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1.
The origins of poor CD (cross machine) moisture profiles In tissue production are discussed generally. CD line force distribution at the first and second presser roll has a significant influence on the CD moisture profile. The crowning of cylinder and presser rolls compensates for the deformation of the Yankee cylinder shell (due to nip load, internal steam pressure and hood operating conditions) and of the presser rolls but only for any one given operating condition. However, during operation the parameters often have to be varied. in a sensitivity analysis the resulting CD line force deviations were calculated and typical figures are given here to demonstrate the relative effect. The shape of the resulting line load curves are drawn and from these the typical shape of the resulting CD moisture- profile can be derived. Means for possible control such as controllable presser rolls, sectionally adjustable hoods and steam boxes as well as eddy current and infra-red -heating are discussed and evaluated.  相似文献   
2.
Web caching has been widely used to alleviate Internet traffic congestion in World Wide Web (WWW) services. To reduce download throughput, an effective strategy on web cache management is needed to exploit web usage information in order to make a decision on evicting the document stored in case of cache saturation. This paper presents a so-called Learning Based Replacement algorithm (LBR), a hybrid approach towards an efficient replacement model for web caching by incorporating a machine learning technique (naive Bayes) into the LRU replacement method to improve prediction of possibility that an existing page will be revised by a succeeding request, from access history in a web log. The learned knowledge includes information on which URL objects in cache should be kept or evicted. The learning-based model is acquired to represent the hidden aspect of user request pattern for predicting the re-reference possibility. By a number of experiments, the LBR gains potential improvement of prediction on revisit probability, hit rate and byte hit rate overtraditional methods; LRU, LFU, and GDSF, respectively.  相似文献   
3.
This present work evaluates the cooling performance and thermal comfort of a thermoelectric ceiling cooling panel (TE-CCP) system composed of 36 TE modules. The cold side of the TE modules was fixed to an aluminum ceiling panel to cool a test chamber of 4.5 m3 volume, while a copper heat exchanger with circulating cooling water at the hot side of the TE modules was used for heat release. Thermal acceptability assessment was performed to find out whether the indoor environment met the ASHRAE Standard-55's 80% acceptability criteria. The standard was met with the TE-CCP system operating at 1 A of current flow with a corresponding cooling capacity of 201.6 W, which gives the COP of 0.82 with an average indoor temperature of 27°C and 0.8 m/s indoor air velocity.  相似文献   
4.
Resilient Packet Ring (RPR), or the Standard IEEE 802.17, is a new IP-based network technology proposed to replace SONET/SDH in metropolitan area networks. RPR is well-adapted to handle multimedia traffc and is effcient. However, when RPR networks are bridged, inter-ring packets, or packets with the destination on a remote RPR network other than on the source network, are flooded on the source and the destination networks, and also on the path of the intermediate networks between the source and the destination networks. This decreases the available bandwidth for other traffc in those networks and is ineffcient. As a result, we propose two solutions based on topology discovery, global topology discovery (GTD) and enhanced topology discovery (ETD), that prevent the flooding of inter-ring packets. GTD enables the bridges to determine the next-hop bridge for each destination. ETD enables the source node to determine a default ringlet, so that packets reach the next-hop bridge without flooding the source network. The proposed solutions were analyzed and the overhead bandwidth and stabilization time were shown to be bounded. Simulations performed showed that the proposed solutions successfully avoid flooding and achieve optimal effciency in the intermediate and destination networks, and in the source networks with one bridge.  相似文献   
5.
The solubility and diffusivity of supercritical carbon dioxide (sc‐CO2) in low‐density polyethylene (LDPE), high‐density polyethylene (HDPE), polypropylene (PP), ethylene‐ethylacrylate copolymer (EEA) and polystyrene (PS) were measured at temperatures from 150°C to 200°C and pressures up to 12 MPa by using the Magnetic Suspension Balance (MSB), a gravimetric technique for gas sorption measurements. The solubility of CO2 in each polymer was expressed by Henry's constant. The interaction parameter between CO2 and polymer could be obtained from the solubility data, and it was used to estimate the Pressure‐Volume‐Temperature relationship and the specific free volume of polymer/CO2 mixtures. The diffusion coefficients were also measured by the MSB for each polymer. The resulting diffusion coefficients were correlated with the estimated free volume of polymer/CO2 mixture. Combining Fujita's and Maeda and Paul's diffusion models, a model was newly developed in order to predict diffusion coefficients for the polymers studied. Polym. Eng. Sci. 44:1915–1924, 2004. © 2004 Society of Plastics Engineers.  相似文献   
6.
