实验与探索

现代科技发展要求学生具有独立探索知识的能力,因此,教师必须帮助学生养成自主探究的习惯.实验教学不仅仅是为了验证某个定律,更重要的是如何利用实验教学生学会探索,学会研究,进行创造性学习.1 利用演示实验让学生感受探究的乐趣 布鲁诺指出:“学习的最好刺激乃是对科学材料的兴趣.”杨振宁教授也曾指出:     

Isolated-utterance speech recognition using hidden Markov modelswith bounded state durations

Hidden Markov models (HMMs) with bounded state durations (HMM/BSD) are proposed to explicitly model the state durations of HMMs and more accurately consider the temporal structures existing in speech signals in a simple, direct, but effective way. A series of experiments have been conducted for speaker dependent applications using 408 highly confusing first-tone Mandarin syllables as the example vocabulary. It was found that in the discrete case the recognition rate of HMM/BSD (78.5%) is 9.0%, 6.3%, and 1.9% higher than the conventional HMMs and HMMs with Poisson and gamma distribution state durations, respectively. In the continuous case (partitioned Gaussian mixture modeling), the recognition rates of HMM/BSD (88.3% with 1 mixture, 88.8% with 3 mixtures, and 89.4% with 5 mixtures) are 6.3%, 5.0%, and 5.5% higher than those of the conventional HMMs, and 5.9% (with 1 mixture), 3.9% (with 3 mixtures) and 3.1% (with 1 mixture), 1.8% (with 3 mixtures) higher than HMMs with Poisson and gamma distributed state durations, respectively     

1.5μm波导声光可调滤光器研究

对１．５μｍ波导型声光ＴＥ－ＴＭ模式转换光滤波器进行了研究。采用了可降低驱动功率的表面声波导结构。在１．５￣１．６μｍ波段实现了可调滤光，通带宽度小于２ｎｍ，达到９７￥以上转换率所需的射频驱动功率约８０ｍＷ（１９ｄＢｍ），器件总插入损耗约９ｄＢ。     

LPCVD系统淀积多晶硅薄膜的发雾分析

叙述了采用LPCVD系统淀积多晶硅薄膜的机理,分析了在淀积多晶硅薄膜过程中引起发雾的因素,指出了保持LPCVD系统的洁净能有效消除在淀积多晶硅薄膜过程中出现的发雾现象.     

GGG晶体板状激光器特性的研究

测试GGG晶体板条的激光性能,并在高功率泵浦下对板条的热聚焦效应进行了研究.     

彩色ACPDP发光效率的测试及计算研究

发光效率是彩色ＡＣ ＰＤＰ的一个重要性能指标。为正确测试该参数，针对器件特有的性能，用不同方法测试其功耗和光通量，计算得发光效率，分析讨论不同方法测得的数值，对其中有的方法测试值予以修正，最后提出一种简易可行的测试方法。     

Transthyretin (prealbumin) gene in human primary hepatic cancer.

From a subtracting cDNA library constructed from normal liver versus human primary hepatic cancer (PHC) a cDNA clone pG8 was isolated. Using it as a probe, RNA extracted from one human liver and 9 PHC samples were analyzed by Northern hybridization. As expected, its mRNA was highly expressed in liver; however, the expression was strikingly suppressed in PHC. Only weak signal was observed in 2 out of 9 PHC, while no signal was detectable in the other 7 samples. Utilizing pG8 as a probe, DNA from the same PHC specimens was analyzed after MspI digestion and Southern hybridization. Deletion of DNA fragment was observed in 4 out of 9 samples. In further study of cancer and non-cancerous liver from other 7 PHC patients, similar deletion of DNA fragments in cancer was observed in 4 out of 7 samples. After sequencing of the clone of 572 bp, it was unexpectedly found that pG8 was completely homologous to the coding sequence of transthyretin, TTR gene, as TTR (or prealbumin) gene has been known to be linked to a hereditary disorder, familial amyloidosis (FAP), and related to thyroxine transport and binding to retinol-RBP (the retinol binding protein) complex. This is the first report of a study on TTR in human primary hepatic cancer. Since TTR gene was strikingly suppressed in mRNA expression and possibly defective in its gene structure, it was strongly implicated that TTR might be an important gene marker or a candidate of anti-oncogene for human PHC. The biological activity of TTR gene is under study.     

脉冲激光辐照下材料的光热特性研究

建立了单脉冲激光加热下材料温度场的三维和一维理论模型，并将其进行比较，存在较大的差异。通过改变多种参数对三维模型进行研究，给出何时三维模型可以用一维模型代替，以及用无限大边界条件下得到的三维温度场模型来处理实际问题的不足。     

n-1／n（G）表决系统中的可靠性分析

本文通过补充变量法研究了n-1/n(G)表决系统中可靠度,可用度,以及故障频度等可靠性的一系列指标.     

142名健康成人血清铜的含量测定

本文用原子吸收法对吉林市１４２名健康成人血清铜的含量进行了测定。结果表明，男性血清铜值稍代于女性，但经统计学处理无显著性差异（Ｐ＞０．０５）。提出其正常值范围。