法国动物纪录片——传统与现状：电影辉煌电视衰败

和英、美等国一样,法国也有历史悠久的动物纪录片拍摄传统。但和英美主要以电视频道播出的形式不同,法国的动物纪录片不单由电视台播出,电影版甚至是法国电影的一大骄傲。《熊》、《微观世界》、《迁徙的鸟》、《帝企鹅日记》等影片都在世界各地名闻遐迩。正如电视剧与故事片之间的区别,电视纪录片和电影纪录片的风格迥异。

10mT极低频磁场四周暴露对家兔脑电的影响

为了探讨极低频磁场对动物脑电的影响,用14只健康的雄性家兔随机分为两组(磁场组和对照组)进行实验。磁场组家兔在10mT,0.1Hz磁场环境中,每天暴露12h、每周5d、连续4周;对照组家兔放置于模拟磁铁环境中。脑电记录电极置家兔右额(F_1)和左额(F_2),用磁带记录仪把脑电信号记录在磁带上,每只家兔每次记录2.5min,在暴露前(适应1周后)、暴露1周、2周、3周、4周及停磁恢复1周后各记录一次。最后把脑电信号输入信号处理机处理。依封根泉等人〔1-2〕的方法。

电池漫谈

电池漫谈陕西永寿县中学（７１３４００）吕忠民一、原电池的发明说起原电池的发明，还有一段有趣的故事。１７８６年，著名的意大利医师、生物学家伽尔伐尼，偶然发现挂在窗前铁栅栏的铜钩上的青蛙腿肌肉，每当碰到铁栅栏就猛烈地收缩一次。这偶然的现象并没有被伽尔伐尼...

从“电妖鱼”到“燃料电池”

从“电妖鱼”到“燃料电池”安徽凤阳中学张国顺“电妖鱼”—动物电１８世纪中期，人们在非洲与南美洲等地的河流中，发现一种带“新式武器”的鱼，当你用两只手同时碰到它的头部和尾部时，会受到“电击”，经实验这种鱼可用来给莱顿瓶充电。人们称这种鱼为“电妖鱼”或“...

生物电小史

1780年11月6日,意大利波洛尼亚(Bolognia)大学解剖学教授伽尔伐尼(Galvani 1737—1798)和他的助手在用蛙腿做实验时,发现了"动物电".经过十多年的实验研究,于1791年发表了《论肌肉活动时的电力》一文,标志着生物电学的正式诞生,伽尔伐尼也因此而成为世界上第一个发现生物电的人.生物电是包括动物、植物和微生物在内的所有生物体共有的生命现象.早在公元前.亚里士多德(384—332)就描述过地中海电鳐的。强烈的震击作用".之后。

揭开电学帷幕之人——伏打

1801年12月21日,应拿破仑的邀请,伏打在法国科学院对他的发明——伏打电堆进行了演讲。当伏打演讲并演示完毕,拿破仑拉着伏打走向讲台的一侧说:"伟大而神秘的自然界面前的帷幕被天才揭开了一角。天才不多见,对他们仅仅赞赏是不够的,应该让他们得到奖励。因此,我为电学领域中天才的发明者设立20万法郎的基金。第一笔奖金,我授予帕维亚大学的亚历山德罗·伏打教授。"

Nature,Characteristics and Uitrastructure Observation of Fibers of Seven Kinds of Special Animals

[Objective]Aimed to study the nature,characteristics and ultrastructure of fibers of Ovis aries and several kinds of special animals.[Method]Wool,cashmere,alpaca,Bactrian camel hairs,rabbit hair,mohair and yak hair were used as the experimental materials,and scanning electron microscopy was used to observe their scale structure.[Result]The rake angle of wool was large with an average of 33.2°,the scale density was 16.2-34.9 scales/mm,the average height of scale was 12.95 μm,and the average thickness was 0.63 μm;the rake angle of cashmere was smaller than wool with an average of 20.6°,the scale density was of 10.3-15.6 scales/mm,the scale distance was large,the average height of scale was 16.09 μm,and the average thickness was 0.46 μm;the average rake angle of alpaca was 34.6°,with the average scale height of 5.85 μm,and average thickness of 0.33 μm;the average rake angle of camel hair was 33.5°,with the average scale height of 11.30 μm and average thickness of 0.37 μm;the average rake angle of rabbit hair was 31.2°,with average scale height of 7.03 μm and average thickness of 0.36 μm;the rake angle value of mohair was between wool and cashmere,and the average of which was 23.7°,the scale density value was also between the wool and cashmere,with the average scale height of 15.82 μm and average thickness of 0.61 μm;the average rake angle yak hair was 33.2°,with the average height of 9.08 μm and average thickness of 0.46 μm.[Conclusion]The results of this study could provide a basis for the identification of different fiber types.

