【文章內容簡介】 ighthanded and lefthanded forms of some organic pounds, which shows in the face development of crystals(enantiomorphism) and in the power of solutions to rotate the plane of polarization of a transmitted beam of polarized light either to the right to the left(optical activity).碳原子的四個價鍵都指向正四面體的四角這一概念，是1874年由范托夫和賴貝爾各自分別提出的，以解釋某些有機化合物的右旋體或左旋體的存在，它們的存在表現(xiàn)在晶面的發(fā)展(對映形態(tài))和溶液把透入的偏振光束的偏振面向右或向左旋轉的能力(旋光性)上。(同位語從句采用倒譯法， ；定語從句譯成并列分句〈　二〉。) procedure eliminates errors caused by the presence of several drops of the substance which may adhere to the sides and tip of the pipette. After this manipulation ,more alcohol is added until a clear solution is obtained.這樣能消除由附著在管壁或管尖的樣品所帶來的誤差。然后再加入乙醇，直至澄清。 second method which is the least accurate is very often used in the industry because of its great ease and convenience.第二種配制方法準確性最初差，但是，由于操作簡單在工業(yè)上經常采用。 the alcohol ordinarily available is the mercial 95 per cent by volume alcohol, this product is used in preparing alcohol of various strengths.既然通常所用的商業(yè)乙醇的濃度為95%（體積比），因此我們可用該濃度的乙醇來制備各種濃度的乙醇液。 reporting the optical rotation of a substance ,one usually writes:optical Rotation at 20 ?C+19?20’ or in abbreviated form αD20+19 ?20’ ,meaning that the rotation taken at 20 ℃, using sodium light (D line) is found to be plus 19 degree and 20 minutes.在報道某物質的旋光度時，我們習慣按下列的寫法。如某物質在20 ?C，旋光度為+19?20’；或簡寫為αD20，+19 ?20’；即表示，在20?C時，用鈉光測定的旋光度為正19度20分。 the cause for the fragrance breakdown is found to lie not in a principal ponent of the product, but in an impurity or gradually developing breakdown product(., rancidity of unsaturated fatty acids and hydrogen chloride from propellant(Ⅱ),it is best to change the product formulation rather than the fragrance—the impurities or breakdown products usually have other undesirable effects in addition to that on the fragrance.如果發(fā)現(xiàn)香料的分解不是出于產品的一個主要成分，而是一種雜質或是一種逐漸產生的分解產物（如不飽和脂肪酸的變質和推進劑2產生的氯化氫），則最好改變產品的配方而不是改變香料的配制，因為這種雜質或分解產物除了對香料產生作用外，通常還會有其他不良的影響。 contrast, crosslinked polymers usually lack the ability to be pletely dissolved by solvents, and usually do not undergoing melting or fusion.相反，交聯(lián)聚合物通常缺乏被溶劑完全溶解的能力，而且經常不能熔化或熔融。, the order with respect to B can be determined by plotting logνA,0 against log[B]0 with [A]0 held constant.類似地，B的級數(shù)可由在[A]0恒定時用logνA,0對log[B]0作曲線而得到。 this is approximately so, over limited ranges of temperature difference for which U is nearly constant ,in practice U may well be influenced both by the temperature difference and by the absolute value of the temperatures.其實在一個有限的溫差范圍內當U幾乎恒定時，是近似如此；但實際上U卻可能受溫差和絕對溫度二者的影響很大。 it is required to know the area needed for the transfer of heat at a specified rate, the temperature difference ΔT, and the value of the overall heat transfer coefficient in any design problem in which heating or cooling is involved.若需知道在一指定速率下進行傳熱所需的面積時，就須知道包括加熱或冷卻在內的設計問題中的溫差ΔT及總傳熱系數(shù)值。, the respective isomer distribution in the individual surfactant classes has great significance, because from it, varying application properties do result.此外，有關的異構體在各類表面活性劑中的分布也可具有重要作用，因為不同的分布確實可以產生不相同的應用性能。 mixture of 1750 g. of crystalline sodium sulfite(Na2SO37H2O),625 sodium bicarbonate and 5 liters of water was agitated at room temperature for about two hours, or until the solid carbonate had disappeared .The solution was then cooled by means of an icebath to 5 ? 10 ? and 500 mercial citral added with vigorous agitation, which was continued for three to four hours ,intimate contact being effected between oil and solution, and air excluded as much as possible. Under these conditions ,only the citral went into solution, namely, as the labile dihydrodisulfonic acid derivative. The solution was agitated thoroughly with about 500 cc. of ether, the ether removed and the process repeated in order to remove all undissolved impurities.在室溫下將1750克晶狀亞硫酸鈉，625克碳酸氫鈉及5L水混合并攪拌兩小時，或攪拌至固體碳酸鹽消失。然后用冰水浴將溫度降至5? 10?，加入500克市售檸檬醛劇烈攪拌，并持續(xù)三、四小時以使油與溶液充分接觸，同時盡可能的排除空氣。在這些條件下，只有檸檬醛進入溶液，即檸檬醛形成不穩(wěn)定的二氫二磺酸衍生物。，除去乙醚，如此重復數(shù)次以除去所有不能溶解的雜質。(十) 書上重點句子Lesson 1 size of atoms decreases from left ot right across a period in the periodic table在元素周期表中沿著周期從左到右的半徑遞減 descending a group in the periodic table such as lithium,sodium,potassium,rubidium,caesium,the size of the atoms increases due to the effect of extra shells of electrons being added。this outweighs the effect of increased nuclear charge.在周期表中同族從上到下例如鋰、鈉、鉀、銣和銫，由于增加額外電子層的影響，原子的半徑遞減，這個影響超過增加核電荷所起的作用。 the effective nuclear charge is increased and the electrons