Sticking Rate Research Articles

Research on Spatial Migration Patterns and Influencing Factors of Western Talents: Based on Data from "Double first-class" Universities in China

The western region's talent loss issue has received widespread attention. Promoting the construction of human resources in the west has become key to forming an important high-quality development pole in western China. This study analyzes the graduate migration data of first-class universities in western China between 2016 and 2020 and draws the following conclusions: Overall, the retention rate of college graduates in western China across seven provinces is high, with a relatively higher retention rate observed in the place of study in four southwestern provinces. The retention rate of different provinces' place of study showed different trends during the period of 2016-2020, and the retention rate of different provinces also showed different trends during the same period. In 2020, western college graduates continued to show a preference for employment in popular provinces such as Guangdong, Beijing, and Shanghai, while they showed a greater inclination towards choosing employment opportunities in the South and Central regions of China. The results based on the directed migration model show that economic factors and natural and educational resources in a city have a greater impact on employment decisions. Analysis of heterogeneity found that graduates from areas with a high sticking rate are more susceptible to population size, human resources, and economic factors, and that cultural resources and transportation resources also have a significant impact on talent migration. Policy recommendations include western provinces taking higher education as a key factor to utilizing employment retention advantages to attract and retain high-quality talents.

Collision-sticking rates of acid–base clusters in the gas phase determined from atomistic simulation and a novel analytical interacting hard-sphere model

Abstract. Kinetics of collision-sticking processes between vapor molecules and clusters of low-volatility compounds govern the initial steps of atmospheric new particle formation. Conventional non-interacting hard-sphere models underestimate the collision rate by neglecting long-range attractive forces, and the commonly adopted assumption that every collision leads to the formation of a stable cluster (unit mass accommodation coefficient) is questionable for small clusters, especially at elevated temperatures. Here, we present a generally applicable analytical interacting hard-sphere model for evaluating collision rates between molecules and clusters, accounting for long-range attractive forces. In the model, the collision cross section is calculated based on an effective molecule–cluster potential, derived using Hamaker's approach. Applied to collisions of sulfuric acid or dimethylamine with neutral bisulfate–dimethylammonium clusters composed of 1–32 dimers, our new model predicts collision rates 2–3 times higher than the non-interacting model for small clusters, while decaying asymptotically to the non-interacting limit as cluster size increases, in excellent agreement with a collision-rate-theory atomistic molecular dynamics simulation approach. Additionally, we calculated sticking rates and mass accommodation coefficients (MACs) using atomistic molecular dynamics collision simulations. For sulfuric acid, a MAC ≈1 is observed for collisions with all cluster sizes at temperatures between 200 and 400 K. For dimethylamine, we find that MACs decrease with increasing temperature and decreasing cluster size. At low temperatures, the MAC ≈1 assumption is generally valid, but at elevated temperatures MACs can drop below 0.2 for small clusters.

Investigating the Relationship Between Special Medical Waste Disposal and Needle Sticking of Staff in Hospitals of Iran University of Medical Sciences

Background: Infectious hospital waste, including needles and sharp instruments, is one of the most important causes of needle sticks. Objectives: The study aimed to investigate the factors affecting the disposal of special medical waste with needle sticks among healthcare workers in hospitals at the Iran University of Medical Sciences. Methods: This descriptive-analytical, retrospective, and cross-sectional study were done regarding the data in the autumn of 2019. Among 6119 medical-service staff, 180 subjects have been exposed to the needle stick at least once. Data were collected in two parts. The data were analyzed using correlation tests by SPSS software version 25. Results: The most devices leading to injury were needles (58%), angiocatheter (21%), ampoules (17%), suture needles (12%), scalpels (9%), other tools (8%), and razor blades (7%). The five wards with the highest needle sticks were the operating room (24.44%), surgery (22.22%), emergency (15%), internal wards (10%), and paraclinical (8.33%). Also, several factors, such as work shifts and the amount of work experience of individuals, can play an essential role in the rate of needle stitching of medical personnel. Importantly, we found a significant relationship between the volume of medical waste and employee needlestick rates. Conclusions: According to the results, we found a significant positive relationship between the volume of medical waste and employees' needle sticking rate. The observance of standard guidelines and the development and increase of occupational safety protection training courses have the most significant role in reducing needle sticks.