青蛙腿的奇迹

当大家打开电灯、电视、电脑,当你使用洗衣机、电冰箱、空调时,大家可曾想过电气化时代竟是从一条青蛙腿引发出来的!

太阳公公感冒了

秋天的一个早晨,太阳公公感冒了,脸上没有一丝笑容,整个天空阴沉沉的。风姐姐知道后。

问答

哪种球类的速度最快?Q:看网球比赛时,看到发球时速多少多少千米,同样,足球比赛中解说员也会说这脚任意球射门时速达到了多少多少。

Long-Lived Coherence Originating from Electronic-Vibrational Couplings in Light-Harvesting Complexes

We theoretically investigate the evolutions of two-dimensional, third-order, nonlinear photon echo rephasing spectra with population time by using an exact numerical path integral method. It is shown that for the same system, the coherence time and relaxation time of excitonic states are short, however, if the couplings of electronic and intra-pigment vibrational modes are considered, the coherence time and relaxation time of this vibronic states are greatly extended. It means that the couplings between electronic and vibrational modes play important roles in keeping long-lived coherence in light-harvesting complexes. Particularly, by using the method we can fix the transition path of the energy transfer in bio-molecular systems.

Electromotive Force for Solid Oxide Fuel Cells Using Biomass Produced Gas as Fuel

The electromotive force （e.m.f.） of solid oxide fuel cells using biomass produced gas （BPG） as the fuels is calculated at 700-1,200 K using an in-house computer program, based on thermodynamic equilibrium analysis. Tour program also predicts the concentration of oxygen in the fuel chamber as well as the concentration of equilibrium species such as H2, CO, CO2 and CH4. Compared with using hydrogen as a fuel, the e.m.f. for cells using BPG as the fuels is relative low and strongly influenced by carbon deposition. To remove carbon deposition, the optimum amount of H2O to add is determined at various operating temperatures. Further the e.m.f, for cells based on yttria stabilized zirconia and doped ceria as electrolytes are compared. The study reveals that when using BPG as fuel, the depression of e.m.f, for a SOFC using doped ceria as electrolyte is relatively small when compared with that using Yttria stabilized zirconia.

Seasonal variation in abundance, diel vertical migration and body size of pelagic tunicate Salpa fusiformis in the Southern Yellow Sea

Mass occurrence of Salpafusiformis June 2007. In order to investigate its population was observed in the Southern Yellow Sea in May and recruitment and environmental adaptation, temporal variation of abundance, diel vertical migration （DVM） and length frequency distribution of both aggregate and solitary forms were studied with samples collected from eight months during September 2006 to August 2007. S. fusiformis presented in six months other than September and October 2006, and average abundance of aggregate and solitary forms peaked in June and May, respectively. In December, aggregate forms were absent in the bottom layer and performed irregular DVM from surface to 50 m depth, while solitary forms was too scarce to perform diel vertical distribution analysis. Both aggregate and solitary forms presented reverse DVM in May and June. They migrated upwards during daytime and concentrated in surface layer at sunset. The bimodal distribution of aggregate forms was found in April and the average size was largest in this month. In other months, the smaller aggregate forms （1-5 ram） dominated in populations except for May, when the modal size ranged from 2 to 8 mm. The average size of solitary forms was largest in December, followed by April. The skewed nomal distribution of solitary forms was found in May and June, with the modal size of 2-7 mm and 5-13 ram, respectively.

Quantum fluctuations of mesoscopic biological cell at finite temperature

On the basis of the quantization of mesoscopic biological cell equivalent circuit,we studied the quantum fluctuations of voltage and current of mesoscopic biological cell equivalent circuit as finite temperature by Bogoliuov transformation.The result shows that the quantum fluctuations of voltage and current not only relate with the parameters of equivalent circuit,temperature,but also decay with time.This result may have significant value on the design and application of the bio-electronic apparatus.

Initial corrosion behavior of pure zinc in simulated tropical marine atmosphereInitial corrosion behavior of pure zinc in simulated tropical marine atmosphere

The initial corrosion behavior of pure zinc in a simulated tropical marine atmosphere was investigated using gravimetric method,scanning electron microscope combined with energy dispersive spectroscopy(SEM-EDS),X-ray diffractometry(XRD),Fourier transform infrared spectrometry(FTIR)and electrochemical impedance spectroscopy(EIS).The kinetics of corrosion process is a decelerating process following the empirical equation D=At^n(n<1).The protectiveness of the corrosion product layer could be attributed to the formation of simonkolleite,Zn5(OH)8Cl2·H2O,which could inhibit the rate determining step,namely charge transfer step,of the electrochemical corrosion process.A model of the evolution process of the product layers formed on zinc was proposed.In addition,the regularity of the corrosion rate of zinc as a function of the NaCl deposition rate can be described by a power function.

