的科学家们，陷入了生物伦理学的争论Scientists at this lab in Burkina Faso have deployed gene warfare against the parasite carrying mosquitoes that spread malaria.布基纳法索一个实验室的科学家已经对传播疟疾同时携带寄生虫的蚊子进行了基因改造。

The conventional tools at our disposal today have reached a ceiling and can't become more efficient than they are right now.我们现在使用的传统工具已经达到了极限，不能比现在的效率更高。

We have no choice but to look at complementary methods.我们别无选择，只能寻找辅助性疗法。

That is why we're using genetically modified mosquitoes.这就是我们对蚊子进行转基因的原因。

Professor Diabate runs the experiment for target malaria, a research consortium backed by the Bill and Melinda Gates Foundation.迪亚巴特教授为目标疟疾组织(比尔和梅琳达.盖茨基金会支持的研究联盟)开展了这项实验。

The group developed an enzyme that sterilizes male mosquitoes.研究小组研发出一种可以使雄蚊绝育的酶，可以使雄蚊绝育。

The action of the enzyme continues after fertilization which means if the male copulates with a female, the embryo is dead and the female can no longer have offspring.这种酶在雌蚊子受精后继续发挥作用，这意味着如果雄蚊子与雌蚊子交配，胚胎就会死亡，雌蚊子就不能再生育后代。

隧道施工大学论文中英文翻译

附录中英文翻译1 介绍国家经济发展最重要的基础设施建设之一就是交通运输，但是中国修建铁路、公路多为多山的地形，为克服各种自然或人工障碍必须要修建隧道。

随着科学技术的发展，隧道建筑的技术正在日趋完善。

特别地，深埋的，特长的，大跨度的隧道在很复杂的地质情况下施工开挖会遇到许多麻烦。

因此，要找到解决这些麻烦的方法。

目前，预先进行地质学调查，选择正确的施工方案和技术，提高早期建筑用材质量，加强数据回应的监控，并进行科学的管理，在施工中可以减少或避免意外事件的发生。

此外，作为上面提到的方法之一，PGP在所有的隧道建筑和几乎所有的地下工程中扮演了一个重要的角色。

PGP技术的目的要通过探测距离工作面以前几十米到上百米的地质情况，预先做出及时应对。

预报内容包括工程地质的情况和水文地质的情况，如基本的地质情况，岩石的质量，围岩等级。

预报地质破碎的地域和水文地质的情况。

为做出正确预报有三个主要的阶段: 第一，挖掘前的地质调查；第二，挖掘期间的地质调查；第三，分析有关数据来预知前面的地质情况。

2 地质的调查方法2.1 隧道建筑前的地质调查挖掘前地质调查的目的要从工程地质学的角度检验挑选的隧道方案，和为选择方案提供工程地质的材料。

地质调查基本的内容要调查隧道开挖经过区域的工程地质的情况和水文情况。

也就是说，了解整个区域的可以看到的地质特征。

2.2 隧道建筑期间的地质调查它的目的要探究在隧道施工期间隧道内外的地质情况。

内容包括地质的大致情况，结构的数值统计，水文观察，地质变动的调查等等。

2.2.1 在隧道内的地质调查1) 地质情况的草图在工作面位置上的地质草图会很快作完。

它包括很多主要内容，像是围岩性质，压碎区域，接缝，破裂带，地下水等。

地质草图不仅在野外是必须的而且在系统前也是必须的。

地质的草图在隧道的开凿和建筑用材选取的情况下起很重要的作用。

因此，为了要探究工作面的地质情况，使用数字仪器扫描工作面和边墙尤为重要。

2) 结构的数值统计岩石结构的数值统计是在发现周围的岩石结构的特性的基础上分析稳定性和预知向前的地质情况。

学术英语_社科Unit5五单元原文及翻译

UNIT 5 Sociology Matters1.Culture is the totality of learned,socially transmitted customs,knowledge,material objects,and behavior.It includes the ideas,values,customs,and artifacts of groups of people.Though culture differ in their customs,artifacts,and languages,they all share certain basic characteristics.Furthermore,cultural characteristics change as cultures develop ,and cultures infuence one another through their technological ,commercial, and artistic achievements.文化是指社会传播学，海关，知识，材料的对象，和行为。

它包括思想，价值观，习俗，和人群的文物。

尽管文化在他们的习俗，文物，和语言不同，但是他们都有一些共同的基本特性。

此外，当文化发展时文化特征也在变化，并且文化通过他们的技术，商业，艺术成就相互影响。

Cultural universals文化共性2.All societies,despite their differences,have developed certain general practices known as cultural universals.Many cultural universals are ,in fact,adaptations to meet essential human needs ,such as people’s need for food ,shelter,and clothing. Anthropologist George murdock compiled a list of cultural that included athletic sports, cooking ,funeral ceremonies,medicine,and sexual restrictions.所有的社会，尽管他们的差别，已经形成了一定的一般做法被称为文化的共性。