We have studied the thermal stability of five potassium strontium vanadates: KSr(VO3)3, K2Sr(VO3)4, K4Sr(VO3)6, K6Sr(VO3)8, and KSrVO4. The double orthovanadate undergoes a reversible polymorphic transformation at 1117°C and is stable up to 1500°C. The double metavanadates melt peritectically in the range 490–517°C to give Sr2V2O7 crystals and peritectic melt. Pulsed cathodoluminescence studies have shown that the potassium: strontium ratio in the vanadates and their crystal structure have little effect on their optical emission properties. The performance parameters of new vanadate-based phosphors have been determined.  相似文献   
7.
Abstract: The effect of milk and milk components on the deodorization of diallyl disulfide (DADS), allyl methyl disulfide (AMDS), allyl mercaptan (AM), allyl methyl sulfide (AMS), and methyl mercaptan (MM) in the headspace of garlic as well as in the mouth- and nose-space after garlic ingestion was investigated using selected ion flow tube-mass spectrometry (SIFT-MS). Fat-free and whole milk significantly reduced the head-, mouth-, and nose-space concentrations of all volatiles. Water was the major component in milk responsible for the deodorization of volatiles. Due to its higher fat content, whole milk was more effective than fat-free milk in the deodorization of the more hydrophobic volatiles diallyl disulfide and allyl methyl disulfide. Milk was more effective than water and 10% sodium caseinate in the deodorization of allyl methyl sulfide, a persistent garlic odor, in the mouth after garlic ingestion. Addition of milk to garlic before ingestion had a higher deodorizing effect on the volatiles in the mouth than drinking milk after consuming garlic. Practical Application: Ingesting beverages or foods with high water and/or fat content such as milk may help reduce the malodorous odor in breath after garlic ingestion and mask the garlic flavor during eating. To enhance the deodorizing effect, deodorant foods should be mixed with garlic before ingestion.  相似文献   
8.
This research focuses on the use of biodiesel as an additive in diesohol preparation. Three types of biodiesel—methyl, ethyl, and butyl esters—were prepared from palm oil through transesterification using a conventional base catalyst. Ethanol is generally used to blend in diesohol; however, butanol is another alcohol which has higher solubility in diesel than ethanol and it can improve the fuel properties of the blends. Therefore, a comparative study of phase stability, the dependence of solubility on temperature (10, 20, and 30 °C), and an evaluation of some basic fuel properties according to the ASTM of diesel-biodiesel-ethanol and diesel-biodiesel-butanol three-component systems at different component concentrations was done. We found that the use of butanol in diesohol could solve the problem of fuel instability at low temperatures because of its higher solubility in diesel fuel. In addition, the fuel properties results indicated that blends containing butanol have properties closer to diesel than those of blends containing ethanol.  相似文献   
9.
Currently, there are a lot of infant incubators being used in hospitals in Thailand. That situation brings about the question on whether the values of physical quantities such as sound pressure or temperature inside the incubator still conform to the requirements of the international standards. The main objective of this research was to study the sound pressure level (SPL) generated within the incubator. The measurement method was based on IEC 60601-2-19:2009. There were two measurement conditions of the SPL in the infant incubator; the measurement during power-off condition and the measurement during the operation of incubator at a controlled temperature of 36 °C with a maximum humidity setting. Both measurement conditions were carried out in an empty incubator. The average values from the three measurement results of each operating incubator subtracted by the value of background noise were reported as the result of SPL generated in the incubator. The SPL results from this study were lower than 60 dBA, which are within the tolerance limit specified in IEC 60601-2-19. The estimated measurement uncertainty was lower than 1.8 dBA. This research will benefit to an investigation of hearing loss in infants possibly caused by the operation of the infant incubators in Neonatal Intensive Care Unit (NICU). Ultimately, this research will be a great evidence to show the NICU staffs in the hospitals in Thailand and also raise their awareness that it is important to sustain the proper maintenance and calibration of the infant incubators.  相似文献   
10.
OBJECTIVE: To analyse the relation between induced abortion and risk of subsequent miscarriage. DESIGN: Case-control study conducted between February 1990 and May 1995. PARTICIPANTS: Case group included 782 women (median age 32 years, range 14-46) admitted for spontaneous abortion (within the 12th week of gestation) to a network of obstetric departments in the greater Milan area. The control group was recruited among women who gave birth at term (> 37 weeks of gestation) to healthy infants on randomly selected days at the hospitals where cases had been identified. A total of 1543 controls (median age 30 years, range 14-45) were interviewed. RESULTS: A total of 102 cases (13%) and 181 controls (12%) reported one or more induced abortions. No clear relation emerged between miscarriage and induced abortions. In comparison with women reporting no induced abortion the odds ratio (OR) for miscarriage were 1.1 (95% CI 0.8-1.4) in women reporting one induced abortion and 0.9 (95% CI 0.4-1.8) in women reporting two or more. Likewise, there was no association between time since last and age at first induced abortion and risk of miscarriage. CONCLUSIONS: This study did not find any strong association between induced and spontaneous abortion.  相似文献   
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