The authors thank the DFG (Hu 997/2-2) for financial support. FS acknowledges the Hanns-Seidel-Stiftung (HSS). SKr was supported by the Elitenetzwerk Bayern in the framework of the doctorate program Material Science of Complex Interfaces. SKi thanks the SFB 863 for financial support.

<ol>
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The authors declare that they have no competing financial interests.

<html> במהלך העשורים האחרונים, ניסויי מולקולה בודדים סיפקו תובנות חסרות תקדים לתוך מנגנונים מולקולריים והתבררו להיות גישה לא יסולא בפז בתחום מדעי חיים ומעבר. כדי להשיג נתונים סטטיסטיים טובים ומשמעותיים מניסויי SMFS, באופן אידיאלי ובעונה אחת המולקולה משמשת מעל כל מהלך הנ...

במהלך 30 השנים האחרונות, במיקרוסקופ כוח אטומי (AFM) התברר להיות טכניקת הדמיה רבת ערך כדי ללמוד 1,2 וסינתטי 3 חומרים ופני שטח ביולוגיים שכן הוא מספק רזולוציה מרחבית מולקולרית בכל שלושת הממדים ויכול להיות מופעל בממס שונים סביבות. בנוסף, כוח מולקולת ספקטרוסקופיה AFM-הורי (SMFS) מאפשרת למדוד כוחות הנעים בין pN לμN משטר ונתנה תובנות חסרות תקדים לדוגמא לחלבון מתקפלות 4,5, פיזיקת פולימר 6-8, ואינטראקציה מולקולה-משטח אחד 9 - 12 רציונל מאחורי .the לומד מולקולות בודדות ולא הרכב של מולקולות הוא להימנע מממוצע השפעות אשר לעתים קרובות להסוות אירועים נדירים או מדינות מולקולריות מוסתרות. יתר על כן, מספר רב של פרמטרים מולקולריים כגון אורך הגובה, אורך Kuhn, אנרגיה חופשית ההידבקות, וכו &#39;יכול להיותהושג. זה מפורט בדוגמאות שלהלן. בניסוי AFM-SMFS טיפוסי, מולקולת הבדיקה היא מצמידים את קצה חד מאוד באמצעות מולקולה מקשר. טיפ עצמו נמצא בסוף שלוחה bendable. אם הקצה הוא הביא במגע עם פני השטח מולקולת הבדיקה תהיה אינטראקציה עם פני השטח זה. על ידי התבוננות הסטייה של שלוחה על הכחשה של הקצה, הכוח, ולכן האנרגיה החופשית, כדי לנתק את המולקולה מפני השטח ניתן לקבוע. כדי לקבל נתונים סטטיסטיים משמעותיים, מספר רב של מה שנקראו עקומות כוח למרחקים שיירכש. יתר על כן, יש ניסויי מולקולה בודדת אמיתיים (כלומר, שימוש ובעונה אחת מולקולת בדיקה על משך הניסוי כולו) מולקולת הבדיקה צריכה להיות בשילוב קוולנטית לקצה AFM. כאן, פרוטוקול ניסוי לfunctionalization שלוחה עם מולקולה בודדת באמצעות קשר קוולנטי מוצג. המולקולה בודדת או יכולה להיות בשילוב באמצעות אמינו או thioקבוצת l לקצה AFM. התהליך הצמידה יכול להתבצע במגוון רחב של ממסים (אורגניים ומימיים) כדי להסביר את תכונות solvation של הפולימרים המשמשים. בחלקו הראשון, פרוטוקול כללי לצרף קוולנטית מולקולה בודדת (&quot;מולקולת בדיקה&quot;) באמצעות מולקולת מקשר לקצה AFM מתואר. לשם כך, NHS- האורגני או maleimide-הכימיה משמשת 13. יחד עם הפרוטוקול לשלוש מולקולות דוגמא, תהליכי רכישת נתונים וניתוח נתונים מתוארים ואזכור לקריאה נוספת מסופק. מולקולות הדוגמא הן: טירוזין הפולימר (ליניארי), פולימר השתל מלק g -PS והאפיפיור השומנים. זה כולל שינויים קלים של הפרוטוקול, למשל לצרף קוולנטית cysteines. בנוסף, סעיף מוקדש להכנת משטחים שונים כגון משטח יהלום, 3 monolayer התאספו -self CH וbilayers שומנים. יש לי ממשקים אלה proven להיות אזכור טוב ודוגמאות.