通过一个等价雷诺数揭示层流到湍流的转捩区域

ResearchGreen Chemical Engineering—ArticleLaminar-to-Turbulence Transition Revealed Through a Reynolds NumberEquivalenceXiao Dong ChenSchool of Chemical and Environmental Engineering,Soochow University,Suzhou 215123,Chinaa r t i c l e i n f o Article history:Received 3August 2018Revised 20September 2018Accepted 27September 2018Available online 23March 2019Keywords:Local Reynolds number equivalenceFlow transition from laminar to turbulent modeUniversal Law of the Wall Pipe ﬂow Plate ﬂow Modelinga b s t r a c tFlow transition from laminar to turbulent mode (and vice versa)—that is,the initiation of turbulence—is one of the most important research subjects in the history of engineering.Even for pipe ﬂow,predicting the onset of turbulence requires sophisticated instrumentation and/or direct numerical simulation,based on observing the instantaneous ﬂow structure formation and evolution.In this work,a local Reynolds number equivalence c (ratio of local inertia effect to viscous effect)is seen to conform to the Universal Law of the Wall,where c =1represents a quantitative balance between the abovementioned two effects.This coincides with the wall layer thickness (y +=1,where y +is the dimensionless distance from the wall surface deﬁned in the Universal Law of the Wall).It is found that the characteristic of how the local derivative of c against the local velocity changes with increasing velocity determines the onset of turbu-lence.For pipe ﬂow,c %25,and for plate ﬂow,c %151.5.These ﬁndings suggest that a certain combina-tion of c and velocity (nonlinearity)can qualify the source of turbulence (i.e.,generate turbulent energy).Similarly,a re-evaluation of the previous ﬁndings reveals that only the geometrically narrow domain can act locally as the source of turbulence,with the rest of the ﬂow ﬁeld largely being left for transporting and dissipating.This understanding will have an impact on the future large-scale modeling of turbulence.Ó2019THE AUTHOR.Published by Elsevier LTD on behalf of Chinese Academy of Engineering and Higher Education Press Limited Company.This is an open access article under the CC BY-NC-ND license(/licenses/by-nc-nd/4.0/).1.IntroductionAt present,predicting the onset of turbulence,even for pipe ﬂow,requires sophisticated instrumentation and/or direct numer-ical simulation (DNS)[1–4],based on observations of the detailed instantaneous ﬂow structure formation and evolution.However,all of this modern research is conducted around the classical criti-cal Reynolds number (Re c ).Osborne Reynolds (1842–1912)carried out thorough laboratory investigations on the behavior of Newto-nian ﬂuids [5,6].His most remarkable discovery was the identiﬁca-tion of the two modes of ﬂow phenomena:laminar ﬂow and turbulent ﬂow [5–7].The experimental methodology and theory proposed by Reynolds to investigate the transition from one type of ﬂow to another have inspired numerous researchers over gener-ations.The transition between these two types of ﬂow is marked by a dimensionless parameter attributed to Reynolds—that is,the Reynolds number (Re ):Re ¼q Ud lð1Þwhere q is the ﬂuid density (kg Ám À3),l is the ﬂuid viscosity (Pa Ás),U is a characteristic velocity (m Ás À1),and d is a characteristic dimen-sion of the object with which the ﬂuid is in contact (m).In a pipe,d is the inner pipe diameter;however,if the ﬂuid ﬂows around the pipe outside (cross-ﬂow),d becomes the outer diameter.This number has often been said to represent the ratio of the inertia forces to the viscous forces.As the most important parameter,the Re ,together with other ﬂuid-related dimensionless parameters,provides a powerful foundation for many friction,heat,and mass-transfer correlations in ﬂuid ﬂow-related problems.These are par-ticularly useful in designing process equipment and process opti-mizations [7].While appreciating the experiments carried out by Reynolds,it is notable that the diameter of the pipe was limited;hence,a large Re might be obtained mainly by changing the ﬂuid viscosity and/or increasing the ﬂuid velocity.Flow visualization took place in the central region of the pipe (the ink ﬂuid was injected at the center location),so it would have been the result of the integrated or cumulative effect of turbulence generation along the pipe wall,transport,and dissipation.These three aspects would have been intertwined in the visualization in the experi-ments,and the Re should be viewed as a global parameter.In 1952,measurements in the proximity of the pipe wall showed aE-mail address:xdchen@very signiﬁcant result:that using the friction velocity(u r)and the product of the kinematic viscosity and the friction velocity(vu r) to scale velocity and distance,respectively,away from the wall,a unique dimensionless velocity proﬁle in the near-wall region was obtained.As calculated,based on the measurements,the rate of tur-bulence generation reaches a sharp maximum at the sub-layer thickness(y+%11.5,where y+is the dimensionless distance from the wall surface deﬁned in the Universal Law of the Wall(ULW)) [8].From a rational perspective,the broad peak as shown may be better qualiﬁed as y+%11.5±5.The commonly acknowledged divide between the laminar sub-layer and the buffer layer is marked at y+=5for a fully developed turbulent wall layer[8,9].Micro-transient details of how aﬂuid transitions from being disturbed by localized perturbation into full-blown turbulence in a(long)pipe have only been captured very recently[1,2].Sampling stations for local behaviors have been set up,facilitated by advanced computing power and modern experimental techniques. Experiments have been conducted below and above the well-known Re c for pipeﬂow—that is,Re c=2300,where the subscript c represents critical.In a small-diameter pipe in a laboratory setting,turbulence that is transient at low Re becomes sustained after a distinct Re c;how-ever,this phenomena was captured locally(unlike the general type of observation originally made by Reynolds)[1,2].The critical point for transiting to sustained turbulence is decided when the local proliferation of puffs outweighs their decay.Experimentally artiﬁ-cial puffs were generated at precision to trigger turbulent behavior. Two timescales were captured(partly established through DNS)for the decay and spreading of the puffs.Plotting the Re dependence of the mean time until a second puff is nucleated and the turbulence fraction increases(declining with increasing Re),and the Re depen-dence of the mean time until the turbulence decays and theﬂow relaminarizes(increasing with increasing Re),creates a very sharp intersect at Re c=2040±10,marking the onset of laminar-to-sustained turbulence in pipeﬂow[1].To explain this transition from laminarﬂow to turbulence,a bi-stability analysis with nonlinear propagation(advection)of turbu-lent fronts has been executed[2].The interesting phenomena of destabilizing turbulence in pipeﬂow were subsequently studied using the same experimental strategies and DNS[3,4].It is worth noting that most practical problems in thisﬁeld, including airplane design,are simulated with semi-empirical tur-bulent models for turbulent kinetic energy and the Reynolds stres-ses.These models make computation more efﬁcient.Although DNS is seen to be the ultimate way to directly generate images of turbu-lence,our knowledge about turbulence still mostly comes from intuitive prospects,whether reported or taught in classes.In the present work,a dimensionless number is reported that is deduced intuitively from the concept of Re but applied to the local ﬂuidﬂow.This dimensionless number is the ratio of the inertia effect to viscous effect,and its deﬁnition allows for an alternative analysis of the onset of turbulence,which has not previously been seen.Three classical cases inﬂuid mechanics are employed to show the effectiveness of the approach:the ULW,ﬂow in a smooth circular pipe,and parallelﬂow on a smooth plate[9].The analytical velocity proﬁles of these cases are well known[9–13],allowing derivations to be made to demonstrate the intended arguments precisely.This philosophy is in line with what Churchill[11] reported in his famous American Institute of Chemical Engineers Institute Lecture—that is,elucidating the fundamentals of trans-port phenomena without computationalﬂuid dynamics.Given this new number,beyond capturing the onset of turbu-lence,the author points to a signiﬁcant possibility that turbulence (i.e.,turbulent energy)originates from a very narrow domain(s) (deﬁned by c(ratio of local inertia effect to viscous effect)and velocity),leaving the rest of theﬂowﬁeld for transporting and dissipating turbulent energies.This perspective creates consider-able scope for controlling turbulentﬂow and provides an idea for future improvements in turbulence-modeling effectiveness on large scales.2.Main analyses2.1.Deﬁning the local ratio of inertia effect to viscous effectTo introduce the new dimensionless number,for simplicity,a semi-inﬁnite Cartesian(x,y)parallelﬂow scheme,with one side bounded by a smoothﬂat solid wall(the smooth plate)is consid-ered.Taking u as the local velocity in the x-direction(parallel to the plate),and recognizing that the predominant velocity gradient occurs in the y-direction,the prominent shear stress can be expressed as s¼Àl@u=@y.The no-slip condition is applied at the plate surface;hence,the scaling consideration leads tos%Àlðu chÀ0Þ=D ch.Here,D ch is a characteristic distance corre-sponding to the representative velocity change of interest and u ch is a characteristic velocity,where the subscript ch represents the characteristic value of the system.Taking the above to represent the viscous effects,a new dimensionless number is deduced: c¼q l2=ðl u ch=D chÞ.As D ch?0,the new local dimensionless num-ber can be expressed locally:c¼q u2l@u=@yj jð2ÞIn Eq.(2),the absolute value is employed to avoid any confu-sion.Based on the derivation,it can be seen that this number is conceptually similar to the Re.It is argued that this number holds important physical meaning when interpretingﬂuid behavior at a ﬁnite point(x,y).If c becomes very large,the viscous effect becomes negligible,and theﬂuid at that point should be able to maintain its pathway without changing direction.If theﬂuidﬂow becomes turbulent,the instantaneous velocity u in Eq.(2)may be replaced with the time-averaged local velocity u,according to con-ventional wisdom.An appropriate value of c must be attained in order to produce an eddy or eddies.On the other hand,theﬂow must be energetic enough to begin with,if turbulence can be sus-tained(i.e.,u must be large).When the two effects are comparable, it should be found that c%1.It is envisaged that for different direc-tions in a generalﬂow domain,c is directionally dependent.It is further noted that c is in fact different from Re,because when the Re increases over a critical value,turbulence must occur.On the other hand,c can vary from zero to inﬁnity,even for laminar ﬂows.2.2.Conforming c to the ULWFirst,it is found that c conforms to the ULW,thus demonstrat-ing signiﬁcant physical meaning.For a large Re,the wall-bounded turbulentﬂows exhibit boundary layers that fall within the dimen-sionless velocity distribution of an approximately universal nature. Many measurements have demonstrated the ULW[7–9].Large-scale(industrial)turbulence modeling often takes advantage of the ULW to create a wall function in order to avoid detailed com-putations near the wall and thereby reduce the computing effort. In the ULW,theﬂuid boundary layer is divided into three regions: a(pure)viscous sub-layer(also called the wall layer),a buffer layer,and an overlap layer[9].For the viscous sub-layer, 0y+\5and u+=y+,where y+=y/d v.The wall layer thickness (y+=1)is d v=v/u r.The friction velocity u r is deﬁned as u r¼ﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃs w=qp,where s w is the time-averaged shear stress at the wall (NÁmÀ2).u+is deﬁned as u+= u=u r.X.D.Chen/Engineering5(2019)576–579577This leads to the following:c ¼yd v2¼y þðÞ2ð3ÞEq.(3)presents a signiﬁcant ﬁnding that,in essence,when y is equal to the wall layer thickness,c =1,the inertia forces are com-parable to the shear forces.It is also interesting to note that y +=5is the conventional divide for the viscous sub-layer and the buffer layer,at which c =25.y +=11.5may also be important,as this is where turbulence production has been reported to peak in the ULW.At this point,it is intuitive to think that there may be a crit-ical c that corresponds to the range marked by the above number moving from laminar to turbulence,provided that the ﬂuid in this location has sufﬁcient energy (or sufﬁciently high velocity).As mentioned above,in both laminar and turbulent ﬂows,c can vary from zero to inﬁnity.Therefore,it is obvious that a single c value cannot be a sole marker for generating turbulence.2.3.Pipe ﬂowThe strategy,then,is to seek the relationship between c and changing velocity.As shown in Appendix A in the Supplementary data ,c can be obtained as a function of r/R (r is the radial coordi-nate and R is the radius of pipe)ﬁrst for different Re (s),where Re is deﬁned using the mean velocity u m .Then,via the relationship between u and r in this classic case,c can be further obtained as a function of u/u m .Differentiating this u/u m dependence function against u/u m ,for both the fully developed laminar and the fully developed turbulent regimes,yields a useful characteristic of c varying with velocity.For laminar ﬂow,it is the parabolic velocity proﬁle;for turbulent ﬂow,it is the 1/7th power velocity proﬁle.It can be shown that at point c xx %25(corresponding to y +=5),where the subscript xx indicates that the inertia effects in the x -direction interact with the shear effects applied in the x -direction as well,the crossover of the two derivatives against u/u m yields Re %2083.At this point,u/u m %0.597(see Fig.S1in the Supplementary data ,which demonstrates the obtainment of this result).When the time-averaged velocity proﬁle for turbulence is generalized to be of the 1/N th order,where N is the power of the classic approximation of the time-averaged velocity distribution in turbulence regime (dimensionless),especially with N =11,it can be shown that Re =2005.75is critical (see Appendix A in the Sup-plementary data ).Here,the velocity at c xx =25and u=u m =0.650(see Fig.S2in the Supplementary data ).This analysis indicates that when c xx =25,if the ﬂuid ﬂow at that location has sufﬁcient power,turbulence occurs.2.4.Plate ﬂowIn contrast to the ﬂow in a pipe,the ﬂow parallel to and above a ﬂat plate is at least two-dimensional.It is well known that the solution to a laminar velocity distribution in the plate boundary layer can be obtained accurately through similarity solution proce-dures [9];that is, u=U 1=f (g ),where g is the dimensionless trans-formation variable g ¼y =ﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃq U 1=2l x p and U 1is the velocity of the bulk ﬂuid.The laminar velocity proﬁle can also be expressed in a parabolic format,while the turbulent proﬁle can be expressed approximately as a 1/7th power format when scaled using the boundary layer thickness (see Appendix B in the Supplementarydata ).Once again,d c xx /d( u=U 1)can be obtained for both ﬂow modes,respectively.The crossover is set at Re x ,c =5.5Â105,which is the oft-mentioned Re c for the onset of turbulence in plate ﬂow.It is found that c xx %154.6(y +%12.4)(see Appendix B in the Supple-mentary data ).At this point, u=U 1=0.441.The obtainment of the critical parameter is shown in Fig.S3in the Supplementary data .In fact,the literature tends to suggest a range for the onset Re for turbulence of 105–106.The low estimate,Re x ,c =105,yieldsc xx =89.24(y +=9.45),for which u=U 1=0.487.This result actually aligns well with the critical condition for pipe ﬂow.2.5.Reversing back from turbulence to laminar ﬂowIf the velocity proﬁle is changed while the ﬂow rate is kept the same in a smooth and straight pipe,it is interesting to see whether Re c for the onset of turbulence changes or not.It is possible to pre-ﬁx c to be 25,and then see whether Re c is inﬂuenced by altering the velocity proﬁle.It is shown that when the law of 1/7th for turbulence is changed to the 1/20th law for turbulence,where the velocity proﬁle becomes ﬂatter,Re c becomes 2485,in contrast to 2083for the 1/7th law.In other words,it is possible to reverse the already turbulent situation ‘‘back”to the laminar situation if the velocity proﬁle is somehow forced to be ﬂatter in the gap of Re =2485–2083.In general,when N becomes greater than 7,Re c also increases.This result aligns well with the original work reported recently [3].3.Further remarksIt has been successfully shown that the onset of turbulence can be interpreted through the introduction of c ,which is the ratio of local inertia effect to viscous effect.Based on the well-established velocity proﬁles,it is possible to evaluate the critical transition Re through the relationship of how the local derivative of c against velocity changes with velocity.The sensitive region for ﬂow transi-tion is narrow,based on the analyses given in this work (see Figs.S1–S3in the Supplementary data ;beyond the crossover points,the change in the local derivative of c against velocity (as well as that of c )increases rapidly with increasing velocity,and no further crossover can be found).Increasing c would dam the tur-bulence,even it was already generated.It is probable that only a very thin or narrow geometrical region (i.e.,a line or a shell)is cap-able of sustaining turbulence generation.Upon a further analysis of previous results [1],albeit not elaborated in that study (see Fig.5in Ref.[1]),where the mean time of a puff from the wall before decay-ing or splitting as a function of Re in the pipe is shown,the occur-rence of a very sharp critical phenomena is suggested.A lesser or greater Re than the Re c has a much lower chance of producing sus-tained randomness (Fig.1).A previous work [2](see Fig.3in Ref.[2])also shows that the level of turbulence reﬂected by the cross-stream velocity ﬂuctuations v 0/U does not actually increasemuchFig.1.Mean lifetime of a puff before decaying (solid line)or splitting (dashed line),plotted using the mean lifetime functions of the Re created previously [1].578X.D.Chen /Engineering 5(2019)576–579with increasing Re,once past the Re c.It is thus highly probable that the source of(strongest)turbulence is located in a narrow region (s);furthermore,if this were true,then the rest of theﬂowﬁeld would largely be left for the transportation and dissipation of tur-bulence energy.This perspective would have a profound inﬂuence on the modeling of turbulence.In future studies,it will be helpful to visualize and compare the c distribution for both laminar and turbulent regimes with the sameﬂow arrangement and in the same device.Finally,it is emphasized again that despite the vast difference between the Re c found for pipeﬂow and for plateﬂow,respectively,the current dimensionless parameters under critical conditions for the two cases are not that different.AcknowledgementsThe author is grateful to his father,Prof.Naixing Chen(1933–2018),who was theﬁrst to introduce him to theﬁeld ofﬂuid mechanics over35years ago;the author had discussed the initial ideas of this paper with him not long before he fell terminally ill. Some17months were spent working on and off as a research assis-tant in Prof.Lixing Zhou’s laboratory at Tsinghua University in 1985–1987,on a code for simulating a two-dimensional multi-phaseﬂow in a sudden-expansion combustion chamber.The per-sonal knowledge of Dr.Tuoc Trinh of Canterbury University and later of Fonterra New Zealand in the late1980s to early1990s, respectively,was a real inspiration in thinking about wall turbu-lence.Dr.Trinh wrote a remarkable PhD thesis in the early2000s on his original ideas on boundary layer turbulence. Nomenclatured characteristic dimension of the object(m)Re Reynolds number(dimensionless)U characteristic velocity(mÁsÀ1)u, u local velocity and time-averaged local velocity,respectively(mÁsÀ1)U1velocity of the bulkﬂuid in plateﬂow(mÁsÀ1)u m mean velocity(mÁsÀ1)u r friction velocity(mÁsÀ1)as deﬁned in the ULW[8–12]v kinematic viscosity(m2ÁsÀ1)r the radial coordinate(m)R the radius of pipe(m)N the power of the classic approximation of thetime-averaged velocity distribution in turbulence regime(dimensionless)u ch a characteristic velocity(mÁsÀ1)x x-coordinate in the Cartesian systemy y-coordinate in the Cartesian systemy+dimensionless distance from the wall surface deﬁned in the ULWd v wall layer thickness(m)[8,13]D c characteristic distance corresponding to the representativevelocity change(m)c ratio of local inertia effect to viscous effect(dimensionless) g dimensionless transformation variable in the classicsimilarity solution of plateﬂowlﬂuid viscosity(PaÁs)qﬂuid density(kgÁmÀ3)s, s shear stress and time-averaged shear stress,respectively(Pa)Appendices A and B.Supplementary dataSupplementary data to this article can be found online at https:///10.1016/j.eng.2018.09.013.References[1]Avila K,Moxey D,de Lozar A,Avila M,Barkley D,Hof B.The onset of turbulencein pipeﬂow.Science2011;333(6039):192–6.[2]Barkley D,Song B,Mukund V,Lemoult G,Avila M,Hof B.The rise of fullyturbulentﬂow.Nature2015;526(7574):550–3.[3]Hof B,de Lozar A,Avila M,Tu X,Schneider TM.Eliminating turbulence inspatially intermittentﬂows.Science2010;327(5972):1491–4.[4]Kühnen J,Song B,Scarselli D,Budanur NB,Ried M,Willis AP,et al.Destabilizingturbulence in pipeﬂow.Nat Phys2018;14(4):386–90.[5]Reynolds O.An experimental investigation of the circumstances whichdetermine whether the motion of water shall be direct or sinuous,and of the law of resistance in parallel channels.Philos Trans R Soc Lond1883;174: 935–82.[6]Tokaty GA.A history and philosophy ofﬂuid mechanics.New York:Dover;1971.[7]Bird RB,Stewart WE,Lightfoot EN.Transport phenomena.2nd ed.NewYork:John Wiley&Sons;2002.[8]Laufer J.The structure of turbulence in fully developed pipeﬂow.NACAtechnical report.United States:National Bureau of Standards;1953Jun.Report No.:NACA-TN-2954.[9]Schlichting H,Gersten K.Boundary-layer theory.8th ed.Berlin:Springer;2003.[10]Churchill SW.Progress in the thermal sciences:AIChE Institute Lecture.AIChE J2000;46(9):1704–22.[11]Nikuradse J.Gesetzmassigkeiten der turbulenten stromung in glattenrohren.Berlin:VDI Verlag;1932.German.[12]Pai SI.On turbulentﬂow in circular pipe.J Franklin Inst1953;256(4):337–52.[13]Çengel YA,Cimbala JM.Fluid mechanics—fundamentals and applications.2nded.New York:McGraw-Hill Higher Education;2006.X.D.Chen/Engineering5(2019)576–579579Engineering 2 (2016) xxx–xxxResearchGreen Chemical Engineering—Article通过一个等价雷诺数揭示层流到湍流的转捩区域陈晓东School of Chemical and Environmental Engineering, Soochow University, Suzhou 215123, Chinaa r t i c l e i n f o摘要Article history:Received 3 August 2018Revised 20 September 2018Accepted 27 September 2018Available online 23 March 2019流动从层流到湍流的转捩现象或其逆过程是工程科学中的最重要研究课题之一。

道德经十五章英译蔽不新成

道德经十五章英译蔽不新成古之善为士者，微妙玄通，深不可识。

夫唯不可识，故强为之容：豫兮若冬涉川，犹兮若畏四邻，俨兮其若客，涣兮若冰之将释，敦兮其若朴，旷兮其若谷，浑兮其若浊。

孰能浊以止？静之徐清。

孰能安以久？动之徐生。

保此道者不欲盈，夫唯不盈，故能蔽不新成。

The ancient Taoist master knew the whys beneath all appearances through the way of complementarity, so he is too deep to be fathomable.Since he is beyond any description, we can only draw a rough picture of him.He looks jittering like walking on a river frozen in winter,hesitating like being threatened by neiboughs,courteous like a guest,easygoing like melting ice,primitive like unformed wood,open-minded like an empty vally,and cloudy like the Chaos.What can settle down the Chaos?It gradually becomes clear when resting in peace.What can maintain the peace for long?It develops a natural equilibrium when being animated.The one who follows the Tao does not want to be filled up.Just because he is never complacent with himself, he can always avoid being blinded by new prejudices.译注：微妙玄通，即通过“玄之又玄”的互补原理，常有以探幽入微，常无以观其奥妙。