Study on the slagging trends of the pre-combustion chamber in industrial pulverized coal boiler under different excess air coefficients by CFD numerical simulation

Industrial pulverized coal boiler (IPCB) usually employ a pre-combustion chamber (PCC) to ensure stable combustion. However, there are potential slagging problems in the PCC, which threaten the safe operation of the boiler. Air-staged combustion technology is an effective method to reduce NOx emission, and different excess air coefficients affect slagging. CFD simulation is an important method for studying slagging in the furnace. In this paper, Using CFD simulation with slagging model embedded by user-defined function, the slagging trends in the PCC are studied under different excess air coefficients. The particles' collision rate (CR), deposition rate (DR), and sticking rate (SR) on the PCC walls are obtained by CFD simulation. As the excess air coefficient in the PCC (αPCC) increases from 0.3 to 1.1, the CR of particles on all walls of PCC (CRPCC) increases exponentially, indicating the abrasion degree on the PCC walls is growing rapidly. In addition, due to the sizeable annular recirculation zone when αPCC = 0.3, the DR of particles on all walls of PCC (DRPCC) and the SR of particles on all walls of PCC (SRPCC) are much larger than those under other conditions, the slagging trend is the worse. As the αPCC increases from 0.3 to 1.1, the slagging trends in the PCC first decrease and then increase. To improve the safety of boiler operation, it is recommended that the αPCC be adjusted between 0.5 and 0.9.

Revealing the mechanisms for inactive rolling and wear behaviour on chemical mechanical planarization

The paper examines the influences of abrasive conditions, silica thickness, and motion parameters on the polishing process of a silicon substrate covered by a thin silica film. The silica film minimizes the direct collision of the abrasive on the silicon substrate. During the polishing process, the adhesion phenomenon plays the main role in atomic removal. Notably, the abrasive sliding motion can generate an inactive rolling motion. The inactive rolling motion can be used to explain the stick-slip motion by showing the system of periodic high-strain marks. In rolling, the deformation behaviors of the workpiece rely on the correspondence between the rolling and the moving speeds. In the fixed diamond abrasive (FDA) cases, the atomic sticking rate is lower but the workpiece deformation is higher than the loose diamond abrasive (LDA) cases. Besides, the FDA cannot create the inactive rolling motion and the stick-slip motion as the LDA. In general, the paper points out the existence of the inactive rolling motion and its role in the atomic removal process through the stick-slip motion phenomenon at the nanoscale, the advantage of this type of motion in a conventional chemical mechanical polishing (CMP) process, and the padding role of the silica layer.

Speed limits of protein assembly with reversible membrane localization.

Protein assembly is often studied in a three-dimensional solution, but a significant fraction of binding events involve proteins that can reversibly bind and diffuse along a two-dimensional surface. In a recent study, we quantified how proteins can exploit the reduced dimensionality of the membrane to trigger complex formation. Here, we derive a single expression for the characteristic timescale of this multi-step assembly process, where the change in dimensionality renders rates and concentrations effectively time-dependent. We find that proteins can accelerate dimer formation due to an increase in relative concentration, driving more frequent collisions, which often win out over slow-downs due to diffusion. Our model contains two protein populations that dimerize with one another and use a distinct site to bind membrane lipids, creating a complex reaction network. However, by identifying two major rate-limiting pathways to reach an equilibrium steady-state, we derive an excellent approximation for the mean first passage time when lipids are in abundant supply. Our theory highlights how the "sticking rate" or effective adsorption coefficient of the membrane is central in controlling timescales. We also derive a corrected localization rate to quantify how the geometry of the system and diffusion can reduce rates of membrane localization. We validate and test our results using kinetic and particle-based reaction-diffusion simulations. Our results establish how the speed of key assembly steps can shift by orders-of-magnitude when membrane localization is possible, which is critical to understanding mechanisms used in cells.