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Materials</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Hellmanex III alkaline liquid concentrate (detergent solution)</td>
			<td>Hellma</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>RCA (ultrapure water, hydrogen peroxide (35 %), ammonia (32%); 5:1:1(v/v/v))</td>
			<td>Sigma</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Vectabond reagent / APTES (3-Aminopropyl)triethoxysilane</td>
			<td>Vectorlabs</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dry acetone (&#60; 50 ppm H2O)</td>
			<td>Sigma</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Dry chloroform (&#62; 99.9 %)</td>
			<td>Sigma</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Triethylamine</td>
			<td>Sigma</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ultrapure water</td>
			<td>Biochrom, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Di-sodium tetraborate (&#62; 99.5 %)</td>
			<td>Biochrom, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Boric Acid</td>
			<td>Biochrom, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Monofunctional &#945;-methoxy-&#969;-NHS PEG, 5kDa, &#8220;methyl-PEG-NHS&#8221;</td>
			<td>Rapp, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Heterobifunctional &#945;,&#969;-bis-NHS PEG, 6 kDa, &#8220;NHS-PEG-NHS&#8221;</td>
			<td>Rapp, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Heterobifunctional &#945;-maleimidohexanoic- &#969;-NHS PEG, 5 kDa, &#8220;Mal-PEG-NHS&#8221;</td>
			<td>Rapp, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Probe molecule (polymer, lipid, etc.)</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Sufficient amount of glass crystallising dishes with spout (10 ml), glass petri dishes (500 &#181;l) and glass lids</td>
			<td>VWR International GmbH, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Laboratory oven model UF30</td>
			<td>Memmert, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Temperature controlled sonicator</td>
			<td>VWR International GmbH, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Plasma system &#34;Femto&#34;, 100 W</td>
			<td>Diener, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>One separate glass syringe for each organic solvent</td>
			<td>VWR International GmbH, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Vortex mixer</td>
			<td>VWR International GmbH, Germany</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Microcentrifuge tubes (0.5 ml or 1.5 ml)</td>
			<td>Eppendorf</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Pipettes: 10-100 &#181;l, 50-200 &#181;l and 100-1000 &#181;l</td>
			<td>Eppendorf</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>AFM with temperature controlled fluid cell (e.g. MFP-3D with BioHeater)</td>
			<td>Asylulm Research, Santa Barbara</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Soft SiN cantilevers cantilever, typically made from silicon nitride (SiN) (spring constant less than 100 pN/nm, e.g. MLCT)</td>
			<td>Bruker AXS, Santa Barbara</td>
			<td></td>
			<td></td>
		</tr>
	</tbody>
</table>