高英二第四课

⾼英⼆第四课Lesson 4 Love Is a Fallacy by Max Shulmas Teaching PointsⅠ. Background Knowledge Ⅱ. Introduction to the Passage Ⅲ. Text analysisⅣ. Rhetorical DevicesⅤ. QuestionsTeaching ProcessWarming upQuestion 1:What is love?Question 2: What is logic?Question 3: Love is blind?Question 4: Love is reason?Introduction to the Passage1. Type of literature: a piece of narrative writing--protagonist/antagonists--climax--denouement2. The main theme3. Well chosen title and words4. Style--a very fast pace with a racy dialogue full of American colloquialism and slang--employing a variety of writing techniques to make the story vivid, dramatic and colorfulText AnalysisVocabulary1. Pay attention to words and expressions in the following aspects respectively:Spelling and PronunciationSynonymsOppositesSimilar words and expressionsSettled or habitual usage2. Word building knowledgeEffective Writing Skills1. Employing colorful lexical spectrum, from the ultra learned terms to the infra clipped vulgar forms2. Too much figurative language and ungrammatical inversion for specific purposes3. The using of short sentences, elliptical sentences and dashes to maintain the speed of narration Rhetorical Devices1. metaphor2. antithesis3. transferred epithet4. hyperbole5. metonymy6. litotes7. ellipsis8. synecdoche9. inversion10. simile11. mixed metaphor12. rhetorical questionsSpecial DifficultiesAnalyzing the logical fallaciesUsing inverted sentences to achieve emphasisEffectively using many figures of speechUnderstanding colloquial expressions and slangAllusions:--Frankenstein--PygmalionParaphrasing some sentencesIdentifying figures of speechQuestions1. Define and give an example of each of the logical fallacies discussed in this essay.2. Can you find any evidence to support the view that the writer is satirizing a bright but self-satisfied young man?3. Comment on the language used by Polly. What effect does her language create?4. Why does the writer refer to Pygmalion and Frankenstein? Are these allusions aptly chosen?5. In what sense is the conclusion ironic?Assignment:Write a composition of classification.Lesson 4 Love Is a Fallacyby Max ShulmanⅠ. Additional Information Related to the Text:1. Max SchulmanMax Schulman (1919-1988) was a 20th century American writer humorist best known for his television and short story character Dobie Gillis, as well as for best-selling novels.He first delved into the world of writing as a journalist student at the University of Minnesota. Max Schulman?s earliest published writing was for Ski-U-Mah, the college humor magazine of the University of Minnesota, in the 1930s. His writing often focused on young people, particularly in a collegiate setting. He wrote his first novel, Barefoot Boy with Cheek《⽆礼的⾚脚少年》a satire on college life, while still a student. Schulman?s works include the novels Rally Round the Flag, Boys!,《孩⼦们，团结在旗帜的周围吧》which was made into a film starring Paul Newman and Joanne Woodward; The Feather Merchant《⾐冠楚楚的商⼈》，The Zebra Derby, Sleep till Noon, and Potatoes Are Cheaper. He was also a co-writer, with Robert Paul Smith, of the long-running Broadway play, The Tender Trap, which was later adapted into a movie starring Frank Sinatra and Debbie Reynolds.Schulman?s college charater, Dobie Gillis, was the subject of a series of short stories complied under the title The Many Loves of Dobie Gillis, which became the basis for the 1953 movie The Affairs of Dobie Gillis. Shulman also wrote the series? theme song. The same year the series began. Schulman published a Dobie Gillis novel, I was a Teenage Dwarf (1959). After his success with Dobie Gillis, Shulman syndicated a humor column, “On Campus”, to over 350 collegiate newspapers at one point.A later novel, Anyone Got A Match? satirized both the television and tobacco industries, as well as the Soth and college football. His last major project was House Calls, which began as a 1978 movie based on one of his stories; it spun off the 1979-1982 television series of the same name. Schulman was the head writer.Also a screenwriter, Schulman was one of the collaborators on a 1954 non-fiction television program, Light’s Diamond Jubilee, timed to the 75th anniversary of the invention of the lihght bulb.2. Logical fallacy:逻辑谬误An argument in logic presents evidence in support of some thesis or conclusion.（逻辑论证，即提⽀持某些论题或结论的论据。

电化学专业词汇锂离子电池

Stoichiometry 化学计量学Cyclability 循环特性Rate capability 倍率性能Life-span 寿命The state of the art 目前的工艺水平Overall assessment 综合评价Basis for 为…打基础Rational selection 合理的选择辅助动力混合电动车（Power-Assist Hybrid Electric Vehicles ，包括HEV和FCV）；•插电式混合电动车（Plug-in Hybrid Electric Vehicles ，包括PHEV 和FCV)•纯电动车（Battery Electric Vehicles ，包括各类EV)R&D （research and development），指在科学技术领域，为增加知识总量（包括人类文化和社会知识的总量），以及运用这些知识去创造新的应用进行的系统的创造性的活动，包括基础研究、应用研究、试验发展三类活动。

可译为“研究与开发”、“研究与发展”或“研究与试验性发展”。

DOE 美国能源部Passivation 钝化Hydrophobic 疏水性Lipophobic 疏酯性Solvophobic 疏溶剂的Aggregate 聚集Micelle 胶团微团Fluorosurfactant 氟表面活性剂Impermeable 不可渗透的Electrolyzer 电解槽Redox flow battery 氧化还原液流电池Intrinsic 本质的固有的Novel approach 新方法Delocalization 离域移位Steric shield 空间屏蔽Nucleophilic attack 亲核攻击Spur 鼓舞马刺刺激鞭策Resurgence 复活再现New platform 新平台Fuel flexibility 燃料灵活性Cusp 风口浪尖Power generator 电力发电机Forklift 铲车Stumbling block 绊脚石Methanol 甲醇Formic acid 甲酸Dimethyl ether 二甲醚Performance decline 绩效下滑Peroxide 过氧化物过氧化氢Chloromethylation氯甲基化Aromatic polymer 芳族聚合物Styrene 苯乙烯Quaternization 碱化反应Benzylchloride 氯化苄Tertiary amine 叔胺Quaternary 四进制的四元的Ammonium 铵Tether 范围Linkage 连接Facile 温和的灵巧的Monomer 单体Precursor 前驱体Brominated 溴化Benzylhalide 苄基氯Subsequent 随后的Backbone 支柱中坚Bucket 水桶Susceptible 易受。

一种适用于任意高阶间断有限元的高精度非分裂完全匹配层吸收边界方法

一种适用于任意高阶间断有限元的高精度非分裂完全匹配层吸收边界方法何洋洋;翁斌;张金淼【摘要】The common absorbing boundary condition used commonly for arbitrary high-order discontinuous Galerkin finite element method could not efficiently absorb wave energy of grazing incidence.A new algorithm of high precision unsplit perfectly matched layer absorbing boundary is proposed for the arbitrary high-order discontinuous Galerkin finite element method.The unsplit perfectly matched layer is applied to seismic wave modeling with arbitrary high-order discontinuous Galerkin method,the new equation of the wave propagation in perfectly matched layer and its solution in triangle element are derived,and the discrete scheme is given. This scheme can obtain arbitrary high-order solutions in both time and space in the unsplit perfect match layer with the same solutions in the computational region,thus reducing the energy of reflectivity from absorbing boundary.Simulation results indicate that the method shows better absorbing effect on incident waves with different angles,and it is suitable for the material with high Poisson's ratio.%任意高阶间断有限元法常用的吸收边界条件存在对切向入射波吸收效果不佳等问题.本文提出了一种适用于任意高阶间断有限元的高精度非分裂完全匹配层吸收边界方法,将非分裂完全匹配层吸收边界应用于任意高阶间断有限元地震波数值模拟方法中,建立了完全匹配层内新的波动方程,推导了其求解过程及在三角形单元内的表达形式,最后给出了离散化格式.该方法在完全匹配层也可以求得任意高阶时间精度和空间精度的数值解,与计算区域的精度一致,减少了边界反射波的能量.数值算例模拟结果表明,本文方法对不同角度的入射波具有较好的吸收效果,适用于高泊松比介质.【期刊名称】《中国海上油气》【年(卷),期】2016(028)001【总页数】7页(P41-47)【关键词】非分裂完全匹配层;任意高阶间断有限元;高精度;不同角度入射波;高泊松比【作者】何洋洋;翁斌;张金淼【作者单位】中海油研究总院北京 100028;中国石油大学(北京)北京 102249;中海油研究总院北京 100028;中海油研究总院北京 100028【正文语种】中文【中图分类】TE132.1+4;P631地震波场数值模拟是勘探地球物理的重要研究手段，实际应用中，可以通过求解弹性波动方程来实现[1-2]。

