热门问答
- 生物显微镜观察标本时会一段模糊一段清晰吗
2017-02-16 10:25:38
369
1
- 压延布一段有牢度一段没牢度是怎么回事
2018-11-23 04:17:14
342
0
- 帮忙翻译一段英语
- Plant material and culture conditions have been described (7). Briefly, a diploid tissue culture line, WOO1C, of wild carrot, Daucus carota L., was maintained in Murashige and Skoog medium supplemented with 0.1 mg of 2,4-dichlorophenoxy... Plant material and culture conditions have been described (7). Briefly, a diploid tissue culture line, WOO1C, of wild carrot, Daucus carota L., was maintained in Murashige and Skoog medium supplemented with 0.1 mg of 2,4-dichlorophenoxyacetic acid (2,4-D). To regenerate plants from the culture, callus tissue was transferred to the same medium devoid of 2,4-D (embryogenic medium). All experiments were performed with cultures grown in liquid medium. For convenience, cultures grown in 2,4-D-containing medium are referred to as "callus cultures", and those grown in medium without 2,4-D as "embryo cultures." The growth of callus cultures was measured by the sidearmturbidity method (7). The number of cells at any time point of growth was estimated from turbidity in a Klett-Summerson calorimeter and was expressed in arbitrary units. For example, Klett 100 corresponds to ="2 X 106 cells per ml. The relationship is linear up to Klett 150 in our Klett-Summerson colorimeter. Suspension cultures ofWOOLC cell line are normally maintained at cell densities between 106 and 107 cells per ml in 0.1 mg of 2,4-D per liter (high-density culture) in shake flasks. During a quantitative study on embryogenesis, we found that maximal embryo production can be achieved by first incubating the culture at high density in medium without 2,4-D for one generation time and then diluting it to 2-3 x 104 cells per ml (low-density culture). To compare cultures of comparable density, callus cultures and embryo cultures were subjected to the same procedure. To initiate low-density embryo or callus cultures, an 8-day-old high-density culture grown at the logarithmic phase was washed three times with fresh callus or embryogenic medium and resuspended at 8 x 105 cells per ml for one generation (3 days) in its corresponding medium. It was then diluted to 2 x 104 cells per ml; 20 ml of the culture was incubated in a plastic Petri dish (9 cm in diameter) at 240C. The morphogenetic events of the cultures were examined and photographed under a dissecting microscope. 请不要用google的那个,我看不懂~~ 展开
2008-02-19 03:32:04
513
2
- 单片机温度传感器一段程序问题
- 这个函数的作用是什么下面是定义和该函数#include
#include typedefunsignedcharU8;//用U8代替unsignedchartypedefunsignedintU16;//用U16代替unsignedintU8U8FLAG... 这个函数的作用是什么 下面是定义和该函数 #include #include typedef unsigned char U8; //用U8代替unsigned char typedef unsigned int U16; //用U16代替unsigned int U8 U8FLAG; U8 U8count,U8temp; U8 U8T_data_H,U8T_data_L,U8RH_data_H,U8RH_data_L,U8checkdata; U8 U8T_data_H_temp,U8T_data_L_temp,U8RH_data_H_temp,U8RH_data_L_temp,U8checkdata_temp; U8 U8comdata; DS18B20=P2^0; void COM(void) { U8 i; for(i=0;i<8;i++) { U8FLAG=2; while((!DS18B20)&&U8FLAG++); Delay_10us(); Delay_10us(); Delay_10us(); U8temp=0; if(DS18B20) U8temp=1; U8FLAG=2; while((DS18B20)&&U8FLAG++); //超时则跳出for循环 if(U8FLAG==1)break; //判断数据位是0还是1 //如果高电平高过预定0高电平值则数据位为1 U8comdata<<=1; U8comdata|=U8temp; //0 } } 展开
2015-11-22 09:06:48
394
2
- 监控视频模糊能处理清晰化吗
- 监控视频模糊能处理清晰化吗... 监控视频模糊能处理清晰化吗 展开
2016-08-26 21:38:03
467
2
- PVC挤出机挤出黑色的料是怎么回事?一段正常,一段时黑色的
2013-05-24 08:08:38
408
3
- 翻译一段纳米材料的摘要(1)