The distribution of motilin receptor in the amygdala of rats and its role in migrating myoelectric complex

Objective:To investigate the distribution of the motilin receptor in the amygdala of rats and its role in regulating the duodenal migrating myoelectric complex(MMC).Methods:The distribution of motilin receptor in the amygdala in adult SD rats was detected by immunohistochemistry methods,and the duodenal interdigestive MMC was recorded via the electrodes implanted in the duodenum and analyzed us- ing a multichannel recorder.Results:Motilin receptor was observed in the amygdala of rats.The great amount of motilin receptor was found in the medial amygdaloid nucleus,which was also abundant in the basolateral nucleus but less abundant in the basomedial amygdaloid nucleus,the central amygdaloid nucle- us and the lateral amygdaloid nucleus.The shortening of the duodenal MMC cycle duration and the in- crease of the amplitude and the frequency of phase $ were recorded after motilin receptors being bound with exogenous motilin in the amygdala.The effects could be completely blocked by the subdiaphragmatic vagotomy but not by the intravenous injections of atropine,phentolamine or propranolol.Anti-motilin serum could partially block these effects,and the destruction of the basolateral nucleus of the amygdala had no significant effects on the duodenal MMC.Conclusion:Motilin receptor is present in all the subnu- clei of the amygdala,with the greatest amount of motilin receptor present in the medial amygdaloid nucle- us.Microinjections of motilin in the amygdala can shorten the duodenal MMC cycle duration and increase the amplitude and the frequency of phaseⅢ.These effects might be accomplished via the amygdala-hy- pothalamus-brainstem-vagus pathway,indicating the important role of the amygdala motilin receptor in the duodenal MMC regulation.

Oxidation of chalcopyrite in air-equilibrated acidic solution: Inhibition with phenacyl derivatives

The effects of 4-(2-hydroxyphenyl)-2-(morpholin-4-yl)-1,3-thiazole(Pr02), 1-(3,5-dibromo-2-hydroxyphenyl)-1-oxoethan-2-yl-N,N-diethyldithiocarbamate(Pr04) and 1-(5-bromo-2-hydroxy-3-methylphenyl)-1-oxoethan-2-yl-Oethyl xanthate(Pr06) on the aqueous oxidation of chalcopyrite(CuFeS2) in air-equilibrated solution at a temperature of 25 ℃ and a pH of 2.5 were studied. The effects were investigated by using potentiodynamic polarization, electrochemical impedance spectroscopy(EIS), scanning electron microscopy coupled with energy dispersive X-ray(SEM/EDX) analysis, aqueous batch experiments, Fourier transform infrared(FTIR) spectroscopy, Raman scattering and quantum chemical calculations. It is found that the anodic current densities decrease in the order of EtOH > Pr02 > Pr04 > Pr06. These results, along with those of the EIS measurements, show that Pr02, Pr04 and Pr06 are effective anodic inhibitors of chalcopyrite aqueous oxidation. Both Raman scattering and FTIR spectroscopy indicate that the elemental sulfur, polysulfide and ferric oxyhydroxides that form on the surface of the mineral are not responsible when it comes to the aqueous oxidation inhibition of chalcopyrite. Quantum chemical calculations show that the adsorption of the tested compounds on the chalcopyrite surface is energetically favorable and so, it can explain the inhibiting effects that were observed.

Sacral anterior root stimulated defecation in spinal cord injuries: An experimental study in canine model

AIM: To investigate whether there was a dominant sacral root for the motive function of rectum and anal sphincter, and to provide an experimental basis for sacral root electrically stimulated defecation in spinal cord injuries. METHODS: Eleven spinal cord injured mongrel dogs were included in the study. After L4-L7 laminectomy, the bilateral L7-S3 roots were electrostimulated separately and rectal and sphincter pressure were recorded synchronously. Four animals were implanted electrodes on bilateral S2 roots. RESULTS: For rectal motorial innervation, S2 was the most dominant (mean 15.2 kPa, 37.7% of total pressure), S1(11.3 kPa, 27.6%) and S3 (10.9 kPa, 26.7%) contributed to a smaller part. For external anal sphincter, S3 (mean 17.2 kPa, 33.7%) was the most dominant, S2 (16.2 kPa, 31.6%) and S1(14.3 kPa, 27.9%) contributed to a lesser but still a significant part. Above 85% L7 roots provided some functional contribution to rectum and anal sphincter. For both rectum and sphincter, the right sacral roots provided more contribution than the left roots. Postoperatively, the 4 dogs had electrically stimulated defecation and micturition under the control of the neuroprosthetic device. CONCLUSION: S2 root is the most dominant contributor to rectal pressure in dogs. Stimulation of bilateral S2 with implanted electrodes contributes to good micturition and defecation in dogs.