苯环上上甲醛

Radical and migratory insertion reaction mechanisms in Schiﬀbase zirconium alkylsPaul D.Knight a ,Guy Clarkson a ,Max L.Hammond a ,Brian S.Kimberley b ,Peter Scott a,*a Department of Chemistry,University of Warwick,Gibbett Hill Road,Coventry CV47AL,UK bResearch &Technology Centre,BP Chemicals snc,Boite Postale No.6,13117Lavera,FranceReceived 9February 2005;received in revised form 22March 2005;accepted 23March 2005Available online 4May 2005AbstractFour salicylaldimine derivatives H 2L 4–7of 2,20-diamino-6,60-dimethylbiphenyl,where the C @N bond is sterically protected by substituents on the phenol ring,form alkyls of zirconium,cis -a -[Zr L 4–7(CH 2Ph)2].Rather than decomposing via the established pathway of 1,2-migratory insertion of an alkyl group to imine,they undergo a radical mechanism.This is evidenced by the large number of products observed,kinetic and thermodynamic data (Rice-Herfeld,3/2order,positive D S à),response to steric factors,and the fact that switching to a less stable radical leaving group inhibits the reaction.In contrast,the 1,2-migratory insertion is a clean,ﬁrst-order intramolecular process with negative D S à.The steric modiﬁcation of the ligands nevertheless transforms an inac-tive precatalyst into a stable system for the polymerisation of ethene.Closely related unbridged salicylaldimine catalysts are known to be highly active catalysts,but in most cases they appear to suﬀer from high temperature instability.The ﬁrst examples of zirco-nium alkyls of this class are isolated,and it is found that they are inherently much more resistant to decomposition by either path-way (migratory insertion or radical).Structural studies are used to interpret this variance in behaviour;the biaryl-bridged complexes are pre-organised for both reactions,while the unbridged systems would have to undergo signiﬁcant ordering prior to activation.Correspondingly,the unbridged systems are not noticeably aﬀected by the same steric modiﬁcation of the ligand,and it is concluded that the more likely mechanism of catalyst death in the latter is ligand loss (i.e.transfer to aluminium from co-catalyst).Ó2005Elsevier B.V.All rights reserved.Keywords:Mechanism kinetics;Zirconium;Alkene polymerisation1.IntroductionA fundamental concern for those using Schiﬀbase complexes in catalytic applications is the reactivity of the C @N bond,speciﬁcally where this limits the number of turnovers.This issue is particularly important in early transition chemistry,where coordination of the imine unit renders it highly electrophilic [1].We have sought to avoid this issue through the replacement of theC @N units with less reactive linkers,and while this has met with some successes in enantioselective catalysis [2],the favourable properties of Schiﬀbase systems –strong ligand–metal bond,ease of synthesis,tunability,crystallinity,structural rigidity –have encouraged us to investigate the possibilities for improvement of their stability in early transition complexes.In this context,salicylaldimine (SA)complexes of the group 4metals,[M(SA)2Cl 2](Fig.1),which when combined with,e.g.methylaluminoxane (MAO)yield extremely active or otherwise useful catalysts for the polymerisation of alk-enes,are of particular interest [3].It is assumed that me-tal alkyls are involved in these catalyses,and evidence0022-328X/$-see front matter Ó2005Elsevier B.V.All rights reserved.doi:10.1016/j.jorganchem.2005.03.043*Corresponding author.Tel.:+442476523238;fax:+442476572710.E-mail address:peter.scott@ (P.Scott).Journal of Organometallic Chemistry 690(2005)5125–5144/locate/jorganchemhas been presented that alkyl cation species [M(SA)2Me]+are formed on treatment of [M(SA)2Cl 2]with MAO [4].Coates has mentioned that analogous ketimino ligands form stable alkyl complexes on treat-ment with [Ti(CH 2Ph)4][5].In contrast with many other oleﬁn polymerisation systems however an alkyl cation has not been isloated.We have recently shown that biaryl-bridged salicyl-aldimine derivatives H 2L 1–3(Fig.2)form,under appro-priate conditions,isolable alkyls of zirconium [Zr L 1–3R 2]with cis -a geometry (C 2-symmetric with cis alkyl ligands)[7].Subsequently,however,they decompose via 1,2-migratory insertion of an alkyl group to imine (Scheme 1)followed in some instances by a second sim-ilar reaction.This provides an explanation for their complete inactivity in oleﬁn polymerisation.Here we re-port a detailed kinetic investigation of this reaction,an attempt to prevent the process by ligand modiﬁcation,discovery of a new decomposition mechanism,and the development of a stable polymerisation catalyst system.We also describe some attempts to apply the lessons learned to the SA catalyst system.Part of this work has been brieﬂy communicated [6].2.Results and discussion 2.1.Ligand designsReducing the steric demand in the phenolate 2-posi-tion (R 0in Scheme 1)reduces the rate of 1,2-migratory insertion in the metal benzyl complexes [Zr L n (CH 2Ph)2](i.e.L 3<L 1<L 2)[7].This is however an unsatisfactory resolution of the problem of complex stability for two reasons;(i)even when this group is hydrogen the 1,2-migratory insertion pathway is still accessible and occurs over a short period of time (<48h),(ii)it is known that group 4iminophenolate complexes require sterically demanding substituents (e.g.t Bu)in this position to fur-nish highly active catalysts for alkene polymerisation [3].We thus sought other modiﬁcations.A space-ﬁlling model of the molecular structure of [Zr L 1(CH 2Bu t )2][7]is shown in Fig.3(a),with the elec-trophilic imine carbon atom indicated *.We envisaged that notionally moving the 4-methyl substituent to the 5-position [Fig.3(b)]would eﬀectively block the ap-proach of a zirconium bound alkyl group to the imine carbon atom.The series of ligands L 1,L 4,L 5was de-signed to examine the eﬀect of steric demand in this 5-position.In addition,it was envisioned that the series L 6,L 4,L 7would allow investigation of the eﬀect of steric demand in the 2-position for this unusual salicylaldi-mine substitutionpattern.Fig. 3.Space-ﬁlling models of (a)[Zr L 1(CH 2CMe 3)2]from X-ray molecular structure and (b)[Zr L 4(CH 2CMe 3)2]based on (a);phenolate 4and 5positions and imine carbon atom (*)indicated.5126P.D.Knight et al./Journal of Organometallic Chemistry 690(2005)5125–51442.2.Synthesis of zirconium alkyl complexesThe synthesis of[Zr L1(CH2Ph)2]was reported previ-ously[7].Reaction of H2L4with zirconium tetrabenzyl in acetonitrile yielded a precipitate which was found to be mainly unreacted H2L4.This was probably due to the low solubility of H2L4in acetonitrile.The complex [Zr L4(CH2Ph)2]was successfully synthesised in dichlo-romethane atÀ78°C.The reaction of the more soluble proligand H2L5with[Zr(CH2Ph)4]in acetonitrile pro-ceeded cleanly giving[Zr L5(CH2Ph)2]in high purity. The complexes[Zr L6(CH2Ph)2]and[Zr L7(CH2Ph)2] were prepared similarly.The NMR spectra of freshly prepared solutions of these complexes were consistent with cis-a geometry.2.3.Solution stability of[Zr L4–7(CH2Ph)2]:initial observationsWe were surprised toﬁnd that the four complexes [Zr L4–7(CH2Ph)2]underwent fairly rapid decomposition in solution,although the spectra of the products were markedly diﬀerent from those expected for1,2-migra-tory insertion processes.After ca.3h at298K,the1H NMR spectrum of a solution of[Zr L4(CH2Ph)2]in d2-dichloromethane displayed a very large number of new peaks in the imine(d7.5–9.5ppm)and aliphatic regions. These features,which were similar for all four complexes with a5-substituent,are consistent with radical decom-position processes.Attempts at isolation of one of the many decomposition products were unsuccessful.2.4.Kinetic studies of the decomposition processesThe decomposition of[Zr L1(CH2Ph)2]in d2-dichloro-methane was followed by1H NMR spectroscopy be-tween283and303K.Values for the integration of the complex imine peak relative to the residual protio sol-vent resonance were obtained over ca.two half-lives where possible.First-order plots were satisfactory over the whole temperature range(Fig.4).Similar vari-able temperature kinetic studies on the complexes [Zr L4–7(CH2Ph)2]showed that they did not decompose viaﬁrst-order processes and after much experimentation it was found that the only satisfactoryﬁt was via1.5or-der plots(e.g.Fig.5).This unusual order was conﬁrmed using VanÕt Hoﬀplots of the data.Activation parameters(Table1)were subsequently obtained via Eyring plots.The uncertainties recorded were calculated using standard methods[8].1The negative value of entropy of activation for the decomposition of[Zr L1(CH2Ph)2]is consistent with the formation of an ordered(four-membered)cyclic transition state in an intramolecular1,2-migratory inser-tion process.As we had proposed,placing a methyl group in the5-position as in complex[Zr L4(CH2Ph)2] inhibits the formation of this cyclic transition state, but unexpectedly a new mechanistic pathway is opened up as evidenced by the number of products formed and by a change in the order of reaction to3/2.Both observations are consistent with Rice–Herzfeld radical propagation kinetics[9,10](vide infra).We propose an initiation step involving homolyticﬁs-sion of the Zr–CH2Ph bond,leading to formation of two radical species(Eq.(1),Bn=CH2Ph).2The benzyl rad-ical can then attack the ligand(e.g.at an imine position) on another complex molecule to form a new radical spe-cies(Eq.(2)).We have previously described a very clo-sely related reaction at a Nb(IV)Schiﬀbase system (Scheme2)leading to oxidation to diamagnetic Nb(V) [11].In the case of Zr the radical character is retained by the ligands(Eq.(2)),and the system may react to form a closed shell complex and a further benzyl radical (Eq.(3)).The lack of a higher oxidation state for zirco-nium thus enables a radical propagation process that terminates when two radicals combine(Eq.(4)).Assum-ing steady state conditions,Eq.(5)is eventually ob-tained[10].We note that the observed rate constant k obs(Eq.(6))and thus the thermodynamic values ob-tained from the Eyring analysis for the process of‘‘acti-vation’’are actually composite parameters arising from initiation,propagation and termination.The positive entropies of activation for the complexes of L4–7(Table 1)are nevertheless consistent with a radical process. Initiation½Zr LðBnÞ2!k1½Zr LðBnÞ ÅþBnÅð1ÞPropagationBnÅþ½Zr LðBnÞ2!k2½ZrðBn–LÞðBnÞ2Åð2Þ½ZrðBnÀLÞðBnÞ2Å!k3½ZrðBn–LÞðBnÞ þBnÅð3ÞTerminationBnÅþBnÅ!k4Bn2ð4ÞRate¼k2k1k40.5½Zr LðBnÞ21.5ð5ÞRate¼k obs½Zr LðBnÞ21.5ð6Þ1Standard error in the slope,SEm ¼s e=ﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃTSS xpand standard error inthe intercept,SE c¼s eﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃﬃð1=nÞþð X2=TSS xqÞ.These were computedusing the LINEST function in Microsoft Excel.2These equations are representative examples of the type of process described.P.D.Knight et al./Journal of Organometallic Chemistry690(2005)5125–51445127Returning to the initiation step,we propose that the proximity of a benzylic H atom to the imine carbon may facilitate the homolytic ﬁssion of the metal–benzyl bond (Fig.6).We note that the observed rate of decom-position of the L 5complex is almost twice that of L 4and this diﬀerence arises in the main from the much greater positive D S àin the former where the proposed H atom donor unit is i Pr rather than Me.Subject to the caveat mentioned above regarding the composite nature of the thermodynamic parameters,wealso note that the enthalpies of activation decrease for the complexes in the order L 6>L 4>L 7,with steric bulk in the phenolate 2-position increasing in the same order (H <Me <i Pr).This is the same trend as observed for the ﬁrst order 1,2-migratory insertion process and is consistent with greater steric compression in the more substituted complexes.The large increase in k rel onTable 1Activation parameters and relative rates for decomposition of [Zr L n (CH 2Ph)2]Complex k rel (298K a )D H à(kJ mol À1)D S à(J K À1mol À1)[Zr L 1(CH 2Ph)2]–+88(±2)–32(±7)[Zr L 4(CH 2Ph)2] 1.0+101(±5)+16(±16)[Zr L 5(CH 2Ph)2] 1.8+113(±10)+62(±34)[Zr L 6(CH 2Ph)2]0.3+108(±7)+29(±23)[Zr L 7(CH 2Ph)2]1.1+91(±5)+17(±16)aRelative rate constant versus [Zr L 4(CH 2Ph)2].5128P.D.Knight et al./Journal of Organometallic Chemistry 690(2005)5125–5144moving from L6to L4is not continued on moving to L7 however,principally because the general trend in D Sàis acting against this.2.5.Reaction of H2L4with[Zr(CH2CMe3)4]We explored brieﬂy the eﬀect of the presence of a less stable radical leaving group on the decomposition pro-cess.Reaction of H2L4with zirconium tetrakis(neopen-tyl)in dichloromethane proceeded smoothly,and a high purity sample of the complex[Zr L4(CH2CMe3)2]was obtained by crystallisation from pentane.This complex only began to show traces of decomposition in solution after leaving for several days at room temperature.2.6.Synthesis and polymerisation activity of[Zr L1À7Cl2]Since the benzyl complexes were prone to decomposi-tion,we attempted to generate the chloride complexes as these had previously been observed to be far more ro-bust[12].Treatment of the ligands with sodium hydride followed by[ZrCl4(THF)2]proceeded without problem. The zirconium chloride complexes,[Zr L1–7Cl2],were then puriﬁed by sublimation at ca.300°C,10À6mm Hg in all cases and found to possess C2symmetry.However, treatment with MAO in toluene in the presence of ethyl-ene at ambient temperature and1.2bar led to very low uptake of gas.This lack of activity may be attributed to the lack of steric bulk in the phenolate2-position[3,13].2.7.Synthesis of[Zr L8,9Cl2]and polymerisation catalysisThese zirconium chloride complexes were synthesised and characterised as before.Ethylene polymerisation re-sults are summarised in Table2.As can be seen,the presence of the phenolate2-tert-butyl group in[Zr L9Cl2] does not give rise to signiﬁcant polymerisation activity on its own.In combination with5-methyl substituent, as in[Zr L8Cl2],polymerisation activity was observed for theﬁrst time using this type of ligand,albeit moder-ate according to GibsonÕs classiﬁcation[14].The catalyst is unusually stable,and there is no noticeable loss of activity at25and50°C over at least a period of1h (Fig.7).The lower average productivity and activity at 50°C is due to the reduced solubility of ethylene in tol-uene at higher temperatures.2.8.Structural implications of phenolate5-methyl substitutionWe obtained X-ray molecular structures(Table3)of [Zr L7Cl2]and[Zr L9Cl2]via crystals obtained from sam-ples of the pure complexes in d2-dichloromethane.The molecular structures are shown in Fig.8with selected bond lengths and angles given in Table4.The view along the Zr–O axes(Fig.9)highlights the inﬂuenceofTable2Polymerisation activity of complexes[Zr L8,9Cl2]:precatalyst,1.39·10À2mmol;toluene(500ml);ethene pressure,1.2bar;MAO:Zrmolar ratio,1000:1Precatalyst Temperature(°C)Average productivity(1h)(kg PE/mol–Zr bar–C2h)[Zr L8Cl2]2565[Zr L9Cl2]25–[Zr L8Cl2]5040[Zr L9Cl2]50–P.D.Knight et al./Journal of Organometallic Chemistry690(2005)5125–51445129the5-methyl substituent;steric compression between this group and the imine-CH has led to a twist in the plane of coordination of the phenolate ring,such that the phenolate–CH3lies between the imine group and the adjacent Zr–Cl group.This increases the hindrance of the pathway for1,2-migratory insertion between the imine carbon and a metal bound alkyl group(in place of Cl).This twisting of the phenolate ring may have an additional consequence in that the phenolate2-alkyl substituent has been directed away from the‘‘active sites’’of the catalyst.This may reduce steric compres-sion at these sites resulting in reduced propensity for decomposition as well as opening the sites for increased catalytic activity.2.9.Synthesis and stability of active species in polymerisation catalysisThe question remained as to whether zirconium alkyl complexes of L8and L9decompose via diﬀerent path-ways.All attempts failed at generating the desired com-plexes by reaction of proligands with zirconium tetrabenzyl and zirconium tetrakis(neopentyl).1H NMR spectra indicated that the reaction was much slower than for less bulky ligands;resonances corre-sponding to unreacted and mono-deprotonated ligand were evident for the neopentyl reaction,and several other products were evident for the benzyl.Attempts at alkylation of the zirconium chloride complexes using Grignard and lithium reagents produced a number of unidentiﬁed products.Reactions of[Zr L8Cl2]and [Zr L9Cl2]in NMR tubes with previously dried MAO (10molar equivalents)in d8-toluene resulted inTable3Experimental data for the X-ray diﬀraction studies[Zr L7Cl2][Zr L9Cl2]ÆCH2Cl2[Zr L11Cl2] Colour Yellow Yellow YellowHabit Block Block BlockMolecular formula C36H38Cl2N2O2Zr C39H44Cl4N2O2Zr C36H40Cl2N2O2Zr Crystal system Monoclinic Monoclinic Monoclinic Space group C2/c C2/c C2/ca(A˚)19.975(4)13.349(3)21.166(4)b(A˚)10.551(2)14.379(3)7.925(2)c(A˚)15.521(3)20.131(4)20.282(4)b(°)97.95(3)96.74(3)100.770(19)Cell volume(A˚3)3239.7(11)3837.4(13)3342.2(14)Z444l(mmÀ1)0.5390.6010.523Total reﬂections10,36412,48113,587 Independent reﬂections[R(int)]3987[0.0183]4650[0.1109]4189[0.0182]R1,wR2[I>2r(I)]0.0235,0.06170.0768,0.19160.0225,0.0585Table4Selected bond lengths(A˚)and angles(°)for molecular structures of[Zr L7Cl2],[Zr L9Cl2]and cis-a-[Zr(L11)2Cl2](vide infra)[Zr L7Cl2][Zr L9Cl2][Zr(L11)2Cl2]Zr–O 1.9987(11) 1.986(3) 1.981(9)Zr–Cl 2.4246(6) 2.4313(17) 2.432(5)Zr–N 2.3221(12) 2.347(4) 2.348(11)O–Zr–O165.30(6)172.2(2)157.40(5)N–Zr–N75.09(6)72.9(2)84.31(6)Cl–Zr–Cl103.82(3)108.36(10)94.38(3) 5130P.D.Knight et al./Journal of Organometallic Chemistry690(2005)5125–5144consumption of the starting complexes and signiﬁcant broadening of the spectra,but no unambiguous indica-tions of the formation of alkyl or alkyl cation species.Since we could not generate zirconium alkyl com-plexes of L 8and L 9,we decided to use complexes of L 4and L 1as models.An NMR tube was charged with [Zr L 1(CH 2Ph)2]and B(C 6F 5)3,and d 2-dichloromethane was distilled into it at À78°C.The 1H NMR spectra were then recorded at À80°C and then at increments of +10°C up to room temperature.A similar reaction was carried out using [Zr L 4(CH 2Ph)2].In both cases,the 1H NMR spectra indicated formation of [B(C 6F 5)3(CH 2Ph)]À[15].Below ca.À40°C,two imine peaks were observed that do not correspond to the start-ing complexes,and the presence of six methyl reso-nances indicate that the species formed were C 1symmetric.For both reactions,new pairs of doublets oc-curred in the region d 2.0–3.5ppm,and we tentatively assign all these features to the desired cationic species [Zr L (CH 2Ph)]+.Upon warming the solution containing the proposed L 4complex cation,signiﬁcant decomposi-tion occurred between À30and 0°C;a large number of new imine peaks are generated and the pair of doublets disappeared.The solution containing the L 1complex also decomposes signiﬁcantly within the same tempera-ture range,however three major new imine peaks are observed along with the disappearance of the pair of doublets.No clear evidence for 1,2-migratory insertion processes was observed in either case.2.10.Application to other catalyst systemsWe sought to investigate the eﬀect of 5-alkyl substitu-tion on Fujita Õs zirconium iminophenolate catalysts.Four proligands H L 10–13(Fig.10)were synthesisedviaFig.9.Salicylaldimine–Zr–Cl fragments of (a)[Zr L 7Cl 2]and (b)[Zr L 9Cl 2]extracted from X-ray molecular structures,highlighting eﬀects of substituents ortho to the iminecarbon.P.D.Knight et al./Journal of Organometallic Chemistry 690(2005)5125–51445131condensation of the appropriate salicylaldehydes with aniline in ethanol.Two of these ligands(H L10,12)have a methyl group in the5-position and two control ligands H L11,13have the traditional2,4-substitution(H L11has previously appeared)[16].Reactions of H L10and H L11with sodium hydride in THF followed by[ZrCl4(THF)2]resulted in the produc-tion of yellow/orange solids which were sublimated at ca.300°C,10À6mm Hg to yield yellow solids of stoichi-ometry[Zr(L10,11)2Cl2],as indicated by mass spectrome-try and CHN analysis.1H NMR spectra revealed that two isomeric complexes were present in both cases. The major products were C2-symmetric,as indicated by the presence of single imine,phenolate methyl and tert-butyl resonances.The minor products(ca.27%for½Zr L102Cl2 and ca.36%for½Zr L112Cl2 )had broad1HNMR spectra at room temperature,but cooling(253K for½Zr L102Cl2 and203K for[Zr L11Cl2])gave riseto sharp resonances.Two imine peaks and two pheno-late methyl and tert-butyl resonances were observed in both complexes.We therefore assigned these species as having the C1-symmetric cis-b topography.The ratio of cis-a to cis-b remains unchanged over a period of days.Interestingly,Fujita and coworkers[16]did not note the presence of cis-b isomers of[Zr L11Cl2], although their NMR data are possibly consistent with this.Coates[5]has noted the presence of cis-b isomers of ketimino titanium complexes and others.Crystals of cis-a-½Zr L112Cl2 were grown from toluenesolution.X-ray analysis revealed that the C2-symmetric complex(Fig.11)crystallises as a dimer via a face-face p–p stacking interaction between N-aryl rings(Fig.12).The distance between H(16A)and the centroid of the proximal aryl ring is ca.3.37A˚[17].The bond dis-tances and angles about Zr(1)are unremarkable for this type of complex[16]and are discussed in more detail through comparison with those of a biaryl-bridged com-plex in Section2.12.Samples of½Zr L102Cl2 and½Zr L112Cl2 were tested at BP laboratories under supported gas-phase conditions with MAO co-catalyst.Both complexes had similarly high activities and catalytic lifetimes were<10min at 50–80°C in both instances.Thus,while substitution of the ligand with a methyl group ortho to the imine carbon atom does not signiﬁcantly alter the intrinsic polymeri-sation activity of the complexes,it fails to increase lon-gevity of the catalyst in this instance.In the hope of shedding further light on the issue of iminophenolate catalyst stability we undertook a study of some alkyl derivatives.2.11.Synthesis and properties of[Zr(L10–13)2(CH2Ph)2]In NMR tube scale experiments,the reactions between two equivalents each of H L10–13with[Zr(CH2-Ph)4]were shown to give cleanly[Zr(L10–13)2(CH2Ph)2]. One example,[Zr L102(CH2Ph)2],was synthesised on a preparative scale and was characterised in the usual way.Attempts to grow single crystals for X-ray analysis were unsuccessful.The1H NMR spectrum of½Zr L102ðCH2PhÞ2indi-cated the adoption of the cis-a structure;in particular the appearance of the C H2Ph as a pair of AB doublets indicated that interconversion between the chiral-at-metal structures(Fig.13)is slow onthis5132P.D.Knight et al./Journal of Organometallic Chemistry690(2005)5125–5144timescale.The spectrum of½Zr L112ðCH2PhÞ2wassimilar.For[Zr(L12,13)2(CH2Ph)2]these C H2Ph reso-nances appeared as a broad singlet.This trend in con-ﬁgurational stability is consistent with an N-dissociative mechanism since bulky groups in the phenolate2-posi-tion would cause steric compression on lengthening of the N–Zr bond,and hence hinder isomerisation[18].All the above complexes were found to be relatively stable with respect to the decomposition reactions de-tailed above.After several days in solution at ambient temperature,samples of the bulky ligand complexes [Zr(L10,11)2(CH2Ph)2]began to show signs of formation of1,2-migratory insertion products,viz.a new single imine peak and a set of three quartets in the regionca.parison of the molecular structures of cis-a-½Zr L9Cl2 and cis-a-½Zr L112Cl2 .P.D.Knight et al./Journal of Organometallic Chemistry690(2005)5125–51445133d 2.5–6.5ppm[1a].Solutions of the complexes [Zr(L12À13)2(CH2Ph)2]showed very little,if any,decom-position over a period of several days.2.12.Stability of[Zr L102CH2Ph]þWe attempted to generate an alkyl cation complex byreaction of½Zr L102ðCH2PhÞ2with B(C6F5)3in an NMRtube atÀ78°C,using d2-dichloromethane as solvent.1H NMR spectra were recorded atÀ80°C and at+10°C increments up to room temperature.Resonances for [B(CH2Ph)(C6F5)3]Àwere observed at low temperature [15],indicating that a reaction had taken place,but while some resonances assignable to a cationic species [Zr(L10)2(CH2Ph)]+were observed,byÀ40°C extensive decomposition had occurred.This result and the at-tempts to form[Zr L1,4(CH2Ph)]+(Section2.8),do not bode well for isolation of a stable alkyl cationic species such as that implicated in oleﬁn polymerisation catalyses by these complexes.Fujita[4]has also detected NMR resonances consistent with such a species on treatment of a dichloride complex with dried MAO.2.13.Biaryl-bridged complexes vs.non-bridged complexesComplexes of our biaryl-bridged ligands above and the non-bridged salicylaldimine type ligands are similar in terms of functionality.Nevertheless,considerable dif-ferences are observed for polymerisation activity.We can see that in comparison to the constrained structure of the biaryl complex[Zr L9Cl2][Fig.14(a)],the N-arylunits in the non-bridged ligand complex½Zr L112Cl2 (b)are directed away from one another.The presence of the biaryl unit also constrains the N–Zr–N0angle toca.72.9°compared with84.3°for½Zr L112Cl2 ,(Table4),and perhaps most importantly reduces the size of the active site by forcing the phenolate units forwards;the O–Zr–O0angles for[Zr L9Cl2]and½Zr L112Cl2 are172.2°and157.4°,respectively.The top view of the com-plexes shows that the phenolate tert-butyl substituents are positioned directly above the zirconium chloride sites in the L9complex,whereas in the L11complex these tert-butyl groups are situated above the zirconium cen-tre.The resultant steric compression in[Zr L9Cl2]forces the chlorides farther apart(108.4°)than in the L11com-plex(94.4°).Given these structural diﬀerences,the vari-ance in intrinsic catalytic activity between[Zr L8Cl2]and½Zr L102Cl2 is not surprising.The variance in response of the two catalysts systems to attempted steric blocking of the1,2-migratory inser-tion reaction also requires comment.For the biaryls, the geometry is essentially pre-organised for the approach of metal-coordinated alkyl towards the carbon atom. Steric compression from phenolic ortho substituents (top view,Fig.14)encourages this further.Nevertheless, the constrained biaryl ligand geometry also dictates that a methyl group ortho to the imine consistently impedes this reaction,thus leading to the remarkable increase in catalyst stability detailed above.The unbridged com-plexes are not pre-organised for this reaction,and as a result the1,2-migratory insertion is inherently slower for these compounds.The observation that phenolate 5-methyl substitution does not aﬀect catalyst longevity suggests that either;(i)despite the fact that complexes [Zr(L10–13)2(CH2Ph)2]appear to be rather stable with respect to1,2-migratory insertion,the greaterﬂexibility allows for imine migratory insertion even in the modiﬁed catalyst,or perhaps more likely(ii)that other processes are responsible for catalyst deactivation(vide infra). 3.ConclusionsOur attempt here to block sterically the1,2-migratory insertion process in our Schiﬀbase group4alkyl com-plexes was successful principally because of the lack of ﬂexibility of the system.This also results however in the complexes being pre-organised for decomposition via a radical process.Kinetic analysis and1H NMR spec-troscopy data highlight the diﬀerences between the two pathways.For the1,2-migratory insertion mechanism a single product was formed in a highly diastereoselective intramolecular manner to give an unstable intermediate. The reaction displayedﬁrst order reaction kinetics with a negative entropy of activation associated with ordered transition state.The radical process gave many products in a1.5order Rice–Herzfeld reaction with positive entro-py of activation,but was inhibited through the use of a less stable radical leaving group(neopentyl)at the metal, thusﬁnally giving a stable metal alkyl.The eﬀect on polymerisation catalysis using the bia-ryl-bridged complexes with this ligand modiﬁcation is signiﬁcant as we transformed an inactive system to one that displays activity(albeit moderate)and also demon-strated that the catalyst is long lived.Application of this simple ligand modiﬁcation to the unbridged salicylaldimine systems did not lead to an in-crease in polymerisation catalyst lifetime at higher tem-peratures.At least two explanations are available which are consistent with observations to date.If imine reac-tivity is at the heart of the instability of the unbridged systems,then the lack of success in inhibiting1,2-migra-tory insertion by our method might be traced to the dif-ferences in precatalyst structure detailed in Section2.13. If on the other hand,loss of a salicylaldimine ligand(e.g. via transfer to aluminium from MAO)causes catalyst death,then this steric modiﬁcation would not be ex-pected to make a signiﬁcant diﬀerence.We note the growing body of evidence for the latter picture,such as the relatively poor polymerising capabilities of mono-salicylaldimine complexes[19]and improved sta-bility of more electron-rich phenolate systems[20].5134P.D.Knight et al./Journal of Organometallic Chemistry690(2005)5125–5144。

