VB中计时器控件的长定时初探

Windows应用程序中通常要用到时间控制的功能,VB中定时器Timer控件不能进行长定时,最大间隔时间是1分多钟,如需要长时间计时,该控件就无法完成。利用计数器和创建超长时间计时器对象能较好地解决长定时问题。

长时定时器

本装置具有30s～24h定时控制电路的功能。电路原理电路如图1所示,由IC_1、C_1、R_(2～6)、D_1、D_2等组成占空比很大的脉冲发生器。IC_2、IC_3、开关K_(2～5)等组成计时电路。IC_5为D触发器。BG_2、继电器J等组成控制电路。IC_4、BG_1等组成启动电路。

方便实用的长时间定时器

定时器线路已不乏资料介绍,这里介绍的是为适应某些生产过程的需要而设计的一种长时间定时装置,其定时时间可取几分钟到几十小时,特别适用于夜间下班后的自动监控。比如,某电镀工艺要求在一定温度的溶液中进行,如果在下班前调好定时器的定时时间,使镀液预先加热以便次日一上班就可进行电镀;又如使烘箱按规定时间断电可免去人工守候。这些无疑会给工作带来极大方便,效益也将明显提高。 1.原理简介为了使定时准确稳定,采用数字电路以计数方式实现定时是较为简便可靠的办法。日1是原理框图。

关于双金属式钢轨测温计检定示值误差时增加检定时长的探讨

本文通过实验的方法,分析双金属式钢轨测温计在示值误差检定中,可以通过增加检定时长的方法,来有效消除或降低对双金属式钢轨测温计检定过程中检定结果的误判。从而保障计量器具的量值准确可靠,确保铁路线路安全。

长链非编码RNA HOTAIR在胃癌中的表达及临床意义

目的:探讨长链非编码RNA HOTAIR在胃癌及癌旁组织中的表达及其与临床病理特征之间的关系。方法:利用实时定量PCR法检测55例胃癌组织及其配对癌旁正常组织中长链非编码RNA HOTAIR的表达情况,并分析其与胃癌临床病理学特征之间的联系。结果:实时定量PCR法检测HOTAIR在胃癌组织中的相对表达量为0.0232±0.0073,其配对癌旁正常组织相对表达量为0.0071±0.0017,差异具有统计学意义(P<0.05)。长链非编码RNA HOTAIR的表达与胃癌患者肿瘤淋巴结转移、远处转移、TNM分期显著相关(P<0.05),与年龄、性别、分化程度等无关(P>0.05)。结论:长链非编码RNA HOTAIR在胃癌组织中表达显著高于癌旁组织,与胃癌转移、TNM分期等病理因素相关,可能在胃癌的侵袭、转移过程中起重要作用。

提高采暖散热器散热量检定系统流量测试精度的新方法

本文提出了消除质量流量测试中由于导流机构的行程差所引起的误差的新方法。

S7-200 PLC在变压器干燥系统中的应用

提出了基于西门子S7-200 PLC的变压器干燥系统的电气设计方案,介绍了部分控制电路及控制程序设计.

流媒体视频存储服务器设计与研究

详细分析了在视频监控系统中流媒体视频存储服务器的作用和功能,针对传统的流媒体定时长存储方式的不足,提出了"固定空间存储"的新策略。该存储策略将总空间初始化为多个固定大小的数据文件,每个数据文件中存储的流媒体时长可能是不相同的。针对新存储策略下出现的"1秒尾巴"、"事件尾巴"等新问题,提出了解决方案。"固定空间存储"策略虽然增加了索引的复杂度,但是有效避免了磁盘碎片的产生,对于改善流媒体视频存储服务器性能具有重要作用。

Quantitative Study on Expression of MSTN Gene in Different Tissues of Tibetan Sheep at Different Ages

[Objective] The aim was to investigate the difference in MSTN gene expression in different tissues of Tibetan sheep at different ages.[Method] According to the sequence（NM_001009428.1）published in GenBank,a pair of specific primers was designed to amplify part of cDNA sequence of MSTN by using QRT-PCR technique.The relative expression level of MSTN gene in rennet stomach,rumen,leg muscle and cardiac muscle of Tibetan sheep at different ages were analyzed.[Result] After normalization with β-actin gene,the relative expression level of MSTN gene in the 6-month-old Tibetan sheep was the highest and it was 2.52 times than that in 12-month-old Tibetan sheep（P0.05）,the relative expression level of MSTN gene in leg muscle was the highest among all tissues and it was 3 984.78 times than that in rumen（P0.01）.[Conclusion] The results established theoretical foundation for the correct use of MSTN antibody.

Real-time Quantitative PCR Analysis of Vascular Endothelial Growth Factor Receptor-2(VEGFR-2) Expression at Zebrafish Different Developmental Stages

[Objective]To investigate the expression of zebrafish vascular endothelial growth factor-2（VEGFR-2） at different developmental stages.[Method]Total RNAs were extracted from 12,24,48,72 and 96 hpf stage zebrafish embryos and larvae.Real-time quantitative RT-PCR was performed to examine the expression of VEGFR-2.The data were analyzed by 2^-△△Ct method.[Result]The expression level of VEGFR-2 gene increased gradually from 12 to 72 hpf,and subsequently decreased at 96 hpf.The expression level was lowest at 12 hpf,highest at 72 hpf,and had significant differences when compared with that of other developmental stages.[Conclusion]The expression level of VEGFR-2 increases gradually before blood vessel maturation and decreases as blood vessels mature.