investigating single molecule adhesion by atomic force spectroscopy

ספקטרוסקופיה כוח האטומית היא כלי אידיאלי ללמוד מולקולות על משטחים וממשקים. פרוטוקול ניסוי לזוג במגוון גדול של מולקולות בודדות קוולנטית על קצה AFM מוצג. באותו הזמן בקצה AFM הוא פסיבציה כדי למנוע אינטראקציות נוקבות בין הקצה ואת המצע, שהוא תנאי הכרחי ללימודי מולקולות בודדות מחוברת לקצה AFM. ניתוח כדי לקבוע את כוח ההידבקות, אורך ההידבקות, ואנרגיה החופשית של מולקולות אלה על משטחים מוצקים וביו-ממשקי זמן קצר הציגו והפניות חיצוניות לקריאה נוספת מסופקות. מולקולות דוגמא הן polytyrosine פולי (חומצת אמינו), פולימר השתל מלק g -PS והאפיפיור פוספוליפידים (1-palmitoyl-2-oleoyl- sn -glycero-3-phosphoethanolamine). מולקולות אלה desorbed ממשטחים שונים כמו CH 3 -SAMs, יהלומי מימן הסתיים ונתמך bilayers שומנים בתנאי ממס שונים. לבסוף,יתרונות של ניסויי מולקולת כוח ספקטרוסקופיות יחידים נדונים לרבות אמצעים כדי להחליט אם באמת מולקולה בודדת נחקרה בניסוי.

בחלק הבא, התוצאות עבור מעל מתוארות מולקולות דוגמא, כלומר polytyrosine פולי פולימרים (חומצת אמינו), פולימר השתל מלק g -PS והאפיפיור פוספוליפידים, מוצגים. ראשית לכל דוגמא, להתנסות פרטים ספציפיים לרכישת נתונים והכנת הנתונים מסופקים. לאחר מכן, תוצאות המופת לניסויים שבם מולק?...

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Investigating Single Molecule Adhesion by Atomic Force Spectroscopy

A protocol to couple a large variety of single molecules covalently onto an AFM tip is presented. Procedures and examples to determine the adhesion force and free energy of these molecules on solid supports and bio-interfaces are provided.

חוקר מולקולה בודדת הדבקה על ידי הכוח האטומי ספקטרוסקופיה

Atomic force spectroscopy is an ideal tool to study molecules at surfaces and interfaces. An experimental protocol to couple a large variety of single ...

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10.2K Views.  Technische Universität München. A protocol to couple a large variety of single molecules covalently onto an AFM tip is presented. Procedures and examples to determine the adhesion force and free energy of these molecules on solid supports and bio-interfaces are provided.

Video: Investigating Single Molecule Adhesion by Atomic Force Spectroscopy

Compact Quantum Dots for Single-molecule Imaging

Single-molecule imaging is an important tool for understanding the mechanisms of biomolecular function and for visualizing the spatial and temporal heterogeneity of molecular behaviors that underlie cellular biology 1-4. To image an individual molecule of interest, it is typically conjugated to a fluorescent tag (dye, protein, bead, or quantum dot) and observed with epifluorescence or total internal reflection fluorescence (TIRF) microscopy. While dyes and fluorescent proteins have been the mainstay of fluorescence imaging for decades, their fluorescence is unstable under high photon fluxes necessary to observe individual molecules, yielding only a few seconds of observation before complete loss of signal. Latex beads and dye-labeled beads provide improved signal stability but at the expense of drastically larger hydrodynamic size, which can deleteriously alter the diffusion and behavior of the molecule under study.
Quantum dots (QDs) offer a balance between these two problematic regimes. These nanoparticles are composed of semiconductor materials and can be engineered with a hydrodynamically compact size with exceptional resistance to photodegradation 5. Thus in recent years QDs have been instrumental in enabling long-term observation of complex macromolecular behavior on the single molecule level. However these particles have still been found to exhibit impaired diffusion in crowded molecular environments such as the cellular cytoplasm and the neuronal synaptic cleft, where their sizes are still too large 4,6,7.
Recently we have engineered the cores and surface coatings of QDs for minimized hydrodynamic size, while balancing offsets to colloidal stability, photostability, brightness, and nonspecific binding that have hindered the utility of compact QDs in the past 8,9. The goal of this article is to demonstrate the synthesis, modification, and characterization of these optimized nanocrystals, composed of an alloyed HgxCd1-xSe core coated with an insulating CdyZn1-yS shell, further coated with a multidentate polymer ligand modified with short polyethylene glycol (PEG) chains (Figure 1). Compared with conventional CdSe nanocrystals, HgxCd1-xSe alloys offer greater quantum yields of fluorescence, fluorescence at red and near-infrared wavelengths for enhanced signal-to-noise in cells, and excitation at non-cytotoxic visible wavelengths. Multidentate polymer coatings bind to the nanocrystal surface in a closed and flat conformation to minimize hydrodynamic size, and PEG neutralizes the surface charge to minimize nonspecific binding to cells and biomolecules. The end result is a brightly fluorescent nanocrystal with emission between 550-800 nm and a total hydrodynamic size near 12 nm. This is in the same size range as many soluble globular proteins in cells, and substantially smaller than conventional PEGylated QDs (25-35 nm).