Reaction mechanisms of H(D) → D(H) + Pt(111) interaction system: Quasiclassical molecular dynamics simulations

Reaction mechanisms of the H(or D) → D(or H) + Pt(111) interaction system have been proposed by using quasiclassical molecular dynamics simulations. First, the adsorbate atoms are dispersed randomly over the surface’s adsorption sites to form 0.18 ML, 0.25 ML, and 0.50 ML of coverages. Since the surface is considered to be resilient, thanks to imitating the multi-layer slab by using a function of many-body embedded-atom potential energy, the slab atoms can move because of the implemented external forces. Thus, energy transfer from the incident atom to surface atoms and adsorbates has been considered a real collision system. Moreover, the London–Eyring–Polanyi–Sato function is modified to model interaction between the adsorbates and slab atoms. In addition to desorption of HD and H2(or D2) after the collision of the incoming H(or D) atom with the surface, subsurface penetration, sticking on the surface, and inelastic reflection of the incident atom have been investigated in detail as the reaction mechanisms on the surface. In addition, isotopic effects on reaction mechanisms have been analyzed in depth and shown. Also, hot-atom and Eley–Rideal mechanisms have been examined and explained. The hot-atom mechanism is responsible for the formation of H2/D2 products. Furthermore, the sticking rate on the surface is lower than the rate of subsurface penetration.

A Novel Shared Guidance Scheme for Intelligent Haptic Interaction Based Swarm Control of Magnetic Nanoparticles in Blood Vessels

Swarm magnetic control is a promising technology for use in nanorobotics. However, automated control schemes for small and large populations of nanoparticles are not effective due to the complexity of real blood vessels, the lack of technologies for motion control feedback of individual particles, and the inaccuracy of the mathematical models. It is quite difficult to control unexpected magnetic particle movements in a real vessel. Specifically, when magnets are used to guide the particles, the sticking of particles to vessel walls causes the dispersion of particles, which is the main reason for low steering efficiency that may cause the occurrence of side effects in non-targeted areas. In addition, when the aggregation of particles occurs inside the vessels, it can cause clogging of the vessel and the randomness of aggregation makes it difficult for the user to control the particles precisely. In the presented work, we suggest a novel intuitive shared guidance scheme for 3D steering of magnetic nanoparticles (MNPs) in a realistic vessel model. We have performed simulation based user studies with different guidance modes (visual feedback (V), shared control (S), shared control and forbidden region mode (S-F), shared control and adaptive forbidden region mode (S-AF)). The results of these studies show that the suggested S-AF mode can significantly ( ${p}$ -value ${p}$ -value < 0.01) reducing the sticking rate of MNPs inside the vessel. The proposed intelligent navigation scheme for MNPs can in the future be combined with real-time magnetic particle imaging (MPI) for targeted drug delivery.

Effect of Surfactant Compound Sprays on The Rate of Adsorption on Different Target Surfaces

The first operation of adsorption on leaf surfaces in pulverization is drop sticking. In the water wettability of the surfaces, the sticking of the drops has a great importance. Drop contact angle, contact height, and contact diameter values in the third and tenth seconds were measured with Drop Shape Analysis 10 device to determine adsorption, spreading, and sticking levels by applying mixtures of ten surface active substances including different contents with pure water to different leaf surfaces. The adsorption and sticking rates of the drops they formed on different leaf surfaces were determined for the time they are obtained from the data obtained in both time periods. Furthermore, the spreading rates of the mixtures prepared by taking into account the change rates during the last seven seconds between these two periods were determined as the sticking rate. Coating shares related to covering rates of different surface active substances with different surface properties on the surface of leaves were evaluated as possible work success according to the adsorption, spreading and sticking levels anticipated in spraying. According to their results on the application surfaces, surface active substances and leaves were evaluated statistically by the SPSS 15 program in terms of their similar properties. It has been found that surface active substance mixtures with sodium carboxymethylcellulose and carboxymethylcellulose contents had the largest drop contact angles and contact heights with the smallest drop contact diameters on the leaf surfaces, and a negative impact on the adsorption performance as they spread very little over seven seconds. It has been determined that drops with surface active substance including trisiloxane + allyloxypolyethyleneglycol and alcoholethoxylate, alkylphenolethoxylate have formed the smallest contact angles, minimum drop heights and largest contact diameters on the surface of the leaves, as well as increased adsorption and sticking by spreading rapidly for seven seconds.