Secure Network Coding Based on Lattice Signature

To provide a high-security guaran- tee to network coding and lower the comput- ing complexity induced by signature scheme, we take full advantage of homomorphic prop- erty to build lattice signature schemes and sec- ure network coding algorithms. Firstly, by means of the distance between the message and its sig- nature in a lattice, we propose a Distance-bas- ed Secure Network Coding （DSNC） algorithm and stipulate its security to a new hard problem Fixed Length Vector Problem （FLVP）, which is harder than Shortest Vector Problem （SVP） on lattices. Secondly, considering the bound- ary on the distance between the message and its signature, we further propose an efficient Bo- undary-based Secure Network Coding （BSNC） algorithm to reduce the computing complexity induced by square calculation in DSNC. Sim- ulation results and security analysis show that the proposed signature schemes have stronger unforgeability due to the natural property of lattices than traditional Rivest-Shamir-Adleman （RSA）-based signature scheme. DSNC algo- rithm is more secure and BSNC algorithm greatly reduces the time cost on computation.

cDNA clone and expression analysis of a-Tropomyosin during Japanese flounder （Parafichthys ofivaceus） metamorphosis

Tropomyosin （TM） plays a critical role in skeletal and cardiac muscle development and function. To assess the fimctional significance of a-TM in Japanese flounder （Paralichthys olivaceus） development and metamorphosis, cDNA from Japanese flounder was cloned and a-TM mRNA measured during development and metamorphosis. The full-length cDNA is 1 191 bp, including a 5＇- untranslated region of 114 bp, a Y-UTR of 222 bp, and an open reading frame of 855 bp encoding a polypeptide of 284 amino acids. Real-time quantitative PCR revealed that a-TM mRNA is initially expressed in unfertilized ovum, indicating the a-TM gene is maternal. Relatively low mRNA levels were observed in different embryonic stages. A higher level of a-TM mRNA was detected 3 days post hatching （dph）, while the highest level was measured at 29 dph （metamorphic climax） after which it declined towards the end of metamorphosis. The expression of a-TM mRNA was up-regulated in thyroid hormone-treated larvae at 36 dph, but there was no marked difference at other stages when compared to control animals. After thiourea treatment, the expression of a-TM mRNA declined slightly. These data provide basic information that can be utilized in further studies into the role of a-TM in P olivaceus development and metamorphosis.

Long Distance GIL PD Fault Localization Method Based on Amplitude Difference and Time Difference Calculation of UHF Coupling Signal

In the long distance GIL under certain conditions, this paper researches and realizes detection of PD characters and accurate fault localization through UHF coupling sensors at different positions of the GIL pipeline. The main methods for the detection are UHF signal amplitude difference （DOA） and time difference （TOF）. We analyze the localization error by using TE and TEM component and high order TE mode component in electromagnetic coaxial wave guide theory. Research and field test prove the DOA detection error can meet the requirements of real-time online diagnosis and for history tracking analysis. The error of TOF detection method can be controlled within 3% and can be applied to the site.

The Straight-Line Depreciation Method Used by Selected Companies and Educational Institutions in the Philippines

The straight-line method in computing for depreciation expense is the prevailing method used in the Philippines. This paper aims to determine the rationale behind the use of this method. The objective of the study is to determine the length of time within which the depreciation method is used, reasons in using the method, the rate of depreciation used by the companies, and the effects of the depreciation expense on their operating expenses. It also determines if the companies＇ decisions to use the straight-line method are influenced by the factors mentioned by Reynolds （196 I）----expected amount of services over the life of assets, the amount and timing of operating costs, the decline in the physical efficiency of the assets, and the rate of return--and if they considered capital investments and tax reduction in using this method. The study shows that companies and educational institutions use the straight-line method of computing depreciation expenses, because it is easy to use in computing the depreciation expenses, in comparing with previous years＇ computations, and in keeping track of the expenses. It is also convenient for tax administration and financial reporting. The rate of depreciation used varies, because the companies and educational institutions use their past experiences in determining the life of fixed assets. The percentage of depreciation to the operating expenses also varies. The companies and educational institutions adhered to the factors mentioned by Reynolds （1961） in choosing the straight-line method of depreciation. The companies did not consider reduction of tax in using the straight-line method.

Interval of effective time-step size for the numerical computation of nonlinear ordinary differential equations

The computational uncertainty principle states that the numerical computation of nonlinear ordinary differential equations（ODEs） should use appropriately sized time steps to obtain reliable solutions.However,the interval of effective step size（IES） has not been thoroughly explored theoretically.In this paper,by using a general estimation for the total error of the numerical solutions of ODEs,a method is proposed for determining an approximate IES by translating the functions for truncation and rounding errors.It also illustrates this process with an example.Moreover,the relationship between the IES and its approximation is found,and the relative error of the approximation with respect to the IES is given.In addition,variation in the IES with increasing integration time is studied,which can provide an explanation for the observed numerical results.The findings contribute to computational step-size choice for reliable numerical solutions.