阅读真题单词及长难句整理 - 学生用

2005 TEXT1a fat pay rise 工资大涨colleague n. 同事slack v. 放松，松懈outrage n/v. 愤怒，愤慨，暴行good-natured adj.和蔼的，和善的tardily adv. 缓慢地，拖延地stagnant adj. 停滞的counterpart n. 副本，配对物，参照对象in exchange for 作为..的交换token n/v.象征，代币slice n.薄片v.切开，切成薄片adjoining adj.邻接的，毗邻的chamber n.小房间adj. 室内的，秘密的in return for 作为...的报答markedly 明显地，显著地，引人注目地luxury n.奢侈，奢华，奢侈品adj.奢侈的grievance n. 不满，不平，委屈v. grieve n. grieftoss n/v 投掷，投币（赌正反面）induce v. 诱导，引诱righteous adj. 正直的，正义的，公正的indignation n.愤慨，愤怒candidate n. 候选人Such characteristics make them perfect candidates for Dr. Brosnan‟s and Dr. de Waal‟s study.这些特性使它们成为。

理想的研究对象。

reluctant adj.不情愿的，勉强的And dead markets partly reflect the paralysis of banks which will not sell assets for fear of booking losses, yet are reluctant to buy all those supposed bargains.paralyze v.使瘫痪(2010 text 4) 死寂的市场一定程度上反映了瘫痪的银行由于怕账面损失既不愿出售资产，也不愿意去购买那些看似不错的廉价资产。