- Abstract Nanomaterials and nanotechnology have been hot issues during the recent decades. This thesis deals with the fabrication and engineering of novel nanomaterials with enhanced functionality, particularly nanocomposites and nanostruc... Abstract Nanomaterials and nanotechnology have been hot issues during the recent decades. This thesis deals with the fabrication and engineering of novel nanomaterials with enhanced functionality, particularly nanocomposites and nanostructured surfaces. The study includes two parts; in the first part, bulk transparent polymer-inorganic nanocomposites were produced by a novel synthesis method and its UV-absorption has been investigated. In the second part, nanostructured microporous surface layers, of copper, were fabricated by electrodeposition process and its effect on material’s performance for pool boiling has been investigated evaluated.In the first part of the thesis, bulk polymer-inorganic nanocomposites composed of poly(methylmethacrylate) (PMMA) and zinc compounds were prepared by an in situ sol-gel transition polymerization of zinc complex in PMMA matrix. The immiscibility of heterophases of solid organic and inorganic constituents was resolved by the in situ sol-gel transition polymerization of ZnO nanofillers within PMMA in the presence of dual functional agent, monoethanolamine, which provided strong secondary interfacial interactions for both complexing and crosslinking of constituents. Comprehensive characterization of the polymer-inorganic hybrid materials has been undertaken using a wide range of techniques; XRD, 1H NMR, FT-IR, TGA, DSC, UV-Vis, ED, SEM, TEM and HRTEM. The homogeneous PMMA-ZnO nanocomposites exhibited enhanced UV-sheltering effects in the entire UV range even at very low ZnO content of 0.02 wt%. 展开
2006-10-18 01:02:42
375
4
- AD10怎么测量一段连线的长度?
2018-04-18 09:23:00
513
2
- 当用低倍镜观察细胞不清晰时应换上高倍镜观察 七上生物显微镜
- 这句话为什么不对?当用低倍镜观察细胞不清晰时要怎么办?... 这句话为什么不对?当用低倍镜观察细胞不清晰时要怎么办? 展开
2012-02-09 03:14:56
350
3
- 生物显微镜观察时需要lbd滤色片吗
2016-07-31 16:46:01
558
2
- 磁翻板液位计装在大型储罐外侧,一般一段是多长
2015-12-30 10:52:01
435
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- 我有一段英文,看不明白,求翻译
- Thetubewillbesupportedbypillarswhichconstrainthetubeintheverticaldirectionbutallowlongitudinalslipforthermalexpansionaswellasdampenedlateralsliptoreducetheriskposedbyeart... The tube will be supported by pillars which constrain the tube in the vertical direction but allow longitudinal slip for thermal expansion as well as dampened lateral slip to reduce the risk posed by earthquakes. In addition, the pillar to tube connection nominal position will be adjustable vertically and laterally to ensure proper alignment despite possible ground settling. These minimally constrained pillars to tube joints will also allow a smoother ride. Specially designed slip joints at each stations will be able take any tube length variance due to thermal expansion. This is an ideal location for the thermal expansion joints as the speed is much lower nearby the stations. It thus allows the tube to be smooth and welded along the high speed gliding middle section. The spacing of the Hyperloop pillars retaining the tube is critical to achieve the design objective of the tube structure. The average spacing is 100 ft (30 m), which means there will be near 25,000 pillars supporting both tubes and solar panels. The pillars will be 20 ft (6 m) tall whenever possible but may vary in height in hilly areas or where obstacles are in the way. Also, in some key areas, the spacing will have to vary in order to pass over roads or other obstacles. Small spacing between each support reduces the deflection of the tube keeping the capsule steadier and the journey more enjoyable. In addition, reduced spacing has increased resistance to seismic loading as well as the lateral acceleration of the capsule. 有些桥墩与管道之间的细节问题希望能仔细处理清楚,十分感谢!! 追加15分! 能手动翻译一下吗?! 展开
2013-12-03 16:23:25