We describe the preparation of colloidal quantum dots with minimized hydrodynamic size for single-molecule fluorescence imaging. Compared to conventional quantum dots, these nanoparticles are similar in size to globular proteins and are optimized for single-molecule brightness, stability against photodegradation, and resistance to nonspecific binding to proteins and cells.

נקודות קוונטיות קומפקטיות להדמית מולקולה בודדה

Single-molecule imaging is an important tool for  understanding the mechanisms of biomolecular function and for visualizing the  spatial and temporal ...

Scanning-probe Single-electron Capacitance Spectroscopy

The integration of low-temperature scanning-probe techniques and single-electron capacitance spectroscopy represents a powerful tool to study the electronic quantum structure of small systems - including individual atomic dopants in semiconductors. Here we present a capacitance-based method, known as Subsurface Charge Accumulation (SCA) imaging, which is capable of resolving single-electron charging while achieving sufficient spatial resolution to image individual atomic dopants. The use of a capacitance technique enables observation of subsurface features, such as dopants buried many nanometers beneath the surface of a semiconductor material1,2,3. In principle, this technique can be applied to any system to resolve electron motion below an insulating surface.
As in other electric-field-sensitive scanned-probe techniques4, the lateral spatial resolution of the measurement depends in part on the radius of curvature of the probe tip. Using tips with a small radius of curvature can enable spatial resolution of a few tens of nanometers. This fine spatial resolution allows investigations of small numbers (down to one) of subsurface dopants1,2. The charge resolution depends greatly on the sensitivity of the charge detection circuitry; using high electron mobility transistors (HEMT) in such circuits at cryogenic temperatures enables a sensitivity of approximately 0.01 electrons/Hz&frac12; at 0.3 K 5.

Scanning-probe single-electron capacitance spectroscopy facilitates the study of single-electron motion in localized subsurface regions. A sensitive charge-detection circuit is incorporated into a cryogenic scanning probe microscope to investigate small systems of dopant atoms beneath the surface of semiconductor samples.

ספקטרוסקופיה קיבוליות חד אלקטרונים סורקות-בדיקה

The integration of low-temperature scanning-probe techniques and single-electron capacitance spectroscopy represents a powerful tool to study the ...

Single Wavelength Shadow Imaging of Caenorhabditis elegans Locomotion Including Force Estimates

This study demonstrates an inexpensive and straightforward technique that allows the measurement of physical properties such as position, velocity, acceleration and forces involved in the locomotory behavior of nematodes suspended in a column of water in response to single wavelengths of light. We demonstrate how to evaluate the locomotion of a microscopic organism using Single Wavelength Shadow Imaging (SWSI) using two different examples.
The first example is a systematic and statistically viable study of the average descent of C. elegans in a column of water. For this study, we used living and dead wildtype C. elegans. When we compared the velocity and direction of nematode active movement with the passive descent of dead worms within the gravitational field, this study showed no difference in descent-times. The average descent was 1.5 mm/sec &#177; 0.1 mm/sec for both the live and dead worms using 633 nm coherent light.
The second example is a case study of select individual C. elegans changing direction during the descent in a vertical water column. Acceleration and force are analyzed in this example. This case study demonstrates the scope of other physical properties that can be evaluated using SWSI while evaluating the behavior using single wavelengths in an environment that is not accessible with traditional microscopes. Using this analysis we estimated an individual nematode is capable of thrusting with a force in excess of 28 nN.
Our findings indicate that living nematodes exert 28 nN when turning, or moving against the gravitational field. The findings further suggest that nematodes passively descend in a column of water, but can actively resist the force of gravity primarily by turning direction.

