画图法解决多元复合函数求导

由于多元复合函数求导重要,难度大。而现在大学里通用的高等数学教材讲解的求导方法不是非常得通俗易懂,本文给出一个简单易懂的方法———画图法,解决多元复合函数求导问题。     

Thermodynamics of the long range assembly of safranine T on molecular surfaces of nucleic acids

Ｔｈｅｓｔｕｄｙｏｆｔｈｅｓｕｐｒａｍｏｌｅｃｕｌａｒｒｅｃｏｇｎｉｔｉｏｎｏｆｏｒｇａｎｉｃｄｙｅｓｗｉｔｈｂｉｏｌｏｇｉｃａｌｍａｃｒｏｍｏｌｅｃｕｌｅｓｈａｓｂｅｃｏｍｅａｎｉｎｃｒｅａｓｉｎｇｌｙｉｎｔｅｒｅｓｔｅｄｒｅｓｅａｒｃｈｆｉｅｌｄ...     

Interactions of pyrogallol red with proteins and the determination of proteins by resonance light-scattering

Ｉｔｉｓｖｅｒｙｉｍｐｏｒｔａｎｔｔｈａｔｔｈｅｄｅｔｅｒｍｉｎａｔｉｏｎｏｆｐｒｏｔｅｉｎｃｏｎｃｅｎｔｒａｔｉｏｎｓｉｎｃｌｉｎｉｃａｌｔｅｓｔｓａｎｄｌａｂｏｒａｔｏｒｙｐｒａｃｔｉｃｅ．Ｕｐｔｏｎｏｗ，ｔｈｅｒｅｈａｖｅｂｅｅｎｍａｎｙｍｅ...     

Allocation of power generating and shipping of Hanjiang upstream cascade

1Generalsituationofthecascades1.1Cascadeshydropowerplants HanjiangRiverisoneofthelongesttributariesof YangtseRiver,originatingfromNingqiangcountyof ShaanxiprovinceandflowingthroughShaanxi provinceandHubeiprovince.HanjiangRiveris1567kmlongintotal,and709kmofitinShaanXi provincerunsthroughHanzhongandAnkangregions fromtheeasttothewest.TheupperreachesofHanjiangfromYangxian countytoBaihecountyinShaanxiprovinceis443km long,anditstotalheadfallsisabout280mhigh.Withabundantwaterpowerresources,its…     

A new research on auto compatible default theory

Ｅｘｔｅｎｓｉｏｎｉｓｔｈｅｍｏｓｔｉｍｐｏｒｔａｎｔｃｏｎｃｅｐｔｉｎｄｅｆａｕｌｔｌｏｇｉｃ．Ｒｅｉｔｅｒｈａｄｍａｄｅｓｏｍｅｒｅｓｅａｒｃｈｏｎｔｈｅｓｐｅｃｉａｌｋｉｎｄｏｆｄｅｆａｕｌｔｌｏｇｉｃ,ｔｈａｔｉｓｎｏｒｍａｌｄｅｆａｕｌｔｌ...     

Systematic studies on the neotropical genus Fusaea (Baill.) Saff.(Annonaceae)

ＴｈｅｇｅｎｕｓＦｕｓａｅａｗａｓｆｏｕｎｄｅｄｂｙＳａｆｏｒｄ［１］ｉｎ１９１４．ＴｈｅｔｙｐｅｓｐｅｃｉｅｓＦ．ｌｏｎｇｉｆｏｌｉａｗａｓｏｒｉｇｉｎａｌｙｄｅｓｃｒｉｂｅｄｂｙＡｕｂｌｅｔ［２］ａｓＡｎｎｏｎａｌｏｎｇｉｆｏｌｉａ．Ｂａｉｌｏ...     

QUALITATIVE ANALYSIS FOR A THIRD-ORDER DIFFERENTIAL EQUATION IN A MODEL OF CHEMICAL SYSTEMS

In this paper a mathematical model of chemical systems is investigated.We present the conditions for the existence and local stability of the steady statesand the periodic solution of the Hopf type.Specifically,we show by using an ana-lytical method that there may exist two or four Hopf bifurcation points separatedat a finite distance from each other;at the same time,a technique for studying theHopf bifurcation value is given.     

Rapid solidification of acoustically levitated Al-Cu-Si eutectic alloy under laser irradiation

Al-27%Cu-5.3%Si ternary eutectic alloy was melted using a YAG laser and then solidified while being acoustically levitated. A maximum undercooling to 195 K (0.24 TL) was achieved with a cooling rate of 76 K/s. The solidification microstructure was composed of (Al+θ+Si) ternary eutectics and (Al+θ) pseudobinary eutectics. During acoustic levitation, the (Al+θ+Si) ternary eutectics are refined and the (Al+θ) pseudobinary eutectics have morphological diversity. On the surface of the alloys, surface oscillations and acoustic streaming promote the nucleation of the three eutectic phases and expedite the cooling process. This results in the refinement of the ternary eutectic microstructure. During experiments, the reflector decreases with increasing alloy temperature, and the levitation distance always exceeds the resonant distance. Because of the acoustic radiation pressure, the melted alloy was flattened, and deformation increases with increasing sound pressure. The maximum aspect ratio achieved was 6.64, corresponding to a sound pressure of 1.8×104 Pa.     

DNA damage stress induces the dissociation of Smurf1/2 from MDM2 in a slow manner

The tumor suppressor p53 locates at the key point of cell growth or apoptosis balance, and the expression level of p53 is tightly controlled by ubiquitin ligases including MDM2. Upon DNA damage stresses, p53 was accumulated and activated, leading to cell cycle arrest or apoptosis. We previously showed that Smad ubiquitylation regulatory factor 1/2 (Smurf1/2) promotes p53 degradation by interacting with and stabilizing MDM2, and consequently enhancing MDM2-mediated ubiquitylation of p53. However, it is uncle...     

Gastric vagal afferent inputs reach the glycemia-sensitive neurons of lateral hypothalamic area in the rat

The lateral hypothalamic area (LHA) is one of the most important central areas in the regulation of feeding behavior[1]. The glycemia-sensitive neurons within the LHA sense the blood glucose level and subsequently trig-ger various visceral and somatic responses for maintaining the homeostasis of blood glucose concentration. Some electrophysiological studies have demonstrated that the gastric vagal afferent inputs could reach the LHA in the cat[2,3], but the studies did not reveal whether th…