270
2
- 如何测定一段已知序列DNA的旁侧序列
2006-03-23 12:05:01
322
2
- 请帮我翻译一段专业英语吧。。急用。。多谢。。。
- Practical applications of colossal magnetoresistive(CMR) oxides are limited by the large magnetic fields and/or low temperature required to observe a significant change in electric resistivity[1-5]. In recent years,research on tunneling mag... Practical applications of colossal magnetoresistive(CMR) oxides are limited by the large magnetic fields and/or low temperature required to observe a significant change in electric resistivity[1-5]. In recent years,research on tunneling magnetoresistance(TMR) is a very active field because of its scientific interest and potential technological applications[6].Polycrystalline Sr2FeMoO6 perovskite is a candidate for magnetic sensors owing to its high ferromagnetic transition temperature …(Tc~420K)and the half-metallic electronic band structure predicted theoretically [7]. The conduction electrons in this compound are expected to be highly spin-polarized even at room temperature. More recently, perovskite Sr2FeMoO6 with nanometer grain size showed large magnetoresistance(~20%) at a low magnetic field of 4k Oe and at room temperature[8].Dai et al.[9]observed two different ordered structures in polycrystalline Sr2FeMoO6 perovskite: the double perovskite and the superstructure with tripled c-axis(ST).In this paper, another new layered structure of body-centered tetragonal phase (BT) is reported for the polycrystalline magnetoresistive Sr2FeMoO6 sample. Ceramic samples of Sr2FeMoO6 were prepared by standard solid state reaction. Stoichiometric materials of SrCO3,Fe2O3 and MoO3 were mechanically mixed, and then calcined at 950℃ for 4h in air.The calcined mixture was then ball-milled and made into pellets followed by sintering at 1250℃for 4h in carbon monoxide atmosphere.Transmission electron microscopy(TEM) specimens were prepared by mechanical polishing,dimpling and ion milling.Electron diffraction patterns were taken at 120kV using a Phillips CM12 electron microscope, and high resolution TEM imaging was conducted using JEOL 2010 microscope. Energy dispersion of X-rays(EDX) was conducted by TEM attached with EDAX PV9100. 展开
2009-05-20 03:06:41
474
1
- 请翻译一段简单的英语(务必准确)
- 用翻仪器的走远!Thetissueishomogenizedwithchloroform/methanol(2/1)toafinalvolume20timesthevolumeofthetissuesample(1gin20mlofsolventmixture).Afterdispersion,thewholemixtur... 用翻仪器的走远! The tissue is homogenized with chloroform/methanol (2/1) to a final volume 20 times the volume of the tissue sample (1 g in 20 ml of solvent mixture). After dispersion, the whole mixture is agitated during 15-20 min in an orbital shaker at room temperature. The homogenate is either filtrated (funnel with a folded filter paper) or centrifuged to recover the liquid phase. The solvent is washed with 0.2 volume (4 ml for 20 ml) of water or better 0.9% NaCl solution. After vortexing some seconds, the mixture is centrifuged at low speed (2000 rpm) to separate the two phases. Remove the upper phase by siphoning and kept it to analyze gangliosides or small organic polar molecules. If necessary (need of removing labelled molecules...), rinse the interface one or two times with methanol/water (1/1) without mixing the whole preparation. After centrifugation and siphoning of the upper phase, the lower chloroform phase containing lipids is evaporated under vacuum in a rotary evaporator or under a nitrogen stream if the volume is under 2-3 ml. 展开
2008-10-10 18:31:56
412
2
- 示波器FFT进行一段声音的频谱分析,如图所示
- 如何判定在300HZ-4000Hz之间的谐波分量的相对声压级在脉冲频率处幅度的正负15dB范围内?
2018-04-12 11:38:08
319
3
- 为什么一段高阻抗传输线可以等效为电感
2017-09-26 16:14:42
519
1
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