Effects and mechanisms of electroacupuncture at PC6 on frequency of transient lower esophageal sphincter relaxation in cats

AIM: To investigate the effects of electroacupuncture (EA) at neiguan (PC6) on gastric distention-induced transient lower esophageal sphincter relaxations (TLESRs) and discuss the mechanisms of this treatment. METHODS: ProtocolⅠ: Twelve healthy cats underwent gastric distention for 60 min on the first day. Electrical acupoint stimulation was applied at the neiguan or a sham point on the hip in randomized order before gastric distention, on the third day and fifth day. Those cats that underwent EA at neiguan on the fifth day were named "Neiguan Group" and the cats that underwent EA at a sham acupoint on the fifth day were named "Sham Group" (control group). During the experiment the frequency of TLESRs and lower esophageal sphincter (LES) pressure were observed by a perfused sleeve assembly. Plasma levels of gastrin (GAS) and motilin (MTL) were determined by radioimmunoassay. Nitrite/nitrate concentration in plasma and tissues were measured by Griess reagent. The nuclei in the brain stem were observed by immunohistochemistry method of c-Fos and NADPH-d dyeing. Protocol Ⅱ: Thirty six healthy cats were divided into 6 groups randomly. We gave saline (2 mL iv. control group), phaclofen (5 mg/kg iv. GABA-B antagonist), cholecystokinin octapeptide (CCK-8) (1 μg/kg per hour iv.), L-Arginine (200 mg/kg iv.), naloxone (2.5 μmol/kg iv.) and tacrine (5.6 mg/kg ip. cholinesterase inhibitor) respectively before EA at Neiguan and gastric distention. And the frequencies of TLESRs in experimental groups were compared with the control group.RESULTS: ProtocolⅠ: Not only the frequency of gastric distention-induced TLESR in 60 min but also the rate of common cavity during TLESRs were significantlydecreased by EA at neiguan compared to that of sham acupoint stimulation. C-Fos immunoreactivity and NOS reactivity in the solitarius (NTS) and dorsal motor nucleus of the vagus (DMV) were significantly decreased by EA at neiguan compared to that of the sham group. However, the positive nuclei of C-Fos and NOS in reticular formation of the medulla (RFM) were increased by EA at neiguan. Protocol Ⅱ: The inhibited effect of EA at neiguan on TLESR’s frequency was completely restored by pretreatment with CCK (23.5/h vs 4.5/h, P < 0.05), L-arginine (17.5/h vs 4.5/h, P < 0.05) and naloxone(12/h vs 4.5/h, P < 0.05). On the contrary, phaclofen (6/h vs 4.5/h, P > 0.05) and tacrine (9.5/h vs 4.5/h, P > 0.05) did not influence it. CONCLUSION: Electric acupoint stimulation at Neiguan significantly inhibits the frequency of TLESR and the rate of common cavity during TLESR in cats. This effect appears to act on the brain stem, and may be mediated through nitric oxide (NO), CCK-A receptor and mu-opioid receptors. But the GABAB receptor and acetylcholine may not be involved in it.

Effect of indomethacin on electrical field stimulation-induced contractions of isolated transverse and longitudinal rat gastric fundus strips

AIM: To study the effects of indomethacin on the isolated transverse and longitudinal rat gastric fundus strips.METHODS: The strips were suspended in an organ bath containing oxygenated Krebs solution, and contractile responses to electrical field stimulation were recorded on a physiograph in an isotonic manner after administration of cumulative concentrations of indomethacin. The effects of indomethacin on the strips pretreated with KATP channel modulators, diazoxide and glybenclamide were studied.RESULTS: Treatment of the transverse strips with indomethacin resulted in a concentration-dependent inhibitory response. In longitudinal strips, biphasic responses were seen, which included a stimulatory response at low concentrations of indomethacin, followed by an inhibitory response at higher concentrations.Diazoxide pre-treatment inhibited the stimulatory response of longitudinal strips. Glybenclamide pre-treatment not only blocked inhibitory effect of the low concentrations of indomethacin on transverse strips, but also increased the amplitude of contractions. Moreover, the drug decreased the amplitude of contractions in longitudinal strips.CONCLUSION: Responses of the isolated longitudinal and transverse rat gastric fundus strips to indomethacin are not similar, and are influenced by KATP channel modulators.