Single Wavelength Shadow Imaging of Caenorhabditis elegans Locomotion Including Force Estimates

The technique presented here measures the path of freely swimming microscopic species using single wavelength exposure. C. elegans are used to demonstrate shadow imaging as an inexpensive alternative to costly microscopes. This technique can be adapted to accommodate various orientations, environments and species to measure direction, speed, acceleration and forces.

אחת אורך גל צל הדמיה של<em&gt; Elegans Caenorhabditis</em&gt; נידות כולל כוח אומדנים

This study demonstrates an inexpensive and straightforward technique that allows the measurement of physical properties such as position, velocity, ...

Atomic Force Microscopy of Red-Light Photoreceptors Using PeakForce Quantitative Nanomechanical Property Mapping

Atomic force microscopy (AFM) uses a pyramidal tip attached to a cantilever to probe the force response of a surface. The deflections of the tip can be measured to ~10 pN by a laser and sectored detector, which can be converted to image topography. Amplitude modulation or &#8220;tapping mode&#8221; AFM involves the probe making intermittent contact with the surface while oscillating at its resonant frequency to produce an image. Used in conjunction with a fluid cell, tapping-mode AFM enables the imaging of biological macromolecules such as proteins in physiologically relevant conditions. Tapping-mode AFM requires manual tuning of the probe and frequent adjustments of a multitude of scanning parameters which can be challenging for inexperienced users. To obtain high-quality images, these adjustments are the most time consuming.
PeakForce Quantitative Nanomechanical Property Mapping (PF-QNM) produces an image by measuring a force response curve for every point of contact with the sample. With ScanAsyst software, PF-QNM can be automated. This software adjusts the set-point, drive frequency, scan rate, gains, and other important scanning parameters automatically for a given sample. Not only does this process protect both fragile probes and samples, it significantly reduces the time required to obtain high resolution images. PF-QNM is compatible for AFM imaging in fluid; therefore, it has extensive application for imaging biologically relevant materials.
The method presented in this paper describes the application of PF-QNM to obtain images of a bacterial red-light photoreceptor, RpBphP3 (P3), from photosynthetic R. palustris in its light-adapted state. Using this method, individual protein dimers of P3 and aggregates of dimers have been observed on a mica surface in the presence of an imaging buffer. With appropriate adjustments to surface and/or solution concentration, this method may be generally applied to other biologically relevant macromolecules and soft materials.

A method for investigating the structure of a protein photoreceptor using atomic force microscopy (AFM) is described in this paper. PeakForce Quantitative Nanomechanical Property Mapping (PF-QNM) reveals intact protein dimers on a mica surface.

מיקרוסקופית כוח האטומי של אורות אדומים קולטני אור שימוש במיפוי PeakForce כמותי nanomechanical נכס

Atomic force microscopy (AFM) uses a pyramidal tip attached to a cantilever to probe the force response of a surface. The deflections of the tip can be ...