灯泡贯流式机组一、二次冷却水混合利用探索

２０２０年第３期２０２０Ｎｕｍｂｅｒ３水电与新能源ＨＹＤＲＯＰＯＷＥＲＡＮＤＮＥＷＥＮＥＲＧＹ第３４卷Ｖｏｌ.３４ＤＯＩ:１０.１３６２２/ｊ.ｃｎｋｉ.ｃｎ４２－１８００/ｔｖ.１６７１－３３５４.２０２０.０３.００６收稿日期:２０１９－０９－１９作者简介:张㊀鑫ꎬ男ꎬ工程师ꎬ主要从事水电站机械设备维护管理工作ꎮ灯泡贯流式机组一㊁二次冷却水混合利用探索张㊀鑫(四川嘉陵江桐子壕航电开发有限公司ꎬ四川武胜㊀６３８４００)摘要:以桐子壕航电枢纽灯泡贯流式水轮发电机组冷却水系统改造为例ꎬ分析探索将传统的一㊁二次冷却水进行混合利用的可行性及效果ꎮ改造效果表明ꎬ这种新型混合冷却方式不仅能显著降低发电机运行温度ꎬ延长主设备使用寿命ꎬ还能有效保护换热设备ꎬ防止水生物大量繁殖堵塞管道ꎬ成功解决了大型灯泡贯流式水轮发电机组普遍存在的冷却效果差的问题ꎮ关键词:灯泡贯流式机组ꎻ混合利用ꎻ冷却水ꎻ温度ꎻ桐子壕航电枢纽中图分类号:ＴＭ３１２㊀㊀㊀文献标志码:Ｂ㊀㊀㊀文章编号:１６７１－３３５４(２０２０)０３－００２３－０３ＭｉｘｅｄＵｔｉｌｉｚａｔｉｏｎｏｆＰｒｉｍａｒｙａｎｄＳｅｃｏｎｄａｒｙＣｏｏｌｉｎｇＷａｔｅｒｉｎＢｕｌｂＴｕｂｕｌａｒＵｎｉｔｓＺＨＡＮＧＸｉｎ(ＳｉｃｈｕａｎＪｉａｌｉｎｇＲｉｖｅｒＴｏｎｇｚｉｈａｏＮａｖｉｇａｔｉｏｎ￣ｐｏｗｅｒＤｅｖｅｌｏｐｍｅｎｔＣｏ.ꎬＬｔｄ.ꎬＷｕｓｈｅｎｇ６３８４００ꎬＣｈｉｎａ)Ａｂｓｔｒａｃｔ:Ｉｎｔｈｅｒｅｎｏｖａｔｉｏｎｏｆｔｈｅｃｏｏｌｉｎｇｗａｔｅｒｓｙｓｔｅｍｉｎｂｕｌｂｔｕｂｕｌａｒｈｙｄｒｏ￣ｔｕｒｂｉｎｅｇｅｎｅｒａｔｏｒｕｎｉｔｓｉｎＴｏｎｇｚｉｈａｏＮａｖｉ￣ｇａｔｉｏｎ￣ｐｏｗｅｒＪｕｎｃｔｉｏｎꎬａｎｏｖｅｌｍｉｘｅｄｕｔｉｌｉｚａｔｉｏｎｓｃｈｅｍｅｏｆｔｈｅｐｒｉｍａｒｙａｎｄｓｅｃｏｎｄａｒｙｃｏｏｌｉｎｇｗａｔｅｒｉｓｅｘｐｌｏｒｅｄ.Ｐｒａｃｔｉ￣ｃａｌｐｅｒｆｏｒｍａｎｃｅｓｈｏｗｓｔｈａｔｔｈｉｓｎｅｗｍｉｘｅｄｃｏｏｌｉｎｇｍｏｄｅｃａｎｎｏｔｏｎｌｙｓｉｇｎｉｆｉｃａｎｔｌｙｒｅｄｕｃｅｔｈｅｏｐｅｒａｔｉｎｇｔｅｍｐｅｒａｔｕｒｅｏｆｔｈｅｇｅｎｅｒａｔｏｒｓａｎｄｅｘｔｅｎｄｔｈｅｓｅｒｖｉｃｅｌｉｆｅｏｆｔｈｅｍａｉｎｅｑｕｉｐｍｅｎｔꎬｂｕｔａｌｓｏｅｆｆｅｃｔｉｖｅｌｙｐｒｏｔｅｃｔｔｈｅｈｅａｔｅｘｃｈａｎｇｅｅｑｕｉｐ￣ｍｅｎｔａｎｄｐｒｅｖｅｎｔｔｈｅｍａｓｓｐｒｏｐａｇａｔｉｏｎｏｆａｑｕａｔｉｃｏｒｇａｎｉｓｍｓｆｒｏｍｂｌｏｃｋｉｎｇｔｈｅｐｉｐｅｌｉｎｅｓ.Ｔｈｅｐｒｏｂｌｅｍｏｆｐｏｏｒｃｏｏｌｉｎｇｅｆｆｅｃｔｔｈａｔｉｓｃｏｍｍｏｎｆｏｕｎｄｉｎｌａｒｇｅ￣ｓｃａｌｅｂｕｌｂｔｕｂｕｌａｒｈｙｄｒｏ￣ｔｕｒｂｉｎｅｇｅｎｅｒａｔｏｒｕｎｉｔｓｉｓｓｏｌｖｅｄｓｕｃｃｅｓｓｆｕｌｌｙ.Ｋｅｙｗｏｒｄｓ:ｂｕｌｂｔｕｂｕｌａｒｕｎｉｔꎻｍｉｘｅｄｕｔｉｌｉｚａｔｉｏｎꎻｃｏｏｌｉｎｇｗａｔｅｒꎻｔｅｍｐｅｒａｔｕｒｅꎻＴｏｎｇｚｉｈａｏＮａｖｉｇａｔｉｏｎ￣ｐｏｗｅｒＪｕｎｃｔｉｏｎ㊀㊀灯泡贯流式水轮发电机组具有效率高㊁体积小㊁造价低㊁建设开挖量少等众多优点ꎬ是开发低水头水力资源的一种良好机型ꎬ被广泛用于低水头电站ꎮ随着制造技术的不断提高与完善ꎬ灯泡贯流式水轮发电机组单机容量不断增大ꎬ目前世界上单机容量最大的灯泡贯流式机组已经达到７５ＭＷꎮ发电机的绝缘受温度影响很大ꎬ随着机组容量的不断增大ꎬ发电机的冷却成为一个难以忽视的技术难题ꎮ由于灯泡贯流式水轮发电机为卧式布置ꎬ且完全淹没在流道中ꎬ出于水力设计方面的考虑ꎬ其发电机尺寸不能设计得过大ꎬ且结构紧凑ꎬ这给发电机的冷却带来了不小的困难ꎮ１㊀大型灯泡贯流式机组常见冷却方式[１－２]灯泡贯流式水轮发电机组传统的冷却水方式主要有以下两种:一种是二次冷却水模式ꎬ即密闭循环水冷却模式(见图１)ꎮ冷却发电机后产生的热空气经空气冷却器传递给循环冷却水ꎬ循环冷却水再通过水－水冷却器(灯泡贯流式机组锥体冷却套或外置式水冷却器)把热量传递至与之外表面接触的河水带走ꎮ该冷却方式因循环水水质良好ꎬ在管道内部不会产生堵塞现象ꎮ但由于水－水冷却器外表面经常被水生物及其他杂物覆盖ꎬ且容易结垢ꎬ散热效果不佳ꎬ特别是环境温度较高时对于大容量机组冷却效果不够理想ꎮ另一种是一次冷却水模式ꎬ即非循环冷却模式(见图２)ꎮ在一次冷却水模式下ꎬ冷却发电机后产生的热空气由空气冷却器中的冷却水吸收ꎬ而该冷却水直接引用河水ꎬ将热量带走后直接排入河道ꎬ一次性使用ꎮ该冷却方式因河水温度较低ꎬ冷却效果好ꎬ但若水３２水电与新能源２０２０年第３期图１㊀二次冷却水原理图质差则易对设备产生损害ꎮ同时ꎬ直接引用河水会导致管道内引入大量蚌类水生物ꎬ此类水生物极易吸附在管壁上大量繁殖ꎬ使较小管径的空气冷却器管路产生堵塞ꎬ最终严重影响冷却效果ꎮ图２㊀一次冷却水原理图２㊀桐子壕灯泡贯流式机组冷却水系统改造情况２.１㊀工程概况四川嘉陵江桐子壕航电枢纽位于四川省武胜县境内的嘉陵江干流上ꎬ距武胜县城１２ｋｍꎬ多年平均气温１７.５ħꎬ系径流式低水头电站ꎬ电站装有３台单机容量３６ＭＷ的灯泡贯流式机组(东方电机有限公司生产)ꎮ电站基本参数如下:上游正常蓄水位２２４.００ｍꎬ死水位２２３.００ｍꎬ正常尾水位２１１.１０ｍꎬ额定水头１０ｍꎬ最大水头１４.８ｍꎬ最小水头４.２ｍꎬ加权平均水头１１.３ｍꎬ多年平均含沙量２.４１ｋｇ/ｍ３ꎬ过机平均含沙量１.０６ｋｇ/ｍ３ꎮ２.２㊀冷却系统概况桐子壕电站发电机采用密闭强迫自循环混合式通风系统ꎬ冷却水系统原设计为二次冷却水模式(密闭水循环方式)ꎬ经空气冷却器热交换后的热水进入锥形冷却套ꎬ利用河水将冷却套内的水冷却ꎬ再通过水泵加压后注入空气冷却器以构成水冷却循环系统ꎮ冷却水系统主要参数如下:设计水温３０ħꎻ二次循环水容量４ｍ３ꎻ二次循环水流量２３０ｍ３/ｈꎮ桐子壕电站３台发电机组自２００３年投产以来ꎬ定子线圈温度一直处于１１０~１３０ħ运行ꎮ投产初期ꎬ为解决定子线圈温度过高的问题ꎬ曾尝试将原设计的６台１１ｋＷ轴流风机全部更换为２２ｋＷ的轴流风机ꎬ但未能解决问题ꎮ机组定子线圈温度过高大大加快了机组的绝缘老化ꎬ减少机组的使用寿命ꎬ威胁到机组的运行安全ꎮ２.３㊀冷却系统改造过程通过对两种传统冷却方式的利弊分析ꎬ最终确定在桐子壕电站２０１０~２０１１年年度检修期间ꎬ对机组冷却方式进行改造ꎬ将传统的各有弊端的两种冷却方式进行优化组合ꎬ取长补短ꎬ合理切换ꎬ既可以有效控制发电机组定子线圈温度在合理范围内ꎬ同时最大限度保证了机组冷却系统的安全性㊁稳定性和可靠性(见图３)ꎮ图３㊀一㊁二次冷却水混合利用原理图经过改造ꎬ两种方式的冷却系统共存ꎮ二次循环冷却水经冷却水泵加压注入空气冷却器ꎬ经空气冷却器热交换后的热水进入锥体冷却套ꎬ利用河水将锥体冷却套内的水冷却ꎬ再进入冷却水泵加压构成水冷却循环系统ꎻ一次冷却水从上游流道直接取水ꎬ经冷却水泵加压㊁滤水器过滤后注入空气冷却器ꎬ经空气冷却器热交换后的热水直接排至流道ꎮ二者独立运行ꎬ可通过阀门进行合理切换ꎮ整个冷却水系统中设置有滤水器㊁水处理器㊁电磁流量计和压差开关等设备ꎬ可分别用于滤除冷却水中较大的杂质ꎬ防止管路及设备内壁４２张㊀鑫:灯泡贯流式机组一㊁二次冷却水混合利用探索２０２０年３月结垢ꎬ监测冷却水流量以及管路堵塞情况ꎮ２.４㊀改造效果说明桐子壕电站机组冷却水系统改造后ꎬ在使用一次冷却水时ꎬ空冷器进㊁出风温度均有较大幅度下降ꎬ进㊁出水温差也明显增大ꎬ显示热交换效率更高(见表１)ꎮ表１㊀不同冷却方式下空冷器相关温度对比表ħ㊀冷却方式空冷器平均进风温度空冷器平均出风温度冷㊁热风平均温差空冷器平均进水温度空冷器平均出水温度进㊁出水平均温差二次水６２.８６４８.５５１４.３１４２.１６４３.９８１.８３一次水５０.３７３４.７６１５.６１２７.２０３０.５５３.４１㊀㊀经统计ꎬ机组改造后定子线圈温度较改造前约降低１５~２０ħꎮ图４为改造前后机组满负荷运行时定子线圈最高温度对比(环境温度相近)ꎮ可见ꎬ此次技改显著降低了机组定子线圈温度ꎮ图４㊀技改前㊁后定子最高温度对比图桐子壕电站机组冷却水系统改造后已经安全稳定运行８年时间ꎮ期间ꎬ即使在环境温度超过４０ħ的超高温季节ꎬ发电机依然可以维持在较低温度运行ꎻ经多年运行ꎬ也未出现空冷器堵塞㊁管路明显磨损等现象ꎮ实践证明ꎬ此次改造是成功的ꎮ３一㊁二次冷却水混合利用的优势及前提由于我国南方地区大部分河流中均生存有一种名叫淡水壳菜的蚌类水生物ꎬ此类水生物由于其繁殖速度惊人ꎬ并且吸附在物体表面的牢固程度很高ꎬ常常使机组安全运行受到威胁ꎬ尤其是在管路系统中ꎬ该类水生物的大量繁殖会使冷却系统供水困难ꎬ有时迫使机组停机ꎬ进行管路的清理工作ꎮ根据一些科研单位和电站的研究和实践ꎬ已初步摸清有关此类水生物的生长规律ꎬ此类水生物依靠自身分泌的足丝牢牢地附生在物体上ꎬ形成层层堆叠的群体ꎬ它最适宜的生活条件是水流速度不大(如阀门背水侧㊁管路拐弯处等)和水温在１６~２５ħ的地方ꎬ当水温超过３２ħ时ꎬ便不易生存[３]ꎮ由于二次冷却水为循环利用ꎬ水温将明显高于该类水生物的生存环境温度ꎮ通过合理切换ꎬ可以直接将一次冷却水中引进的蚌类水生物杀死ꎬ使其脱落ꎬ防止水生物在管道内大量繁殖ꎬ从而有效避免了管道堵塞ꎮ此外ꎬ由于一㊁二次冷却水供水设备及供水对象均为共用ꎬ在传统的单一冷却水模式基础上仅需增加取㊁排水管路ꎬ设备布置集中ꎬ造价低ꎬ施工及运行维护方便ꎮ为达到预期冷却效果ꎬ同时维持设备安全稳定运行ꎬ需制定相应的运行规程ꎮ在实际应用中ꎬ两种冷却方式切换的合理性是达到预期目标的最大保障ꎮ为此ꎬ桐子壕电站在运行规程中作出如下规定:一㊁二次冷却水系统的启用主要取决于环境温度ꎬ当环境温度低于３０ħ时ꎬ使用二次密闭循环冷却水系统ꎻ当环境温度长时间高于３０ħ时ꎬ经批准后ꎬ切换为一次冷却水系统运行ꎮ此外ꎬ当洪水来临时ꎬ由于水中泥沙含量及漂浮物大幅度增加ꎬ同时由于流量较大时水头较低ꎬ机组无法满负荷运行ꎬ自身发热不高ꎬ此时切换为二次冷却水系统运行ꎬ避免水质差对设备产生磨损ꎮ４㊀结㊀语目前国内大中型贯流式水轮发电机组普遍存在发电机温度过高(二次冷却水)㊁冷却水系统管网水生物堵塞及设备磨损严重(一次冷却水)等情况ꎮ针对以上这些问题ꎬ大多数机组利用机组年度检修时进行清理等方法来改善ꎬ但是此法耗时耗力ꎮ若机组正常运行过程中因这些问题导致机组被迫降低负荷或停机ꎬ更将造成巨大的经济损失ꎮ为解决现有技术的上述缺点ꎬ就急需一种冷却效果好㊁可靠性高ꎬ并能有效克服上述不足的冷却方式ꎮ该技术方案能很好地克服传统冷却方式的不足ꎬ且安装维护方便㊁造价低廉ꎬ便于在行业内推广ꎮ目前ꎬ由桐子壕电站冷却水系统技改为基础延伸的灯泡贯流式水轮发电机组一㊁二次冷却水混合利用系统已获国家发明专利授权(专利号:ＺＬ２０１２１０１９０４４３.２)ꎬ有望为行业中普遍存在的灯泡贯流式水轮发电机组冷却效果不佳的问题提供一个普遍性的解决方案ꎮ参考文献:[１]陈梁年ꎬ刘玲.大型灯泡贯流机组研制的若干技术问题[Ｊ].水电站机电技术ꎬ２００１ꎬ２４(４):２９－３３[２]龙海军ꎬ耿清华.循环冷却水技术供水系统在某水电站的设计及应用[Ｊ].吉林水利ꎬ２０１４(２):５０－５２ꎬ５９[３]水电站机电设计手册编写组.水电站机电设计手册水力机械[Ｍ].北京:水利电力出版社ꎬ１９８３５２。

Realization of Voevodsky's motives

2.2 Review of mixed realizations . . . . . . . . . . . . . . . . . . 27
2.3 The mixed realization functor . . . . . . . . . . . . . . . . . . 30
3 The motive of BGL
The main aim of the present article is to provide the expected functor between the two sides. More precisely, we construct a realization functor from Voevodsky's triangulated category of geometrical motives (which should be thought of as the derived category of mixed motives) to the \derived category" of mixed realizations which we constructed in Hu1]. Indeed, most of the present article is a follow-up of loc. cit. where the realization functor was constructed on the category of simplicial varieties. As a direct corollary we also obtain realizations functors to continuous l-adic cohomology and to absolute Hodge cohomology. Their existence is not a surprise (cf. Vo2]) but was not in the literature yet.