New Study of Mgo Nps in Drilling Fluid to Reduce Stick-Slip Vibration in Drilling System

Stick-slip is kind of vibration which associated with drilling operation in around the bottom hole assembly (BHA) due to the small clearance between drill string &amp; the open hole and due to the eccentric rotating of string. This research presents results of specific experimental study that was run by using two types of drilling mud (Fresh water Bentonite &amp; Polymer), with/without Nanoparticle size materials of MgO in various ratios and computes the rheological properties of mud for each concentration [Yield point, plastic viscosity, Av, PH, filter loss (30 min), filter cake, Mud Cake Friction, Friction Factor]. These results then were used to find a clear effects of Nanoparticle drilling mud rheology on stick - slip strength by several perspectives through a special “Torque and Drag” software which simulate the torque amount expected on BHA during drilling a vertical well in different conditions using real drilling string design that usually used in Iraqi oil fields. Thus to mitigate or to prevent stick–slip and cure the sequence events that could happen to both of drilling string and the well, i.e. Bit/BHA wear, pipe sticking, borehole instability and low Rate of penetration. Our study concluded that there are good reduction in the torque from (2031lb-ft) to (1823lb-ft) using polymer mud and torque reduction from (4000lb-ft) to (3450lb-ft) using Fresh Water Bentonite, these results do not include any breaking in the satisfactory range of other mud rheology.

Chemical nitrogen fractionation in dense molecular clouds

Nitrogen-bearing molecules display variable isotopic fractionation levels in different astronomical environments such as in the interstellar medium or in the Solar system. Models of interstellar chemistry are unable to induce nitrogen fraction in cold molecular clouds as exchange reactions for 15N are mostly inefficient. Here, we developed a new gas–grain model for nitrogen fractionation including a thorough search for new nitrogen fractionation reactions and a realistic description of atom depletion on to interstellar dust particles. We show that, while dense molecular cloud gas-phase chemistry alone leads to very low fractionation, 14N atoms are preferentially depleted from the gas phase due to a mass-dependent grain surface sticking rate for atomic nitrogen. However, assuming an elementary 14N/15N ratio of 441 (equal to the solar wind value), our model leads to only low 15N enrichment for all N-containing species synthesized in the gas phase with predicted 14N/15N ratios in the range 360–400. Higher enrichment levels can neither be explained by this mechanism, nor through chemistry, with two possible explanations: (i) The elementary 14N/15N ratio in the local ISM is smaller, as suggested by the recent work of Romano et al., with a hypothetic 15NNH+ and 15NNH+ depletion due to variation of the electronic recombination rate constant variation with the isotopes and (ii) N2 photodissociation leads to variable nitrogen fractionation in diffuse molecular clouds where photons play an important role, which is conserved during dense molecular cloud formation as suggested by the work of Furuya & Aikawa.

Potential of Nano-Fluid Application in Deep Well Drilling Operation Challenges

Nanotechnology have vast potentials for applications in oil & gas industry. Nanoparticles are ultra-fine in nature, usually larger than an atom cluster but smaller than ordinary micro particles and thus have very high specific surface area with enormous potential interactions with its surroundings. In fact, some nanoparticles exhibit high thermal conductivity ability and affinity to acid gases. These traits and features possessed by nanomaterials intrigues the industry players and makes them zoomed on its potential application in the industry. In this study, the potentials of nanomaterials application in formulating “smart” drilling fluids for deep well drilling operations are discussed. Major deep well drilling fluid related challenges such as narrow drilling tolerance window, HPHT environment, excessive fluid loss and extensive formation damage, wellbore stability issues, differential sticking and low rate of penetration could be addressed through the addition of specific functionally tailored nanoparticles in the fluid formulation. It has been proven at least experimentally in laboratories and some minor field applications that addition of nanomaterials to the formulation would bring positive impacts on the plastic viscosity, yield strength, gel strength, filtrate loss volume and the lubricating effects of drilling fluids, making them feasible to be used in addressing the challenges in deep well drilling operations as discussed in this project paper. Due to the rheological enhancements, nano-fluids application is deemed technically feasible, cost effective and more environmental friendly due to the low concentrations requirement, in formulating smart fluids that could help to combat and address the major and prominent challenges in deep well drilling operations.