The Constitution and Working Mechanism of the Fast Fashion Enterprise Financial Competitiveness

With the Pearson Correlation Coefficient measurement method, this paper studies the correlation between the various elements influencing the financial competitiveness of the fast fashion enterprieses and the long-term financial stability, which shows that the financial resilience has the biggest correlation with the long-term financial stability, which is followed in sequence by financial management capacity, financial resources capacity, financial performance capacity, and financial activity capacity. This is due to the fact that such factors as financial solvency, financial operations, profitability, growth capacity and the ability to generate cash exert effect upon the long-term stability of the financial competitiveness.

The difference between multi-drug resistant cell line A549/Gem and its parental cell A549

Objective:To discuss the difference between multi-drug resistant cell line A549/Gem and its parental cell A549 on the basis of establishment of human gemcitabine-resistant cell line A549/Gem so as to elaborate the possible mechanisms of gemcitabine resistance.Methods:Human gemcitabine-resistant non-small cell lung cancer cell line A549/Gem was estab-lished by the method of repeated clinical serous peak concentration plus gradually increasing concentration of gemcitabine from its parental cell human lung adenocarcinoma cell line A549 which was sensitive to gemcitabine.During the course of inducement,we had monitored their morphology,checked their resistance indexes and resistant pedigree by MTT method,gathered their growth curves and calculated their doubling time,examined their DNA contents and cell cycles by FCM;at the same time,we had measured their expressions of P53,EGFR,Cerb-B-2,PTEN,PCNA,c-myc,VEGF,MDR-1,Bcl-2,nm23,MMP-9,TIMP-1,and CD44v6 proteins via immunocytochemistry staining,RRM1 and ERCC1 mRNA by real-time fluorescent quantitative-PCR.Results:The resistance index of A549/Gem' cells(the deputy of cells in the process of inducement) to gemcitabine was 163.228,and the cell line also exhibited cross-resistance to vinorelbine,taxotere,fluorouraci,etoposide and cisplatin,but kept sensitivity to paclitaxol and oxaliplatin.The doubling time of A549/Gem' was shorter and figures in G0-G1 phases were increased than A549 cells.Compared with A549 cells,A549/Gem' cells achieved EGFR and c-myc proteins expressions,nm23 protein expression enhanced,P53,Cerb-B-2 and Bcl-2 proteins expressions reduced,PTEN,PCNA and MDR-1 proteins expressions vanished,but those of MMP-9,VEGF,CD44v6 and TIMP-1 proteins changed trivially.Meanwhile,expressions of RRM1 and ERCC1 mRNA were augmented markedly.The resistance index of A549/Gem cells to gemcitabine was 129.783,and the cell line also held cross-resistance to vinorelbine,taxotere,etoposide,cisplatin and sensitivity to paclitaxol.But the resistance to fluorouracil and sensitivity to oxaliplatin vanished.And the expression of RRM1 and ERCC1 mRNA decreased visibly.The doubling time of A549/Gem cells was longer and figures in G0-G1 phases were decreased than A549/Gem' cells.In A549/Gem cells,expressions of P53,EGFR,PCNA and MDR-1 proteins was same to those of A549/Gem' cells.A549/Gem cells achieved TIMP-1 and PTEN proteins expressions,Cerb-B-2,MMP-9,c-myc and Bcl-2 proteins expressions enhanced,nm23 protein expressions vanished,but the expressions of VEGF and CD44v6 proteins changed trivially.Furthermore,Compared with its parental cell A549,A549/Gem cell was mixed with giant cells of different sizes and was larger and more irregular.Conclusion:The human gemcitabine-resistant non-small cell lung cancer cell line A549/Gem had achieved multi-drug resistance and great changes of biological characters compared with its parental cells A549.And these changes possibly participated in the formation of multidrug resistance.

Evolutions of texture and grain boundary plane distributions in a ferritic stainless steel

The grain size, textures and grain boundary plane distributions in a cold-rolled and annealed ferritic stainless steel were investigated by means of EBSD techniques. The results show that, following cold rolling with the thickness reduction of 85%, relatively low temperature （780℃） annealing brings an extremely sluggish grain growth and no grain texture develops when the annealing time varies from 5 min to 480 min. The free energy reduction of the system is mainly caused by the grain boundary plane re-orientation in addition to minor grain growth because the distributions of grain boundary planes are moderately preferred on { 100} according to the five parameter analyses （FPA） concerning the grain boundary plane characteristics. However, in the case of high-temperature （1 000 ℃） annealing, the average grain size does not increase until annealing time is prolonged to 90 min, after which extensive grain growth occurs and strong {100}（hkl） texture emerges whereas nearly random grain boundary plane distributions are observed. The free energy reduction of the system is most likely attributed to the selective growth.