爱默生

core of his thinking, and include such well-known essays as Self-Reliance, The Over-Soul, Circles, The Poet and Experience. Together with Nature, these essays made the decade from the mid-1830s to the mid-1840s Emerson's most fertile period.
Pቤተ መጻሕፍቲ ባይዱge 3
A brief introduction of Ralph Waldo Emerson
his distrust of democracy, romantic belief and his h i g h l y in the power of the individual. Emerson's friendship with Carlyle was both lasting and significant; the insights of the British thinker helped Emerson formulate his own philosophy.
Nature, Emerson believed, was often overlooked and taken for granted by the masses. He believed mankind toiled and suffered in their desire for material pursuits, when happiness could be achieved by living a simple life.

LasPinas-ZapoteRiverSystem：拉斯皮尼亚斯萨波特水系

Las Pinas-Zapote River SystemRehabilitation Program, PhilippinesBackground/ContextRapid increases in population and commercial activity have brought about concomitant environmental problems, and water and air pollution have become a great chall enge to the lead ers of Las Pinas City in the Philippines.Las Pinas has two major river systems: the Las Pinas River and the Zapote River. The Zapote River spans 18.3 kilometers, whil e the Las Pinas River runs 12.6 kilometers mostly through the interior of the city into Manila Bay. The two are linked by 25.1 kilometers of tributaries.As late as the mid-1970s, the river was teeming with freshwater fish and edibl e snails. It was a popular place for picnics. Las Pinas woul d not have been known for the whiteness of its saltproduce had the watersbeen less than pristine.As Manila began to spreaditself as a metropolis,industrial areas were firstpushed outsid e itsconfines to the outer rim.The first casualty of this industrial push was the salt beds. As Metro Manila took its place as one of the worl d's most populated mega-cities, the industrial areas were again pushed towards the south, l eaving the Las Pinas area as valuabl e suburbia. Domestic wastes were freely dumped without any sewage treatment into the rivers, until the waters turned dark, fetid, and dangerous.Pollution caused by the dumping of various waste products kill ed the marine life in the rivers of Las Pinas and turned it into a vast fl oating garbage bin – unsightly, filthy and smelly. What used to be a source of life turned into a source of disease. A larger problem came regularly – fl oods.Many peopl e in Las Pinas shrugged their should ers at the fact that their rivers were moribund, feeling this was the price of progress. After all, they had seen how the two other major rivers of Metro Manila had died: the Pasig and Potrero Rivers had l ong l ost any claim to life.The heavily silted and rivers in Las Pinas City became id eal dumping sites for all types of waste by the public, exhibiting a lack of concern for the environment.Disease-carrying organisms feeding on d ecomposing uncoll ected garbage within the erod ed riverbanks, and fl oods became threats to the life and health of the peopl e, especially women and children.Congressional Representiative Cynthia Villar was one of the few who believed that the environment shoul d not be the sacrificial lamb at the altar of progress and d evel opment. She believed that the Las Pinas and Zapote Rivers coul d be revived. Unfortunately, there was no mod el for success in the rehabilitation of a river in Metro Manila.As Representative of the Lone District of Las Pinas City to Congress for nine years, Cynthia A. Villar was one of the few who believed that the environment should not be the sacrificial lamb at the altar of progress and d evelopment. She believed that the Las Pinas and Zapote Rivers could be revived. She d ecid ed to d evel op and impl ement a comprehensive management scheme for the rehabilitation of the Las Pinas-Zapote river system.The Las Pinas-Zapote River System Rehabilitation ProjectRepresentative Cynthia Villar launchedthe Sagip Ilog project to bring life backinto the rivers of Las Pinas. Theprogram was launched on December13, 2002 with Senator Manny Villard onating a backhoe on a barge, aspeedboat and a dump truck tocelebrate his birthday.Within the 56-kilometer stretch of thisriver system, 30 kilometers are beingregularly cl eaned. This involves daily coll ection of floating garbage, as well as the installation of 5 units of steel garbage traps/wire mesh strainers in the Las Pinas and Zapote rivers to filter the waste/d ebris.Training and Information, Education and Communication (IEC) on River Rehabilitation and ProtectionFrom 2002 to 2005, 9,070 resid ents from various communities along the river system in Las Pinas City, Paranaque City and Bacoor, Cavite were trained on ecol ogical solid waste and river management. Some of them were d esignated river watch volunteers, grouped into 98 teams with 3,576 members. This und ertaking has been the commitment of the Couples for Christ-Oikos Ministry volunteers who, since June 2003, have d evoted every Saturday conducting values formation and solid waste management education for the Las Piñas resid ents. They were trained on ecol ogical solid waste management as an important component of the program. Some of them became river watch volunteers.The l ocal government officials andnearby communities activelyparticipated in the information driveand capacity buil ding activities. Of the9,070 resid ents who attend ed thetraining seminars on rivermanagement, 62% were female whil e32% were mal e. Of those who wered esignated river watch volunteers tomonitor illegal acts within the projectsites, 56% were mal e and 44% were female.To date, there are 3,120 trained and active volunteers. The volunteers were organized into different river watch teams in the areas that bord er on the rivers: 174 teams in Las Piñas, 31 in Paranaque, and 55 in Cavite.Urban Forestry Development: The BambusetumsIn 2001, the Coastal Environment Program of the Department of Environment and Natural Resources-National Capital Region (DENR-NCR) replanted bamboo species, l ocally known as kawayang tinik, to rehabilitate the Marikina and Las Pinas Rivers. These rivers which are both situated in Metro Manila are major contributors to the rapid environmental d egradation of Manila Bay.During the project, one kilometer of theLas Pinas riverbank in Barangay(village) Aldana was replanted with 500culms of the above-stated bamboospecies. The 100 bamboo culms thatsurvived grew alongsid e existingmangroves in the area because theplanting site was near the river mouthtowards the Bay.This inspired Congresswoman Cynthia Villar to replicate the said effort within the Las Piñas riverbank in Barangay Pulang Lupa I, just opposite Brgy. Al dana.Five kilometers of the said river system were targeted for re-greening using bamboos, mangroves and other related species for soil erosion control. To highlight this effort, two separate portions of the riverbanks were d eveloped into “bambusetums”, planted with various species of end emic/exotic bamboos.Re-greening of the river banks minimized soil erosion that caused siltation of the river system. The two established bambusetums, the first in Metro Manila, are id ealfor educational and scientific purposes. The propagation of culms from the 37 species of bamboos available in the area, have been sources of income through the harvesting of matured pol es, sol d to interested handicraft/furniture makers. This is asid e from the jobs provid ed by the program to some 62 workers for the river dredging, cl ean-up, and re-greening activities.The re-greening effort has been sustained by replicating the established bamboo plantation strips within the remaining d enud ed portions of the riverbanks. The Sagip Ilog(river rehabilitation) personnel, who were previously trained by the DENR on bamboo propagation and management, coul d already produce culms and cuttings from matured bamboo clumps and bougainvill ea, respectively. As of August 2010, 10,000 bamboo culms are already planted on the riverbanks measuring 20 kilometers.The Las Piñas City Government through its Environmental Sanitation Center has passed in 2005 the institutionalization of sl ope protection through the approval of City Ordinance No. 658-05.Social Enterprises from River Rehabilitation and Waste ManagementSeveral related social enterprises have sprung from the river rehabilitation initiative: Composting or production of organic fertilizer from wet garbage: Each of the 20 barangays in Las Pinas City now has at l east one composting facility. One rotary composter can process the wet garbage of around 500 families or househol ds (HHs). There are now 37 composters in the city for 18,500 households. By year-end, the number is expected to increase to 50 serving 25,000 househol ds; in three years, 100 composting facilities for al l of Las Piñas City’s 50,000 households. Each composting machine produces 10 sacks of 40 kilograms of compost or 400 kil ograms a week, so that the 37 machines produce 14,800 kilograms weekly for a total monthly production of 59,200 kilograms or 59.2 tons. The selling price of compost is currently at PhP100 per 40-kilogram sack.Since July 2007, vermi-composting isnow being d one in two barangays:Pampl ona 2 and Talon 2, both on acommercial l evel for ad ditional incomeof the resid ents. Producing 400kilograms a week, each l ocation sellstheir produce to farmers in a nearbyprovince as alternative fishmeal asid efrom organic fertilizer. It helps reducethe amount of biod egradabl e waste andcontributes to the promotion of organic farming. This process involves the conversion of waste from households into organic fertilizer through the digestive action of earthworms.On August 12, 2010 a “re-cycling day” was launched in five barangays, engaging resid ents to sell their recyclabl es to junkshop owners. There is now a monthly “re-cycling day” in all 20 barangays of the city.The purchase of a plastic pulverizing machine is und erway to crush non-biod egradabl e materials into powd er form to be sol d to manufacturers of pavers and holl ow bl ocks. This will significantly reduce garbage and provid e income to l ocals.Making of Christmas lanterns and other decorative items from bamboo, capiz shells and other materials that are endemic to the city; the parols (lanterns) makeuse of bamboo for frames. The supply ofbamboo is assured by the thrivingbamboo plantation along the river banksand some vacant l ots in the city throughthe Bambusetum project and thePagtatanim para sa Kinabukasan(“planting for the future”) program.In July 2007, a Certificate ofStewardship was award ed to the parolmakers, giving them joint responsibilityfor the management of thebambusetum, together with the Office ofCongresswoman Villar. This was a joint venture of the DENR and the Sagip Ilog project of Congresswoman Villar. Bamboo culms were also given to the group in the same year.Weaving of baskets from water lilies that posed a problem to the river’s ecosystem and caused fl ooding in the city; water lily stalks are now used as the primary raw materials in the Las Pinas Basket Weaving Center. Started in October 2005, hundreds of families have benefited from the program from villages all over the country.Production of coco nets and coco peatfrom coconut husks that were justthrown into the river; a d ecorticatingmachine shreds the coconut husks l eavingtwo distinct forms: a fiber used formanufacture of coco coir for sl opeprotection and a granular form, a pottingmedium to enrich soil.。