Making Record-efficiency SnS Solar Cells by Thermal Evaporation and Atomic Layer Deposition

Tin sulfide (SnS) is a candidate absorber material for Earth-abundant, non-toxic solar cells. SnS offers easy phase control and rapid growth by congruent thermal evaporation, and it absorbs visible light strongly. However, for a long time the record power conversion efficiency of SnS solar cells remained below 2%. Recently we demonstrated new certified record efficiencies of 4.36% using SnS deposited by atomic layer deposition, and 3.88% using thermal evaporation. Here the fabrication procedure for these record solar cells is described, and the statistical distribution of the fabrication process is reported. The standard deviation of efficiency measured on a single substrate is typically over 0.5%. All steps including substrate selection and cleaning, Mo sputtering for the rear contact (cathode), SnS deposition, annealing, surface passivation, Zn(O,S) buffer layer selection and deposition, transparent conductor (anode) deposition, and metallization are described. On each substrate we fabricate 11 individual devices, each with active area 0.25 cm2. Further, a system for high throughput measurements of current-voltage curves under simulated solar light, and external quantum efficiency measurement with variable light bias is described. With this system we are able to measure full data sets on all 11 devices in an automated manner and in minimal time. These results illustrate the value of studying large sample sets, rather than focusing narrowly on the highest performing devices. Large data sets help us to distinguish and remedy individual loss mechanisms affecting our devices.

Tin sulfide (SnS) is a candidate material for Earth-abundant, non-toxic solar cells. Here, we demonstrate the fabrication procedure of the SnS solar cells employing atomic layer deposition, which yields 4.36% certified power conversion efficiency, and thermal evaporation which yields 3.88%.

מה שהופך את התאים סולריים שיא יעילות SNS על ידי אידוי תרמי ואטומית שכבת הפקדת

Tin sulfide (SnS) is a candidate absorber material for Earth-abundant, non-toxic solar cells. SnS offers easy phase control and rapid growth by congruent ...

Sub-nanometer Resolution Imaging with Amplitude-modulation Atomic Force Microscopy in Liquid

Atomic force microscopy (AFM) has become a well-established technique for nanoscale imaging of samples in air and in liquid. Recent studies have shown that when operated in amplitude-modulation (tapping) mode, atomic or molecular-level resolution images can be achieved over a wide range of soft and hard samples in liquid. In these situations, small oscillation amplitudes (SAM-AFM) enhance the resolution by exploiting the solvated liquid at the surface of the sample. Although the technique has been successfully applied across fields as diverse as materials science, biology and biophysics and surface chemistry, obtaining high-resolution images in liquid can still remain challenging for novice users. This is partly due to the large number of variables to control and optimize such as the choice of cantilever, the sample preparation, and the correct manipulation of the imaging parameters. Here, we present a protocol for achieving high-resolution images of hard and soft samples in fluid using SAM-AFM on a commercial instrument. Our goal is to provide a step-by-step practical guide to achieving high-resolution images, including the cleaning and preparation of the apparatus and the sample, the choice of cantilever and optimization of the imaging parameters. For each step, we explain the scientific rationale behind our choices to facilitate the adaptation of the methodology to every user's specific system.

We present a method for achieving sub-nanometer resolution images with amplitude-modulation (tapping mode) atomic force microscopy in liquid. The method is demonstrated on commercial atomic force microscopes. We explain the rationale behind our choices of parameters and suggest strategies for resolution optimization.

הדמיה ברזולוציה משנה ננומטר עם מיקרוסקופית כוח אטומי משרעת אפנון בנוזל

Atomic force microscopy (AFM) has become a well-established technique for nanoscale imaging of samples in air and in liquid. Recent studies have shown ...

Quantitative Analysis of Vacuum Induction Melting by Laser-induced Breakdown Spectroscopy