Dust Coagulation Regulated by Turbulent Clustering in Protoplanetary Disks

Abstract The coagulation of dust particles is a key process in planetesimal formation. However, the radial drift and bouncing barriers are not completely resolved, especially for silicate dust. Since the collision velocities of dust particles are regulated by turbulence in a protoplanetary disk, turbulent clustering should be properly treated. To that end, direct numerical simulations (DNSs) of the Navier–Stokes equations are requisite. In a series of papers, Pan &amp; Padoan used a DNS with Reynolds number Re ∼ 1000. Here, we perform DNSs with up to Re = 16,100, which allow us to track the motion of particles with Stokes numbers of 0.01 ≲ St ≲ 0.2 in the inertial range. Through the DNSs, we confirm that the rms relative velocity of particle pairs is smaller by more than a factor of two, compared to that by Ormel &amp; Cuzzi. The distributions of the radial relative velocities are highly non-Gaussian. The results are almost consistent with those by Pan &amp; Padoan or Pan et al. at low Re. Also, we find that the sticking rates for equal-sized particles are much higher than those for different-sized particles. Even in the strong-turbulence case with α-viscosity of 10−2, the sticking rates are as high as ≳50% and the bouncing probabilities are as low as ∼10% for equal-sized particles of St ≲ 0.01. Thus, turbulent clustering plays a significant role in the growth of centimeter-sized compact aggregates (pebbles) and also enhances the solid abundance, which may lead to the streaming instability in a disk.

Infrared problem in quantum acoustodynamics at finite temperature

The phonon-assisted sticking rate of slow moving atoms impinging on an elastic membrane at nonzero temperature is studied analytically using a model with linear atom-phonon interactions, valid in the weak coupling regime. A perturbative expansion of the adsorption rate in the atom-phonon coupling is infrared divergent at zero temperature, and this infrared problem is exacerbated by finite temperature. The use of a coherent state phonon basis in the calculation, however, yields infrared-finite results even at finite temperature. The sticking probability with the emission of any finite number of phonons is explicitly seen to be exponentially small, and it vanishes as the membrane size grows, a result that was previously found at zero temperature; in contrast to the zero temperature case, this exponential suppression of the sticking probability persists even with the emission of an infinite number of soft phonons. Explicit closed-form expressions are obtained for the effects of soft-phonon emission at finite temperature on the adsorption rate. For slowly moving atoms, the model predicts that there is zero probability of sticking to a large elastic membrane at nonzero temperature and weak coupling.

Study on External Stimulation and Toxicity of Swelling Analgesic Agent Babu

Through the observation of irritation and allergic swelling analgesic agent Babu, safety evaluation of swelling analgesic agent Babu, and provide experimental basis for clinical application. Intact and damaged skin irritation test and toxicity test in healthy rabbits； To paste the drug into the back of Kunming mice and the experimental group members on the forearm wrist 5cm, Observation of rabbit skin edema and erythema, behavior, fur luster, diet, weight and death; rat hair cover patch area and patch on the residual hair of volunteers, and record the subjects whether the skin white, itching, and comfortable in 24h.Compared with the control group, no obvious swelling analgesic agent Babu plaster irritation to rabbit skin. Residual swelling analgesic agents on Babu rat hair number were significantly decreased (P < 0.01).The number of hairs on the residual Babu agent between the groups showed a relatively balanced. Babu did not show the swelling analgesic agent, itching of skin white.Toxicological study results show that the swelling analgesic agent Babu is safe and non-toxic, compared with rubber swelling analgesic ointment, the advantages of the skin irritation swelling analgesic agent has prominent small Babu, the low rate of allergy and sticking is comfortable, and has a good mucoadhesive property.

Radiative corrections to quantum sticking on graphene

We study the sticking rate of atomic hydrogen to suspended graphene using four different methods that include contributions from processes with multiphonon emission. We compare the numerical results of the sticking rate obtained by: (1) the loop expansion of the atom self-energy, (2) the non-crossing approximation (NCA), (3) the independent boson model approximation (IBMA), and (4) a leading-order soft-phonon resummation method (SPR). The loop expansion reveals an infrared problem, analogous to the infamous infrared problem in QED. The 2-loop contribution to the sticking rate gives a result that tends to diverge for large membranes. The latter three methods remedy this infrared problem and give results that are finite in the limit of an infinite membrane. We find that for micromembranes (sizes ranging 100 nm to 10 $\mu$m), the latter three methods give results that are in good agreement with each other and yield sticking rates that are mildly suppressed relative to the lowest-order golden rule rate. Lastly, we find that the SPR sticking rate decreases slowly to zero with increasing membrane size, while both the NCA and IBMA rates tend to a nonzero constant in this limit. Thus, approximations to the sticking rate can be sensitive to the effects of soft-phonon emission for large membranes.