Rump-Parliment

T he Rump Parliament is the name given to the Long Parliament after Pride's Purge ofDecember 1648 in which those MPs who sought a negotiated settlement with King Charles I were forcibly expelled by the New Model Army. The Rump regarded itself as the lawful Parliament of the Commonwealth of England but the derisive name first used widely in 1660 became its enduring nickname after the Restoration.After the purge of December 1648, the Rump Parliament consisted of around eighty MPs. Supported by the New Model Army, the Rump declared itself "the supreme power in this nation" on 4 January 1649 with authority to pass Acts of Parliament without the consent of the King or the House of Lords. One of its first actions was to set up the High Court of Justice, specially convened for the trial of King Charles I.During the weeks between Pride's Purge and the King's execution, approximately 100 MPs who were not on the list of proscribed members stayed away from Parliament in order to avoid involvement in the trial and regicide. Many returned to Westminster when the Commonwealth was established. During February 1649, around eighty MPs were re-admitted upon registering their dissent to the vote of 5 December 1648 to continue negotiations with the King. The re-admitted MPs assumed that their absence during December and January would absolve them of complicity in the regicide. Of the 470 MPs elected to the Long Parliament, around 200 sat in the Rump Parliament between Pride's Purge and Cromwell's dissolution of Parliament in April 1653, including significant numbers of Presbyterians. Sixty or seventy Members attended Westminster regularly during this period.Within days of the King's execution, the Rump Parliament resolved to abolish both the House of Lords and the institution of monarchy itself. England was declared a republican "Commonwealth and Free State" on 19 May 1649. During the early 1650s, attempts were made to incorporate Scotland and Ireland into the Commonwealth with England. Under the Commonwealth régime, and under Cromwell's Protectorate after 1653, the three nations were ruled by a single government for the first time in British history.The Rump Parliament had unprecedented legislative and executive powers. It was solely responsible for governing the nation without the traditional hierarchy of nobles, princes and bishops. Much of its administrative work in central and local government was carried out through the network of committees and commissions that had been established during the early 1640s. T he Council of State was appointed in February 1649 to implement domestic and foreign policy and to ensure the security of the nation. It was stressed that the executive Council of State was subordinate to the legislature, the House of Commons, which remained the supreme authority in the nation.Following the trauma of Pride's Purge and the King's execution, the Rump Parliament adopted a conciliatory and cautious approach towards policy and legislation, particularly after the re-admission to Parliament of moderate MPs who had stayed away to avoid involvement in the regicide. Radicalism was discouraged in order to appease moderate and Presbyterian opinion in the nation as a whole, which might otherwise tend to favour the Royalists. After the final defeat of the Royalist cause at the battle of Worcester in 1651, the Rump came under the scrutiny of the Army radicals and quickly grew to resentwhat it regarded as the Army's unwarranted interference in the political process.T HE C HURCHThe Rump Parliament was widely expected to introduce immediate and radical changes in the Church but few concessions were made to the radicals who wanted universal toleration for the Protestant sects, and steps were taken to curb the excesses of Millenarians and Ranters. With the disappearance of the old Church courts, moral offences were made into secular crimes. The Adultery Act of May 1650 imposed the death penalty for adultery and fornication (though this was never applied in practice); the Blasphemy Act of August 1650 was aimed at curbing extreme religious "enthusiasm". Censorship was imposed in order to limit the propagation of millenarian pamphlets and the first government journal giving the official version of events was published. Although observance of the Sabbath was enforced, there were also concessions towards freedom of worship when the statute that required compulsory attendance at Church was repealed in the T oleration Act of September 1650. This statute, which dated back to the reign of Elizabeth I, had been a mainstay of the power of the Anglican bishops.The process of establishing a Presbyterian church settlement in England, which had started with the Scottish alliance of 1643, slowed to a halt. In an attempt to regulate the clergy and to establish acceptable doctrine, a Committee for the Propagation of the Gospel was proposed to control the appointment of clergy so that only approved ministers were licensed to preach. The propagation scheme was pursued in Wales and northern England, which Puritans regarded as strongholds of Anglican and Catholic influence. Measures for the propagation of the gospel in New England and Ireland were also passed in 1649 and 1650, but discussion of a general propagation Act for the whole of England proceeded slowly. A committee was appointed to consider the proposals for a general religious settlement put forward by the distinguished divine Dr John Owen, but no conclusions had been reached by the time that Cromwell dissolved the Rump in April 1653.Although a commission was established to review parish livings, the problem of funding clergymen was never settled by the Rump. The ancient and controversial system of tithes, under which parishioners were compelled to pay a portion of their income towards the upkeep of the minister, remained in place despite demands from the radicals for its removal.T HE L AWDemands for reform of the law were made by sectarians, the Levellers and the Army radicals. Lawyers were widely despised as corrupt; the central courts, especially that of Chancery, were overworked; the entire legal system was over-complex, slow and prohibitively expensive. Radicals regarded the law as the "Norman Y oke" that had oppressed England since the days of William the Conqueror and called upon Parliament to simplify arcane legal procedures and to curb the power of lawyers by excluding them from Parliament."Commonwealthsmen" like Ludlow, Ireton and Marten regarded a rationalised legalsystem as an integral part of their reform programme. In January 1652, a 21-man commission chaired by the distinguished lawyer Matthew Hale was appointed to investigate legal reform. However, despite a wide-ranging set of proposals for the removal of abuses and for a partial reconstruction of the court system, only minor reforms were ever enacted by Parliament that fell far short of the changes envisaged by the radicals. Common-law courts were empowered to grant probate of wills, which had formerly been a function of Church tribunals; more lenient punishments for debtors were introduced; the special privileges of peers and MPs before the law were removed; the use of English in legal proceedings rather than Latin was authorised. Little was done to reduce legal fees or to provide easier access to the courts.The failure of the reform movement was widely attributed to the malign influence of lawyer-MPs who were reluctant to make changes likely to weaken their privileged position. The conservative Bulstrode Whitelocke MP, one of the commissioners of the Great Seal, was prominent in opposing moves towards radical legal reform.F INANCEThe Rump inherited a large financial deficit from the Long Parliament and finance remained at the heart of the government's problems throughout the Commonwealth period. The two principal means of raising revenue introduced by the Long Parliament were continued by the Rump: an assessment tax on property owners and a general excise duty on goods and commodities. Both these taxes were extremely unpopular. The government claimed that without them, it would be necessary to impose free quarter of soldiers on the civilian population.Finance was also raised by continuing the process of "compounding" whereby the former owners of confiscated Royalist estates were allowed to buy their property back from the government. This proved counter-productive because it caused resentment against the Commonwealth and discouraged reconciliation with the Royalists. In order to raise security for loans from the City of London, the government began selling off former Church and Crown lands from April 1649.Owing to the expense of military campaigns in Ireland and Scotland (1649-51), as well as the Anglo-Dutch war(1652), and the need to maintain a powerful army and navy to defend the Commonwealth, Parliament remained short of money. T axation reached record levels and was deeply resented. The demands of war and the maintenance of national security diverted Parliament's time and resources from the implementation of many proposed social reforms, to the disgust of radicals outside Parliament.F OREIGN P OLICYThe execution of King Charles horrified governments throughout Europe. No foreign power was prepared to recognise the Commonwealth and there was every possibility of foreign intervention in helping the Stuarts to regain the throne. In 1649, Parliament controlled only England and Wales; Scotland declared its allegiance to Charles II and most of Ireland was in Royalist hands. Colonial settlements in Virginia, Maryland and Barbados remained Royalist; the Scillies, the Channel Islands and the Isle of Man wereused as bases for Royalist privateers to prey upon Commonwealth shipping, and a privateering squadron commanded by Prince Rupert began operating from Kinsale in southern Ireland in February 1649.Leaders of the Rump recognised that the key to the survival of the Commonwealth was a strong navy to complement the New Model Army. The office of Lord High Admiral was abolished and the powers of the Navy Committee were increased. Sir Henry Vane came to dominate naval administration, while command of the fleet was given to joint "Generals-at-Sea" of proven loyalty and dedication to the Commonwealth. From March 1649, a major programme of shipbuilding was undertaken and by the end of 1651, twenty powerful new warships had been built and a further twenty-five had been bought or captured, almost doubling the size of the fleet.The Commonwealth navy provided vital support for Oliver Cromwell's invasions of Ireland and Scotland during the Third Civil War, which secured the Commonwealth government's control of the British Isles. General-at-Sea Robert Blake chased Rupert's squadron from Ireland to Portugal, and in 1650 Parliament authorised Blake to attack Portuguese shipping, which coerced King John of Portugal to abandon his support for Rupert and to officially recognise the Commonwealth. Spain expelled Royalist envoys and recognised the Commonwealth in December 1650, partly as a result of England's aggressive policy towards Spain's enemies Portugal and France. Outlying Royalist privateer bases were captured during 1651, and General-at-Sea George Ayscue subjugated Barbados and the American colonies early in 1652.France was slow to recognise the Commonwealth because of close family ties between the Stuart and Bourbon dynasties. Unofficial hostilities broke out between French and English shipping, and Royalist privateers were allowed to operate from French ports. In September 1652, Parliament ordered Blake to intervene in the Franco-Spanish war by attacking and destroying a French fleet sailing to relieve the siege of Dunkirk, which forced the town to surrender to Spain. Alarmed at England's increasing naval power, France came to terms and formally recognised the Commonwealth in December 1652. Despite apparent ideological similarities between the English Commonwealth and the United Provinces of the Netherlands, the First Anglo-Dutch war broke out in 1652 —largely a result of trade rivalry between the two nations.T op of PageD ISSOLUTION OF THE R UMP P ARLIAMENT 1653The Rump Parliament was not intended to be a permanent body. It regarded itself as an interim government with responsibility for preparing the way for a new representative. Oliver Cromwell's decisive victory at the battle of Worcester in September 1651 ended any direct Royalist military threat to the Commonwealth and it was expected that elections would soon take place. However, Parliament was divided over the form that the new representative should take. Sir Henry Vane and his supporters proposed a redistribution of constituencies but with sitting members of the Long Parliament retaining their seats and further "recruiter" elections to fill the vacant places; Oliver Cromwell and the Council of Officers criticised Vane's scheme for promoting theself-interest of sitting MPs and demanded a general election for an entirely new Parliament.A committee to supervise the drafting of plans for new elections was set up soon after Cromwell's return to Parliament after Worcester. A date was finally set for Parliament's dissolution, but MPs were easily distracted from further preparations for the new representative, particularly after the outbreak of the Anglo-Dutch War in May 1652. During the early months of 1653, tension between Parliament and the Army increased. At a conference between Army officers and MPs at Whitehall on 19 April 1653, Cromwell proposed that the parliamentary system be temporarily suspended and replaced with an interim council of godly men to govern while final preparations for an election were put in place. The MPs present agreed to suspend discussion of the new representative at least until Cromwell's proposal has been debated. The following day, however, Cromwell was incensed to learn that discussion of the new representative was continuing in Parliament regardless.At 11 o'clock in the morning of 20 April 1653, Cromwell led a company of musketeers to Westminster. Having secured the approaches to the House, he addressed the Members, calmly at first, then with rising anger as he told them that their sitting was permanently at an end and they must leave. At Cromwell's signal, Lieutenant-Colonel Worsley marched in with the musketeers to drive out the MPs. Major-General Harrison is said to have personally pulled the Speaker of the House from his chair. After the Members had departed, the doors of the Parliament House were sealed and a wit pinned up a notice outside reading: "This House is to be let: now unfurnished."Cromwell's exact reasons for expelling Parliament at this time are unclear. The traditional view is that he had come to believe that Parliament was planning to perpetuate itself by adopting Sir Henry Vane's scheme to allow sitting MPs to remain and to fill vacant places with "recruiter" elections. This view has been questioned by historians in recent times, but no clear explanation of his actions has emerged. There were no plans for an alternative government in place and Cromwell made no attempt to take power himself.The Rump Parliament was replaced by the Nominated Assembly and other constitutional experiments of the 1650s.T op of PageT HE R UMP P ARLIAMENT RECALLED,1659After Oliver Cromwell's death in 1658, his successor Richard Cromwell was forced by Army officers to dissolve the Third Protectorate Parliament in April 1659. The officers, led by their commander-in-chief Charles Fleetwood, intended to keep Richard in power but dependent upon the Army. However, republican Commonwealthsmen were determined to bring the quasi-monarchical Protectorate to an end. They gained the support of junior officers and the rank-and-file of the soldiery by issuing tracts and pamphlets acclaiming the "Good Old Cause" and promising arrears of pay and religious liberty. Fleetwood and the Grandees were unable to resist the soldiers' demands for the return of the Commonwealth.On 5 May 1659, the Council of Officers resolved to recall surviving MPs of the Rump under certain conditions: the Protectorate Council and Upper House would be replaced with a Senate that would include army officers; MPs would grant freedom of worship and undertake to reform the law; Richard Cromwell's safety would be guaranteed. Having provided for new elections, Parliament was then expected to dissolve itself. Around fifty surviving members of the Parliament expelled by Oliver Cromwell in April 1653 duly re-assembled on 7 May 1659. Richard Cromwell made no appeal for support. His formal abdication was read in Parliament on 25 May, bringing the Protectorate to an end. Although welcomed by republicans and religious radicals, the reinstated Parliament did little to implement the promised reforms. It was determined above all to gain control of the Army. Several officers were appointed to the Council of State, but the Speaker was given power to grant commissions and promotions rather than Fleetwood and a committee was appointed to supervise the nomination of officers. Any officer whose loyalty was suspect could be cashiered without being heard by a court-martial.John Lambert, who had resigned in 1657 over the terms of the Humble Petition and Advice, was recalled to command of his regiment during the crisis that led to Richard Cromwell's resignation. Lambert quickly regained his former prominence and, as Parliament's most capable commander, led the troops that suppressed Booth's Uprising in August 1659. The following month, Lambert's officers stationed at Derby (possibly at Lambert's instigation) petitioned Parliament to implement the reforms promised in May, to guarantee that no officer would be dismissed without a court-martial and to restore Lambert himself to the rank of major-general. In a deliberate trial of strength, Parliament forbade further petitioning of Parliament, and, when this failed, revoked the commissions of nine senior officers, including Lambert, Disbrowe and Berry. A seven-man commission was appointed to replace Fleetwood as commander-in-chief. In response to this challenge, Lambert and the senior officers resolved to expel the Rump, as Oliver Cromwell had done in 1653.T wo loyal regiments were ordered to guard the Parliament House but on 13 October 1659, Lambert's troops encircled Westminster, blockaded all approaches by land and water and turned back MPs trying to reach the House. In order to avoid bloodshed, the Council of State ordered the guards at Westminster to stand down. The next day, Lambert ignored the Council's order to withdraw his troops from Westminster. The Council continued to sit until 25 October, then dissolved itself. A new Committee of Safety was hastily appointed as an interim government.Responding to Sir Arthur Hesilrige's call for support against Lambert and the senior officers, General George Monck, the commander-in-chief in Scotland, stepped in to demand Parliament's recall as the only legally constituted government. Lambert marched north to confront Monck in November 1659, but his troops were reluctant to fight their comrades in Monck's army. Hesilrige went to Portsmouth where the garrison mutinied in support of Parliament and vice-admiral Lawson brought the Channel fleet up to Gravesend, threatening to blockade London. Faced with almost universal opposition, the military junta collapsed and Fleetwood was obliged to recall the Rump Parliament, which resumed its sitting on 26 December 1659. MPs grateful for Monck's intervention appointed him commander-in-chief in England as well as Scotland. Lambert's supportersin the army were dismissed.In January 1660, at the invitation of Parliament, Monck marched for London. When Sir Thomas Fairfax emerged from retirement to declare his support for him, army support for Monck became unanimous. Monck arrived in London in February 1660 against a background of apprentice riots and widespread demands across the country for the return of the MPs expelled by Pride's Purge in December 1648. It was during this tumultuous period that the purged Parliament acquired its derisive and enduring nickname of the "Rump" of the Long Parliament. After initially supporting Parliament's orders to suppress the agitation, Monck agreed to support the re-admission of the excluded MPs under certain conditions: he was to be confirmed as commander-in-chief of the Army; a national Presbyterian church was to be established with toleration of separatist groups; Parliament should dissolve itself and call new elections.On 21 February 1660, Monck reversed Pride's Purge by securing the re-admission of the excluded MPs and the final session of the Long Parliament began. After some debate, Monck's conditions were met. The restored Long Parliament voted to dissolve itself on 16 March 1660 and to call new elections. The pro-Royalist Convention Parliament duly assembled on 25 April 1660.[文档可能无法思考全面，请浏览后下载，另外祝您生活愉快，工作顺利，万事如意!]。

水果型番木瓜组织培养的研究

水果型番木瓜组织培养的研究谢恩倍;欧善生;姚军;石梅娟;梁盛;朱国兵;闵华;赵广存【摘要】[目的]研究水果型番木瓜的组织培养.[方法]以经预处理的种子为试材,通过MS基本培养基附加不同浓度的6-BA和IBA,对水果型番木瓜组培快繁技术进行了研究.[结果]无菌条件下用75%酒精均匀擦拭水果型番木瓜果皮表面,取出种子,用无菌水冲洗3次是较好的灭菌方法,种子污染率仅为2.52%;水果型番木瓜种子经1 000 mg/L GA3+1 mg/L 6-BA(等体积混合)浸泡18 h后接种于MS培养基中培养,种子发芽率、胚芽长度、胚根长度和苗高达到较高值,分别为68.42%、2.25 cm、0.80 cm和1.52 cm,幼苗整体生长较好;继代增殖培养基为MS+0.5 mg/L 6-BA+0.1 mg/L IBA时增殖系数最高(7.92),幼苗长势较好;组培苗玻璃化随着光照强度的增强而呈减弱趋势,3 000 lx处理下玻璃化苗比率最低(3.21%).[结论]该研究为水果型番木瓜的组培快繁研究提供了参考.【期刊名称】《安徽农业科学》【年(卷),期】2010(038)028【总页数】3页(P15495-15497)【关键词】番木瓜;种子;GA3;6-BA;组培【作者】谢恩倍;欧善生;姚军;石梅娟;梁盛;朱国兵;闵华;赵广存【作者单位】广西农业职业技术学院,广西南宁,530007;广西农业职业技术学院,广西南宁,530007;广西农业职业技术学院,广西南宁,530007;广西农业职业技术学院,广西南宁,530007;广西农业职业技术学院,广西南宁,530007;广西农业职业技术学院,广西南宁,530007;广西农业职业技术学院,广西南宁,530007;广西农业职业技术学院,广西南宁,530007【正文语种】中文【中图分类】S661.6番木瓜(Carica papaya L.)是一种广泛分布于世界热带、亚热带地区的多年生常绿果树作物，具有重要的食用和工业价值。