Vacuum induction melting is a popular method for refining high purity metal and alloys. Traditionally, standard process control in metallurgy involves several steps, include drawing samples, cooling, cutting, transport to the laboratory, and analysis. The whole analysis process requires more than 30 minutes, which hinders on-line process control. Laser-induced breakdown spectroscopy is an excellent on-line analysis method that can satisfy the requirements of vacuum induction melting because it is fast and noncontact and does not require sample preparation. The experimental facility uses a lamp-pumped Q-switched laser to ablate melted liquid steel with an output energy of 80 mJ, a frequency of 5 Hz, a FWHM pulse width of 20 ns, and a working wavelength of 1,064 nm. A multi-channel linear charge coupled device (CCD) spectrometer is used to measure the emission spectrum in real time, with a spectral range from 190 to 600 nm and a resolution of 0.06 nm at a wavelength of 200 nm. The protocol includes several steps: standard alloy sample preparation and an ingredient test, smelting of standard samples and determination of the laser breakdown spectrum, and construction of the elements concentration quantitative analysis curve of each element. To realize the concentration analysis of unknown samples, the spectrum of a sample also needs to be measured and disposed with the same process. The composition of all main elements in the melted alloy can be quantitatively analyzed with an internal standard method. The calibration curve shows that the limit of detection of most metal elements ranges from 20-250 ppm. The concentration of elements, such as Ti, Mo, Nb, V, and Cu, can be lower than 100 ppm, and the concentrations of Cr, Al, Co, Fe, Mn, C, and Si range from 100-200 ppm. The R2 of some calibration curves can exceed 0.94.

During vacuum induction melting, laser-induced breakdown spectroscopy is used to perform real-time quantitative analysis of the main-ingredient elements of a molten alloy.

אנליזה כמותית של אינדוקציה ואקום התכה על-ידי ספקטרוסקופיית לייזר המושרה

Vacuum induction melting is a popular method for refining high purity metal and alloys. Traditionally, standard process control in metallurgy involves ...

An Efficient Method for Selective Desalination of Radioactive Iodine Anions by Using Gold Nanoparticles-Embedded Membrane Filter

Here, we demonstrate a detail protocol for the preparation of nanomaterials-embedded composite membranes and its application to the efficient and ion-selective removal of radioactive iodines. By using citrate-stabilized gold nanoparticles (mean diameter: 13 nm) and cellulose acetate membranes, gold nanoparticle-embedded cellulose acetate membranes (Au-CAM) have easily been fabricated. The nano-adsorbents on Au-CAM were highly stable in the presence of high concentration of inorganic salts and organic molecules. The iodide ions in aqueous solutions could rapidly be captured by this engineered membrane. Through a filtration process using an Au-CAM containing filter unit, excellent removal efficiency (&gt;99%) as well as ion-selective desalination result was achieved in a short time. Moreover, Au-CAM provided good reusability without significant decrease of its performances. These results suggested that the present technology using the engineered hybrid membrane will be a promising process for the large-scale decontamination of radioactive iodine from liquid wastes.

An efficient method for the rapid and ion-selective desalination of radioactive iodine in several aqueous solutions is described by using gold nanoparticles-immobilized cellulose acetate membrane filters.

שיטה יעילה לצורך התפלה סלקטיבי של יוד רדיואקטיבי אניונים באמצעות זהב חלקיקים-מוטבע ממברנה מסנן

Here, we demonstrate a detail protocol for the preparation of nanomaterials-embedded composite membranes and its application to the efficient and ...

Atomic Force Microscopy Cantilever-Based Nanoindentation: Mechanical Property Measurements at the Nanoscale in Air and Fluid

An atomic force microscope (AFM) fundamentally measures the interaction between a nanoscale AFM probe tip and the sample surface. If the force applied by the probe tip and its contact area with the sample can be quantified, it is possible to determine the nanoscale mechanical properties (e.g., elastic or Young&#39;s modulus) of the surface being probed. A detailed procedure for performing quantitative AFM cantilever-based nanoindentation experiments is provided here, with representative examples of how the technique can be applied to determine the elastic moduli of a wide variety of sample types, ranging from kPa to GPa. These include live mesenchymal stem cells (MSCs) and nuclei in physiological buffer, resin-embedded dehydrated loblolly pine cross-sections, and Bakken shales of varying composition.
Additionally, AFM cantilever-based nanoindentation is used to probe the rupture strength (i.e., breakthrough force) of phospholipid bilayers. Important practical considerations such as method choice and development, probe selection and calibration, region of interest identification, sample heterogeneity, feature size and aspect ratio, tip wear, surface roughness, and data analysis and measurement statistics are discussed to aid proper implementation of the technique. Finally, co-localization of AFM-derived nanomechanical maps with electron microscopy techniques that provide additional information regarding elemental composition is demonstrated.