Mathematical modeling and experimental validation of ash deposition in a pulverized-coal boiler

A dynamic mathematical model of the fly ash transport and sticking in a pulverized-coal boiler was developed by a direct simulation Monte Carlo (DSMC) method. In this paper, the critical velocity model was used to calculate ash sticking rate during the initial deposition stage and the viscosity model was used to describe the outer layer deposition. The dynamic process of ash deposition was simulated and the distributions of adhesion particle size were obtained. The simulation results show that the ash deposit thickness increases by 47.52% with the load increases by 20% and the Alkaline Earth Metal (AAEM)-rich enhanced deposits of bulk ash particles are apparently stickier than the other ash particles. The experiments were carried out at two different loads and the morphology of ash deposit samples was analyzed by SEM/EDS. The propotion of particle size in 2μm were most in the deposition inner layer. The mean deposit thickness calculated by the DSMC method agreed with the measured value and the maximum relative error was 5.23%. A parametric study quantified the influence of changed operational conditions and ash material properties on the deposit formation process.

Modeling of ash deposition in a pulverized-coal boiler by direct simulation Monte Carlo method

In this paper, a mathematical model of the fly ash deposition in a 660MW supercritical once-through boiler was developed. The mechanism of particle-particle and particle-wall collisions has been considered. Particle collision is modeled by a direct simulation Monte Carlo (DSMC) method. Three submodels (impaction, thermophoresis, and sticking) were included in the mathematical model. In the ash deposition model, the critical velocity model was used to calculate the ash sticking rate during initial deposition, and the viscosity model was used for the outer layer deposition. An ash deposition probe was inserted into the peephole and ash deposits were collected. The morphology of these samples was analyzed using SEM. The deposit thickness and the distributions of adhesion particle size were obtained by mathematical model. The mean deposit thickness calculated by the DSMC method agreed with the value measured by the ash deposition probe with the relative error within 3.79%. The simulation results show that the deposition inner layer consists of fine particles less than 10μm in size and sticky fine particles were selectively captured during the initial deposition stage. The DSMC method may be a practical alternative for studies of ash deposit formation.

Infrared dynamics of cold atoms on hot graphene membranes

We study the infrared dynamics of low-energy atoms interacting with a sample of suspended graphene at finite temperature. The dynamics exhibits severe infrared divergences order by order in perturbation theory as a result of the singular nature of low-energy flexural phonon emission. Our model can be viewed as a two-channel generalization of the independent boson model with asymmetric atom-phonon coupling. This allows us to take advantage of the exact non-perturbative solution of the independent boson model in the stronger channel while treating the weaker one perturbatively. In the low-energy limit, the exact solution can be viewed as a resummation (exponentiation) of the most divergent diagrams in the perturbative expansion. As a result of this procedure, we obtain the atom's Green function which we use to calculate the atom damping rate, a quantity equal to the quantum sticking rate. A characteristic feature of our results is that the Green's function retains a weak, infrared cutoff dependence that reflects the reduced dimensionality of the problem. As a consequence, we predict a measurable dependence of the sticking rate on graphene sample size. We provide detailed predictions for the sticking rate of atomic hydrogen as a function of temperature and sample size. The resummation yields an enhanced sticking rate relative to the conventional Fermi golden rule result (equivalent to the one-loop atom self-energy), as higher-order processes increase damping at finite temperature.

Wall sticking of high water-cut crude oil transported at temperatures below the gel point

Some high water-cut crude oils can flow in the temperature below the oil gel point, while oil particles may adhere to the pipe wall as paste; this process is known as 'wall sticking'. This can cause partial or even total blocking of the transportation pipe. Several experiments using a laboratory flow loop were conducted to study the wall sticking characteristics of high water-cut crude oils. The experimental results indicated that the predominant influencing factors of wall sticking included shear stress, water-cut and differences between gel point and wall temperature. The wall sticking rate and occurrence temperature decrease with the increase of water-cut and shear stress. The criterion for the wall sticking occurrence temperature (WSOT), and the regression formula of the wall sticking thickness for high water-cut crude oil were then established. Typical case studies indicated that the prediction results obtained from the WSOT criterion and the wall sticking thickness regression formula were in accordance with the measured values. The wall sticking rate and WSOT vary widely under different conditions and it is necessary to consider its non-uniformity in production.