Quantifying the contact area and force applied by an atomic force microscope (AFM) probe tip to a sample surface enables nanoscale mechanical property determination. Best practices to implement AFM cantilever-based nanoindentation in air or fluid on soft and hard samples to measure elastic modulus or other nanomechanical properties are discussed.

מיקרוסקופ כוח אטומי ננו-הזחה מבוססת Cantilever: מדידות תכונות מכניות בקנה מידה ננומטרי באוויר ובנוזל

An atomic force microscope (AFM) fundamentally measures the interaction between a nanoscale AFM probe tip and the sample surface. If the force applied by ...

מערכי קנטיליבר פעילים מקבילים ב-AFMS כדי לאפשר בדיקות בתפוקה גבוהה

Active Probe Atomic Force Microscopy with Quattro-Parallel Cantilever Arrays for High-Throughput Large-Scale Sample Inspection

An Atomic Force Microscope&#160;(AFM) is&#160;a powerful and versatile tool for nanoscale surface studies to capture 3D topography images of samples. However, due to their limited imaging throughput, AFMs have not been widely adopted for large-scale inspection purposes. Researchers have developed high-speed AFM systems to record dynamic process videos in chemical and biological reactions at tens of frames per second, at the cost of a small imaging area of up to several square micrometers. In contrast, inspecting large-scale nanofabricated structures, such as semiconductor wafers, requires nanoscale spatial resolution imaging of a static sample over hundreds of square centimeters with high productivity. Conventional AFMs use a single passive cantilever probe with an optical beam deflection system, which can only collect one pixel at a time during AFM imaging, resulting in low imaging throughput. This work utilizes an array of active cantilevers with embedded piezoresistive sensors and thermomechanical actuators, which allows simultaneous multi-cantilever operation in parallel operation for increased imaging throughput. When combined with large-range nano-positioners and proper control algorithms, each cantilever can be individually controlled to capture multiple AFM images. With data-driven post-processing algorithms, the images can be stitched together, and defect detection can be performed by comparing them to the desired geometry. This paper introduces principles of the custom AFM using the active cantilever arrays, followed by a discussion on practical experiment considerations for inspection applications. Selected example images of silicon calibration grating, highly-oriented pyrolytic graphite, and extreme ultraviolet lithography masks are captured using an array of four active cantilevers (&#34;Quattro&#34;) with a 125 &#181;m tip separation distance. With more engineering integration, this high-throughput, large-scale imaging tool can provide 3D metrological data for extreme ultraviolet (EUV) masks, chemical mechanical planarization (CMP) inspection, failure analysis, displays, thin-film step measurements, roughness measurement dies, and laser-engraved dry gas seal grooves.

מחבר זרקור: מבוא למיקרוסקופ כוח אטומי של בדיקה פעילה עם מערכי קנטיליבר קוואטרו-מקביליים

Large-scale sample inspection with nanoscale resolution has a wide range of applications, especially for nanofabricated semiconductor wafers. Atomic force microscopes can be a great tool for this purpose, but are limited by their imaging speed. This work utilizes parallel active cantilever arrays in AFMs to enable high-throughput and large-scale inspections.

מיקרוסקופ כוח אטומי פעיל של בדיקה עם מערכי קנטיליבר קוואטרו-מקביליים לבדיקת דגימות בקנה מידה גדול בתפוקה גבוהה

An Atomic Force Microscope&#160;(AFM) is&#160;a powerful and versatile tool for nanoscale surface studies to capture 3D topography images of samples. ...